Ultimate Greens 8 In 1 With Protein Blueberry Flavor [Discontinued] by OL Olympian Labs, Inc.

POSSIBLY EFFECTIVE

• Vitamin C deficiency. Orally, consuming acerola might help to prevent or treat vitamin C deficiency since acerola contains a significant amount of vitamin C. Details: Acerola is a rich source of vitamin C (30260). Therefore, taking acerola orally might prevent vitamin C deficiency and scurvy. An infant with scurvy was successfully treated with acerola juice by the Puerto Rican researchers who first identified acerola as a good source of vitamin C (93207).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Atherosclerosis. Although there is interest in using oral acerola for atherosclerosis, there is insufficient reliable information about the clinical effects of acerola for this condition.
• Common cold. Although there is interest in using oral acerola for the common cold, there is insufficient reliable information about the clinical effects of acerola for this condition.
• Diarrhea. Although there is interest in using oral acerola for diarrhea, there is insufficient reliable information about the clinical effects of acerola for this condition. More evidence is needed to rate acerola for these uses.

(Read more about ACEROLA)

POSSIBLY EFFECTIVE

• Acne. Topical aloe gel may reduce acne lesions when used with topical tretinoin in children and adults with acne. Details: One clinical trial in children and adults with acne shows that topical application of a gel containing aloe 50% in the morning and evening, in addition to topical application of tretinoin 0.025% cream and twice daily cleansing with a medical soap, improves acne lesions by approximately 35% more than using the same treatments without aloe (90124).
• Burns. Topical aloe gel or cream may reduce healing time in patients with superficial or partial thickness burns. Details: A meta-analysis of four small clinical trials in patients with second-degree burns shows that use of topical aloe vera reduces time to healing by about 4.4 days when compared to control groups treated with silvadene, silver sulfadiazine, or gauze containing 0.5% chlorhexidine acetate (110209). Most clinical research shows that applying aloe gel or cream topically up to twice daily reduces healing time when compared with silver sulfadiazine (19771,110210,110212), framycetin (19775), vaseline gauze (19773), or placebo (101,97320) in patients with superficial or partial thickness burns. Topical application of aloe cream up to twice daily might also decrease wound size when compared with silver sulfadiazine and framycetin (19771,19775). In addition, some clinical research in patients with burns caused by sulfur mustard shows that applying cream containing aloe and olive oil twice daily for 6 weeks improves pruritus similarly to betamethasone 0.1% cream and may lead to further reductions in excoriation and fissure (19768). However, some preliminary clinical research shows that applying fresh aloe mucilage or aloe extract daily is no more effective than silver sulfadiazine for reducing wound healing time in patients with superficial or partial thickness burns (19774,19776).
• Constipation. Oral aloe latex may improve symptoms in patients with constipation; however, the U.S. Food and Drug Administration (FDA) has banned the use of aloe latex as a laxative due to safety concerns. Details: Taking aloe latex 100-200 mg daily or aloe extract 50 mg as a stimulant laxative seems to relieve constipation due to the cathartic effects of the anthraquinones in the aloe (4,5,8). Taking 1-3 capsules of a formulation containing aloe 150 mg, celandine 300 mg, and psyllium 50 mg also seems to improve stool consistency and the mean number of stools in patients with chronic constipation when compared with placebo (19747). However, in 2002, the U.S. FDA banned the use of aloe latex for constipation due to safety concerns (8229,8443).
• Diabetes. Oral aloe may reduce blood glucose and glycated hemoglobin (HbA1c) in patients with diabetes. It may be most effective in patients with fasting blood glucose levels of 200 mg/dL or greater. Details: Most clinical research in adults with prediabetes and diabetes shows that taking aloe vera orally can reduce fasting blood glucose by 30-47 mg/dL and HbA1c by 0.41% to 1% (12164,17488,17489,19756,95943,95945,95946). One meta-analysis of 92 patients shows that aloe vera is associated with a larger overall reduction of fasting blood glucose in those with a baseline fasting blood glucose level greater than or equal to 200 mg/dL (95945). Another meta-analysis of 206 patients shows that aloe vera increases high-density lipoprotein (HDL) levels and reduces triglyceride, total cholesterol, and low-density lipoprotein (LDL) levels when compared with placebo in adults with prediabetes and untreated diabetes (95943). These analyses include studies that used multiple forms of aloe vera, including gel powder, extract, raw crushed leaves, and fresh extracted juice, as well as multiple doses ranging from 100-1000 mg of powder and 15-150 mL of juice taken for durations ranging from 4-14 weeks. Significant heterogeneity between studies, small sample sizes, and wide variability in the form and dose of aloe used limit the validity of these findings and the ability to identify an effective dose (95943,95945,95946). Additionally, some research has shown no benefit. This may be due to the different forms and doses of aloe used. One clinical study shows that taking aloe gel as 15 mL twice daily or taking aloe juice 15 mL twice daily does not decrease glucose levels in patients with type 2 diabetes (17420). Other clinical research shows that taking a specific aloe gel complex (Aloe QDM complex, Univera Inc.) containing processed aloe gel 147 mg twice daily for 8 weeks does not affect glycemic indices when compared with placebo in patients with diabetes or prediabetes (90121).
• Genital herpes. Topical aloe extract cream may improve healing of genital herpes lesions. Details: Clinical research in males with genital herpes shows that applying a cream containing aloe extract 0.5% three times daily, 5 days weekly, for up to 2 weeks increases healing rates when compared with aloe gel or placebo. The mean time to healing after application of the aloe extract was 5 days, compared with 12 days with placebo (12164,19745,19746).
• Lichen planus. Rinsing the mouth with aloe-containing mouthwash or applying aloe gel to the mouth or vulva may reduce pain and improve lesion healing in patients with lichen planus. Details: Clinical research in patients with oral lichen planus shows that using 0.4 mL of mouthwash containing aloe gel 70% three times daily for 12 weeks or applying a gel containing aloe mucilage 70% twice daily for 8 weeks is up to 6 times more likely to reduce pain when compared with placebo (19762,19763,19764). However, these findings are questionable due to poor study design. Other clinical research in patients with oral lichen planus shows that using 2 tablespoons of aloe-containing mouthwash four times daily for a month, or applying aloe gel three times daily for 8 weeks, reduces pain and improves lesion healing at least as much as triamcinolone acetonide paste (0.1% in one study) (19765,90130). However, aloe gel may not be as beneficial as laser therapy. A clinical study in patients with lichen planus show that applying a gel containing aloe powder 500 mg to the affected site three times daily for 2 months is less effective for improving pain and lesion healing than receiving low-level laser therapy twice weekly for 2 months. However, no between-group differences were maintained at 7 months after treatment completion (108722). A network meta-analysis of 2 small clinical trials shows that applying aloe trails only purslane of the herbal agents studied with regard to clinical improvement as measured by the Thongprasom scale. However, aloe does not seem to improve complete clinical resolution, clinical scores, or pain (111640). In patients with vulval lichen planus, clinical research shows that topical application with aloe gel twice daily for 8 weeks increases the number of patients who experience clinical improvement of at least 50% when compared with placebo (19766).
• Obesity. Oral aloe gel may modestly reduce body weight and fat mass in adults who are overweight or obese. Details: One clinical trial in overweight and obese adults with diabetes or prediabetes shows that taking a specific aloe gel complex (Aloe QDM complex, Univera Inc.) containing processed aloe gel 147 mg twice daily for 8 weeks reduces body weight by 0.6 kg and fat mass by 1 kg when compared with placebo (90121).
• Oral submucous fibrosis. Topical aloe may reduce burning sensations in patients with oral submucous fibrosis, but it may not improve mouth opening, tongue protrusion, or cheek flexibility in these patients. Details: A meta-analysis of five small clinical studies in patients with oral submucous fibrosis shows that topical application of aloe gel for 3 months reduces burning sensation, possibly for up to two months after treatment, when compared with placebo or active control. A network meta-analysis also found that aloe is most effective in reducing burning sensation, ranked only after treatment with corticosteroids, hyaluronidase, and antioxidants (113514). However, aloe does not seem to improve mouth opening, tongue protrusion, or cheek flexibility (100256). One of the studies included in the analysis used a specific aloe gel (Sheetal lab Surat) 5 mg applied topically on each side of the buccal mucosa three times daily for 3 months (90131). All of the studies included in the analysis were conducted in India, so it is unclear if the results are generalizable to other geographic locations. Limited research has also evaluated the use of topical and oral aloe vera in combination. A small clinical study shows that consuming pure aloe vera juice (Hamant Sai, Sun Vision Company) 30 mL twice daily and applying pure aloe vera gel (Hamant Sai, Sun Vision Company) three times daily for 3 months improves cheek flexibility and tongue protrusion when compared with a treatment regimen consisting of intralesional injections of hydrocortisone acetate 25 mg and hyaluronidase 1500 IU weekly for 6 weeks and supplementation with Cap SM Fibro (Indoco Remedies) twice daily for 3 months. Both treatment regimens show an improvement in mouth opening and burning sensation when compared to baseline, with the aloe vera treatment producing a more rapid improvement in burning sensation (95944). It is not clear how this combination of oral and topical aloe vera compares with topical aloe vera alone.
• Psoriasis. Topical aloe extract cream may reduce erythema and scaling and improve the resolution of psoriatic plaques in patients with psoriasis. Limited research suggests that topical aloe gel does not have the same effects. Details: Applying aloe extract 0.5% cream topically three times daily for 4 weeks significantly improves and increases the resolution of psoriatic plaques when compared with placebo (101,12096,12164). Aloe extract cream also seems to reduce desquamation, erythema, and infiltration (12096). Other preliminary clinical research shows that applying cream containing aloe mucilage 70% twice daily for 8 weeks improves psoriasis severity more effectively than triamcinolone 0.1% cream, although both treatments had similar effects on dermatology-specific quality of life (19741). Treatment with aloe gel does not seem to improve erythema, infiltration, and desquamation associated with psoriasis when compared with placebo (19748).
• Radiation dermatitis. Although some individual research disagrees, topical aloe gel may prevent or delay dermatitis in patients undergoing radiation therapy. Details: A meta-analysis of 7 clinical trials in patients with various types of cancer shows that topical aloe does not reduce the incidence or severity of radiation dermatitis and does not reduce the incidence of erythema, pruritis, moist desquamation, or dry desquamation when compared with control (110325). However, the included studies are limited by a lack of blinding, questionable methodological quality, and a high risk of bias. In contrast, another meta-analysis of generally poor quality randomized controlled trials shows that topical pre-treatment application with aloe as gel, cream, lotion, or fresh plant reduces the risk of radiation dermatitis by 23%, especially mild to moderate radiation dermatitis, when compared with a control group not treated with aloe (110214). One U.S. study included in the analysis shows that applying aloe 98% gel twice daily starting within three days of radiation initiation does not reduce radiation dermatitis when compared with a placebo gel or no treatment (12163). Other research has focused on specific side effects. One clinical trial shows that applying aloe 98% gel three times daily throughout radiation treatment and after treatment does not seem to reduce symptoms of radiation dermatitis in patients being treated for breast cancer (12098). Some research shows that applying aloe 100% gel 6-8 times daily might prolong the time before radiation-related side effects occur, but only when the cumulative dose of radiation is high (>2,700 cGy) (12159). In addition, applying aloe-based gel once daily after radiation treatment is less effective than applying anionic phospholipid-based cream for reducing dryness, erythema, and peeling in children being treated for Hodgkin disease (19855). Aloe has also been evaluated in combination with other ingredients. A small cohort study in patients with head and neck cancer receiving radiation therapy shows that applying aloe 2% and radish 4% gel twice daily until ten days after the last radiotherapy session prevents radiation dermatitis as shown by fewer cases of radiation dermatitis in the 10^th, 30^th, and 35^th radiation sessions when compared with placebo. Furthermore, after the 35th session, the subjects prophylactically treated with the aloe and radish gel had milder grades of radiation dermatitis when compared with control (111662). A preliminary clinical study shows that applying a specific cream product (Radioskin 2, Herbalab di Perazza Massimiliano Company), which contains aloe, ginkgo extract, and metal esculetina, along with another specific cream product (Radioskin 1, Herbalab di Perazza Massimiliano Company), which contains alga atlantica and ethylbisiminomethylguaicolo manganese cloruro, may improve skin hydration and reduce skin toxicity associated with radiation therapy in patients with breast cancer (89727). These creams were applied topically 2-3 times daily at least 3 hours before and after radiation treatment, from 15 days prior to radiation until one month after completion.
• Traumatic oral ulcers. Topical aloe gel may prevent oral ulcers after application of orthodontic appliances in adolescents and adults. Details: Clinical research in patients aged 12 years and older shows that applying a gel containing aloe 80% to the gums twice daily for one month after the cementation of orthodontic appliances prevents the development of mouth ulcers when compared with a chlorhexidine gel. Ulcers occurred in about 6% of patients using the aloe gel compared with 81% of those using the chlorhexidine gel. Bleeding and inflammation were also reduced (103305).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alveolar osteitis. It is unclear if topical aloe or the aloe constituent acemannan is beneficial in patients with alveolar osteitis. Details: One small clinical trial in patients with alveolar osteitis shows that applying a patch containing the aloe constituent acemannan (SaliCept patch) to the tooth socket, once after curettage and irrigation and again 3 days later, reduces pain intensity and improves clinical symptoms when compared with curettage and irrigation alone (19754).
• Amenorrhea. Although there has been interest in using oral aloe for amenorrhea, there is insufficient reliable information about the clinical effects of aloe for this purpose.
• Anal fissures. It is unclear if topical aloe is beneficial in patients with anal fissures. Details: One small clinical study in patients with chronic anal fissures shows that applying an aloe cream containing 0.5% powdered spray-dried inner aloe leaf juice (Zarban Phyto-Pharmaceutical Co) three times daily for at least 3 weeks, as an adjuvant to sitz baths three times daily, using a laxative, and eating a full fiber diet, improves pain, wound healing, and bleeding severity when compared with placebo (90129).
• Asthma. Although there has been interest in using oral aloe for asthma, there is insufficient reliable information about the clinical effects of aloe for this purpose.
• Atopic dermatitis (eczema). Topical aloe has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical trial in patients with atopic dermatitis shows that application of a specific combination cream (Olivederma, Kimi Daru Pharmaceutical Co.) containing aloe gel and virgin olive oil twice daily for 6 weeks improves disease severity and quality of life when compared with betamethasone cream (105020). It is unclear if this effect is due to aloe, olive oil, or the combination.
• Breast engorgement. It is unclear if topical aloe improves lactation-associated breast pain. Details: Meta-analyses of 4-5 clinical trials in lactating patients show that use of topical aloe modestly reduces nipple/breast pain and irritation when compared with no treatment, routine care with topical breast milk or breast massage, or treatment with lanolin (110213). However, studies included in this analysis were not specific to breast engorgement.
• Burning mouth syndrome. It is unclear if topical aloe is beneficial in patients with burning mouth syndrome. Details: One small clinical trial in patients with chronic burning mouth syndrome shows that applying 0.5 mL of aloe 70% gel to sore areas on the tongue three times daily prior to wearing a tongue protector for 12 weeks does not improve pain or symptoms when compared with placebo gel or using the tongue protector alone in patients with chronic burning mouth syndrome (90127). However, differences in baseline pain ratings between study groups limit the validity of these findings.
• Cancer. Oral aloe has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study in patients with lung cancer shows that, when administered with standard chemotherapy, three daily doses of 10 mL of a mixture consisting of fresh aloe leaves 300 grams plus honey 500 grams dissolved in 40 mL of alcohol 40% increases the rate of complete response, partial response, or disease control when compared with chemotherapy alone (19752).
• Canker sores. Small clinical studies suggest that applying the aloe constituent acemannan to cancer sores may reduce ulcer size, but not pain. However, the effect of aloe is unclear. Details: Meta-analyses of clinical research show that topical aloe is no more effective than control interventions for reducing the size and pain of oral ulcers (110216). Control interventions have included carrier gel or triamcinolone acetonide 0.1% (19751,110216). However, a recent clinical trial shows that topical aloe gel (G.U.M Canker-X, Sunstar Americas, Schaumburg, USA) after meals and before bedtime for 5 days is more effective than amlexanox 5% paste and placebo for reducing pain and the size of canker sores in patients with recurrent symptoms (110215). Other small clinical trials have investigated the effects of fermented aloe or the aloe constituent acemannan. One small clinical trial in adults with recurrent canker sores shows that applying a fermented aloe gel to oral ulcers three times daily seems to accelerate healing time when compared with chitosan gel (104173). Another small clinical trial in patients with canker sores shows that using a wound dressing containing the aloe constituent acemannan (Carrisyn Gel Wound Dressing) shortens the average healing time of canker sores when compared with an oral analgesic (Orabase-Plain) (19750). Other clinical research shows that applying acemannan 0.5% in Carbopol 934P NF three times daily for 7 days reduces ulcer size, but not pain, when compared with Carbopol 934P NF alone in patients with canker sores (90123). However, applying triamcinolone acetonide 0.1% appears to be more effective in reducing pain and similarly effective in reducing ulcer size when compared with acemannan 0.5% (90123).
• Common cold. Although there has been interest in using oral aloe for the common cold, there is insufficient reliable information about the clinical effects of aloe for this purpose.
• Dental plaque. Using aloe-containing toothpaste may reduce dental plaque in adults; however, it is unclear if this is more effective than fluoride-containing toothpaste. Rinsing with an aloe-containing mouthwash may reduce dental plaque in children. Details: One small clinical trial in adults shows that brushing teeth with a dentifrice containing aloe gel (Forever Bright, Forever Living Products) three times daily for 30 days does not reduce the occurrence of plaque better than a fluoridated dentifrice (Sorriso Dentes Brancos, Kolynos do Brasil), although both treatments seem to show improvement when compared to baseline (19755). Another small clinical study in adults with gingivitis shows that using toothpaste containing aloe daily for 24 weeks reduces plaque more effectively than placebo or triclosan-containing toothpaste (19760). In children aged 8-14 years with mild plaque, using a mouth wash containing aloe vera 7% twice daily for 4 weeks reduced plaque by a large amount when compared with placebo. In addition, it was as effective as chlorhexidine 0.2% (103306).
• Depression. Although there has been interest in using oral aloe for depression, there is insufficient reliable information about the clinical effects of aloe for this purpose.
• Diabetic foot ulcers. Topical aloe has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical trial in patients with a stage 1 or 2 diabetic foot ulcer who are receiving oral antibiotics shows that applying a topical product containing aloe and great plantain twice daily for 4 weeks reduces ulcer surface area and time to healing, but not ulcer depth, when compared with antibiotics alone (97323). The effect of applying aloe gel alone without concomitant oral antibiotic therapy is unknown.
• Diaper rash. Topical aloe has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical trial shows that applying a cream containing aloe gel and olive oil three times daily for 5-10 days reduces diaper rash severity in children less than 3 years of age when compared to baseline; however, it does not seem to be as effective as calendula ointment (19779). The validity of this finding is limited by the lack of a placebo group.
• Dry mouth. It is unclear if rinsing with an aloe-containing mouthwash is beneficial for dry mouth. Details: In patients with dry mouth related to type 2 diabetes, clinical research shows that an aloe vera 50% mouthwash, as 20 mL swished and spit three times daily for 14 days, modestly reduces symptoms of dry mouth when compared with rinsing with a saline control mouthwash (106068). The validity of this study is limited due to unclear reporting.
• Dry skin. Topical aloe or oral aloe sterols may improve some measures of dry skin. However, findings are mixed due to the use of varied formulations and doses. Details: One small clinical trial shows that applying a cream containing freeze-dried aloe extract 0.1% to 0.5% to the skin for 2 weeks increases the amount of water in the stratum corneum, but does not reduce transepidermal water loss, when compared with placebo (19758). Another small clinical study in females with occupational dry skin shows that wearing gloves coated in aloe 8 hours daily for 30 days improves symptoms of dry skin when compared with no treatment (19759). However, it is not clear if the benefits resulted from applying aloe or wearing gloves. One small clinical trial in healthy females shows that consumption of a yogurt containing 500 mg of aloe vera gel powder (0.4 mg of aloe sterol) daily for 12 weeks increases skin hydration, skin elasticity, and collagen content of the dermis while reducing markers of skin fatigue and transepidermal water loss when compared with placebo (95942). However, another study in healthy females shows that taking aloe sterol-enriched aloe extract 0.5 grams daily for 12 weeks does not improve skin hydration when compared with placebo, although redness, itching, collagen content, and transepidermal water loss were improved (101577).
• Epilepsy. Although there has been interest in using oral aloe for epilepsy, there is insufficient reliable information about the clinical effects of aloe for this purpose.
• Frostbite. Although there has been interest in using topical aloe for frostbite, there is insufficient reliable information about the clinical effects of aloe for this purpose.
• Gingivitis. Using aloe-containing toothpaste may reduce gingivitis in adults, but it does not seem to be more effective than fluoride-containing toothpaste. Rinsing with an aloe-containing mouthwash may reduce gingivitis in children. Details: One small clinical trial in adults shows that brushing teeth with a dentifrice containing aloe gel (Forever Bright, Forever Living Products) three times daily for 30 days does not reduce the occurrence of gingivitis more effectively than a fluoridated dentifrice (Sorriso Dentes Brancos, Kolynos do Brasil), although both treatments seem to show improvement when compared to baseline (19755). Another small clinical study in adults with gingivitis shows that using aloe-containing toothpaste daily for 24 weeks reduces gingivitis more effectively than placebo, but not more than triclosan-containing toothpaste (19760). In children aged 8-14 years with mild gingivitis, using a mouthwash containing aloe vera 7% twice daily for 4 weeks reduced gingivitis by a large amount when compared with placebo. In addition, it was as effective as chlorhexidine 0.2% (103306).
• Heart failure. It is unclear if oral aloe is beneficial in patients with systolic heart failure. Details: A very small clinical study in adults with moderate to moderately severe chronic systolic heart failure shows that taking aloe vera gel capsules 150 mg twice daily for 8 weeks in addition to standard treatment decreases New York Heart Association (NYHA) functional class, improves Minnesota Living with Heart Failure Questionnaire (MLHFQ) total, physical, emotional, and social scores, and enhances sleep quality but does not reduce the severity of obstructive sleep apnea scores or improve six-minute walk test distance when compared with placebo (111663). The study may have been inadequately powered to detect a difference between groups. Additionally, the validity of these effects may be limited by the small sample size.
• Hematopoietic stem cell transplant (HSCT). Oral and topical aloe have only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients undergoing hematopoietic stem cell transplantation shows that treatment with colostrum and aloe orally (Remargin Colostrum Gastro-Gel, Solimè srl, Cavriago, Reggio Emilia, Italy) and as a mouthwash (Remargin Colostrum OS, Solimè srl, Cavriago, Reggio Emilia, Italy) modestly reduces the risk and duration of severe oral mucositis and febrile neutropenia when compared with historical values. There was no effect on the duration of neutropenia, the length of hospital stay, pain, or duration of medications. All patients were also given standard care. The mouthwash was used after each oral hygiene, and the oral treatment was 3 to 5 times daily depending on symptoms (110211).
• Hepatitis. It is unclear if oral aloe is beneficial in patients with hepatitis. Details: One small clinical trial in patients with liver fibrosis primarily caused by hepatitis B or hepatitis C shows that taking a high molecular weight fraction of aloe 0.05 grams three times daily for 12 weeks reduces fibrosis, attenuates liver enzyme activity, and decreases hepatic glutathione content when compared with placebo (19780).
• HIV/AIDS. Small clinical studies suggest that oral aloe or the aloe constituent acemannan may not improve CD4 counts or viral load in patients with HIV. Details: One small clinical trial in patients with HIV shows that taking the aloe constituent, acemannan, 400 mg four times daily does not significantly improve CD4 counts, ratio of CD4 to CD8, or viral load when compared with placebo (19851). Another small clinical study in patients with HIV shows that taking aloe gruel 30-40 mL daily does not improve CD4 counts when compared with those treated with antiretroviral therapy, although both groups show similar increases in weight compared to baseline (19852).
• Hyperlipidemia. Although there has been interest in using oral aloe for hyperlipidemia, there is insufficient reliable information about the clinical effects of aloe for this purpose.
• Hypertrophic scars. Topical aloe has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical trial in patients undergoing median sternotomy shows that applying a silicone gel containing aloe extract and other herbal extracts (Bangkok Botanica) to postoperative hypertrophic scars for 6 months reduces the height of the scar and improves pliability by a moderate amount when compared with a silicone placebo gel. There was no effect on pigmentation or vascularity (102793). It is unknown whether any benefit is related to aloe, other ingredients, or their combination.
• Influenza. Oral aloe has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in healthy adults shows that taking a combination supplement containing aloe vera gel, rosemary, and poria mushrooms twice daily 28 days before administering the influenza vaccine and 28 days after vaccination does not improve immunologic markers or reduce symptom severity, symptom duration, frequency of upper respiratory tract infection symptoms, or the use of cold and flu medications when compared with placebo (111921).
• Irritable bowel syndrome (IBS). Small clinical studies suggest that oral aloe extract or juice may not improve symptoms in patients with IBS. Details: Most research suggests that aloe is not effective for improving symptoms of IBS; however, the available evidence is of low-quality, with some studies having high dropout rates or inadequate power to detect significant differences. Two clinical trials show that taking a specific aloe extract (AVH200, Calmino Group AB) 250-500 mg twice daily for 4 weeks does not improve IBS-related symptoms or response rates when compared with placebo (101579,104169), although one of these studies did find a trend toward a higher response rate, defined as a 50% or greater improvement in symptom scores, with aloe over placebo (104169). Also, a pooled analysis of these two studies shows that taking this specific product improves IBS-related pain severity and frequency in patients with diarrhea-prominent IBS (IBS-D) when compared with placebo, but does not seem to improve stool consistency or frequency (108718). Clinical trials evaluating aloe juice 50 mL four times daily for 1 month or 60 mL twice daily for 5 months show no significant improvement in quality of life scores or IBS symptoms when compared with placebo (104170,104171), although one study did find a trend toward improved response in patients with IBS-D (104171). Despite a lack of significant findings in the individual studies, a pooled analysis of the two smallest studies above (104169,104171) shows that aloe extract or juice, taken for 4 weeks, may increase the rate of symptom response by almost 70% when compared with placebo (103307).
• Nipple Fissures. It is unclear if application of an aloe poultice improves nipple-related complications of breastfeeding, such as nipple fissures. Details: A clinical study in females who have just given birth and are breastfeeding for the first time shows that applying a poultice containing aloe gel to the nipples after breastfeeding six times daily for 5 days improves nipple eschar when compared with no treatment. Although there were modest improvements in other outcomes, such as redness, fissures, and epidermolysis, these differences were not significant (108721). Participants were instructed to clean with purified water before the next breastfeeding session.
• Multiple sclerosis (MS). Although there has been interest in using oral aloe for MS, there is insufficient reliable information about the clinical effects of aloe for this purpose.
• Oral mucositis. Small clinical studies suggest that oral aloe juice or application of aloe solution inside the mouth may prevent oral mucositis in patients receiving chemotherapy or radiation. Details: Some clinical research shows that drinking 15 mL of juice containing aloe 80% three times daily during radiation therapy decreases the risk of developing moderate or severe mucositis by approximately 39% when compared with placebo (19767,19964). In addition, in children aged 3-6 years undergoing chemotherapy for leukemia, application of a solution containing aloe 70% twice daily inside the mouth, starting three days before chemotherapy, reduces the severity of oral mucositis and delays its onset by 2 weeks when compared with sodium bicarbonate 5% (103304). Other clinical research in adults with head and neck cancer shows that rinsing and then swallowing 20 mL of a solution containing aloe juice 94.5% four times daily throughout the course of radiation therapy does not prevent mucositis when compared with placebo (19963). However, this study was not adequately powered to detect significant differences between study groups. Aloe has also been evaluated in combination with other ingredients for the treatment of oral mucositis. Preliminary clinical research in patients undergoing hematopoietic stem cell transplantation shows that treatment with colostrum and aloe orally (Remargin Colostrum Gastro-Gel, Solimè srl, Cavriago, Reggio Emilia, Italy) and as a mouthwash (Remargin Colostrum OS, Solimè srl, Cavriago, Reggio Emilia, Italy) modestly reduces the risk and duration of severe oral mucositis when compared with historical values. There was no effect on overall risk or time of onset of mucositis. All patients were also given standard care. The mouthwash was used after each oral hygiene, and the oral treatment was 3 to 5 times daily depending on symptoms (110211). Another small clinical study in adults with head and neck cancer receiving radiotherapy shows that rinsing with 5 mL of a mouthwash containing aloe, German chamomile, peppermint oil, and honey 3 times daily for 60 seconds for 6 weeks starting on the first day of radiotherapy reduces oral mucositis incidence, severity, and pain when compared with chlorhexidine and placebo (111291). It is unclear if these findings are due to aloe, other ingredients, or the combination.
• Osteoarthritis. Although there has been interest in using oral and topical aloe for osteoarthritis, there is insufficient reliable information about the clinical effects of aloe for this purpose.
• Peptic ulcers. Although there has been interest in using oral aloe for peptic ulcers, there is insufficient reliable information about the clinical effects of aloe for this purpose.
• Periodontitis. It is unclear if application of aloe inside the mouth is beneficial for chronic periodontitis. Details: A meta-analysis of small clinical studies in patients with chronic periodontitis shows that using various aloe-containing gels, mouthwashes, and toothpastes improves plaque index when compared with placebo or other treatments (i.e., chlorhexidine rinse, metformin, and tea tree oil). The effect of these aloe products on gingival index could not be determined (108719). The validity of this finding is limited by the variety of aloe formulations and comparators used in the included studies.
• Pressure ulcers. It is unclear if topical aloe is beneficial for the prevention or treatment of pressure ulcers. Details: One small clinical study shows that applying a gel containing the aloe constituent acemannan to pressure ulcers daily for 10 weeks does not reduce the time to healing when compared with management with moist saline gauze (12160,19853). Other clinical research shows that cleansing wounds with a saline spray containing aloe, silver chloride, and decyl glucoside for 2 weeks improves pressure ulcer healing when compared with isotonic saline spray (19854). It is unclear if this improvement is due to aloe, other ingredients, or the combination in the spray. Aloe has also been evaluated for the prevention of pressure ulcers. A small clinical study in hospitalized patients in an orthopedic ward shows that applying aloe vera gel to the hips, sacrum, and heels twice daily for 10 days reduces pressure ulcer occurrence to 3 of 39 patients, compared to 12 of 38 patients of those receiving placebo (98816). However, methodological limitations with this study, including differences in how the gels were applied, limit the reliability of these results. A clinical study in hospitalized patients receiving intensive care has evaluated either aloe gel 94%, olive oil 100%, or a compounded product containing aloe vera and olive oil in a 3:2 ratio, applied to pressure areas as 10-15 mL every 8 hours. At the end of 30 days, pressure ulcers occurred in 17% of patients receiving the combination product, 20% receiving olive oil, 33% receiving aloe gel, and 37% receiving standard care, suggesting that any benefit may be due to olive oil (108723).
• Radiation proctopathy. It is unclear if topical aloe is beneficial for the prevention or treatment of radiation proctopathy. Details: One very small clinical study in females with radiation proctopathy shows that applying 1 gram of an ointment containing aloe vera 3% rectally twice daily in conjunction with taking sulfasalazine 500 mg four times daily for 4 weeks modestly reduces diarrhea, fecal urgency, radiation toxicity, and clinical symptoms when compared with sulfasalazine alone (95941). This same product, applied twice daily for 6 weeks starting on the first day of radiotherapy, has also been evaluated for the prevention of radiation proctopathy. One small clinical study in patients with pelvic cancer shows that applying this ointment prevents proctopathy-related diarrhea, rectal bleeding, and fecal urgency when compared with placebo. Proctopathy-related symptoms occurred in 5% of patients using aloe, compared with 65% of those using placebo. However, there was no difference in rectal pain, constipation, or symptoms of cystitis between groups (101578). A very small clinical study in patients with colorectal cancer shows that applying this ointment prevents proctopathy-related diarrhea and reduces proctopathy severity, but does not improve rectal bleeding, rectal pain, fecal urgency, or symptoms of cystitis, when compared with placebo (108717). Reasons for discrepancies are unclear but might relate to differences in cancer diagnosis and radiation regimens.
• Scabies. It is unclear if topical aloe is beneficial in patients with scabies. Details: One small open-label clinical study in children and adults with scabies shows that application of crude aloe gel for 3 consecutive days, repeated again after one week, may reduce itching and lesions similar to benzyl benzoate lotion in patients with scabies when compared to baseline (19769). The validity of this finding is limited by the lack of a placebo group.
• Seborrheic dermatitis. It is unclear if topical aloe is beneficial in patients with seborrheic dermatitis. Details: One small clinical study in adults with seborrheic dermatitis shows that applying aloe 30% emulsion twice daily for 4-6 weeks reduces scaling, itching, and the number of sites involved, but not erythema, when compared with placebo (19749).
• Stretch marks (striae gravidarum). It is unclear if topical aloe is effective for the prevention or treatment of stretch marks. Details: One small clinical trial in nulliparous patients shows that topical application of a cream containing aloe twice daily, starting at gestational week 16-18, reduces erythema and itching related to abdominal stretch marks, but does not seem to decrease the number of stretch marks, when compared with a base cream (97322). Aloe gel has also been evaluated in combination with fractional carbon dioxide (CO2) laser treatments. A small clinical trial shows that applying a gel containing aloe 87.4% twice daily for up to one month after each of three CO2 laser treatments improves the texture of the skin for up to 6 months after the last laser treatment when compared to baseline. This was as effective as topical recombinant human epidermal growth factor (rhEGF) and CO2 laser treatments. However, when specific sites were examined, only the texture of stretch marks on the buttocks were improved, and these improvements were less than those seen with rhEGF (101580). The effect of aloe for the prevention of stretch marks is unknown.
• Sunburn. Although there has been interest in using topical aloe for sunburn, there is insufficient reliable information about the clinical effects of aloe for this purpose.
• Tungiasis. Topical aloe has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One clinical study shows that applying a product containing coconut oil, jojoba oil, and aloe leaf extract (Zanzarin, Engelhard Arzneimittel GmbH & Co. KG) to the feet twice daily for one-week intervals seems to reduce the number of embedded sandfleas in individuals with tungiasis when compared with a control group (19778). It is not clear if this effect is due to aloe, the other ingredients, or the combination.
• Ulcerative colitis. It is unclear if oral aloe gel is beneficial in patients with ulcerative colitis. Details: One small clinical trial in patients with mild to moderate ulcerative colitis shows that taking aloe gel for 4 weeks, starting at 25-50 mL twice daily for the first 3 days and increasing to 100 mL twice daily thereafter, reduces symptoms when compared with placebo (11984).
• Vaginitis. It is unclear if topical aloe is beneficial for vaginitis. Details: One small clinical trial in postmenopausal patients with atrophic vaginitis shows that applying 5 mg of a vaginal cream containing aloe gel 2% nightly for 2 weeks, then 3 nights per week for 4 weeks, reduces vaginal dryness, burning, and pain during intercourse and improves measures of vaginal health and maturity when compared to baseline. These effects were similar to those seen with estrogen vaginal cream (104175).
• Varicose veins. Although there has been interest in using oral and topical aloe for varicose veins, there is insufficient reliable information about the clinical effects of aloe for this purpose.
• Wound healing. There is conflicting evidence about the effectiveness of topical aloe products for improving wound healing. These conflicting findings may be due to differences in study designs, products used, and application practices. Details: One small clinical study shows that applying aloe gel to a caesarean wound after surgery, followed by a dry gauze, improves wound healing over the first 24 hours when compared with the dry gauze alone (90128). However, other clinical research in a small number of patients undergoing gynecologic surgery or cesarean section shows that applying an aloe gel extract (Carrington Dermal Wound Gel) to surgical wounds may actually delay wound healing (11982). Another small clinical trial shows that applying a formulation of aloe gel 0.5% cream (Zarband, Phytopharmaceutical Co.) to hemorrhoidectomy wounds three times daily for 4 weeks improves healing rates and pain relief scores and decreases intake of narcotic analgesics when compared with placebo (17418). However, another clinical trial in patients with biopsy wounds shows that application of a hydrogel containing the aloe constituent, acemannan (Carrasyn, Carrington hydrogel), does not improve wound epithelialization, wound infections, or pain when compared with conventional therapy (19856). Additionally, there is contradictory evidence about the effectiveness of aloe for improving skin graft donor site healing. One small clinical study shows that applying aloe gel 87.4% daily to split-thickness skin graft donor sites reduces time to complete healing by about 2 days when compared with placebo (97320). However, another small clinical study shows that applying aloe cream three times daily to split-thickness skin graft donor sites does not improve healing time when compared with placebo (97321).
• Wrinkled skin. Although there has been interest in using topical aloe for wrinkled skin, there is insufficient reliable information about the clinical effects of aloe for this purpose. More evidence is needed to rate aloe for these uses.

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LIKELY EFFECTIVE

• Coronary heart disease (CHD). Consuming barley 3-3.6 grams daily as a source of dietary fiber appears to reduce the risk of CHD. Details: Clinical research shows that a diet containing foods high in soluble fiber, such as whole grain barley or dry milled barley, reduces the risk of heart disease (2737,4962,4963,4964,4965,4966,4967,4968). In 1993, the US Food and Drug Administration (FDA) approved a health claim stating that consuming at least 3 grams of soluble fiber per day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of CHD (5792,5797,102336). However, some clinical research shows that at least 3.6 grams of soluble fiber daily is needed to reduce the risk of CHD (5788,5795).
• Hypercholesterolemia. Consuming barley 3-12 grams daily seems to reduce total cholesterol and low-density lipoprotein (LDL) cholesterol levels in adults with hypercholesterolemia. Details: Clinical research shows that taking barley significantly reduces total cholesterol and low-density lipoprotein (LDL) cholesterol when used with a normal diet or added to the National Cholesterol Education Program's Step I diet (11134,11986,17129,33734,33748,33752). A meta-analysis of 11 clinical trials shows that consuming preparations containing barley 3-12 grams daily for at least 4-12 weeks reduces total cholesterol and LDL cholesterol levels by around 12 mg/dL and 10 mg/dL, respectively, with no change in triglyceride or high-density lipoprotein (HDL) cholesterol levels. These changes did not appear to be dose-dependent (17129). However, a small clinical study in males with hypercholesterolemia shows that the effect of barley on cholesterol is modestly dose-dependent. Taking 0.4 grams, 3 grams, or 6 grams of soluble fiber from barley daily for 5 weeks reduces total cholesterol by 14%, 17%, and 20%, respectively, and reduces LDL cholesterol by 17%, 17%, and 24%, respectively, when compared to baseline (11986). The form of barley used may alter its effect on cholesterol levels. Some research has shown that barley highly enriched (75% by weight) with beta-glucans does not seem to significantly affect cholesterol. This lack of effect seems to be the result of processing the barley into a highly enriched beta-glucans product (10166). Food processing seems to affect beta-glucans structure or solubility and therefore decreases the cholesterol lowering effects of barley.

POSSIBLY INEFFECTIVE

• Colorectal cancer. Increased consumption of barley as a source of fiber does not appear to be beneficial for primary or secondary prevention of colorectal cancer. Details: Clinical and observational research shows that consuming dietary cereal fiber, including barley fiber, does not reduce the risk of colorectal cancer or prevent colorectal cancer recurrence (160,4819,4820,4821,5104).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Coronavirus disease 2019 (COVID-19). It is unclear if oral barley is beneficial in patients with COVID-19. Details: A small clinical study in Iranian adults hospitalized with moderate COVID-19 shows that drinking 250 mL of Persian barley water daily for 2 weeks, along with conventional treatment, decreases length of hospital stay, body temperature, and markers of inflammation when compared with conventional treatment alone. However, Persian barley water does not appear to improve oxygen saturation or symptoms of COVID-19 (111148). The validity of these findings is limited by a lack of placebo control and concerns related to the statistical methods used.
• Diabetes. Although there has been interest in using oral barley for diabetes, there is insufficient reliable information about the clinical effects of barley for this purpose.
• Diarrhea. Although there has been interest in using oral barley for diarrhea, there is insufficient reliable information about the clinical effects of barley for this purpose.
• Gastric cancer. It is unclear if oral barley is effective for the prevention of gastric cancer. Details: Observational research suggests that increased consumption of dietary fiber, a component of barley, is associated with 70% lower odds of gastric cancer when compared with low consumption of dietary fiber (10435).
• Gastritis. Although there has been interest in using oral barley for gastritis, there is insufficient reliable information about the clinical effects of barley for this purpose.
• Hypertension. Although there has been interest in using oral barley for hypertension, there is insufficient reliable information about the clinical effects of barley for this purpose.
• Obesity. Although there has been interest in using oral barley for obesity, there is insufficient reliable information about the clinical effects of barley for this purpose.
• Ulcerative colitis. Small clinical studies suggest that oral barley might improve symptoms associated with ulcerative colitis. Details: Several small, open-label trials in patients with ulcerative colitis show that consuming food containing germinated barley 20-30 grams daily for 4-24 weeks reduces symptoms of ulcerative colitis when compared to baseline (33725,33729,33732,33777). However, the validity of these findings is limited by a lack of comparator groups. Barley has also been studied in combination with other ingredients. A small clinical study in adults with mild to moderate ulcerative colitis shows that taking a specific nutritional supplement (Profermin, Nordisk Rebalance) containing barley malt flour, oat flour, Lactobacillus plantarum, and lecithin twice daily for 8 weeks decreases symptom scores by at least 50% in an additional 26% of patients when compared with a control nutritional supplement. Disease remission occurred in 31% of patients taking this product compared with 15% of patients in the control group (92818). It is unclear if these findings are due to barley, other ingredients, or the combination. More evidence is needed to rate barley for these uses.

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POSSIBLY EFFECTIVE

• Athletic performance. Oral beet may improve athletic performance associated with aerobic activities. However, it is not clear who is most likely to benefit, for which type of competition it is most useful, or what dose or duration of use is most appropriate. Details: Several small clinical trials, most of which enrolled males only, as well as a meta-analysis of some of these studies, show that beet improves various measures of athletic performance. Conversely, another meta-analysis of several small clinical studies, that includes some of these studies, shows that taking beetroot does not improve performance in high-intensity or sprint interval training (111159). The most commonly used doses in all studies, regardless of effect, have included an acute dose of beetroot juice 70-500 mL up to 3 hours prior to exercise (93844,94463,94464,94466,94467,94473,97726,100142,100143,105761)(105762,111159) or chronic dosing of up to 500 mL daily for 3-6 days (94459,94464,94469,100145,100147,100153,111159). Less commonly, beetroot juice 70-140 mL daily, betalain-rich concentrate 100 mg daily, or a beetroot-based nutritional gel 100 grams daily, have been taken for longer dosing schedules of 7-15 days (97720,100144,100148,100152,105763). Brands of juice used in clinical trials have included Beet It Sport (James White Drinks Ltd.) (94455,94458,94465,100142,100143,100144,100148,105761,105763), Beet It Stamina Shot (James White Drinks Ltd.) (93844), Beet It (James White Drinks Ltd) (94457,94459,94460,94467,94469,97726,100145,100153,105762,111159), and Love Beets Beetroot Juice (Gs Fresh Ltd.) (94461,94462). Although plasma levels have not been analyzed in all studies, the majority of studies suggest that these doses are adequate to increase levels of nitrates or nitrites, which is thought to be essential for increasing athletic potential (93844,94455,94458,94459,94460,94465,94467,94469,94466,94473,97726). The evidence also suggests benefit in both normoxic and hypoxic environments (94465,100148,105763). Research in recreationally-trained athletes or sedentary individuals has shown some benefit. Clinical research shows beetroot juice improves the use of oxygen during exercise testing in recreationally-trained athletes, especially with severe exercise testing (94460,94463,94467,100147,105762). There is also some evidence of improvement in ability or strength (93844,94464,94468,100143,100150,100152). Also, in obese adolescents, taking beetroot juice daily for 6 days increases the time to exhaustion from severe exercise, but does not improve moderate exercise (100145). However, results are not consistent even within the same publication, suggesting that some differences might be related only to chance. By contrast, the majority of research in elite athletes does not support the use of beetroot juice to decrease the time needed to complete a task, aid in some sort of graded exercise test, or improve the use of oxygen during exercise testing (94455,94458,94460,94461,94464,94465,94466,94469,94473,100142,100153,105763). However, some research does suggest that specific sprint sets might be improved (94469) and that beet may improve power output and anaerobic capacity during morning workouts (105761). Also, higher doses or a longer duration might be necessary to improve the time to complete a running or cycling trial. Benefits in elite athletes, most often related to time trials, are usually limited to studies using chronic dosing of 7-15 days, which is longer than the duration of 6 days used in the majority of studies (94473,97720,100144,100148). The supposed lack of effect of beetroot juice in elite athletes might be related to the natural production of nitrates and nitrites in the body or the increased ability to use oxygen that comes from extensive training (94458,94463). Alternatively, any changes might be very small (<1%) and not identified with statistical comparisons, although even very small changes might be beneficial in competition (94464).
• Exercise-induced muscle soreness. Drinking beetroot juice 7-8 times over 48 hours after strenuous exercise may reduce exercise-induced muscle soreness. Details: Some clinical research shows drinking beetroot juice (Love Beets Beetroot Juice, Gs Fresh Ltd.) 125 mL or 250 mL seven times over 48 hours after strenuous box jumps improves muscle soreness when compared with placebo and sodium nitrite (96964,97722). Also, a small clinical study shows that drinking beetroot juice 250 mL as eight separate doses over 48 hours after a repeated sprint test improves muscle soreness when compared with placebo (94461). However, drinking this same beetroot juice 250 mL as seven separate doses over 48 hours after running a marathon does not appear to reduce muscle soreness when compared with placebo (94462). These studies were also included in a meta-analysis along with 2 other small studies. This analysis of mostly healthy or physically active males shows that drinking beetroot juice improves the pressure pain threshold, which is a measure of muscle soreness, at 48- and 72-hours post-exercise when compared with a fruit-flavored drink. However, beetroot juice does not improve subjective muscle soreness scores (111160). The validity of the findings from this meta-analysis is limited by the heterogeneity of the beetroot juice regimens among the included studies. Further, these results should not be generalized to elite athletes.

POSSIBLY INEFFECTIVE

• Chronic obstructive pulmonary disease (COPD). Drinking beetroot juice for up to 14 days may not improve exercise capacity in patients with COPD. Details: A meta-analysis of eight small clinical trials in patients with COPD shows that taking nitrate-rich beetroot juice does not improve most measures of exercise capacity, including the 6-minute walk test, cycling ergometry endurance time, and maximum rate of oxygen consumption (VO2 max), when compared with placebo. Additionally, beetroot juice did not reduce blood pressure or heart rate. However, the analysis did show a significant improvement in scores on the Borg Rating of Perceived Exhaustion scale with beetroot juice over placebo. Nitrate-rich beetroot juice doses ranged from 70-140 mL daily for up to 14 days (104200).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Cognitive function. It is unclear if drinking beetroot juice is beneficial for cognitive function. Details: A small clinical study in adults with overweight or obesity on a calorie-restricted diet shows that drinking 70 mL of concentrated beetroot juice daily for 14 days improves the time to complete part B of the trail making test, which is a test of cognitive function, but not part A, when compared with controls (111158). However, the duration and size of this study limits its validity. Further, it is unclear whether any improvement is clinically significant.
• Coronary heart disease (CHD). It is unclear if oral beetroot extract is beneficial in patients with CHD. Details: A small clinical trial in patients with CHD shows that taking red beetroot extract 500 mg, containing around 25 mg betalains, twice daily for 2 weeks reduces total cholesterol and low-density lipoprotein (LDL) cholesterol by 15 mg/dL and reduces triglycerides by 8 mg/dL when compared to baseline. Slight improvements in blood pressure and blood glucose were also reported, but these changes were not clinically significant (103883). The validity of these findings is limited by the lack of a comparator group. Also, it is unclear whether beetroot can reduce the risk of cardiovascular events in patients with CHD.
• Dyslipidemia. It is unclear if oral beetroot is beneficial in patients with dyslipidemia. Details: A meta-analysis of small clinical studies in healthy individuals or patients with dyslipidemia, cardiovascular disease, or overweight or obesity, shows that consuming beetroot juice or leaves does not improve levels of triglycerides or total, low-density lipoprotein, or high-density lipoprotein cholesterol when compared with controls (111163). However, the validity of the findings from this meta-analysis is limited by the heterogeneity of the enrolled patients and beetroot regimens.
• Exercise-induced muscle damage. It is unclear if oral beetroot juice improves recovery from muscle damage after exercise. Details: A meta-analysis of 4 small clinical studies in healthy or physically active individuals, most of which enrolled males only, shows that drinking beetroot juice improves measures of muscle recovery at 72 hours post-exercise when compared with a fruit-flavored drink. However, beetroot juice does not consistently improve recovery at earlier time points post-exercise, nor does it reduce levels of creatine kinase or markers of inflammation (i.e., interleukin-6, interleukin-8, c-reactive protein, or tumor necrosis factor-alpha) (111160). However, the validity of the findings from this meta-analysis is limited by the heterogeneity of the beetroot juice regimens among the included studies, which usually varied from 210-250 mg of nitrate in 7-11 servings over 3-7 days. Further, these results should not be generalized to elite athletes.
• Hypertension. Oral beet may slightly reduce blood pressure in healthy individuals, but it is unclear if it is beneficial in patients with hypertension. Details: Meta-analyses of small studies show the potential for a minor reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP) in healthy adults taking beetroot juice (94470,97718,97728). The average reduction in SBP and DBP with beetroot juice consumption is about 4 mmHg and 1 mmHg, respectively, which is greater than the effect seen with consuming blackcurrant juice or nitrate-depleted beetroot juice. The most benefit is seen when beetroot juice is taken for at least 2 weeks or at doses of 500 mL daily (97728). Another small clinical study shows that consuming beet 100 grams baked into bread modestly decreases DBP over a 6-hour period when compared with white bread (97725). It is possible that genetics might play a role in the magnitude of effect seen with beetroot consumption. Adults with a specific gene polymorphism, eNOS Glu298Asp, experienced a greater reduction in DBP after consuming beet-containing bread (97724). Despite positive findings in studies of healthy individuals, research on the use of beetroot juice in patients with hypertension is unclear. A small clinical study in adults with hypertension who were taking antihypertensive medications shows that drinking nitrate-rich beetroot juice (Beet it; James White Drinks Ltd.) 70 mL twice daily for one week does not lower blood pressure when compared with nitrate-depleted beetroot juice (94457). Also, in patients with mild to moderate hypertension, clinical research shows that taking a combination of beetroot powder (Sensient) 300 mg, olive leaf extract 1000 mg, and green coffee bean extract 200 mg daily for 6 weeks does not lower blood pressure when compared with placebo (97723). However, some evidence suggests that at least part of the blood pressure lowering effects of beet might be independent of nitrate (97728). Furthermore, some research suggests that identifying effects on blood pressure might be dependent on the method of measurement, including clinic resting measurements, 24-hour monitoring, or morning/evening home resting measurements (97729).
• Hypertriglyceridemia. It is unclear if oral beet is beneficial in patients with hypertriglyceridemia. Details: A small clinical study in overweight or obese individuals with dyslipidemia shows that taking freeze-dried beet leaf 2.8 grams daily for 4 weeks in addition to nutritional guidance does not lower triglyceride levels when compared with nutritional guidance alone (100146). Beet has also been evaluated in combination with other ingredients. A small clinical trial in patients at risk for heart disease shows that a specific combination of beet and hawthorn berry (Neo40-Daily, Neogenis Labs), taken twice daily for 30 days, can modestly reduce blood triglyceride levels when compared to baseline (18222). It is unclear if these findings are due to beet, hawthorn berry, or the combination.
• Liver disease. Although there has been interest in using oral beet for liver disease, there is insufficient reliable information about the clinical effects of beet for this purpose.
• Muscle strength. It is unclear if oral beetroot juice is beneficial for muscle strength. Details: A small clinical study in adults with overweight or obesity on a calorie-restricted diet shows that drinking 70 mL of concentrated beetroot juice daily for 14 days improves handgrip strength by approximately 18% compared with 4% in controls (111158). However, it is unclear whether any improvement is clinically significant.
• Obesity. It is unclear if oral beet leaf or beetroot juice is beneficial for weight loss. Details: A small clinical study in patients with overweight or obesity and dyslipidemia shows that taking freeze-dried beet leaf 2.8 grams daily for 4 weeks in addition to nutritional guidance does not reduce body weight or body mass index (BMI) when compared with nutritional guidance alone (100146). Similarly, a small clinical study in adults with overweight or obesity on a calorie-restricted diet shows that drinking 70 mL of concentrated beetroot juice daily for 14 days does not improve weight loss when compared with controls (111158). However, the size and duration of this study may have been inadequate to detect differences between groups.
• Pregnancy-induced hypertension. It is unclear if oral beetroot juice is beneficial in patients with pregnancy-induced hypertension. Details: A small clinical trial in pregnant patients with hypertension who are at approximately 22-35 weeks gestation shows that taking beetroot juice (James White Drinks Ltd) 70 mL daily for 8 days does not reduce blood pressure when compared with a nitrate-depleted beetroot juice (100151). However, the study was small and designed to investigate the feasibility of using beetroot juice in this population.
• Pulmonary hypertension. It is unclear if oral beetroot juice is beneficial in patients with pulmonary hypertension. Details: A small clinical study shows that taking beetroot juice (Beet-It Sport; James White Drinks Ltd) 70 mL twice daily for 7 days does not improve right ventricular systolic function when compared with nitrate-depleted beetroot juice in patients with pulmonary hypertension (100149). However, this study was small and not adequately powered to detect differences between groups.
• Raynaud syndrome. It is unclear if oral beetroot juice is beneficial in patients with Raynaud syndrome. Details: A small clinical study in patients with Raynaud syndrome undergoing cold sensitivity tests shows that drinking beetroot juice (Beet-It, James White Drinks Ltd) 70 mL daily for 13 days, followed by 140 mL prior to testing, does not reduce pain in the hands or feet, but might improve thermal comfort in the feet, when compared to baseline (103884). The validity of this finding is limited by the lack of a comparator group. More evidence is needed to rate beet for these uses.

(Read more about BEET)

POSSIBLY EFFECTIVE

• Irritable bowel syndrome (IBS). Oral Bifidobacterium bifidum seems to be beneficial for reducing symptoms of IBS. Details: Clinical research shows that taking live or heat-inactivated B. bifidum MIMBb75 is beneficial for improving gastrointestinal symptoms in patients with IBS (105155,105160). Taking 1 billion colony-forming units (CFUs) daily for 4 weeks results in an overall responder rate of 57%, compared with 21% in the placebo group. There were specific improvements in abdominal pain, bloating, and urgency (105160). When taking the heat-inactivated form of B. bifidum MIMBb75 (SYN-HI-001) 1 billion cells daily for 8 weeks, 34% of patients experienced at least a 30% improvement in abdominal pain and overall relief of symptoms in at least 4 of the 8 weeks, compared with only 19% of those taking placebo (105155). A clinical study in patients with diarrhea-predominant IBS shows that taking a specific combination product (NordBiotic, MBM Biotix) containing B. bifidum BF030, Bifidobacterium breve BB010, Bifidobacterium longum BL020, Bifidobacterium animalis subsp. lactis BL040, Lacticaseibacillus rhamnosus LR110, Lacticaseibacillus paracasei LPC100, Lactobacillus acidophilus LA120, Lacticaseibacillus casei LC130, Lactiplantibacillus plantarum LP140, and Streptococcus thermophilus ST250 as 2.5 billion CFUs total twice daily for 8 weeks improves overall symptom severity, as well as pain severity, pain frequency, and quality of life, when compared with placebo. Symptom severity was rated as mild by approximately 60% of those taking the probiotic mixture, compared with 30% of those taking placebo (107516).
• Respiratory tract infections. Most clinical research shows that taking Bifidobacterium bifidum may reduce the risk of respiratory infections in otherwise healthy individuals. Details: One clinical study shows that taking B. bifidum R0071 3 billion colony-forming units (CFUs) daily for 6 weeks decreases the percentage of college students who experience at least one day of cold or flu by about 35% when compared with placebo. The number of cold or flu episodes is also decreased by 32% when compared with placebo (90272). Some studies have evaluated probiotics containing B. bifidum along with other species. One study shows that taking a specific combination (Infloran) of B. bifidum and Lactobacillus acidophilus 1 billion CFUs each twice daily for 3 months reduces the number of school-aged children who experience cold-related fever, cough, or school absence when compared with placebo (90286). In healthy children aged 3-10 years, clinical research shows that taking 12.5 billion CFUs daily of a specific combination of B. bifidum CUL20, L. acidophilus CUL21 and CUL60, and Bifidobacterium animalis subsp. lactis CUL34 (Lab4) plus vitamin C 50 mg daily reduces the risk of cough by 16% and sore throat by 20% and modestly reduces school absenteeism and antibiotic use when compared with placebo. However, nasal symptoms, fever, and wheezing were not reduced (106943).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Age-related cognitive decline. Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in healthy adults over 65 years shows that taking a total of one billion colony-forming units (CFUs) of B. bifidum BGN4 and Bifidobacterium longum BORI daily for 12 weeks modestly improves mental flexibility when compared with placebo. However, there were no benefits on cognitive function, including language, memory, or attention (110968).
• Allergic rhinitis (hay fever). Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in patients with seasonal allergies shows that taking B. bifidum G9-1 0.15 billion colony-forming units CFUs), Bifidobacterium longum MM-2 0.15 billion CFUs, and Lactobacillus gasseri KS-13 1.2 billion CFUs twice daily for 8 weeks during allergy season modestly improves quality of life, specifically nasal symptoms, when compared with taking placebo. However, eye symptoms were not improved (110972).
• Alzheimer disease. Although there has been interest in using oral Bifidobacterium bifidum for Alzheimer disease, there is insufficient reliable information about the clinical effects of B. bifidum for this condition.
• Antibiotic-associated diarrhea. Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A large clinical trial shows that taking a total of 60 billion colony-forming units (CFUs) of B. bifidum CUL20 NCIMB 30153, Bifidobacterium lactis CUL 34 NCIMB 30172, and Lactobacillus acidophilus CUL60 NCIMB 30157 and CUL 21 NCIMB 30156 daily for 21 days does not reduce the risk of antibiotic-associated diarrhea when compared with placebo (92255). An additional large clinical trial in children aged 3 months and up shows that taking B. bifidum in combination with other probiotics does not reduce the risk of antibiotic-associated diarrhea when compared with taking placebo, when the more stringent definition is considered excluding diarrhea of other etiologies. However, the risk of diarrhea of any etiology is reduced by 35%. The probiotic supplement provided a total of 10 billion CFUs of B. bifidum W23, Bifidobacterium animalis subsp. lactis W51, Lactobacillus acidophilus W37, Lactobacillus acidophilus W55, Lacticaseibacillus paracasei W20, Lactiplantibacillus plantarum W62, Lacticaseibacillus rhamnosus W71, and Ligilactobacillus salivarius W24 daily from the first day of antibiotic treatment until 7 days after treatment ended (110969). A meta-analysis of 4 clinical trials in hospitalized or outpatient adults shows that taking B. bifidum in combination with up to 8 other probiotic strains does not reduce the risk of antibiotic-associated diarrhea when compared with placebo (107635).
• Atopic dermatitis (eczema). Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking a combination of B. bifidum, Ligilactobacillus salivarius, Lacticaseibacillus paracasei, and Bifidobacterium animalis subsp. lactis during pregnancy, from approximately 35 weeks' gestation until birth, and then giving this same combination to the infant after birth until 6 months of age, does not reduce the incidence of eczema at age 2 years, although it does appear to reduce the risk of atopic sensitization by 57% when compared with placebo (90234).
• Bacterial vaginosis. Although there has been interest in using oral Bifidobacterium bifidum for bacterial vaginosis, there is insufficient reliable information about the clinical effects of B. bifidum for this condition.
• Cancer. Although there has been interest in using oral Bifidobacterium bifidum for cancer prevention or treatment, there is insufficient reliable information about the clinical effects of B. bifidum for this condition.
• Clostridioides difficile infection. It is unclear if oral Bifidobacterium bifidum is beneficial for preventing C. difficile infection. Details: Preliminary clinical research in patients undergoing elective colon cancer surgery shows that taking B. bifidum does not prevent C. difficile infection when compared with taking no additional treatment. All patients received a single intravenous dose of antibiotics before surgery. B. bifidum (Biofermin) provided 10 billion colony-forming units daily for 7 days before surgery and for 10 days after surgery starting on postoperative day 5 (110982). B. bifidum has also been investigated in combination with other probiotics. A large clinical study in hospitalized adults aged 65 years or older shows that taking a combination of B. bifidum, Bifidobacterium animalis subsp. lactis, and Lactobacillus acidophilus as 60 billion colony-forming units (CFUs) daily for 21 days does not reduce the incidence of C. difficile diarrhea when compared with placebo (92255). Also, taking B. bifidum and L. acidophilus is not beneficial for reducing the incidence of C. difficile diarrhea when compared with placebo (95364). However, one small clinical study shows that taking B. bifidum along with L. acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, and Streptococcus thermophilus as 12 billion CFUs total daily, starting 1 day after beginning antibiotic treatment, reduces the risk of C. difficile diarrhea by about 72% in adult inpatients (95364).
• Colic. Although there has been interest in using oral Bifidobacterium bifidum for colic, there is insufficient reliable information about the clinical effects of B. bifidum for this condition.
• Common cold. Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in healthy adults shows that taking B. bifidum, in combination with other probiotics and vitamins/minerals, daily for at least 3 months reduces the duration of common cold episodes by approximately 2 days when compared with taking a placebo providing only the vitamins/minerals. However, there was no difference in the number of common cold episodes. The probiotic supplement provided B. bifidum MF 20/5 5 million colony-forming units (CFUs), Bifidobacterium longum SP 07/3 5 million CFUs, and Lactobacillus gasseri PA 16/8 40 million CFUs (Tribion Harmonis) daily (110978).
• Constipation. It is unclear if oral Bifidobacterium bifidum is beneficial for constipation. Details: Clinical research shows that taking B. bifidum CCFM16 (Jiangsu WECARE-Probiotics Biotechnology Co., Ltd) 2 billion colony-forming units (CFUs) daily for 28 days does not improve patient-described symptoms of constipation or increase the number of weekly spontaneous bowel movements when compared with placebo. However, 42% of patients taking B. bifidum had at least 3 spontaneous bowel movements weekly, compared with 12% of those taking placebo. Stool consistency was also improved (107579). B. bifidum has also been investigated in combination with other probiotics and ingredients in clinical research in adults with chronic constipation. One study shows that taking B. bifidum in combination with Bifidobacterium longum, B. longum subsp. infantis, Lactobacillus acidophilus, Lacticaseibacillus casei, and Lactobacillus delbrueckii subsp. lactis (Hexbio) as 30 billion CFUs twice daily for 7 days increases the number of weekly bowel movements by about 2 when compared with placebo (90266). Another study shows that taking B. bifidum UABb-10 300 million CFUs daily for 4 weeks in combination with Bifidobacterium longum UABl-14 300 million CFUs, Bifidobacterium animalis subsp. lactis UABla-12 7.8 billion CFUs, Lactobacillus acidophilus DDS-1 6.6 billion CFUs, and fructo-oligosaccharides (FOS) 7 mg does not improve symptoms of constipation when compared with a placebo providing FOS (110970).
• Dental plaque. It is unclear if oral Bifidobacterium bifidum is beneficial for dental plaque. Details: A small clinical study in children ages 8-10 years shows that eating 110 grams of probiotic fruit yogurt (Activia Çilekli Meyveli, Danone) containing B. bifidum DN-173 010 1.1 trillion colony-forming units daily for 2 weeks does not reduce dental plaque when compared with a placebo fruit yogurt (102410). This study was limited by small size and the use of a sweet yogurt, which might increase dental plaque.
• Depression. Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with major depression shows that taking Bifidobacterium bifidum, Lacticaseibacillus casei, and Lactobacillus acidophilus daily for 8 weeks reduces symptoms of depression measured on the Beck Depression Inventory (BDI) when compared with placebo (99780). However, the validity of the results from this study is limited by incomplete reporting. For example, patient baseline BDI scores were not reported.
• Diabetes. It is unclear if oral Bifidobacterium bifidum is beneficial for diabetes. Details: Clinical research in patients with gestational diabetes shows that taking freeze-dried B. bifidum, Lactobacillus acidophilus, and Lacticaseibacillus casei, each as 2 billion colony-forming units (CFUs) per gram daily for 6 weeks, decreases fasting plasma glucose levels by 5-9 mg/dL and reduces insulin resistance and insulin levels when compared with placebo (95416,98430). In contrast, a large clinical trial shows that taking B. bifidum sp9 cs at least 6 billion CFUs, L. acidophilus LA1 at least 7.5 billion CFUs, and Bifidobacterium longum sp54 cs at least 1.5 billion CFUs daily from 14-24 weeks' gestation does not reduce the incidence of gestational diabetes when compared with taking placebo (107520). Limited evidence has also assessed the effects of B. bifidum for type 2 diabetes. A small clinical trial in patients taking metformin shows that taking B. bifidum G9-1 (Biofermin) 72 mg three times daily for 10 weeks modestly improves symptoms of diarrhea and constipation when compared with baseline. However, there was no effect on levels of fasting blood glucose or glycated hemoglobin (110975). A small clinical study shows that taking a combination of B. bifidum, L. acidophilus, and Streptococcus thermophilus daily for 12 weeks does not reduce levels of fasting blood glucose or glycated hemoglobin when compared with placebo (107521).
• Diabetic nephropathy. Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in patients with diabetic nephropathy who are not taking antidiabetes drugs shows that taking a combination of B. bifidum, Lactobacillus acidophilus, and Streptococcus thermophilus daily for 12 weeks modestly reduces the ratio of microalbuminuria/creatinine (mAlb/Cr), a marker of kidney damage, when compared with placebo. However, there was no effect on the estimated glomerular filtration rate (eGFR) (107521).
• Diarrhea. It is unclear if oral Bifidobacterium bifidum is beneficial for diarrhea. Details: The European Society for Pediatric Infectious Diseases recommends probiotics in hospitalized children with diarrhea (98469) and the Infectious Disease Society of America (IDSA) recommends probiotics for the outpatient treatment of acute diarrhea (95388). However, B. bifidum is not a specific focus of the guidelines and most evidence on the use of this species is low quality.
• Exercise-induced respiratory infections. Although there has been interest in using oral Bifidobacterium bifidum for preventing exercise-induced respiratory infections, there is insufficient reliable information about the clinical effects of B. bifidum for this use.
• Familial hypercholesterolemia. It is unclear if oral B. bifidum is beneficial for familial hypercholesterolemia. Details: Preliminary clinical research in children 6-18 years of age with high cholesterol shows that taking a probiotic containing B. bifidum MB 109, Bifidobacterium animalis subsp. lactis MB 2409, and Bifidobacterium longum BL04 daily for 12 weeks reduces total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride levels by 2% to 3% and increases HDL cholesterol levels by about 2% when compared with placebo. However, these changes might not be considered clinically significant (98736).
• Generalized anxiety disorder (GAD). Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in patients newly diagnosed with GAD shows that taking sertraline 25 mg plus probiotics daily for 8 weeks may modestly reduce some symptoms of anxiety when compared with sertraline alone. However, the reduction in anxiety score was small and change was not consistent between rating scales. Also, the quality of life was not improved. The probiotics provided a total of 18 billion colony-forming units of B. bifidum, Bifidobacterium longum, Bifidobacterium animalis subsp. lactis, and Lactobacillus acidophilus (110977).
• Helicobacter pylori. Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One preliminary clinical trial in children with symptomatic H. pylori infection shows that taking a combination probiotic containing B. bifidum and Lactobacillus acidophilus daily for 6 weeks, in conjunction with triple therapy, increases the H. pylori eradication rate by an additional 19% when compared with triple therapy alone (90602). However, other individual clinical trials have shown that taking B. bifidum, L. acidophilus, Lacticaseibacillus rhamnosus, and Streptococcus faecium may not improve eradication rates when taken with triple therapy consisting of furazolidone, tetracycline, and lansoprazole (90279).
• HIV/AIDS. Although there has been interest in using oral Bifidobacterium bifidum for HIV/AIDS, there is insufficient reliable information about the clinical effects of B. bifidum for this condition.
• Hyperlipidemia. Although there has been interest in using oral Bifidobacterium bifidum for hyperlipidemia, there is insufficient reliable information about the clinical effects of B. bifidum for this condition.
• Necrotizing enterocolitis (NEC). It is unclear if oral Bifidobacterium bifidum is beneficial or safe for NEC prevention. Details: Meta-analyses of clinical research generally show that giving various bifidobacteria species alone does NOT reduce the risk of NEC or all-cause mortality (95344,95351,103437,105164). However, giving bifidobacteria in combination with lactobacilli or Enterococcus faecalis to preterm infants appears to reduce the risk of NEC and giving bifidobacteria with a prebiotic appears to reduce the risk of mortality (3162,90252,95351,102419,103437,103448,104157,105162,105164). The effects of B. bifidum, specifically, are unclear. Also, guidance among regulatory agencies and clinical organizations varies with respect to the use of probiotics in very low birth weight infants under 1000 grams. The US Food and Drug Administration (FDA) warns that preterm infants given probiotics are at risk of serious infections caused by the bacteria or fungi contained in probiotics due to cases reported in this group of infants (111610). Also, The American Academy of Pediatrics does not support the routine administration of probiotics to preterm infants, particularly those with a birth weight below 1000 grams, due to conflicting data on safety and efficacy and potential for harm in this vulnerable population (111608). The Canadian Paediatric Society, the American Gastroenterological Association, and the European Society for Paediatric Gastroenterology, Hepatology and Nutrition state that probiotic combinations may be of benefit in reducing the incidence of NEC in preterm neonates over 1000 grams. However, B. bifidum is not specifically recommended (103003,111609,111611).
• Nonalcoholic fatty liver disease (NAFLD). Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In children with NAFLD, clinical research shows that taking a specific combination (Prokid, Gostaresh Milad Pouya Company) of B. bifidum ATCC SD6576 2 billion colon-forming units (CFUs), Lactobacillus acidophilus ATCC B3208 3 billion CFUs, Lacticaseibacillus rhamnosus DSMZ 21690 2 billion CFUs, and Bifidobacterium animalis subsp. lactis DSMZ 32269 6 billion CFUs daily for 12 weeks normalizes liver sonography findings in 53% of children, compared with 17% of those taking placebo. In addition, levels of alanine aminotransferase and aspartate aminotransferase decreased by 30% and 25%, respectively. There was no effect on body mass index or blood lipids when compared with placebo (105156). However, a small clinical trial in adults shows that taking a combination of B. bifidum BMCM 02290, Bifidobacterium longum BCMC 02129, B. longum BCMC 02120, Lactobacillus acidophilus BCMC 12,130, Lacticaseibacillus casei BCMC 12,313, and Lactobacillus delbrueckii subsp. lactis BCMC 12,451 as 30 billion CFUs twice daily for 6 months has no beneficial effects on hepatic steatosis or fibrosis, liver enzyme levels, blood lipids, or fasting blood glucose levels when compared with placebo (107523).
• Nonalcoholic steatohepatitis (NASH). Although there has been interest in using oral Bifidobacterium bifidum for NASH, there is insufficient reliable information about the clinical effects of B. bifidum for this condition.
• Obesity. Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking 50 billion CFUs of a specific combination of B. bifidum, Bifidobacterium animalis subsp. lactis, Lactobacillus acidophilus, and Lactiplantibacillus plantarum (Lab4P) for 24 weeks reduces body weight by an additional 1.3 kg more than placebo (103439).
• Oropharyngeal candidiasis. Although there has been interest in using oral Bifidobacterium bifidum for oropharyngeal candidiasis, there is insufficient reliable information about the clinical effects of B. bifidum for this condition.
• Pharyngitis. Although there has been interest in using oral Bifidobacterium bifidum for pharyngitis prevention, there is insufficient reliable information about the clinical effects of B. bifidum for this condition.
• Polycystic ovary syndrome (PCOS). Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In patients with PCOS, clinical research shows that taking a combination of B. bifidum T1 (IBRC-M10771), Lactobacillus acidophilus T16 (IBRC-M10785), and Lacticaseibacillus casei T2 (IBRC-M10783) 2 billion colony-forming units each, plus inulin 800 mg, daily for 12 weeks modestly reduces serum insulin and triglyceride levels and improves insulin resistance and insulin sensitivity when compared with placebo. There was no effect on levels of cholesterol or fasting glucose (105159). Another clinical trial shows that 31.3% of patients with PCOS taking B. bifidum in combination with other probiotics daily for 6 months had regular menstrual cycles compared with 12.5% of those taking placebo. There were also modest improvements in testosterone levels and waist circumference, but not other hormones, insulin resistance, body weight, or most measures of quality of life. The product provided B. bifidum UBBB-55, Lactiplantibacillus plantarum UBLP-40, Lacticaseibacillus casei UBLC-42, and Limosilactobacillus fermentum UBLF-31, one billion colony-forming units (CFUs) each, as well as Lactobacillus acidophilus UBLA-34, Lacticaseibacillus rhamnosus UBLR-58, Limosilactobacillus reuteri UBLRu-87, 2 billion CFUs each, and fructo-oligosaccharides (FOS) 100 mg daily for 2 months and then twice daily for 4 months. All patients also underwent dietary and lifestyle changes (110974).
• Postoperative infection. It is unclear if oral Bifidobacterium bifidum is beneficial for preventing postoperative infection. Details: Preliminary clinical research in patients undergoing elective colon cancer surgery shows that taking B. bifidum does not prevent surgical site or other infection or leakage when compared with taking no additional treatment. All patients received a single intravenous dose of antibiotics before surgery. B. bifidum (Biofermin) provided 10 billion colony-forming units daily for 7 days before surgery and for 10 days after surgery starting on postoperative day 5 (110982).
• Pouchitis. Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study shows that taking a specific product (Trilac, Allergon AB) containing B. bifidum 600 million colony-forming units (CFUs), Lactobacillus acidophilus 600 million CFUs, and Lactobacillus delbrueckii subsp. bulgaricus 400 million CFUs per capsule, taken in doses of 2 capsules three times daily for 9 months, can reduce pouchitis severity and the number of patients experiencing pouchitis when compared to baseline (90296).The validity of these findings is limited by the lack of a comparator group.
• Prematurity. It is unclear if oral Bifidobacterium bifidum is beneficial for growth and development of premature infants. Details: Clinical research in very low birthweight premature infants shows that taking B. bifidum OLB6378 2.5 billion colony-forming units (CFUs) in two divided doses daily until body weight reached 2000 grams or 4.4 pounds reduces the time to established enteral feeding by 1.1 days when compared with taking placebo. There was no effect on other outcomes, including growth, length of hospital stay, mortality, or morbidities (110971).
• Psoriasis. Oral B. bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in patients with psoriasis shows that taking a mixture of probiotics for 8 weeks modestly improves overall symptoms and feelings of depression when compared with placebo. The percentage of patients achieving at least a 50% or 75% reduction in overall symptom score was 40% and 24%, respectively, in those taking the probiotic mixture, compared with 16% and 8% of those taking placebo. Each probiotic capsule was used twice daily and provided a total daily dose of 2.6 billion colony-forming units (CFUs) of B. bifidum, Bifidobacterium animalis subsp. lactis, Bifidobacteruim longum, and Lactobacillus acidophilus (107498).
• Radiation-induced diarrhea. Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in patients undergoing pelvic radiotherapy with weekly cisplatin shows that taking B. bifidum (Infloran) and Lactobacillus acidophilus as 1 billion colony-forming units (CFUs) each twice daily, from seven days before starting radiotherapy and continuing during radiotherapy, reduces the incidence of moderate to severe diarrhea and the need for antidiarrheal medication when compared with placebo. Moderate to severe diarrhea occurred in 9% of patients taking probiotics, compared with 45% of those taking placebo (107580).
• Rheumatoid arthritis (RA). Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study in patients with moderate-to-severe RA shows that taking capsules containing freeze-dried strains of B. bifidum, Lactobacillus acidophilus, and Lacticaseibacillus casei daily for 8 weeks does not reduce RA severity, the number of tender or swollen joints, or joint pain when compared with placebo (95418).
• Ulcerative colitis. Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Some preliminary clinical research shows that taking a fermented milk (Yakult, Yakult Honsha Co., Ltd.) containing B. bifidum, Bifidobacterium breve, and Lactobacillus acidophilus as an adjunct to standard maintenance therapy might help prevent relapse in ulcerative colitis patients when compared with a control group (12775,14338). Preliminary clinical research in patients with moderate to severe symptoms taking mesalazine 1200 mg daily shows that taking an unknown dose of B. bifidum BGN4 twice daily along with Lactobacillus acidophilus and Ligilactobacillus salivarius (Acronelle, Bromatech srl, Milan, Italy) for 2 years modestly improves patient- and physician-scales of overall symptoms when compared with taking mesalazine alone. There were also improvements in stool frequency and rectal bleeding (110981).
• Urinary tract infections (UTIs). Oral Bifidobacterium bifidum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In children aged 4 months to 5 years with a previous UTI, clinical research shows that taking a specific combination (Complete Probiotic Platinum) of B. bifidum 200 million colony-forming units (CFUs), Bifidobacterium animalis subsp. lactis 750 million CFUs, Lactobacillus acidophilus 750 million CFUs, and Lacticaseibacillus rhamnosus 50 million CFUs per kg twice daily for 18 months increases the median time to the first incidence of recurrence by approximately 3 months and increases the percentage of children without a UTI during the study period from 83% to 97% when compared with placebo (103436). More evidence is needed to rate Bifidobacterium bifidum for these uses.

(Read more about BIFIDOBACTERIUM BIFIDUM)

POSSIBLY INEFFECTIVE

• Night vision. Most research suggests that oral bilberry does not improve night vision in healthy individuals. Details: There is contradictory evidence about the effectiveness of bilberry for improving night vision; however, much of the research is of poor quality. In general, the most rigorous research shows that bilberry is not effective for improving night vision in healthy individuals (8139,9739,14280,35446). Whether bilberry can improve night vision in patients with night blindness is unclear.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Age-related cognitive decline. Oral bilberry has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study of elderly Norwegian males with subjective cognitive impairment shows that drinking 330 mL of bilberry and red grape juice twice daily for 9 weeks does not improve measures of memory or motor skills when compared with placebo (110641).
• Age-related macular degeneration (AMD). Although there has been interest in using oral bilberry for AMD, there is insufficient reliable information about the clinical effects of bilberry for this purpose.
• Asthenopia (eye strain). Small clinical studies suggest that oral bilberry fruit extract may improve objective measures of asthenopia, but it is unclear if oral bilberry improves subjective symptoms of asthenopia. Details: Two small clinical studies in adults who report general eye strain or those who look at computer or other display screens at work for long periods of time show that taking bilberry-derived anthocyanins 43.2 mg daily for 6 weeks or bilberry extract 240 mg daily for 12 weeks improves objective measures of eye strain after staring at computer screens when compared with placebo (103190,104195). However, bilberry extract did not improve subjective measures of eye strain in the study that evaluated these outcomes (104195). This study may have been underpowered to detect significant differences between groups. Bilberry has also been evaluated in combination with other ingredients for improving eye strain. A small clinical trial in patients with eye strain shows that a combination of fish oil, lutein, and bilberry extract containing bilberry anthocyanidins 59 mg, taken daily for 4 weeks, reduces dry eye, lower back pain, shoulder stiffness, and stuffy head when compared with placebo (35470). It is unclear if these effects are due to bilberry, other ingredients, or the combination.
• Atherosclerosis. Although there has been interest in using oral bilberry for atherosclerosis, there is insufficient reliable information about the clinical effects of bilberry for this purpose.
• Cataracts. Although there has been interest in using oral bilberry for cataracts, there is insufficient reliable information about the clinical effects of bilberry for this purpose.
• Chronic venous insufficiency (CVI). It is unclear if oral bilberry is beneficial in patients with CVI. Details: One small clinical study in patients with CVI shows that taking bilberry extract containing anthocyanins 173 mg daily for 30 days reduces symptoms of CVI when compared with placebo (35510).
• Diabetes. It is unclear if oral bilberry is beneficial in patients with diabetes. Details: One small clinical trial in patients with type 2 diabetes shows that taking a specific extract of bilberry fruit (Mirtoselect, Indena S.p.A) 470 mg once, prior to taking an oral glucose tolerance test, lowers plasma glucose levels when compared with placebo (91507). However, a small crossover trial in Chinese patients with type 2 diabetes shows that taking bilberry fruit extract 700 mg twice daily for 4 weeks does not improve glycated hemoglobin (HbA1c), body weight, blood pressure, or lipid levels when compared with placebo (104194). The validity of the HbA1c-related findings is limited due to the short study duration.
• Diabetic retinopathy. It is unclear if oral bilberry is beneficial in patients with diabetic retinopathy. Details: One small clinical trial in adults with diabetic and hypertensive retinopathy shows that taking bilberry fruit extract 160 mg daily for 6 months, in addition to standard management, improves edema and measures of retinal circulatory health when compared with standard management alone. Bilberry in the form of a generic, commercially available product appears to produce less dramatic improvements than a branded formulation (Mirtoselect, Indena S.p.A.) containing matching anthocyanin content. This specific product also reduced flow velocity in those with high-flow, diabetic retinopathy when compared with either the generic bilberry extract or standard management alone (97032).
• Dry eye. Oral bilberry has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with severe dry eye symptoms suggests that taking bilberry extract 600 mg and docosahexaenoic fish oil 240 mg once daily for 3 months may modestly improve measures of tear quality and patient-reported scores for dry eye symptoms when compared with control (112415). However, the validity of these results is limited by the lack of a statistical comparison between groups. Additionally, it is unclear if these effects are due to bilberry, fish oil, or the combination.
• Dysmenorrhea. It is unclear if oral bilberry is beneficial in patients with dysmenorrhea. Details: One small clinical study in patients with dysmenorrhea shows that a specific bilberry product (Tegens) containing bilberry anthocyanoside 160 mg, taken twice daily beginning 3 days prior to menses and continuing for 8 days, reduces pelvic pain, lumbosacral pain, breast pain, nausea, vomiting, and headache when compared with placebo (35512).
• Exercise-induced muscle soreness. It is unclear if oral bilberry is beneficial for reducing exercise-induced muscle soreness. Details: A small clinical study in trained athletes shows that drinking 200 mL of bilberry juice, containing about 744 mg phenols and 80 mg anthocyanins, twice daily for 5 days prior to running a half-marathon modestly worsens muscle soreness immediately after the run when compared with placebo. There was no longer a difference in muscle soreness between groups within 1-2 days after the run (99540).
• Glaucoma. Small clinical studies suggest that oral bilberry fruit extract, when taken with maritime pine extract, may lower intraocular pressure in patients with glaucoma. It is unclear if oral bilberry alone is beneficial in patients with glaucoma. Details: One small, uncontrolled clinical trial in Japanese patients with open-angle glaucoma shows that taking a specific product (Sante Glagenox, Saten Pharmaceutical Co. Ltd.) containing bilberry fruit extract 90 mg and maritime pine extract 40 mg daily for 4 weeks reduces intraocular pressure by 8.7% when compared to baseline (104192). Another small clinical study in patients with high intraocular pressure shows that taking a specific product (Mirtogenol) containing bilberry fruit extract (Mirtoselect, Indena S.p.A.) 80 mg and maritime pine extract (Pycnogenol, Horphag Research) 40 mg twice daily for 6 months lowers intraocular pressure and improves intraocular blood flow when compared with no treatment (35456). It is unclear if these findings are due to bilberry, maritime pine, or the combination. A retrospective chart review of patients with normal tension glaucoma has found that taking bilberry anthocyanin 60 mg twice daily for at least 12 months is associated with improvements in visual function when compared to pretreatment (35472).
• Hemorrhoids. Although there has been interest in using oral bilberry for hemorrhoids, there is insufficient reliable information about the clinical effects of bilberry for this purpose.
• Hyperlipidemia. It is unclear if oral bilberry is beneficial in patients with hyperlipidemia. Details: A small clinical study in adults with hyperlipidemia shows that taking bilberry-derived anthocyanins 320 mg daily for 4 weeks does not improve total cholesterol, low-density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, or triglyceride levels. Further, no improvements in other biomarkers of cardiovascular disease were reported (110640). The validity of this study is limited by its short duration.
• Hypertension. Oral bilberry has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study in adults with hypertension shows that consuming 500 mL of a juice containing bilberry, red grape, and chokeberry, with or without black currant (MANA Blue, TINE SA), daily for 12 weeks does not improve blood pressure when compared with placebo (92371).
• Hypertensive retinopathy. It is unclear if oral bilberry is beneficial in patients with hypertensive retinopathy. Details: One small clinical trial in adults with diabetic and hypertensive retinopathy shows that taking bilberry fruit extract 160 mg daily for 6 months, in addition to standard management, improves edema and measures of retinal circulatory health when compared with standard management alone. Bilberry in the form of a generic, commercially available product appears to produce less dramatic improvements than a branded formulation (Mirtoselect, Indena S.p.A.) containing matching anthocyanin content. This specific product also increased flow velocity for those with ischemic, hypertensive retinopathy when compared with either the generic bilberry extract or standard management alone (97032).
• Impaired glucose tolerance (prediabetes). Oral bilberry has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults with impaired glucose tolerance and two markers of metabolic syndrome shows that consuming a diet high in whole grain products, fatty fish, and bilberries three times daily for 12 weeks reduces levels of plasma glucose when compared to baseline (35468). However, it is unclear if these findings are due to bilberry, another component of the diet, or the combination.
• Irritable bowel syndrome (IBS). Oral bilberry has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical trial in adults with IBS shows that consuming a formula containing powdered bilberry fruit, aerial agrimony parts, cinnamon quills, and slippery elm bark modestly improves bowel movement frequency and reduces symptoms such as abdominal pain, bloating, flatulence, and straining when compared to baseline (35462). It is unclear if these findings are due to bilberry, other ingredients, or the combination.
• Metabolic syndrome. It is unclear if oral bilberry is beneficial in patients with metabolic syndrome. Details: One small clinical study in patients with metabolic syndrome shows that consuming a diet containing 400 grams of fresh bilberries daily does not affect body weight, glucose metabolism, or lipid metabolism when compared with a control diet (35473).
• Myopia. It is unclear if oral bilberry is beneficial in patients with myopia. Details: One small clinical trial in adults with myopia shows that a specific fermented bilberry fruit extract (Fermented Blueberry, Ajinomoto, Co., Inc.) 200 mg, taken twice daily for 4 weeks, improves night vision as well as the eye's ability to adjust focus when compared with placebo. The amplitude of accommodation was also significantly increased from 4.62 to 5.33 (91505).
• Obesity. It is unclear if oral bilberry is beneficial in patients with obesity. Details: One small clinical study in obese and overweight females shows that consuming 100 grams of frozen, whole bilberries daily for 33-35 days decreases weight and waist circumference when compared to baseline (35463). The validity of these findings is limited by the lack of a comparator group.
• Osteoarthritis. Although there has been interest in using oral bilberry for osteoarthritis, there is insufficient reliable information about the clinical effects of bilberry for this purpose.
• Ulcerative colitis. It is unclear if oral bilberry is beneficial in patients with ulcerative colitis. Details: One small, open-label clinical study in adults with mild-to-moderate ulcerative colitis shows that consuming sieved bilberries and concentrated bilberry juice (Symrise GmbH & Co) 160 grams daily for 6 weeks induces remission in 46% of patients. Furthermore, 91% of patients achieved remission at the end of treatment, and 72% of patients achieved remission at the end of the study (91506). The validity of these findings is limited by the lack of a comparator group.
• Urinary tract infections (UTIs). Although there has been interest in using oral bilberry for UTIs, there is insufficient reliable information about the clinical effects of bilberry for this purpose.
• Varicose veins. Although there has been interest in using oral bilberry for varicose veins, there is insufficient reliable information about the clinical effects of bilberry for this purpose. More evidence is needed to rate bilberry for these uses.

(Read more about BILBERRY)

POSSIBLY INEFFECTIVE

• Hypertension. Most clinical research suggests that consuming freeze-dried blueberries or blueberry powder does not lower blood pressure in patients with hypertension, prehypertension, or other risk factors for cardiovascular disease. Details: Although conflicting results exist (92386,99139), a meta-analysis of 6 clinical trials including approximately 200 patients with hypertension, prehypertension, or other risk factors for cardiovascular disease shows that consuming freeze dried blueberries or blueberry powder 22-50 grams daily for 6-8 weeks does not significantly lower systolic or diastolic blood pressure when compared with placebo (92390).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Anxiety. It is unclear if oral blueberry can improve symptoms of anxiety. Details: A small clinical study in healthy adults shows that drinking 30 mL of blueberry juice diluted in 100 mL of water twice daily for 20 days reduces measures of state and trait anxiety when compared with placebo (111235).
• Age-related cognitive decline. Small clinical studies suggest that oral blueberry products may slightly improve some measures of cognitive function in older adults with age-related cognitive decline. Details: Most clinical evidence shows that blueberry can improve some aspects of cognitive decline, but it has minimal effect on other measures. One small clinical trial in older patients with self-reported cognitive decline shows that taking freeze-dried blueberry powder 12.5 grams twice daily for 6 months modestly improves cognitive performance in daily activities but most measures of cognitive function did not improve (97181). Another small clinical study in patients 60 years of age and older with self-reported memory complaints shows that taking a wild blueberry extract (ThinkBlue, Naturex Inc) 100 mg daily with cysteine and glutathione modestly improves episodic memory at 3 months, but not at 6 months, when compared with placebo. However, taking this same blueberry extract or a wild blueberry powder 450 mg or 900 mg daily with cysteine and glutathione does not improve sequence recall, working memory, or executive function (99139). Other small clinical studies show a benefit in some, but not all measures of executive functioning and memory (96467,111234)
• Aging. It is unclear if consuming blueberry can improve functional mobility in adults 60 years of age and older. Details: One small clinical study in adults over 60 years of age shows that consuming 2 cups of frozen blueberries daily for 6 weeks improves some measures of functional mobility, such as foot placement and balance, when compared with drinking carrot juice. However, blueberry does not seem to improve hand grip strength, executive function, or other measurements of gait speed when compared with carrot juice (92387). Another small clinical study in this same age group shows that consuming 12 grams of powdered blueberry mixed with liquid twice daily for 3 months does not improve measures of functional mobility when compared with placebo (96467).
• Athletic performance. Small clinical studies suggest that oral freeze-dried blueberry powder may not reduce exertion or improve long-distance running performance in trained runners. Details: Two small clinical studies in adults with running experience show that taking freeze-dried blueberry powder 24 grams three times daily for four days does not improve perceived exertion, the time to run 8 km, or distance run over 30 minutes when compared with placebo. However, blueberry does appear to modestly attenuate increases in blood lactate after running (101963,107282).
• Cancer. Although there has been interest in using oral blueberry for preventing cancer, there is insufficient reliable information about the clinical effects of blueberry for this purpose.
• Cardiovascular disease (CVD). Small clinical studies suggest that oral blueberry supplementation might modestly improve body weight and triglyceride levels, but not body mass index (BMI), glycemic control, or cholesterol levels, in patients at risk for CVD. Details: A meta-analysis of 11 small and low-quality clinical studies involving a total of 497 adults with various risk factors for CVD shows that taking blueberry for 4-16 weeks modestly reduces weight and triglyceride levels, but does not improve other risk factors for CVD, including BMI, glycemic indices, cholesterol levels, and certain inflammatory mediators, when compared with placebo or other control. In a sub-group analysis, weight reduction was slightly more favorable in studies of longer than 6 weeks' duration (mean reduction of 0.91 kg) and in studies using blueberry powder or freeze-dried blueberry (mean reduction of 0.86 kg) (105702). The validity of these findings is limited by the heterogeneity and small size of the included studies. Additionally, it is unclear if blueberry is beneficial for reducing the risk for CVD or CVD-related complications.
• Cataracts. Although there has been interest in using oral blueberry for preventing cataracts, there is insufficient reliable information about the clinical effects of blueberry for this purpose.
• Cognitive function. Small clinical studies suggest that oral blueberry products may improve some, but not most, measures of cognitive function in children and adults. Details: Several small clinical studies in children 7-10 years of age show that drinking a blueberry drink containing 30 grams of freeze-dried blueberries or 200 grams of fresh blueberries as a single dose does not improve most measures of cognitive function when compared with placebo. These trials showed small improvements in some measures of cognitive function, including auditory-verbal learning, word recognition, and delayed memory, but these specific findings were not consistent across all studies (92394,96465,101961). Additionally, a small clinical trial in healthy young adults shows that taking a combination of blueberry and grape extracts (Memophenol, Activ'Inside) 600 mg increases the ability to complete serial three subtraction by 2.5-fold when compared with placebo. However, there were no other improvements in working memory or attention during a sustained cognitive effort (101960).
• Depression. It is unclear if oral blueberry extract or freeze-dried powder is beneficial in patients with depression. Details: One small clinical study in adults with cerebral venous thrombosis (CVT)-associated depression and depression-associated gastrointestinal infection shows that taking blueberry extract 10 mg daily for 3 months reduces symptoms of depression by 49% and gastrointestinal infection rates by 84% when compared to baseline; when compared with placebo, these changes are significant (96464). Another small clinical study in healthy adults shows that drinking 30 mL of blueberry juice diluted in 100 mL of water twice daily for 20 days reduces symptoms of depression when compared with placebo (111235). A small clinical study in healthy adolescents 11-17 years of age without diagnosed mental health issues at baseline shows that drinking freeze-dried wild blueberry powder 13 grams daily for 4 weeks improves self-reported depressive symptoms, but not anxiety symptoms or transient affect, when compared with placebo. The adolescents enrolled in this study were found to have suboptimal fruit and vegetable intake at baseline (105703).
• Diabetes. It is unclear if oral freeze-dried blueberry powder is beneficial in patients with diabetes. Details: A small clinical study in males 45-75 years of age with type 2 diabetes shows that drinking 11 grams of freeze-dried highbush blueberry powder mixed with water twice daily with a meal for 8 weeks reduces glycated hemoglobin (HbA1c) values and triglyceride levels, but not body weight, fasting plasma glucose, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, or blood pressure, when compared with placebo. This study may have been inadequately powered to detect a difference between groups (105701). Blueberry has also been evaluated for the prevention of gestational diabetes. A small clinical study in patients with a history of gestational diabetes shows that consuming 280 grams of blueberries plus 12 grams of soluble fiber daily for 18 weeks, starting at less than 20 weeks' gestation, along with standard care reduces maternal weight gain and blood glucose levels after glucose challenge testing when compared with standard care alone. However, neither gestational diabetes incidence nor infant birth weight was lower with blueberry supplementation when compared with standard care alone (107281).
• Hyperlipidemia. It is unclear if oral blueberry is beneficial in patients with hyperlipidemia. Details: One small clinical study in healthy adults shows that drinking blueberry juice 30 mL twice daily for 20 days reduces total cholesterol and low-density lipoprotein (LDL) cholesterol when compared with placebo (111235). Additionally, drinking a combination of blueberry, apple, chokeberry, and cranberry juice 300 mL daily for 6 weeks appears to decrease total cholesterol and increase high-density lipoprotein (HDL) cholesterol when compared to baseline in females with overweight or obesity and at least one risk factor for cardiovascular disease (111233). However, the validity of the study is limited by its small size, short duration, and lack of a comparator group. It is unclear if these effects are due to blueberry, other ingredients, or the combination. In contrast, other small clinical studies suggest that blueberry does not improve lipid levels (105701,111234). A small clinical study in males 45-75 years old shows that blueberry has no effect on total cholesterol, HDL cholesterol, and LDL cholesterol, but may reduce triglycerides, when compared with placebo. However, in a sub-group of patients also taking lipid-lowering medications, blueberry reduced levels of total cholesterol and LDL cholesterol when compared with placebo (105701). Another small clinical study in middle-aged adults with overweight shows that taking oral blueberry powder daily for 12 weeks does not impact total cholesterol, LDL cholesterol, HDL cholesterol, or triglycerides when compared with placebo (111234). However, these studies may have been inadequately powered to detect a difference between groups.
• Hypertriglyceridemia. It is unclear if oral blueberry leaf extract is beneficial in patients with hypertriglyceridemia. Details: A small clinical trial in patients with mild to moderate hypertriglyceridemia shows that taking a single dose of a blueberry leaf extract 300 mg along with a high-fat meal reduces postprandial triglyceride levels, but not postprandial glucose or insulin levels, when compared with placebo (101959).
• Juvenile idiopathic arthritis (JIA). It is unclear if oral blueberry juice is beneficial in children with JIA. Details: A small clinical study in children with JIA shows that adding 50 mL of blueberry juice daily to treatment with etanercept 50 mg twice weekly for 6 months increases the percentage of patients who achieve a 20% improvement in symptoms based on American College of Rheumatology criteria when compared with taking etanercept along with placebo juice. About 75% of patients in the blueberry juice group experienced a 20% improvement in symptoms, compared with 51% of patients in the placebo group, suggesting that for every four patients that drink blueberry juice along with etanercept therapy, one additional patient will experience a 20% or greater improvement in symptoms. Drinking blueberry juice also appears to reduce side effects caused by etanercept, including weight gain, infection, diarrhea, and anorexia (92388).
• Metabolic syndrome. Small clinical studies in patients with metabolic syndrome, along with an analysis of studies in patients at risk for metabolic syndrome, suggest that oral freeze-dried blueberries do not improve body weight or glycemic control, but may slightly lower blood pressure and cholesterol levels. Details: A small clinical study in patients with metabolic syndrome shows that taking freeze-dried blueberry powder 26 grams daily for 6 months improves flow-mediated dilation by 45% when compared with placebo, but does not affect low-density lipoprotein (LDL) cholesterol levels, insulin resistance, or blood pressure. In a sub-group of patients not taking statins, blueberry increased levels of high-density lipoprotein (HDL) cholesterol by 3 mg/dL; however, a lower dose of 13 grams daily had no beneficial effects (101958). Another small clinical trial in patients with metabolic syndrome shows that consuming freeze-dried blueberries 25 grams twice daily for 8 weeks reduces systolic blood pressure by around 4% and diastolic blood pressure by around 3% when compared with placebo, but does not affect body weight, lipid levels, or glycemic control (107278). Additionally, a small clinical trial in patients with metabolic syndrome shows that drinking a smoothie containing freeze-dried blueberry powder 22.5 grams twice daily for 6 weeks does not improve blood pressure, body weight, glycemic control, or lipid levels when compared with placebo, although it does improve measures of endothelial function (107279). A meta-analysis evaluating the studies above, along with 9 small clinical trials in patients at risk for metabolic syndrome, shows that blueberry supplementation does not improve body weight, glycemic control, triglyceride levels, or systolic blood pressure. However, it reduces total cholesterol by around 8 mg/dL, low-density lipoprotein (LDL) cholesterol by around 9 mg/dL, and diastolic blood pressure by around 2 mmHg when compared with placebo (107280).
• Muscle strength. Oral blueberry has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in young, healthy males shows that taking blueberry extract 200 mg plus phosphocreatine disodium salts 5 grams daily for 28 days improves peak torque and average power during leg extension exercises when compared to baseline, while individuals taking placebo saw no improvements in these measures (107284). It is unclear if these findings are due to blueberry, phosphocreatine, or the combination.
• Night vision. Although there has been interest in using oral blueberry for improving night vision, there is insufficient reliable information about the clinical effects of blueberry for this purpose.
• Obesity. Oral blueberry has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in females with overweight or obesity and at least one risk factor for cardiovascular disease shows that drinking a combination of blueberry, apple, chokeberry, and cranberry juice 300 mL daily for 6 weeks does not reduce body weight, body mass index (BMI), or blood pressure but might improve total cholesterol and high-density lipoprotein (HDL) cholesterol when compared to baseline (111233). However, the validity of these findings is limited by the small study size, short duration, and lack of a comparator group. It is unclear if these effects are due to blueberry, other ingredients, or the combination.
• Urinary tract infections (UTIs). Although there has been interest in using oral blueberry for preventing UTIs, there is insufficient reliable information about the clinical effects of blueberry for this purpose. More evidence is needed to rate blueberry for these uses.

(Read more about BLUEBERRY)

POSSIBLY EFFECTIVE

• Hypertension. Oral blue-green algae seem to modestly reduce blood pressure in patients with hypertension. Details: Some small clinical studies show that blue-green algae can decrease blood pressure in patients with hypertension (97206,99654). A meta-analysis of five small clinical trials in patients with hypertension, type 2 diabetes, or chronic pain shows that taking spirulina blue-green algae 1-8 grams daily for up to 12 weeks reduces systolic blood pressure (SBP) by 5 mmHg and diastolic blood pressure (DBP) by 7 mmHg when compared with placebo. The effect size was larger in patients with hypertension and in those treated for at least 12 weeks (109964). Another small clinical study shows that taking spirulina blue-green algae (A. maxima) 4.5 grams daily for 6 weeks decreases blood pressure in adults with hypertension, with the number of subjects fulfilling the criteria for hypertension decreasing from 45% to 14% when compared to baseline (18297). A more recent clinical study in patients with hypertension shows that consuming a salad dressing containing 2 grams spirulina blue-green algae daily for 8 weeks reduces SBP by around 6 mmHg and DBP by around 4 mmHg when compared to baseline. While overall reduction in blood pressure with spirulina dressing was larger when compared with patients consuming a control dressing, the study groups were heterogenous at baseline, limiting the validity of any statistical comparisons between groups (109965).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Allergic rhinitis (hay fever). It is unclear if oral blue-green algae are beneficial in allergic rhinitis. Details: Preliminary clinical research shows that taking spirulina blue-green algae (A. platensis) 2 grams daily for 6 months, improves self-rated scores for sneezing, nasal discharge, nasal congestion, and itching when compared with placebo in adults with allergic rhinitis (18300).
• Antiretroviral-induced insulin resistance. It is unclear if oral blue-green algae are beneficial for insulin resistance due to antiretrovirals. Details: Preliminary clinical research shows that taking spirulina blue-green algae (A. platensis) 19 grams daily for 2 months increases insulin sensitivity by about 225% when compared to baseline in patients with antiretroviral-induced insulin resistance (75944). The validity of this finding is limited by the lack of a comparator group.
• Anxiety. Although there has been interest in using oral blue-green algae for anxiety, there is insufficient reliable information about the clinical effects of blue-green algae for this condition.
• Arsenic poisoning. It is unclear if oral blue-green algae are beneficial for chronic arsenic toxicity. Details: Preliminary clinical research in people living in areas of Bangladesh with high arsenic levels in drinking water shows that taking a combination of an alcoholic extract of spirulina blue-green algae 250 mg and zinc 2 mg orally twice daily for 16 weeks, in addition to use of filtered drinking water, increases urinary arsenic excretion, reduces hair arsenic levels, and improves skin manifestations of chronic arsenic toxicity when compared with placebo plus filtered water (18301).
• Athletic performance. Most research suggests that oral blue-green algae are not beneficial for improving athletic performance; however, the available studies are small. Details: AAlthough some research disagrees, most small or preliminary clinical trials show that taking spirulina blue-green algae does not improve athletic performance in trained or untrained adults. One study shows that, when compared with placebo, taking spirulina blue-green algae (Hawaiian Spirulina, Cyanotech Corporation) 3 grams daily for up to 8 weeks has no effect on exercise output during a 30-minute elliptical trainer workout in active males (97203). In elite rugby players, taking spirulina blue-green algae (Algae Green Value) 5.7 grams daily for 7 weeks does not improve jump or sprint performance or body composition when compared to placebo (104567). In healthy untrained males, a small study shows that taking spirulina blue green algae 6 grams daily for 7 days does not increase the time to fatigue related to arm cycling following a 30-minute submaximal exercise bout (104566). In male recreational runners, spirulina blue-green algae (A. platensis) 2 grams three times daily for 4 weeks was not associated with any change in exercise intensity during a 2-hour treadmill jogging period. However, sprinting time to exhaustion following the 2-hour jog increased from 2.05 minutes to 2.7 minutes (18306). Also, a study of athletes and non-athletes shows that taking spirulina blue-green algae (Parry Nutraceuticals) 2 grams daily for 8 weeks has a small effect on isometric muscle strength, but not muscle endurance, when compared with placebo (104568).
• Attention deficit-hyperactivity disorder (ADHD). Oral blue-green algae have only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking 3 mL of a specific combination of spirulina blue-green algae, peony, ashwagandha, gotu kola, bacopa, and lemon balm (Nurture and Clarity, Tree of Healing-LD) diluted in 50-60 mL of water three times daily for 4 months improves ADHD scores when compared with placebo in previously untreated children aged 6-12 years (19272). It is unclear if this effect is due to blue-green algae, other ingredients, or the combination.
• Beta-thalassemia. It is unclear if oral blue-green algae are beneficial in beta-thalassemia. Details: In children with beta-thalassemia, preliminary clinical research shows that taking spirulina blue-green algae (GNC Natural Brand Spirulina, General Nutrition Corporation) 250 mg/kg daily, up to a maximum dose of 4 grams daily, for 3 months reduces the percentage of children requiring blood transfusion during an interval of less than 2 weeks from 66% to 40%. There were also improvements in red blood cell count and levels of hemoglobin, ferritin, and liver function enzymes (104569). However, the validity of these findings is limited by the lack of a comparator group.
• Blepharospasm. It is unclear if oral blue-green algae are beneficial when used in conjunction with botulinum toxin injections. Details: Preliminary clinical research shows that taking a specific product containing the blue-green algae species Aphanizomenon flos-aquae (Super Blue-Green Algae, Cell Tech) 1500 mg per day orally for 6 months in addition to botulinum toxin-A injections does not reduce eyelid spasms when compared with botulinum toxin-A alone in people with essential blepharospasm or Meige syndrome (14842).
• Cancer. Although there has been interest in using oral blue-green algae for cancer, there is insufficient reliable information about the clinical effects of blue-green algae for this condition.
• Cardiovascular disease (CVD). Although there has been interest in using oral blue-green algae for CVD, there is insufficient reliable information about the clinical effects of blue-green algae for this condition.
• Cognitive Impairment. It is unclear if oral blue-green algae are effective for improving cognitive impairment. Details: A small clinical study in patients aged 60 or older with mild cognitive impairment shows that taking blue-green algae extract 1 gram 3 times daily for 12 weeks slightly improves some components of cognitive function testing related to visual learning, memory, and vocabulary when compared with placebo (112001). However, the validity of these findings is limited by lack of adjustment for multiple comparisons, which may explain the discrepant results with the other components of the cognitive function tests.
• Depression. Although there has been interest in using oral blue-green algae for depression, there is insufficient reliable information about the clinical effects of blue-green algae for this condition.
• Diabetes. It is unclear if oral blue-green algae are beneficial in diabetes. Details: A meta-analysis of seven small clinical studies in patients with type 2 diabetes shows that taking spirulina blue-green algae 0.8-14 grams daily for 6-12 weeks reduces fasting blood glucose and improves total cholesterol, triglycerides, and high-density lipoprotein (HDL) cholesterol, but does not affect low-density lipoprotein (LDL) cholesterol, when compared with placebo. There was no reduction in glycated hemoglobin (HbA1c); however, all but two of the studies lasted less than 12 weeks, limiting the validity of the findings related to HbA1c (109970).
• Dyslipidemia. It is unclear if oral blue-green algae are beneficial in dyslipidemia. Details: Several clinical studies in patients with normal or elevated cholesterol levels show that doses of spirulina blue-green algae (A. platensis, A. maxima, A. fusiformis) ranging from 1-10 grams daily for 1-6 months may reduce total cholesterol by 8% to 27%, low-density lipoprotein (LDL) cholesterol by 10% to 65%, and triglycerides by 0% to 23%; and increase high-density lipoprotein (HDL) cholesterol by 0% to 66% (18297,18298,18299,91705,91708,91710,91717,102689). However, the validity of these studies is limited by methodological weaknesses and heterogeneous population characteristics. A meta-analysis of 23 small studies, several of which were in patients with type 2 diabetes or obesity, shows that taking blue-green algae 0.8-10 grams for 4 to 24 weeks modestly improves levels of LDL, HDL, triglycerides, and total cholesterol when compared with placebo or no treatment (112004). The interpretation of these findings is limited by the high heterogeneity of the included studies which enrolled patients of varying health status and employed various study designs.
• Dyspepsia. Although there has been interest in using oral blue-green algae for dyspepsia, there is insufficient reliable information about the clinical effects of blue-green algae for this condition.
• Exercise-induced muscle soreness. It is unclear if oral blue-green algae are effective for the prevention of exercise-induced muscle soreness. Details: A small clinical study in recreationally trained males shows that taking spirulina blue-green algae 2 grams three times daily does not reduce delayed onset muscle soreness after eccentric exercise when compared with placebo (109967).
• Hepatitis C. Evidence for the use of oral blue-green algae in hepatitis C is conflicting. Details: One clinical study in adults with chronic hepatitis C who are unresponsive to interferon treatment shows that taking spirulina blue-green algae (A. platensis) 500 mg orally three times daily for 6 months is associated with greater improvements in alanine aminotransferase (ALT) levels than taking silymarin 140 mg three times daily. Complete virological response rates were 13% with blue-green algae and 3% with silymarin, although this difference was not statistically significant (63247). However, in another study in people with chronic hepatitis B or C, liver function enzyme levels worsened after one month of treatment with oral spirulina blue-green algae (18304).
• HIV/AIDS. It is unclear if oral blue-green algae are beneficial for people with HIV/AIDS who do not have access to antiretrovirals. Details: One clinical study in adults with untreated HIV shows that taking spirulina blue-green algae (A. platensis) powder 5-10 grams daily for 3-6 months does not affect CD4 counts, viral load, or weight gain in patients with HIV (75927,91707). However, in one study, the incidence of opportunistic infections, respiratory disease, gastrointestinal symptoms, and fatigue was 43% for patients taking spirulina blue-green algae, compared to 70% for patients taking placebo (91707).
• Iron deficiency anemia. Although there has been interest in using oral blue-green algae for iron deficiency anemia, there is insufficient reliable information about the clinical effects of blue-green algae for this condition.
• Lichen planus. It is unclear if oral blue-green algae are beneficial in patients with oral lichen planus. Details: A small clinical study in patients with oral lichen planus shows that taking spirulina blue-green algae 500 mg twice daily for 8 weeks along with application of triamcinolone acetonide 0.1% oral paste three times daily for 1 week reduces pain and lesion size when compared with only triamcinolone acetonide three times daily for 8 weeks (109963).
• Malnutrition. Evidence for the use of oral blue-green algae in malnutrition is conflicting. Details: Some clinical research in severely undernourished children shows that adding spirulina blue-green algae (A. platensis) 5 grams orally twice daily for 8 weeks to a traditional diet results in an average daily weight gain of 25 grams, compared with only 15 grams for those given the traditional diet alone. Similarly, giving blue-green algae 10 grams twice daily for 8 weeks in addition to a misola diet (millet, soy, peanut kernel, sugar, and salt) results in an average daily weight gain of 34 grams, compared with only 20 grams for children given the misola diet alone (18308). However, a small clinical study in malnourished children aged 3 months to 3 years shows that giving spirulina blue-green algae 5 grams daily for 3 months in addition to a traditional diet fails to increase weight gain more than the traditional diet alone (18309). Similarly, a moderate-size crossover study in preschool-aged children in Cambodia shows that taking blue-green algae 2 grams 5 times a week during the first hour of school for 8 weeks does not improve weight gain or height but may reduce the proportion of children with anemia when compared with placebo (112002). The interpretation of these findings is limited by the high rate of patients lost to follow-up and the lack of statistical adjustment for confounding factors, such as parasitism and home diet.
• Memory. Although there has been interest in using oral blue-green algae for memory, there is insufficient reliable information about the clinical effects of blue-green algae for this condition.
• Menopausal symptoms. It is unclear if oral blue-green algae are beneficial for improving symptoms of menopause. Details: A preliminary clinical study shows that taking a product containing the blue-green algae species Aphanizomenon flos-aquae (Klamin, Nutrigea) 1.6 grams daily for 8 weeks reduces anxiety and depression when compared with placebo in menopausal adults aged 50-60 years. The treatment has no effect on vasomotor symptoms or hormone levels (18310).
• Mental alertness. It is unclear if oral blue-green algae are beneficial for reducing mental fatigue. Details: A preliminary clinical study shows that taking spirulina blue-green algae (Hawaiian Spirulina, Cyanotech Corporation) 3 grams daily for up to 8 weeks improves performance on a mathematical based mental fatigue test in healthy men when compared with placebo. Subjective improvement in mental alertness over placebo was also reported (97203).
• Metabolic syndrome. It is unclear if oral blue-green algae are beneficial in patients with metabolic syndrome. Details: A small clinical study in patients with metabolic syndrome shows that taking spirulina blue-green algae (Spirulysat, AlgoSource), providing phycocyanin 20 mg, daily for 12 weeks improves triglyceride levels, but does not reduce body mass index, waist circumference, blood pressure, glycemic indices, or other lipid levels, when compared with placebo (109971).
• Nonalcoholic fatty liver disease (NAFLD). Although there has been interest in using oral blue-green algae for NAFLD, there is insufficient reliable information about the clinical effects of blue-green algae for this condition.
• Obesity. Evidence for the use of blue-green algae in obesity is conflicting. Details: Small, low-quality clinical trials have shown mixed results in people with obesity (18295,91717,97205,99655,99703,102688). When results are analyzed together, there is evidence of a very small benefit for both body weight and plasma lipid levels. Two meta-analyses show that taking spirulina blue-green algae may increase weight loss by up to 1.85 kg when compared with placebo (102690,104565). A greater effect is seen in patients with obesity when compared with overweight patients. In addition, there is a small effect on fat loss (102690). However, there is evidence from two studies lasting longer than 12 weeks that taking blue-green algae may slightly increase BMI (104565). A meta-analysis of small clinical trials also shows that taking spirulina blue-green algae reduces fasting blood sugar and total cholesterol levels by a small amount when compared with placebo, but has no effect on low-density lipoprotein (LDL) cholesterol or triglyceride levels, in patients with obesity (102689). When combined with an exercise program, taking spirulina blue-green algae increases weight loss by 1.4 kg and improves exercise tolerance and total, LDL, and high-density lipoprotein (HDL) cholesterol levels when compared with exercise alone (99655,102688). Doses have included a specific product containing the spirulina blue-green algae species A. fusiformis (Multinal, New Ambadi Estate Pvt. Ltd.) 1 gram twice daily or four times daily for 3 months (91717) or spirulina blue-green algae 2 grams daily for 3 months, or 4.5 grams daily for 6 weeks, alone or in combination with exercise (97205,99655,102688).
• Oral leukoplakia. It is unclear if oral blue-green algae are beneficial for oral leukoplakia in tobacco chewers. Details: Preliminary clinical research shows that taking spirulina blue-green algae (A. fusiformis) orally 1 gram daily for 12 months produces regression of precancerous oral leukoplakia lesions in 45% of tobacco chewers, compared to only 7% of those receiving placebo. Regression rates appear to be highest in those with homogeneous lesions and lowest in those with ulcerated or nodular lesions (15782).
• Periodontitis. It is unclear if injecting blue-green algae into periodontal pockets is beneficial in periodontitis. Details: Preliminary clinical research shows that injecting a 4% w/v gel prepared from spirulina blue-green algae into periodontal pockets of adults with chronic periodontitis, after scaling and root planing, is associated with a decrease in probing pocket depth of 1.57 mm after 120 days, compared with only 0.84 mm in patients receiving scaling and root planing alone (91709).
• Premenstrual syndrome (PMS). Although there has been interest in using oral blue-green algae for PMS, there is insufficient reliable information about the clinical effects of blue-green algae for this condition.
• Stress. Although there has been interest in using oral blue-green algae for stress, there is insufficient reliable information about the clinical effects of blue-green algae for this condition.
• Ulcerative colitis. It is unclear if oral blue-green algae are beneficial in patients with ulcerative colitis. Details: A small clinical study in patients with ulcerative colitis shows that taking spirulina blue-green algae 500 mg twice daily for 8 weeks improves quality of life scores and reduces stress and sleep disturbances when compared with placebo. However, there was no effect on most measures of sleep quality, mood, and fatigue (109969).
• Wound healing. Although there has been interest in using oral blue-green algae for wound healing, there is insufficient reliable information about the clinical effects of blue-green algae for this condition. More evidence is needed to rate blue-green algae for these uses.

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EFFECTIVE

• Dyspepsia. Oral calcium carbonate is approved by the US Food and Drug Administration (FDA) as an antacid. Details: Taking calcium carbonate orally as an antacid is effective for treating dyspepsia (1843). Calcium carbonate has FDA approval as an antacid.
• Hyperkalemia. Intravenous calcium gluconate is approved by the US Food and Drug Administration (FDA) for preventing hyperkalemia-induced cardiac abnormalities. Details: Administering calcium gluconate intravenously can reverse electrocardiographic changes and arrhythmias induced by hyperkalemia (12946). Intravenous calcium gluconate is FDA-approved for preventing hyperkalemia-induced cardiac abnormalities.
• Hypocalcemia. Oral calcium treats and prevents hypocalcemia. Intravenous calcium is used to treat severe hypocalcemia. Details: Taking calcium orally is effective for treating and preventing hypocalcemia. Intravenous calcium gluconate, acetate, gluceptate, or chloride is effective for severe hypocalcemia or hypocalcemic tetany (12928).
• Kidney failure. Oral calcium carbonate or calcium acetate is used as a phosphate binder during kidney failure. Details: Taking calcium carbonate or calcium acetate orally is effective as a phosphate binder. Calcium acetate (PhosLo) appears to control hyperphosphatemia better than sevelamer (Renagel) (12943,12944,38990). Calcium citrate is not recommended for this purpose because it increases aluminum absorption and does not bind phosphate as efficiently as calcium acetate or calcium carbonate (21631). Some clinical research also shows that taking calcium orally reduces blood pressure in patients with kidney failure (975).

LIKELY EFFECTIVE

• Corticosteroid-induced osteoporosis. Oral calcium in combination with vitamin D prevents bone density loss that occurs during long-term treatment with corticosteroids. Details: Taking calcium in combination with vitamin D as adjunctive therapy seems to be effective for reducing bone mineral density loss in people using corticosteroids long-term (982,1046,1830,1831,1832,4462,4463,4464,4465,4466)(4467,12945,38493). One specific product used in clinical research is Oscal (Marion Merrel Dow Inc.), which contains elemental calcium 500 mg per tablet plus vitamin D 125 IU per tablet (982). Another product used is Oscal 250 + D (SmithKline Beecham Healthcare), which contains elemental calcium 250 mg and vitamin D 125 IU per tablet (1046).
• Hyperparathyroidism. Oral calcium reduces parathyroid hormone levels in patients with secondary hyperparathyroidism due to kidney failure. Details: Taking calcium orally reduces parathyroid hormone levels in patients with kidney failure and secondary hyperparathyroidism (1827,1828,1829,39174,39425). In elderly women, the combination of calcium and vitamin D reverses secondary hyperparathyroidism and reduces hip fracture risk (8818). Also, population research suggests increased calcium intake from the diet and supplements reduces the risk of primary hyperparathyroidism in women. Supplemental intakes of at least 500 mg/day and dietary intakes of approximately 1100 mg/day are considered to be protective (91353).
• Osteoporosis. Adequate calcium intake, from the diet and/or supplements, is recommended for the prevention and treatment of osteoporosis. Details: The Bone Health and Osteoporosis Foundation (BHOF) recommends ensuring adequate calcium intake in line with the recommended dietary allowance (RDA) by age, along with adequate vitamin D intake, for the prevention and treatment of osteoporosis in adults over 50 years of age. Supplementation can be used to augment dietary intake when adequate dietary intake is not feasible (109425). In the US and Canada, foods containing at least 200 mg calcium with less phosphorous content than calcium can be labelled with a health claim regarding the relationship between adequate calcium intake and a reduced risk for osteoporosis (11940,102148). However, calcium supplementation is not recommended specifically for the primary prevention of osteoporosis. The US Preventive Task Force (USPSTF) states that the current evidence is insufficient to assess the balance of benefits and harms of vitamin D and calcium supplementation, alone or in combination, for the primary prevention of fractures in community dwelling adults without osteoporosis (95695). Also, calcium supplements do not seem to be effective for preventing loss of bone mineral density (BMD) during lactation (988), in patients who have had bone marrow transplantation (1817), or in patients who have had renal transplantation (4823,38736,38871). Maximal bone growth occurs in the teenage years, and then BMD in females remains relatively constant until age 30-40. After age 40, bone loss typically occurs at rates of 0.5% to 1% per year. In males, this occurs several decades later. Bone loss is more pronounced if dietary calcium intake is below the RDA, which is the case for many Americans (2571,2578). One meta-analysis of randomized controlled trials in healthy children 7-14 years old shows that fortifying food with calcium 250-1000 mg daily for up to 24 months modestly improves femoral neck BMD, but not hip or spine BMD. However, the included trials did not supplement vitamin D (107232). During the 5 years immediately after menopause, calcium supplementation has very little effect on bone loss (2569,2570,2575,2576). The rapid loss of estrogen causes a high bone resorption rate, which increases serum calcium levels and therefore decreases intestinal absorption of calcium (2570). After this period, the typical rate of bone loss is 2% per year (2572,2576). Taking calcium 1000-1600 mg daily as carbonate, citrate, lactate gluconate, or citrate malate salt decreases this rate by 0.25% to 1% annually (977,979,981,2569,2571,2572,2575,2576,2578,6850)(38978,38980,39064). The greatest reductions (1% or more) are seen in the first 1-2 years of supplementation when bone remodeling foci can be filled (2569,2576). After this period, the differences in rate of loss between supplemented and non-supplemented females are closer to 0.25% per year (2569,2577). A meta-analysis of clinical evidence suggests that there is no additional benefit after 4 years (38980). Small clinical studies have found that continuous calcium supplementation at an average daily dose of 1050 mg, started after menopause and continued for 1.5-4 years, may reduce fracture rates by 26% when compared with no calcium supplementation. The largest of these studies was conducted in nursing home residents who also received daily vitamin D; the benefits of calcium, specifically, are unclear (39386). Some research also suggests that calcium and vitamin D improves primary prevention of osteoporotic fractures in some older individuals with osteoporosis, particularly the elderly and those who are no longer community dwelling (12930,38875,38849,39026,109471). However, not all research is positive. One large clinical trial in elderly adults with a low-trauma fracture show that taking calcium 1000 mg daily with or without vitamin D 800 IU daily for 2-7 years does not reduce the risk of a second fracture when compared with placebo (13073). Another clinical study shows that taking calcium 1000 mg daily plus vitamin D 800 IU daily does not prevent a second fracture in elderly patients, or prevent a first fracture in elderly patients with other risk factors such as low body weight (less than 58 kg, 127.6 pounds), smoking, family history of hip fracture, or fair or poor self-reported health (12929). Also, some exploratory research suggests that supplements may need to be continued indefinitely; in adults over 68 years of age, any effects of 2 years of calcium supplements on BMD appear to be lost within 2 years after discontinuing supplements (6853). Calcium has additive effects when used with other agents such as vitamin D, estrogens, or calcitonin. Whereas calcium alone generally reduces or prevents loss of BMD, combination with other agents can produce small increases in BMD ranging from 0.3% to 3.3% depending on the combination and dosages used (978,980,1836,2570,2571,2572,2576). However, one meta-analysis in healthy adults shows that fortifying foods with calcium 250-1000 mg daily, in conjunction with vitamin D supplementation, for up to 24 months does not improve BMD when compared with control (107232). The full potential of osteoporosis treatments cannot be realized without adequate calcium intake (2569,2570,2571,2572). Advise patients taking agents such as estrogens, calcitonin, bisphosphonates, or raloxifene (Evista) to ensure that their daily calcium intake meets the RDA. Use supplements if necessary. The usefulness of calcium in preventing osteoporosis in males is not as well-studied. Some observational research has found that calcium 870 mg daily is not associated with changes in BMD and bone loss in males (97201). However, clinical evidence suggests that taking calcium 1000 mg daily for 2 years might improve trabecular or cortical bone mass by 2% to 4% (980,8827,8873). Dietary supplementation with calcium and vitamin D seems to moderately reduce bone loss measured in the femoral neck, spine, and total body, and seems to reduce the incidence of nonvertebral fractures in older patients with osteopenia or low BMD (980).
• Premenstrual syndrome (PMS). Adequate calcium intake seems to prevent symptoms of PMS. Details: There seems to be a link between low dietary calcium intake and symptoms of PMS (2004,6847,39007). Taking calcium 1000-1336 mg daily seems to significantly reduce depressed mood, water retention, and pain, especially if daily calcium intake is inadequate (1822,1823,1824,2004,95821). Calcium carbonate 1200 mg daily seems to decrease PMS symptom scores by about 18% when compared with placebo (1822). Increasing dietary calcium intake is also associated with a decreased risk of developing PMS. Consuming an average of 1283 mg of calcium per day from foods is associated with about a 30% lower risk of developing PMS compared with consuming an average of 529 mg daily (13094); however, taking calcium supplements does not appear to be associated with the risk of developing PMS.

POSSIBLY EFFECTIVE

• Colorectal cancer. Oral calcium seems to be beneficial for preventing colorectal cancer, especially in those with adequate vitamin D levels and normal body mass index (BMI). Details: Population studies have found that increased intake of dietary or supplemental calcium is associated with a reduced risk of colorectal cancer and colorectal adenomas (1047,8820,12120,38951,98898,98899). Clinical trials and meta-analyses of clinical research also show that taking calcium supplements 1.2-2 grams daily for up to 4 years can reduce the risk of colorectal adenoma recurrence by up to 29% (970,12118,12950,15267,34596,38718,39042,95817). However, not all research has been positive. Some meta-analyses of clinical research or observational studies suggest that taking calcium does not reduce the risk of familial adenomatous polyposis or colorectal cancer (34596,39042,39349). Other contradictory research suggests that postmenopausal females who take calcium 1000 mg daily plus vitamin D 400 IU daily do not have a reduced risk of developing colorectal cancer (14290); however, this finding may not be reliable due to the high baseline intake of calcium in study participants. The reason for these conflicting findings is not entirely clear. Vitamin D might be an important factor. People with lower than average vitamin D levels do not seem to get any benefit from calcium supplements (12118). Also, one meta-analysis of previous trials suggests that taking calcium 1200 mg daily reduces the risk of colorectal adenomas in people with a normal BMI, but not in those who are overweight or obese (99715). Despite this conflicting evidence, the US Food and Drug Administration (FDA) approved a qualified health claim in 2005 stating that calcium supplements may reduce the risk of colorectal cancer and colorectal adenomas. However, the FDA has determined that there is little scientific evidence to support this claim (102366).
• Fetal bone mineralization. If calcium intakes are low during pregnancy, oral calcium seems to be beneficial for increasing fetal bone density. Details: With low dietary calcium intake (less than 562 mg elemental calcium daily) during pregnancy, calcium supplementation increases fetal bone mineralization and density. However, calcium supplementation does not offer any additional benefit if calcium intakes are adequate (3263,3264).
• Hypertension. Oral calcium seems to reduce blood pressure by a small amount. However, it is unclear if this reduction is clinically significant. Details: Many clinical trials and observational studies show that intake of calcium supplements or dietary calcium modestly reduces blood pressure in patients with or without hypertension, usually around 1-2 mmHg. Calcium seems to be more effective for certain subpopulations of patients, such as salt-sensitive people and patients with low baseline dietary calcium intake (945,972,974,976,984,1818,1819,1820,1821,6852)(13138,14406,38803,39063,39094,39221). Also, a meta-analysis of clinical research shows that calcium intake during pregnancy reduces systolic blood pressure in offspring by 1-2 mmHg (38852). However, a large-scale clinical trial in postmenopausal females shows that taking vitamin D (cholecalciferol) 400 IU daily in combination with elemental calcium 1000 mg daily does not lower blood pressure or reduce the risk of developing hypertension (16714). Additionally, a meta-analysis of 8 clinical trials shows that taking calcium in combination with vitamin D for up to 7 years has no effect on blood pressure (98861). The validity of this finding is limited by the poor methodological quality of the included studies. Some observational research suggests that calcium can reduce the risk for hypertension. Population research in females aged 45 years and older suggests that higher intake of calcium from both diet and supplement sources is linked to a lower risk of developing hypertension when compared to lower calcium intake (14265). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim stating that calcium supplements may reduce the risk of hypertension. However, the FDA has concluded that this claim is based on supporting, rather than conclusive, evidence (102367).
• Osteomalacia. Oral calcium seems to reverse osteomalacia caused by very low calcium intakes. Details: Osteomalacia is commonly caused by vitamin D deficiency; however, very low calcium intake can also lead to osteomalacia in children and adults. Calcium supplementation can reverse osteomalacia caused by calcium deficiency. Along with appropriate vitamin D supplementation, individuals at risk of osteomalacia need sufficient calcium intake (94819).
• Pre-eclampsia. Oral calcium seems to reduce the risk of pre-eclampsia in high risk pregnancies, especially if calcium intakes are low. Details: Although there is some conflicting evidence (971,38756), most clinical research shows that taking calcium orally 1-2 grams daily reduces pregnancy-related hypertension and pre-eclampsia (973,1833,8828,39043,39319,39426,96480). Calcium appears to reduce the risk of pre-eclampsia by about 50% when compared with placebo. One meta-analysis of 19 controlled trials involving over 29,000 pregnancies found that for every 19 females treated with calcium, one episode of pre-eclampsia would be avoided (96480). Calcium appears to have the greatest effect in individuals at high-risk of pre-eclampsia or with low calcium levels, and when taken at greater than or equal to 20 weeks of gestation (15029,38497,96480,99714). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim regarding the use of calcium supplements to reduce the risk of pregnancy-induced hypertension and pre-eclampsia. However, due to the limited and conflicting research available at that time, the FDA stated that this outcome was highly unlikely. Since then, large, high-quality clinical research has supported this finding. In fact, in 2016 the World Health Organization (WHO) released a recommendation to prescribe oral calcium supplementation 1.5-2 grams daily during pregnancies at high risk of pre-eclampsia if dietary calcium intakes are low, in order to prevent pre-eclampsia (97347).
• Rickets. Oral calcium seems to reverse rickets caused by very low calcium intakes. Details: Rickets is commonly caused be vitamin D deficiency; however, very low calcium intake can also lead to rickets. Calcium supplementation can reverse rickets caused by calcium deficiency (94819). A small clinical study in children with nutritional rickets shows that taking calcium 500-2000 mg daily for 24 weeks improves radiographically measured rickets caused by calcium deficiency. Rickets seems to improve more rapidly with calcium 1000 mg compared to calcium 500 mg. However, increasing the calcium dose to 2000 mg daily is not more beneficial than calcium 1000 mg daily (98904).
• Tooth retention. Oral calcium with vitamin D seems to help with tooth retention in the elderly population. Details: A clinical trial in the elderly population shows that taking calcium citrate malate 500 mg daily along with vitamin D3 (cholecalciferol) 700 IU daily orally for 3 years reduces the risk of tooth loss by about 52% when compared with placebo (8816).

POSSIBLY INEFFECTIVE

• Breast cancer. Oral calcium does not seem to be beneficial for breast cancer prevention. Details: Although some population research disagrees (15631,39041,95811,107237), most research shows that increased calcium intake is not associated with a reduced risk of breast cancer (15631,16715,98895,107236,107237). Subgroup analyses of population research suggest that calcium intake may reduce the risk of breast cancer in postmenopausal, but not pre-menopausal, adults (15631,107237). Another subgroup analysis in a large meta-analysis of population research also suggests that dietary intake may reduce estrogen receptor(ER)-negative breast cancer, but not ER-positive breast cancer (107236). However, most other research has not evaluated the effects of calcium supplementation or intake on breast cancer subtypes. The best evidence to date, from a large scale clinical trial (Women's Health Initiative), shows that taking vitamin D (cholecalciferol) 400 IU daily plus calcium 1000 mg daily for 7 years after menopause does not reduce the risk of developing invasive breast cancer at the end of the study and 5 years after the end of the intervention (16715,98895).
• Fractures. Although oral calcium prevents fractures in osteoporosis, most evidence shows that calcium does NOT prevent factures in people who do not have osteoporosis. See Osteoporosis discussion for more information on the use of calcium for this purpose. Details: The most recent and robust meta-analysis of clinical research shows that calcium supplementation with or without vitamin D is NOT associated with reduced fractures in older adults without osteoporosis (95822). A large-scale study in postmenopausal females aged 50-79 years suggests calcium 1000 mg plus vitamin D 400 IU daily for 7 years only modestly improves bone mineral density (BMD) and does not significantly reduce fracture risk. This lack of effect may have been due to low adherence to the treatment regimen. In those who were 80% adherent, the combination of calcium plus vitamin D reduced the risk of hip fracture by about 29% (14282). Also, some clinical research shows that taking calcium carbonate 1000 mg and vitamin D 400 IU for 5 years does not attenuate loss of height after menopause when compared with placebo (95810). Additional meta-analyses of clinical and observational evidence suggest that calcium supplementation is not associated with a reduced risk of vertebral or nonvertebral fractures, such as hip fractures (38589,38888,98895). Some other research has suggested that calcium in combination with vitamin D reduces fracture risk in older patients without osteoporosis (980,1836,8818,12930,12933,12952,38849,102145,107235); however, this research is confounded by a number of variables, including the presence of hormonal therapy and differing levels of fracture risk at baseline (1836,8818,95822). Conflicting findings on this topic might also be due to genetic differences in patient populations. A population analysis of the Women's Health Initiative study found that, in older females with the lowest genetic susceptibility to low bone mineral density (BMD), taking calcium with vitamin D is associated with a reduction in fracture risk. However, in females with a higher genetic susceptibility to low BMD, there is no association between supplementation and fracture risk. This might be because individuals with a lower susceptibility to low BMD are also more responsive to calcium and vitamin D supplementation (97357). As of April 2018, the U.S. Preventative Services Task Force (USPSTF) concludes that there is insufficient evidence to determine whether supplementing with vitamin D >400 IU daily along with calcium >1000 mg daily is safe and effective for preventing fractures in community dwelling adults without vitamin D deficiency, osteoporosis, or a history of fracture. USPSTF recommends against supplementing with calcium 1000 mg daily or less along with vitamin D 400 IU daily or less for preventing primary fractures in community-dwelling postmenopausal females (95695).
• Obesity. Oral calcium does not seem to improve weight loss. Details: Observational research has found that adults and children with low calcium intake are more likely to gain weight, have a higher body mass index (BMI), and be overweight or obese when compared to people with high calcium intake (12124,12125,12126,12127,14265). Additional observational research has found that increasing calcium intake is associated with weight loss in females; the results in males have been conflicting (12127,15602,15603). Despite these findings from observational research and a few small clinical studies (12128,15397,14438,98905), most clinical research has found that increased calcium intake does not increase weight loss (12052,13138,15396,15399,38985,39004,97356). The most recent meta-analysis of 20 clinical studies shows that daily dietary and supplemental calcium intake that meets the dietary reference intake (DRI) of 1000 mg or more daily does not increase weight loss in overweight individuals or patients with obesity when compared with intake below the DRI (95813). An older meta-analysis of 13 clinical trials also shows that increased dietary and supplemental calcium intake does not increase weight loss (15605).
• Overall mortality. Oral calcium does not seem to reduce overall mortality. Details: While some population research has found that calcium taken in combination with vitamin D in older females is associated with a lower risk of death (97353), most evidence shows that calcium, with or without vitamin D, has no effect on all-cause mortality (93533,97308).

INEFFECTIVE

• Cardiovascular disease (CVD). Oral calcium does not reduce the risk of developing CVD and may actually increase risk in some patients. Details: Clinical research shows that calcium does not decrease CVD risk. Several separate meta-analyses of clinical and population research involving over 50,000 patients show that taking calcium 600-1200 mg daily for up to 7 years does not reduce the risk of CVD-related outcomes, including stroke and myocardial infarction, cardiovascular death, or overall mortality (39018,91350,92994,93533,97308,98902,107231,107233). No association was found between total dietary or supplemental calcium intake with or without vitamin D and the risk of CVD or mortality (91350,93533,97308). In fact, some population and clinical research has found that when calcium is used alone or with vitamin D, there is an INCREASED risk of CVD and coronary heart disease (38077,107233). However, other clinical research disagrees (93533). One meta-analysis of high-quality randomized controlled trials shows that taking calcium for 2-7 years increases the risk of CVD and coronary heart disease by 1.1-1.2 times when compared with control. However, the majority of the included research evaluated postmenopausal females and it is unclear if this finding is applicable to other populations (107233).
• Chemotherapy-induced peripheral neuropathy. Intravenous calcium does not prevent nerve pain in patients given oxaliplatin. Oral calcium has not been evaluated for this purpose. Details: While pooled analyses of cohort studies and randomized controlled trials suggest that calcium and magnesium infusion decreases the incidence of oxaliplatin-induced neurotoxicity, a meta-analysis of only randomized controlled trials shows that the infusion has no effect in preventing neurotoxicity (90028,90029,90031). Additionally, clinical trials show that administering calcium gluconate 1 gram with magnesium sulfate 1 gram intravenously immediately before, or before and after, the administration of a single oxaliplatin cycle (90005), or over the entire 6-cycle course of oxaliplatin, does not improve symptoms of neurotoxicity when compared with placebo (96474).
• Myocardial infarction (MI). Oral calcium does not prevent MI. When taken in the absence of vitamin D, oral calcium may increase the risk of MI. Details: Population research has found that increased dietary intake of calcium is associated with a decreased risk of MI (91350). However, a 2010 meta-analysis of clinical research shows that taking calcium at a dose of at least 500 mg daily is associated with an approximate 30% INCREASE in the risk of MI in patients over the age of 40. According to this analysis, one additional case of MI will occur for every 69 patients that take calcium for 5 years (17482). A more recent meta-analysis of high-quality randomized controlled trials shows that taking calcium for 2-7 years increases the risk of MI by 1.2 times when compared with control. However, the majority of the included research studied postmenopausal females and it is unclear if this finding is applicable to other populations (107233) In contrast, other meta-analyses of clinical research have shown that taking calcium for up to 7 years is NOT associated with an increased risk of MI, including a meta-analysis that only included postmenopausal females (93533,107231). Reasons for these discrepancies are not entirely clear. It may relate to whether calcium is taken as monotherapy or in combination with vitamin D. When taken with vitamin D, which is commonly recommended, calcium supplementation does not appear to be associated with an increased risk of MI in postmenopausal females (93533). Also, the association between calcium supplementation and MI risk may be influenced by the amount of calcium consumed as part of the diet. Supplementation with calcium may be associated with an increased risk of MI in people with dietary calcium intake above 805 mg daily, but not in those with dietary calcium intake below 805 mg daily (17482)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alcohol use disorder. It is unclear if oral calcium is beneficial for alcohol use disorder. Details: Preliminary clinical research shows that taking calcium carbonate 800 mg and vitamin D 200 IU orally daily for 14 days modestly reduces alcohol craving scores and withdrawal scores when compared with placebo in adults with alcohol dependence that are undergoing withdrawal. Taking calcium carbonate did not reduce the need for diazepam; however, the study may have been inadequately powered to detect a difference between groups (107234).
• Atherosclerosis. It is unclear if oral calcium is beneficial for atherosclerosis. Details: A population study has found that taking calcium 1.2 grams daily for 3 years has no effect on carotid intima thickness or carotid atherosclerosis incidence. A total calcium intake (dietary and supplemental) of at least 1794 mg daily in older females may be associated with a decreased risk of carotid atherosclerosis when compared with a total calcium intake below 1010 mg daily (97351).
• Autism spectrum disorder. It is unclear if oral calcium during pregnancy is beneficial for reducing the odds of autism spectrum disorder in the offspring. Details: A small observational study found that calcium supplementation during pregnancy is associated with a 52% reduced odds of an autism spectrum disorder in the offspring (98900).
• Cancer. Oral calcium alone does not seem to prevent cancer. It is unclear if oral calcium with vitamin D is beneficial for preventing cancer. Details: Taking calcium alone does not seem to significantly reduce the risk of cancer (12118,15629). The role of calcium in cancer prevention when taken along with vitamin D is controversial, as conflicting results exist. One clinical trial shows that healthy postmenopausal females who take supplemental calcium 1400-1500 mg daily plus vitamin D3 (cholecalciferol) 1100 IU daily have a 60% lower relative risk for developing cancer of any type. Approximately 25 postmenopausal females would need to take this combination for 4 years to prevent one occurrence of cancer (15629). However, a more recent clinical study shows that healthy postmenopausal females who take supplemental calcium 1500 mg daily plus vitamin D3 (cholecalciferol) 2000 IU daily do not have a reduced risk of cancer at 4 years (93943). Reasons for the disparate results are not entirely clear. The discrepancies do not appear to be related to baseline vitamin D levels or different study populations. It is possible that, given the 10-year time lapse between the two publications, the discrepancies result from differences in cancer detection capability. Also, since cancer risk was a secondary outcome measure in the earlier study and a primary outcome measure in the more recent study, it is possible that the discrepancies result from differences in statistical methodologies. The effect of vitamin D and calcium on cancer risk in males and younger patients is not known. There is also interest in using calcium for reducing the risk of hematological malignancies. An analysis of the Women's Health Initiative study shows that taking calcium 1000 mg daily in combination with vitamin D3 400 IU for up to 10 years is associated with a 20% reduction in the risk of hematologic malignancies when compared with placebo. However, no effect on hematologic malignancy related mortality was seen (97354).
• Depression. It is unclear if oral calcium is beneficial for depression prevention. Details: Population research has found no association between a higher dietary intake of calcium and the risk of depression when compared with a lower dietary intake of calcium (96480).
• Diabetes. It is unclear if oral calcium is beneficial for type 2 diabetes prevention. Details: Some population research has found that a higher intake of calcium from diet or supplements, alone or in combination with vitamin D, is associated with a lower risk of developing type 2 diabetes when compared with lower calcium intake (14265,16713,96473). However, population research is often limited by confounding variables. For example, one analysis found that any beneficial effect might be influenced by concomitant magnesium intake (96473). Furthermore, other population research has found that serum calcium levels higher than 9.6 mg/dL are associated with greater risk of developing diabetes in Chinese adults with osteoporosis. This study is limited because it was not determined whether increased serum calcium was due to increased calcium intake or another factor such as parathyroid function (95815).
• Dysmenorrhea. It is unclear if oral calcium is beneficial for reducing pain associated with dysmenorrhea. Details: Clinical research shows that taking calcium carbonate 1000 mg with vitamin D 5000 IU daily for three menstrual cycles does not reduce pain when compared with placebo in patients with primary dysmenorrhea (95821). However, calcium carbonate 1000 mg taken alone seems to reduce pain when compared with placebo.
• Endometrial cancer. It is unclear if oral calcium is beneficial for endometrial cancer prevention. Details: A meta-analysis of population research suggests that calcium supplements may reduce the risk of endometrial cancer, but dietary calcium does not seem to have any effect (38893).
• Fall prevention. It is unclear if oral calcium with vitamin D is beneficial for preventing falls. Details: Research suggests that calcium in combination with vitamin D, but not calcium alone, might prevent falls by decreasing body sway and normalizing systolic blood pressure (6362,11939,39038). Some experts think the combination of calcium and vitamin D may be important (11916). Preliminary clinical research in adults residing in a health care facility shows that taking vitamin D supplements while increasing dietary calcium and protein for 2 years reduces falls by 11% when compared with standard diets. Intervention diets were supplemented with milk, yogurt, and cheese to provide calcium 1142 mg and protein 69 grams daily (107235). There might also be different effects in females compared to males. In one study, females aged 65 years or older who took vitamin D 700 IU plus calcium citrate 500 mg daily over a 3-year period had a 46% lower risk of falling. However, this combination did not decrease falls in males (14291).
• Fluorosis. Oral calcium has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Taking calcium orally, in combination with ascorbic acid (vitamin C) and vitamin D, seems to be effective for reducing excessive fluoride levels in children and improving symptoms of fluorosis in children aged 6-12 years (990).
• Heart failure. It is unclear if oral calcium in combination with vitamin D is beneficial for preventing heart failure. Details: Based on a secondary analysis of a large-scale clinical trial (Women's Health Initiative), taking calcium 1000 mg with vitamin D 400 IU daily does not reduce the risk of heart failure in the overall population or in individuals at high risk. However, in a subgroup of postmenopausal females without risk factors for heart failure, calcium and vitamin D supplementation might reduce the risk of developing heart failure by about 37% (97307).
• Hypercholesterolemia. It is unclear if oral calcium is beneficial for hypercholesterolemia. Details: Some evidence shows that taking calcium carbonate 400 mg three times daily reduces low-density lipoprotein (LDL) cholesterol levels by 4% and increases high-density lipoprotein (HDL) cholesterol levels by 4% after 6 weeks of treatment when used in combination with a low-fat diet (American Heart Association Step 1) (2557). In contrast, a study in females with dyslipidemia shows that taking calcium 800 mg daily for 2 years might INCREASE total cholesterol levels by about 12 mg/dL when compared with placebo. This same study showed an association between calcium supplementation and an increase in total cholesterol levels and carotid intimal thickness in postmenopausal females, but not premenopausal females (97350). A recent meta-analysis of randomized controlled trials which included both healthy patients and patients with dyslipidemia shows that taking calcium 500-2000 mg daily and vitamin D 200-7142 IU daily modestly improves HDL cholesterol and triglyceride levels, but not LDL cholesterol levels, when compared with placebo. Subgroup analyses suggest that calcium and vitamin D supplementation is more effective in patients with dyslipidemia at baseline. It is unclear if this effect is due to calcium, vitamin D, or the combination (107227). However, other research shows that taking a specific supplement containing calcium 600 mg plus vitamin D 200 IU (Caltrate 600 D, Wyeth Consumer Healthcare Inc.) twice daily in combination with calorie restriction does not reduce total or LDL cholesterol levels when compared with placebo (15601).
• Lead toxicity. It is unclear if oral calcium is beneficial for reducing blood levels of lead. Details: Lead is mobilized along with calcium from bone during pregnancy and lactation, resulting in increased serum concentrations of lead. One clinical study suggests that calcium supplementation does not significantly decrease these elevated lead concentrations (1586). However, another clinical study suggests that taking calcium reduces blood lead levels by 11% when compared with placebo, with greatest effects observed in those with high baseline levels of lead (38957).
• Lyme disease. Although there is interest in using oral calcium for Lyme disease, there is insufficient reliable information about the clinical effects of calcium for this condition.
• Metabolic syndrome. It is unclear if oral calcium alone or with vitamin D is beneficial for metabolic syndrome prevention. Details: Population research has found that a higher intake of calcium from diet and supplements alone, or in combination with vitamin D, is associated with a lower risk of developing metabolic syndrome when compared with lower calcium intake (14265,16713).
• Nephrotic syndrome. It is unclear if oral calcium with vitamin D is beneficial for preventing nephrotic syndrome. Details: Clinical research shows that taking calcium 500-1000 mg daily for 3 months in combination with vitamin D3 60,000 IU daily or weekly for 4 weeks has no effect on bone mineral density or the risk of relapse in children with steroid-sensitive nephrotic syndrome (97355).
• Nonmelanoma skin cancer. It is unclear if oral calcium is beneficial for preventing keratinocyte carcinomas. Details: In middle aged and older adults recently diagnosed with a colorectal adenoma, clinical research shows that taking calcium 1200 mg daily as calcium carbonate for 3-5 years does not reduce the incidence of keratinocyte cancer when compared with placebo over a median of 8 years. A sub-group analysis shows that taking calcium alone or with vitamin D3 1000 IU daily reduced the risk of invasive cutaneous squamous cell carcinoma by a moderate amount, but had no effect on the risk of basal cell carcinoma (104622).
• Oral mucositis. When used in combination with fluoride treatments, a calcium phosphate mouth rinse seems to prevent and reduce mucositis-related pain in patients undergoing hematopoietic stem cell transplantation (HSCT). Details: A small clinical study in patients undergoing HSCT shows that using a particular mouth rinse (Caphosol, EUSA Pharma) containing calcium phosphate, in combination with fluoride treatments, reduces days of mucositis, the duration of pain, and the dose and days of morphine used when compared with placebo and fluoride treatment (38611).
• Ovarian cancer. It is unclear if oral calcium is beneficial for ovarian cancer prevention. Details: An older meta-analysis of 12 cohort studies found that dietary calcium intake is not associated with a reduced risk of ovarian cancer (38792). However, a more recent pooled analysis of 15 cohort and case-control studies has found that the highest intake of dietary or dairy calcium is associated with a 20% lower risk of ovarian cancer when compared to the lowest intake (97349).
• Postpartum depression. It is unclear if oral calcium is beneficial for reducing postpartum depression risk. Details: Preliminary clinical research shows that taking calcium 2 grams daily beginning at 11-21 weeks gestation reduces depression at 12 weeks postpartum when compared with placebo. However, no benefit is seen at 6 weeks postpartum (39447).
• Pregnancy-related leg cramps. It is unclear if oral calcium is beneficial for preventing leg cramps during pregnancy. Details: A small clinical study shows that taking calcium 1 gram twice daily (as a mixture of salts) for 2 weeks can reduce pregnancy-related leg cramps during the second half of pregnancy when compared with no treatment (2567).
• Prostate cancer. It is unclear if oral calcium is beneficial for prostate cancer prevention. Details: Some clinical research shows that taking calcium 1200 mg daily might decrease the risk of developing prostate cancer (14133). However, some epidemiological research suggests that consuming very high doses of calcium, over 2000 mg daily, might actually increase the risk of developing prostate cancer (14134). Some epidemiological research also suggests that doses greater than 1500 mg daily increase the risk of poorly differentiated, clinically advanced, and fatal prostate cancer (14132). Consumption of dairy products has also been weakly linked to a modest increase in risk of prostate cancer (98894). However, contradictory research suggests that there is no association between dietary intake of calcium and overall risk of prostate cancer (14131,14132,104630).
• Stroke. It is unclear if oral calcium is beneficial for stroke prevention. Details: Some population research has found that increasing dietary calcium intake is associated with a decreased risk of ischemic stroke (4822,38678). However, other population research has found that increasing dietary calcium intake is not associated with a decreased risk of stroke (91350). One meta-analysis of high-quality randomized controlled trials shows that taking calcium for 2-7 years does not affect the risk of stroke when compared with control. However, the majority of the included research evaluated postmenopausal females, and it is unclear if this finding is applicable to other populations (107233).
• Vertigo. Oral calcium with vitamin D might reduce positional vertigo; the effect of calcium when used alone is unclear. Details: A large clinical study in adults with recurrent benign paroxysmal positional vertigo shows that taking calcium 500 mg and vitamin D 400 IU twice daily for one year reduces annual recurrence of vertigo by 27% when compared with no treatment. The number needed to treat to prevent vertigo was 3.7 (103681). It is unclear if this benefit is due to vitamin D, calcium, or the combination. More evidence is needed to rate calcium for these uses.

(Read more about CALCIUM)

POSSIBLY EFFECTIVE

• Vitamin A deficiency. Some preliminary clinical research shows that consuming one spoonful of carrot jam daily for 10 weeks improves growth velocity when compared with control in children with vitamin A deficiency (25819). Other preliminary research shows that consuming 100 grams of grated carrot daily for 60 days improves vitamin A status when compared with placebo in lactating women at risk for vitamin A deficiency (67861).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Breast cancer. A meta-analysis of observational research has found that consuming a diet highest in carrots is associated with a 21% decreased odds of developing breast cancer when compared with consuming a diet lowest in carrots (101715).
• Colorectal cancer. A large observational study in older Danish adults shows that self-reported high consumption of raw carrot (2-4 carrots weekly or greater than 32 grams daily) is associated with a 17% lower likelihood of colorectal cancer diagnosis, whereas lower carrot consumption is not associated with a decreased risk. The validity of these findings may be limited by selection bias, recall bias, and other confounding factors (106559).
• Fibromyalgia. Preliminary clinical research shows that consuming a mostly raw, pure vegetarian diet that includes two to four 240 mL servings of carrot juice daily for 7 months might improve fibromyalgia symptoms in some people (98057). The effect of carrot alone on fibromyalgia is unknown.
• Prostate cancer. Population research has found that higher intake of carrot is associated with an 18% decrease in the odds of developing prostate cancer. Increasing carrot consumption by 10 grams daily or 1 serving per week is associated with a 4% to 5% decrease in the odds of developing prostate cancer (96307). More evidence is needed to rate carrot for these uses.

(Read more about CARROT)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Bladder cancer. Epidemiologic research has found that eating about 1 cup per week of cruciferous vegetables, such as cabbage, Brussels sprouts, cauliflower, broccoli, kale, or collards, is associated with a 30% decreased risk of developing bladder cancer in men and women (14864). Other population research has also found that higher intake of cruciferous vegetables, such as cauliflower, Brussels sprouts, cabbage, broccoli, and kale, is associated with a 51% reduction in the risk of developing bladder cancer in men. However, higher intake of cauliflower alone does not seem to be associated with a reduced risk of bladder cancer (26184).
• Breast cancer. Population research has found that higher intake of cruciferous vegetables, including broccoli, Brussels sprouts, cabbage, cauliflower, collards, and kale, is associated with a slight increase in the risk of breast cancer in premenopausal women, while higher intake of these vegetables is associated with a slight, but statistically insignificant, decrease in the risk of breast cancer in postmenopausal women (26188).
• Diabetes. Population research suggests that higher intake of cruciferous vegetables, including broccoli, cabbage, cauliflower, and Brussels sprouts, is not associated with a reduced risk of developing type 2 diabetes in women (26187).
• Lung cancer. Population research has found that increased dietary intake of cauliflower is associated with a 61% reduction in the risk of lung cancer in women; however, it does not seem to be associated with a reduced risk of lung cancer in men (26185).
• Non-Hodgkin lymphoma. Population research has found that, for women, consuming at least half a serving of cauliflower or other green vegetables daily is associated with a lower risk of developing non-Hodgkin lymphoma, particularly the follicular lymphoma subtype, compared with eating these vegetables less often. However, eating cauliflower and other green vegetables does not appear to be associated with a reduced risk of non-Hodgkin lymphoma in men (26186).
• Prostate cancer. Population research has found that people who consume higher amounts of cauliflower and other cruciferous vegetables have a lower risk of developing prostate cancer (25420).
• Stroke. Population research has found that higher intake of cauliflower and other cruciferous vegetables is associated with a 32% reduced risk of ischemic stroke (7394). More evidence is needed to rate cauliflower for these uses.

(Read more about CAULIFLOWER)

POSSIBLY EFFECTIVE

• Pregnancy-related iron deficiency. Oral chlorella, which contains iron, can help to prevent iron deficiency and anemia in pregnancy. Details: A small clinical study in Japanese patients in their first trimester of pregnancy shows that taking chlorella (Sun Chlorella A, Sun Chlorella Corp.) 2 grams three times daily, providing 7.2 mg iron daily, starting at the 12-18th week of gestation and continuing until delivery, reduces the incidence of maternal anemia, defined as a hemoglobin level less than 11 g/dL, to about 30%, compared with about 60% in patients receiving no intervention (95013).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Brain tumor. It is unclear if oral chlorella is beneficial in patients with glioma. Details: A small clinical study in patients with glioma shows that taking chlorella tablets plus chlorella liquid extract over 2 years might improve tolerability of chemotherapy and radiotherapy, but does not seem to affect tumor progression or survival, when compared to baseline (6804). The validity of this finding is limited by the lack of a comparator group.
• Depression. It is unclear if oral chlorella is beneficial as an adjunct to conventional antidepressant therapy in patients with major depressive disorder. Details: One open-label clinical trial in patients with major depressive disorder shows that taking chlorella extract tablets (ALGOMED, Bioprodukte Prof. Steinberg Produktions-und Vertreibs GmbH & Co.) 600 mg three times daily in addition to standard antidepressant therapy for 6 weeks improves subjective symptoms of depression and anxiety, measured on the Beck Depression Inventory II and the Hospital Anxiety and Depression Scale, when compared with standard antidepressant therapy alone (92132). The validity of this finding is limited by the large number of patients lost to follow-up and a lack of blinding.
• Dysmenorrhea. It is unclear if oral chlorella improves symptoms of dysmenorrhea. Details: A small clinical study in females 18-35 years of age with primary dysmenorrhea shows that taking chlorella (American Super Golden Med) 1500 mg daily for 8 weeks modestly decreases the severity and duration of painful menstrual cramps when compared with placebo (99882). This study is limited by small sample size and unclear allocation concealment.
• Exercise-induced respiratory infections. It is unclear if oral chlorella can prevent respiratory infections related to exercise. Details: A small clinical trial in physically active adults shows that taking chlorella (Sun Chlorella A, Sun Chlorella Corp.) 3 grams twice daily for 6 weeks increases salivary IgA, a marker of immune response, but doesn't improve the duration or severity of upper respiratory symptoms or reduce the risk for upper respiratory tract infections when compared with placebo (99881). However, this study was likely underpowered to detect differences in these outcomes.
• Fatigue. It is unclear if oral chlorella improves fatigue from exercise. Details: A small clinical trial in healthy males shows that taking chlorella (Chlorella Kogyo Co., Ltd) 2 grams three times daily for 4 weeks does not decrease exercise-induced fatigue or fatigue at rest when compared with placebo (99880).
• Fibromyalgia. It is unclear if oral chlorella improves symptoms of fibromyalgia. Details: A small open-label clinical trial in people with fibromyalgia shows that taking chlorella tablets (Sun Chlorella) 10 grams plus a liquid chlorella extract (Wakasa Gold) 100 mL daily for 2 months improves general symptoms and pain scores when compared with baseline (5890). The validity of this finding is limited by the lack of a comparator group.
• Halitosis. Although there is interest in using oral chlorella for halitosis, there is insufficient reliable information about the clinical effects of chlorella for this purpose.
• Hepatitis C. It is unclear if oral chlorella improves outcomes in patients with chronic hepatitis C infection. Details: A small clinical trial in patients with chronic hepatitis C virus (HCV) genotype 1 infection shows that taking chlorella tablets (Sun Chlorella A, Sun Chlorella Corp) 1500 mg twice daily for one week, then 1500 mg three times daily for 11 weeks, in addition to an extract containing 82 mg/mL of chlorella (Wakasa Gold, Sun Chlorella Corp) 30 mL twice daily for 12 weeks, decreases alanine aminotransferase (ALT) levels, but not aspartate aminotransferase (AST) or HCV RNA levels, when compared to baseline (92130). The validity of this finding is limited by the lack of a comparator group.
• Hyperlipidemia. It is unclear if oral chlorella reduces lipid levels. Details: A small clinical trial in patients with mild hypercholesterolemia, defined as total cholesterol between 200-250 mg/dL, who are not using lipid-lowering medications, suggests that taking chlorella (Daesang Corp.) 1664 mg three times daily for 4 weeks reduces total cholesterol by 1.6% and triglycerides by 10.3%, but does not affect low-density lipoprotein cholesterol or high-density lipoprotein cholesterol, when compared with placebo (92131). This study was limited by its short duration and small size.
• Hypertension. It is unclear if oral chlorella is beneficial in patients with hypertension. Details: Preliminary clinical research in patients with mild to moderate hypertension shows that taking chlorella 10 grams and chlorella extract 100 mL daily for 1-2 months does not reduce blood pressure when compared to baseline (41811).
• Metabolic syndrome. Although there is interest in using oral chlorella for metabolic syndrome, there is insufficient reliable information about the clinical effects of chlorella for this condition.
• Nonalcoholic fatty liver disease (NAFLD). Oral chlorella has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small open-label clinical trial in patients with NAFLD shows that taking chlorella extract 1200 mg with metformin 750 mg and vitamin E 200 mg daily for 3 months decreases alanine aminotransferase (ALT), aspartate aminotransferase (AST), and triglyceride levels when compared to baseline. Treatment with metformin 1250 mg and vitamin E 200 mg daily without chlorella does not appear to improve these outcome measures (99878). This study is limited by the lack of statistical comparison between groups.
• Peptic ulcers. Although there is interest in using oral chlorella for peptic ulcers, there is insufficient reliable information about the clinical effects of chlorella for this purpose.
• Pregnancy-induced hypertension. It is unclear if oral chlorella is beneficial for preventing pregnancy-induced hypertension. Details: A small clinical study in healthy Japanese patients in their first trimester of pregnancy shows that taking chlorella (Sun Chlorella A, Sun Chlorella Corp.) 2 grams three times daily, starting at the 12-18th week of gestation and continuing until delivery, reduces proteinuria and leg edema, but does not affect blood pressure, when compared with no intervention (95013). It is unclear if chlorella is beneficial in patients who are at risk for hypertension during pregnancy.
• Ulcerative colitis. Although there is interest in using oral chlorella for ulcerative colitis, there is insufficient reliable information about the clinical effects of chlorella for this condition. More evidence is needed to rate chlorella for these uses.

(Read more about CHLORELLA)

POSSIBLY EFFECTIVE

• Chronic venous insufficiency (CVI). Oral grape leaf extract might improve CVI symptoms. It is unknown if other grape products are beneficial for CVI. Details: Some clinical trials in patients with CVI show that taking a specific grape leaf extract, known as red vine leaf extract (AS 195, Antistax, Boehringer Ingelheim), seems to improve leg edema after 6 weeks of treatment when compared with placebo. Doses of 360 mg and 720 mg daily were both effective, but the higher dose produced a slightly greater effect. Patients also reported decreases in subjective complaints such as tired or heavy legs, tension, and tingling and pain after 2-12 weeks of treatment (2538,52985,53005,53206).

POSSIBLY INEFFECTIVE

• Allergic rhinitis (hay fever). Oral grape seed extract does not seem to improve hay fever symptoms. Details: A clinical study in patients with seasonal allergic rhinitis shows that taking grape seed extract 100 mg twice daily for 8 weeks before ragweed pollen season does not seem to decrease seasonal allergic rhinitis symptoms or antihistamine usage when compared with placebo (9182).
• Chemotherapy-induced nausea and vomiting (CINV). Drinking grape juice does not seem to improve CINV. Details: Clinical research shows that taking 4 ounces of chilled Concord grape juice 30 minutes prior to meals for a week following each of four cycles of chemotherapy does not seem to reduce CINV when compared with placebo (53175).
• Lower urinary tract symptoms (LUTS). Drinking grape juice does not seem to improve LUTS. Details: Clinical research in middle-aged and older men with LUTS shows that drinking 100% Concord grade juice 240 mL daily for 3 months does not improve symptoms when compared with placebo (96190).
• Mastalgia. Oral grape seed extract does not seem to improve mastalgia symptoms. Details: Clinical research in patients treated for early breast cancer using high-dose radiotherapy shows that taking the grape seed extract constituent proanthocyanidin 100 mg orally three times daily for 6 months does not reduce breast tissue hardness, pain, or tenderness when compared with placebo (53048).
• Obesity. Oral grape products do not seem to improve weight loss. Details: Clinical research in overweight or obese individuals shows that drinking Concord grape juice 480 mL daily for 12 weeks does not improve weight or body composition when compared to baseline (53181). Furthermore, taking grape pomace alone or in combination with schisandra fruit extract daily for 4-10 weeks does not improve body composition, abdominal fat, or body weight when compared with control (96200,99269,99270). Taking grape pomace 7-8 grams daily for 4-6 weeks seems to improve insulin resistance by about 33%, but does not affect blood lipids or blood pressure, when compared with placebo in overweight or obese adults with at least one metabolic syndrome factor (99269,99270).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aging skin. Oral grape skin extract has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small study in adults with signs of aging skin shows that taking a specific combination product (Celergen, Laboratories-Dom) containing grape skin extract 10 mg, marine collagen peptides 570 mg, coenzyme Q10 10 mg, luteolin 10 mg, and selenium 0.05 mg, one capsule with breakfast and dinner for 2 months, might improve skin elasticity when compared with baseline. However, there was no effect on moisture or biological skin age (97930). It is not clear if these effects are due to grape skin extract, the other ingredients, or the combination.
• Age-related macular degeneration (AMD). Although there is interest in using oral grape seed for AMD, there is insufficient reliable information about the clinical effects of grape for this condition.
• Atherosclerosis. Oral grape seed extract has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in postmenopausal adults shows that taking a specific combination product (Karinat, INAT-Farma) containing grape seed extract constituent proanthocyanidin 40 mg, garlic 100 mg, hops 160 mg, green tea 115 mg, vitamin C 30 mg, silicon 8 mg, vitamin E 6.6 mg, and beta-carotene 0.5 mg three capsules daily for 12 months might slow the progression of atherosclerosis as measured by mean carotid intima thickness when compared with placebo. However, the combination product does not seem to affect the growth of existing plaques, and it does not seem to improve lipid parameters (97929). It is not clear if these effects are due to grape seed extract, the other ingredients, or the combination.
• Athletic performance. It is unclear if oral grape products are beneficial for athletic performance. Details: A small study in elite athletes shows that taking a specific grape extract (Powergrape, Naturex SA) 400 mg daily for one month can increase total power in a jumping task when compared with placebo, but has no effect on initial power and maintenance of power (53310). Another small study in recreationally active young adults shows that drinking juice prepared from 46 grams of a freeze-dried preparation of whole grapes daily for 6 weeks prior to a running exercise test does not improve maximal oxygen uptake or work capacity during exercise when compared with placebo (91540).
• Atopic dermatitis (eczema). Topical grape products have only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with atopic dermatitis shows that twice daily application with a cream containing grape polyphenols, vitamin E, and epigallocatechin gallate for 28 days does not improve symptoms or reduce the affected area based on physician assessment when compared with placebo (96196).
• Attention deficit-hyperactivity disorder (ADHD). Although there is interest in using oral grape seed for ADHD, there is insufficient reliable information about the clinical effects of grape for this condition.
• Canker sores. Although there is interest in using oral grape seed for canker sores, there is insufficient reliable information about the clinical effects of grape for this condition.
• Cardiovascular disease (CVD). It is unclear if oral grape products are beneficial for reducing CVD risk. Details: There is preliminary evidence that taking grape products, such as purple grape juice or red grape juice concentrate, might improve endothelium-dependent vasodilation, prevent low-density lipoprotein (LDL) oxidation, reduce markers of inflammation, and suppress platelet-mediated thrombosis. Theoretically, chronic ingestion of these products might reduce the risk of CVD in various patient populations, including adults with type 2 diabetes or hypercholesterolemia, those undergoing hemodialysis, and children with metabolic syndrome (8745,8746,52954,53030,53062,53106,53155,53174). However, a large meta-analysis shows that although taking grape products, including grape extract, grape juice, raisins, and grape seed extract, reduces levels of blood fats by a small amount in a mixed population of adults, these effects were not present in a subgroup of patients with CVD when compared with placebo. There was a small benefit on total cholesterol and high-density lipoprotein (HDL) cholesterol (102610).
• Cognitive function. It is unclear if oral grape products improve cognitive function. Details: Clinical research in healthy adults aged 55-75 years with no cognitive decline shows that taking a specific grape fruit extract (Cognigrape, Bionap srl) 250 mg daily for 12 weeks improves cognitive functioning by 4.5%, and overall neuropsychological status, including attention, language, and recall, by 6%, compared with no change in the placebo group (96198). Also, a preliminary clinical study in middle-aged women under moderate stress shows that drinking Concord grape juice 355 mL daily for 12 weeks improves immediate spacial memory and may improve executive function and verbal recall when compared with placebo (96195).
• Cognitive impairment. Small clinical studies suggest that oral grape products may not slow cognitive decline in older patients with cognitive impairment. Details: One very small study in in patients with mild cognitive decline shows that taking a freeze-dried grape powder 36 grams twice daily for 6 months does not improve most measures of cognitive function and memory, including immediate memory, delayed memory, speed of information processing, cognitive ability, or language, when compared with placebo (96199). Another very small study in older adults with signs of memory decline shows that drinking 100% Concord grape juice 6-9 mL/kg daily for 12 weeks does not improve delayed verbal recall or spatial memory when compared with placebo, although it does seem to moderately improve verbal learning (53166).
• Colorectal cancer. Oral grape seed extract is has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in patients with colorectal cancer shows that taking a product containing grape seed extract, turmeric extract, fermented soybean extract, green tea extract, spirulina, and Taiwanofungus camphoratus, 1920 mg three times daily for 16 weeks during a chemotherapy regimen might modestly increase the effectiveness of treatment when compared with placebo. No patients in the treatment group experienced disease progression, compared with 15.8% (6 patients) of the placebo group. However, there was no significant effect on overall survival or the best response to treatment (96183).
• Constipation. Although there is interest in using oral grape products for constipation, there is insufficient reliable information about the clinical effects of grape for this condition.
• Dental caries. Although there is interest in using topical grape seed for dental caries, there is insufficient reliable information about the clinical effects of grape for this purpose.
• Diabetes. Oral grape extract has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A large clinical study of males with type 2 diabetes mellitus and erectile dysfunction suggests that an oral combination product containing alpha lipoic acid, Gingko biloba, and grape extract (Blunorm Forte, Uriach S.p.A.) taken for 3 months may decrease fasting plasma glucose and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) score both alone and when combined with avanafil when compared with baseline and placebo (110707).
• Diabetic retinopathy. It is unclear if oral grape seed extract is beneficial in patients with diabetic retinopathy. Details: A preliminary clinical study in patients with non-proliferative diabetic retinopathy shows that taking a specific grape seed proanthocyanidin extract (Entelon, Hanlim Pharm) 50 mg three times daily for 12 months reduces the severity of hard exudates when compared with calcium dobesilate or placebo. Grape seed extract had a treatment success rate 3-fold and 5.5-fold higher than those of calcium dobesilate and placebo, respectively. Treatment success was defined as a 2-grade decrease in hard exudate severity. No significant improvements in retinopathy grade or visual acuity were reported (100954). However, the study may not have been adequately powered to detect a difference in these outcomes.
• Erectile Dysfunction (ED). Oral grape extract has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A large study of males with type 2 diabetes mellitus and erectile dysfunction suggests that a specific combination product containing alpha lipoic acid, grape extract, and gingko biloba (Blunorm Forte, Uriach S.p.A.) administered orally for three months with avanafil prior to sexual acts improves International Index of Erectile Function (IIEF) scores when compared with either product alone, placebo, and baseline, and may reduce markers of ED including high sensitivity-c-reactive protein, nitrates/nitrites, and metalloproteinases-2 and -9. These results suggest that an oral combination nutraceutical consisting of alpha lipoic acid, grape extract, and gingko biloba (Blunorm Forte, Uriach S.p.A.) may react synergistically with avanafil to enhance sexual performance in males with type 2 diabetes and erectile dysfunction. It is unclear if this effect is due to the alpha lipoic acid, grape extract, or gingko biloba, but researchers theorize that it may be due to the inhibition of phosphodiesterase-5 enzymes by grape extract (110707).
• Hemorrhoids. Although there is interest in using oral grape seed for hemorrhoids, there is insufficient reliable information about the clinical effects of grape for this purpose.
• Hypercholesterolemia. Small clinical studies suggest that oral grape products reduce cholesterol levels by a small amount. Details: A large meta-analysis of heterogeneous clinical trials shows that taking grape products, including grape extract, grape juice, raisins, or grape seed extract, for 2-54 weeks reduces levels of total and low-density lipoprotein (LDL) cholesterol, as well as triglycerides, by a small amount when compared with placebo in a mixed population of adults. In a sub-group of patients with any hyperlipidemia, the mean decreases in LDL cholesterol and triglycerides were 11 mg/dL and 14 mg/dL, respectively. There was no effect on levels of high-density lipoprotein (HDL) in the mixed population or in adults with hyperlipidemia (102610). Although some individual studies disagree, the most evidence for benefit is related to use of whole grape extract or grape seed extract. It is not clear if benefit is dependent on dose or duration of use. These results suggest a benefit of grape products in patients with hypercholesterolemia, but any benefit is likely to be small (42585,96816,102610).
• Hypertension. Some research suggests that oral grape products may modestly lower blood pressure; however, results are inconsistent. Details: Some clinical trials have shown modest benefit in patients with prehypertension, mild hypertension, or metabolic syndrome (18228,53149,96197), but conflicting results exists (91541,90079). A 2016 meta-analysis including 16 trials of 810 patients shows that when compared with placebo, grape seed extract or polyphenols reduces systolic blood pressure (SBP) and diastolic blood pressure (DBP) by about 6 mmHg and 3 mmHg, respectively, with greatest improvements observed in those with obesity or metabolic syndrome. This meta-analysis suggests that a minimum treatment duration of 8 weeks may be necessary before benefit is seen (96194). However, other research in adults with hypertension shows that taking grape seed polyphenols 1000 mg daily for 6 weeks does not alter blood pressure. Also, when grape seed polyphenols were combined with vitamin C 500 mg daily, some patients experienced an increase in blood pressure and worsening of nighttime and daytime variation in blood pressure (13162,90079). The reason for these conflicting findings is unclear but may due to patient characteristics and comorbidities. A meta-analysis of clinical research in various patient populations shows that taking grape seed extract 150-2100 mg for 2-25 weeks improves DBP and heart rate when compared with control, but does not improve SBP or flow-mediated dilation, regardless of dose, duration, sex, BMI, or health status. Additionally, subgroup analyses suggest that blood pressure effects may be greater in patients who are otherwise healthy, female, overweight, and/or under 50 years of age. Also, the use of lower doses and longer treatment durations may be associated with greater benefit (108090). The validity of these findings is limited by the high heterogeneity of included studies. A clinical study in adults with mildly elevated blood pressure shows that a specific grape seed extract (Enovita; Indena SpA) standardized to provide at least 95% oligomeric proanthocyanins, taken as 150 mg twice daily for 16 weeks, does not reduce SBP or DBP when compared with placebo. However, a subgroup analysis suggests that taking grape seed extract improves blood pressure in males, but not in females, when compared with placebo (108091). Some research has also evaluated the effects of grape juice on blood pressure. Two clinical studies in patients with hypertension show that drinking grape juice can reduce blood pressure when compared to baseline; however, another study shows that drinking grape juice does not reduce blood pressure when compared with placebo in these patients (53018,53156,53199).
• Melasma. It is unclear if oral grape seed extract is beneficial in patients with melasma. Details: A very small clinical study in Japanese females with melasma shows that taking grape seed extract (Gravinol, Kikkoman Co) containing 54 mg of proanthocyanidins three times daily for 6-11 months reduces skin hyperpigmentation when compared to pretreatment (53016). The validity of this finding is limited by the lack of a control group.
• Menopausal symptoms. It is unclear if oral grape seed extract is beneficial in patients with menopausal symptoms. Details: Preliminary clinical research in adults with at least one menopausal symptom shows that taking grape seed extract (Gravinol, Kikkoman Biochemifa Co) containing proanthocyanidin 200 mg daily for 8 weeks reduces anxiety when compared with placebo. It also reduces hot flashes and other physical symptoms when compared to baseline, but not when compared with placebo. A lower dose of proanthocyanidin 100 mg daily does not appear to improve these outcomes. Neither doses improved insomnia or depression (91542).
• Metabolic syndrome. Small studies suggest that various oral grape products might improve lipid levels and blood pressure in patients with metabolic syndrome. Details: A meta-analysis of small clinical studies in adults with type 2 diabetes or metabolic syndrome shows that taking grape products, usually grape seed or grape extract, for 4-48 weeks reduces levels of total and low-density lipoprotein (LDL) cholesterol, as well as triglycerides, by a small amount when compared with placebo. The mean decreases in LDL cholesterol and triglycerides were 2.6 mg/dL and 11 mg/dL, respectively (102610). These findings are limited by significant heterogeneity of the included research. Also, a small clinical study in overweight or obese adults, most with metabolic syndrome, shows that taking grape pomace 8 grams daily for 6 weeks improves insulin resistance by about 33%, but does not affect blood lipids, blood pressure, or fasting glucose, when compared with placebo (99270). Some grape products have also shown benefit for improving blood pressure in patients with metabolic syndrome. One small clinical crossover study in males with metabolic syndrome shows that taking 46 grams daily of a freeze-dried, dehydrated preparation of grape polyphenols (equivalent to about 250 grams of fresh grapes daily) for 30 days seems to modestly lower systolic, but not diastolic, blood pressure, and increase brachial artery flow-mediated dilation (FMD) when compared with placebo (18228). Also, a small clinical study in adolescents with metabolic syndrome suggests that drinking natural grape juice 18 mL/kg daily for one month improves FMD when compared with baseline (53174).The validity of this finding is limited by the lack of a control group. A very small clinical study in patients with metabolic syndrome shows that taking a specific grape seed extract (Meganatural BP, Polyphenolics) 150-300 mg daily for 4 weeks modestly reduces blood pressure when compared with placebo (53149). The validity of this finding is limited due to small study size and because patients in the treatment groups had higher blood pressure at baseline.
• Minor bleeding. Topical grape vine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that topically applying 4 mL of a specific product (Ankaferd blood stopper) containing grape vine, alpinia, licorice, thyme, and stinging nettle reduces bleeding, but does not improve the surgical time for episiotomy repair, when compared with saline (31010). It is unclear if this effect is due to grape vine, other ingredients, or the combination.
• Muscle soreness. It is unclear if oral grape products improve muscle soreness. Details: One small study in active young adults shows that drinking juice, prepared from 46 grams of freeze-dried whole grapes, daily for 6 weeks prior to an eccentric arm exercise test does not reduce muscle inflammation or pain at 24 or 48 hours post-exercise when compared with placebo (91540).
• Night vision. Although there is interest in using oral grape seed extract for improving night vision, there is insufficient reliable information about the clinical effects of grape for purpose.
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral grape seed extract reverses fatty liver in patients with NAFLD. Details: One small clinical study in adults with NAFLD shows that taking grape seed extract 1000 mg twice daily for 3 months improves some, but not all, markers of liver damage and improves the grade of fatty liver change when compared with vitamin C supplementation (53190).
• Ocular stress. Although there is interest in using oral grape seed extract for ocular stress, there is insufficient reliable information about the clinical effects of grape for this purpose.
• Premenstrual syndrome (PMS). Although there is interest in using oral grape seed extract for PMS, there is insufficient reliable information about the clinical effects of grape for this condition.
• Wound healing. Limited research suggests that topical grape seed extract might improve wound healing. Details: A small clinical study in adults undergoing surgical removal of minor skin lesions shows that applying red grape seed extract 2% cream twice daily to the affected areas reduces the time to complete wound healing by about 6 days when compared with a placebo cream (91539). Also, preliminary clinical research in patients recovering from cesarean section shows that applying grape seed extract 5% ointment twice daily to cesarean section wounds for 14 days improves wound healing, as measured by a scoring system assessing redness, edema, ecchymosis, discharge, and wound closure, when compared with a placebo ointment. A 2.5% ointment did not improve wound healing measures when compared with placebo (100955). More evidence is needed to rate grape for these uses.

(Read more about GRAPE)

LIKELY EFFECTIVE

• Human papillomavirus (HPV). A specific green tea extract ointment (Polyphenon E ointment 15%) is approved by the US Food and Drug Administration (FDA) for treating external genital warts caused by HPV. Details: A specific green tea extract ointment (Veregen, Bradley Pharmaceuticals; Polyphenon E ointment 15%, MediGene AG) providing 150 mg of sinecatechins per gram of ointment, applied three times daily to external warts, completely clears external genital and perianal warts in 24% to 60% of patients after 10-16 weeks of treatment (15067,36438,36442,53777,53907,54018). This green tea extract is an FDA-approved prescription product (15067).

POSSIBLY EFFECTIVE

• Cardiovascular disease (CVD). Drinking green tea seems to reduce the risk of CVD and CVD-related mortality. Details: Large-scale population research in Japan suggests that consuming at least 3-5 cups of green tea daily is associated with a reduced risk of cardiovascular mortality when compared with drinking less than 1 cup daily. This association appears to be primarily related to a decrease in risk for cerebral infarction and heart disease. This association appears to be stronger in females than in males (14498,53789,100202). Population research also suggests that drinking green tea is associated with a reduced risk of CVD. One meta-analysis suggests that drinking green tea is associated with a 28% reduced risk of CAD (54017). Another meta-analysis suggests that consuming small to moderate amounts of green tea, 1-5 cups or 300 to 1500 mL daily, is associated with an 8% to 16% reduced risk of coronary heart disease over 5 to 13 years when compared with consuming no green tea (111017). One meta-analysis suggests that a 1 cup increase in green tea consumption is associated with a 5% reduced risk of CVD mortality and a 3% reduced risk of CVD events (102728). When compared with drinking less than 1 cup of green tea daily, epidemiological research in a population at high risk of coronary artery disease (CAD) suggests that drinking more than 3 cups of green tea daily is associated with a 46% reduced odds of having CAD, especially severe CAD, as determined by a coronary angiography (104588). A sub-group analysis suggests that these odds only occurred in individuals consuming fruits more than 4 times weekly and not in individuals consuming fruits less often (104588). However, some population research suggests that any association seems to be greater for males than females (53691). Other population studies suggest that general tea consumption might protect against ischemic heart disease or death from CVD; however, many of the tea drinkers in some of these studies consumed black tea rather than green tea (8119,8120,8121,102728).
• Endometrial cancer. Drinking green tea seems to be beneficial for endometrial cancer prevention. Details: Meta-analyses of epidemiological research have found that people who drink green tea often, usually more than once daily, have a 21% to 23% reduced risk of developing endometrial cancer when compared with those who never or rarely drink green tea (53919,92409,102716). One of these meta-analyses also found that increasing green tea intake by one cup per day is associated with an 11% reduced risk of developing endometrial cancer (92409).
• Hyperlipidemia. Oral green tea seems to reduce levels of low-density lipoprotein (LDL) cholesterol by a small amount. Details: Clinical research and a meta-analysis of clinical research in people with or without hyperlipidemia shows that consuming green tea or green tea extract containing 150-2500 mg catechins daily for up to 24 weeks reduces total cholesterol by about 5-24 mg/dL and LDL cholesterol by about 2-25 mg/dL when compared with control (11308,54038,54048,90146,90161,97135,104605). There is also preliminary evidence that taking a green tea extract containing catechins 676 mg daily for 12 weeks reduces oxidation of LDL cholesterol when compared with placebo, which might lead to reduced damage to the vascular endothelium and reduced arteriosclerosis (98458). Epidemiological research has found that higher consumption of green tea, especially 10 cups daily or more, is associated with improved serum lipids in males, but not females (6403,97134).
• Ovarian cancer. Drinking green tea seems to be beneficial for ovarian cancer prevention. Details: Consuming tea, including green tea or black tea, appears to significantly lower the risk of developing ovarian cancer when compared with never or seldom consuming tea (9228,13208,90144,102716). One meta-analysis of population research suggests that the highest intake of green tea is associated with a 36% reduced risk of ovarian cancer when compared with the lowest intake (102716). Also, one prospective population study found that those who consume 2 or more cups of tea daily have a 46% lower risk of ovarian cancer when compared with those who don't regularly consume tea (13208). There also appears to be a trend that suggests higher consumption of tea or longer duration of use further reduces the risk of ovarian cancer (9228,13208). However, green tea does not appear to prevent ovarian cancer recurrence. Preliminary clinical research shows that drinking 500 mL of double-brewed green tea (DBGT), prepared with 35 grams/L of tea leaves standardized to contain approximately 640 mg/L of EGCG, daily for up to 18 months does not prevent cancer recurrence in adults with a history of advanced stage serous or endometrioid ovarian cancer (90175).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Topical green tea might reduce acne lesions by a small amount. It is unclear if oral green tea is beneficial for acne. Details: A meta-analysis of preliminary clinical research shows that topical application of green tea extract reduces the number of inflammatory and non-inflammatory lesions by a small amount (104609). In one small study, applying a solution containing the green tea constituent epigallocathechin-3-gallate (EGCG) 1% or 5% twice daily for 8 weeks was used (54074). However, oral green tea extract had limited or no effect in one study included in a meta-analysis (104609). Higher quality studies are needed to confirm this finding.
• Age-related cognitive decline. It is unclear if oral green tea is beneficial for cognitive decline associated with age. Details: In elderly individuals living in the community, clinical research shows that taking matcha green tea powder (Yabukita, Kyoeiseicha Co., Ltd.) 3 grams daily for 12 weeks does not improve overall measures of cognitive function when compared with placebo. However, a sub-group analysis in females found a small improvement in language, but not other measures, including memory, impulsivity, and attention (104602). Other clinical research in middle aged and older adults shows that taking green tea extract (Thea-Flan 90S, ITO EN Ltd.) providing catechins 336.4 mg daily for 12 weeks does not improve most measures of cognitive function, although there was a small effect on one measure of working memory. In addition, a single dose has a small effect on errors during an attention task (104603).
• Amyloidosis. It is unclear if oral green tea is beneficial for amyloidosis. Details: Preliminary clinical research in patients with cardiac transthyretin amyloidosis shows that drinking green tea (Green Darjeeling, FTGFOP1, Teekampagne Projektwerkstatt GmbH) 1.5-2 liters standardized to contain epigallocatechin-3-gallate (EGCG) 340 mg/L and/or taking specific capsules (Praevent-loges, Dr. Loges + Co. GmbH) containing 300 mg green tea extract standardized to contain EGCG 75 mg/capsule for 12 months protects against an increase in left ventricular wall thickness and left ventricular myocardial mass (54064).
• Anxiety. Although there has been interest in using oral green tea for anxiety, there is insufficient reliable information about the clinical effects of green tea for this condition.
• Athletic performance. The evidence on the effects of green tea constituents for athletic performance is conflicting. Details: Some preliminary clinical research shows that taking green tea extract containing up to 572.8 mg of catechins as a beverage does not improve respiration efficiency, maximal oxygen uptake, or time trial performance in individuals undergoing endurance training when compared with beverages without catechins (53987,53991). However, other preliminary research shows that taking specific pills (Teavigo, Healthy Origins) containing epigallocatechin-3-gallate (EGCG) 135 mg/pill, taken three times daily with meals for a total dose of seven pills, improves maximal oxygen uptake but not maximum work rate or respiration efficiency, in healthy adults when compared with placebo (53944). Also, a small study in untrained adults shows that taking a single dose of green tea polyphenols 640 mg, 90 minutes before exercise, increases maximal oxygen uptake. However, the effect on athletic performance was not determined (104606).
• Beta-thalassemia. It is unclear if oral green tea is beneficial for reducing iron accumulation in beta-thalassemia. Details: A small clinical trial shows that taking green tea 3 cups daily after meals for 12 months, in addition to usual treatment with blood transfusions and deferasirox, an iron chelator, reduces levels of liver iron and serum ferritin by moderate amounts when compared with usual treatment alone. Hemoglobin values did not differ between groups. Each green tea bag contained 2 grams green tea (Lipton, Unilever Gulf) (104601).
• Bladder cancer. It is unclear if drinking green tea is beneficial for bladder cancer prevention. Details: Some epidemiological evidence suggests that drinking green tea is associated with a reduced risk of bladder cancer (1458,1459,90179). However, conflicting evidence exists. A meta-analysis of some epidemiological evidence suggests that drinking green tea is not associated with a reduced risk of bladder cancer (54077,90166,102716).
• Breast cancer. Evidence evaluating the association between green tea intake and breast cancer risk is inconsistent; any association may be dependent on genotype and menopausal status. Details: Meta-analyses of cohort and case-control studies have found that green tea intake is not associated with a reduced risk of breast cancer (98460,102716). However, some individual population studies suggests that green tea intake is associated with a reduced odds of developing breast cancer in Asian-American (14427,53866), but not Asian (13189,14426,90181), populations. Any protective effect of green tea on breast cancer risk might depend on patient genotype or menopausal status. Green tea consumption does not seem to lower breast cancer risk in Asian females with low-activity angiotensin-converting enzyme (ACE) genotype, although it does seem to decrease breast cancer risk in Asian females with high-activity ACE genotype (14430). Similarly, Asian-American females who drink green tea seem to have a lower breast cancer risk if they have low-activity catechol-O-methyltransferase (COMT) genotype. However, they do not seem to benefit if they do not have the low-activity COMT genotype (14431). Additionally, some observational research suggests that there is a link between green tea and modestly reduced breast cancer risk in pre-menopausal, but not postmenopausal, females (99788). Some research has evaluated the effect of green tea on breast cancer recurrence. Population research suggests that Asian females who have had stage I or II breast cancer who drink at least 3 cups of green tea daily seem to have reduced risk of breast cancer recurrence (3926,13189,54112). However, drinking green tea does not seem to significantly reduce the risk of recurrence of later-stage breast cancer. In April 2012, the US Food and Drug Administration (FDA) determined that it would allow a qualified health claim stating that consuming green tea may reduce the risk of breast cancer, although the FDA has concluded that there is very little scientific evidence to support this claim (102106).
• Cervical cancer. It is unclear if oral green tea is beneficial for cervical cancer. Details: Clinical research in adults with persistent high-risk HPV (HR HPV) infection and concomitant low-grade cervical intraepithelial neoplasia shows that taking a specific green tea extract (Polyphenon E), four capsules standardized to contain epigallocatechin-3-gallate (EGCG) 200 mg/capsule, once daily for 4 months does not affect HR HPV-positive status or histological outcomes when compared with placebo (90145).
• Cervical dysplasia. It is unclear if topical green tea is beneficial for cervical dysplasia. Details: Preliminary clinical research shows that applying a specific ointment (Polyphenon E ointment 15%, MediGene AG) containing epigallocatechin-3-gallate (EGCG) to human papilloma virus (HPV)-infected cervical lesions twice weekly and/or taking a specific green tea extract (Polyphenon E) 200 mg daily containing EGCG by mouth for 8-12 weeks can improve lesion appearance when compared with control (11310).
• Chronic fatigue syndrome (CFS). Although there has been interest in using oral green tea for CFS, there is insufficient reliable information about the clinical effects of green tea for this condition.
• Chronic obstructive pulmonary disease (COPD). It is unclear if drinking green tea reduces the risk of COPD. Details: One prospective, observational study in older adults has found that consumption of at least 3 cups daily of tea, including green tea, oolong tea, and black tea, is associated with a 23% reduction in COPD prevalence and a 65% reduced risk of developing COPD in models adjusted for potential confounders when compared with the lowest tea consumption (107201). However, green tea was only consumed by about 19% of the population included in this study and consumption of green tea itself was not associated with a reduced risk of COPD.
• Cognitive function. It is unclear if oral green tea improves cognitive function in healthy adults. Details: A small clinical study in adults ages 50-69 years shows that taking matcha powder (Hojin no shiro, Ito En, Ltd.) 9 capsules daily for 12 weeks, providing 170 mg total catechins daily, modestly improves some measures of attention and work performance when compared with taking placebo or caffeine. However, there was no effect on other measures of these outcomes, or on verbal memory tasks, visual information processing, working memory, motor function, or facial expression recognition (107168). Another small clinical study shows that taking a single dose of the green tea constituent, epigallocathechin-3-gallate (EGCG), 135 or 270 mg does not seem to improve mood or cognitive performance in healthy adults (54059).
• Cognitive impairment. It is unclear if oral green tea is beneficial for the prevention or treatment of mild cognitive impairment in elderly adults. Details: Some population research in elderly individuals has found that drinking green tea at least once per week is associated with a 53% reduced incidence of dementia or mild cognitive impairment when compared to not consuming green tea (104598). In addition, drinking at least two cups of green tea daily was associated with a 54% lower prevalence of cognitive impairment (104611). Some clinical research shows that taking two capsules of a specific combination product containing green tea extract 360 mg/capsule and L-theanine 60 mg/capsule (LGNC-07, LG Household & Health Care, Ltd) twice daily after meals for 16 weeks improves memory and attention in patients with mild cognitive impairment when compared with placebo (54019).
• Colorectal adenoma. It is unclear if oral green tea extract is beneficial for reducing colorectal adenoma recurrence. Details: A large clinical trial in patients with previously removed colorectal adenomas shows that taking green tea extract (Dr. Loges + Co. GmbH) standardized to epigallocatechin gallate (EGCG) 150 mg twice daily for 3 years does not affect the risk of developing new metachronous adenomas when compared with taking placebo (111020). However, a sub-group analysis shows that taking green tea extract results in a 10% absolute reduction in risk of adenoma formation in males, but not females (111020). Also, preliminary clinical research in patients with previously removed colorectal adenomas shows that taking green tea extract 1.5 grams daily for 12 months reduces the incidence of metachronous adenomas when compared with placebo (53816).
• Colorectal cancer. It is unclear if oral green tea is beneficial for colorectal cancer prevention. Details: Although evidence from individual population studies is mixed (9222,9223,14498,90176,90178,90181,102718), meta-analyses of population research suggest that a high intake of green tea is associated with a reduced risk of colorectal cancer (36416,102716). The highest intake of green tea is associated with a 16% reduced risk when compared with the lowest; however, the benefit appears to be specific to colon cancer, not rectal cancer (102716). When subdivided according to gender, evidence from case-control research suggests that green tea is associated with a reduced risk of colon and rectal cancer for females (54096).
• Common cold. It is unclear if oral green tea is beneficial for the common cold. Details: Preliminary clinical research shows that taking two capsules of a specific formulation (ImmuneGuard, Nutraceutical Holdings LLC) containing L-theanine (Suntheanine, Taiyo International) plus epigallocatechin gallate (Sunphenon, Taiyo International) twice daily for 3 months reduces cold or flu symptoms and duration of symptoms when compared with placebo in healthy adults (53754).
• Crohn disease. Although there has been interest in using oral green tea for Crohn disease, there is insufficient reliable information about the clinical effects of green tea for this condition.
• Dementia. It is unclear if drinking green tea is beneficial for dementia prevention. Details: A meta-analysis of observational studies in over 20,000 adults suggests that the risk of any cognitive deficit (including mild cognitive impairment and dementia) is associated with a 6% reduction per cup of green tea consumed daily (107829). Some population research in elderly individuals suggests that drinking green tea at least once per week is associated with a 53% reduced incidence of dementia or mild cognitive impairment when compared to not consuming green tea (104598). Other population research in adults ages 40-74 years suggests that drinking at least 600 mL of green tea daily is not associated with a reduced risk of developing dementia when compared with drinking less than 60 mL daily. However, there is a modest reduction in dementia risk specifically in individuals ages 60-69 years (107164). A prospective, observational study suggests that consumption of tea, including both green and black tea, of at least 4 cups, in conjunction with 0.5-1 cups of coffee, daily is associated with a 30% reduced risk of dementia when compared with not drinking tea or coffee. Also, drinking 2-3 cups daily of both tea and coffee is associated with a 28% reduced risk of dementia when compared with not drinking tea and coffee (107204). Any association between drinking green tea specifically and developing dementia cannot be determined from this study.
• Dental plaque. It is unclear if oral or topical green tea is beneficial for reducing dental plaque. Details: A meta-analysis of clinical research shows that use of oral or topical products containing green tea modestly reduces dental plaque when compared with control products, including triclosan toothpaste, placebo, and chlorhexidine rinse. However, a sub-group analysis shows that a green tea rinse is no more effective than a chlorhexidine rinse. Green tea products in these studies included mouth rinse, paste, tea, capsules, and strips (107156). Many of these studies are limited by a lack of clear blinding. A more recent clinical study in children ages 10-14 years with plaque and gingivitis shows that using a mouthwash containing green tea extract 5% twice daily, alone or at half strength with ginger extract, for 30 days reduces plaque and gingivitis severity. The mouthwash containing the combination of green tea and ginger extract was most effective, and the green tea extract alone was at least as effective as chlorhexidine (107163).
• Depression. It is unclear if drinking green tea is beneficial for depression prevention. Details: Epidemiological research suggests that consuming green tea is associated with a reduced prevalence of depression and depressive symptoms. In Japanese adults, drinking four or more cups of green tea daily is associated with a 44% to 51% lower prevalence of mild to severe depression when compared to consuming one cup or less daily (90160,90163). A meta-analysis suggests that the highest green tea consumption is associated with a 34% reduced risk of depressive symptoms when compared with the lowest (111024). Other research in a general population of Chinese adults suggests that consuming at least 1 cup of green tea daily is associated with a 22% decreased risk of depressive symptoms over 2 years when compared with almost never consuming green tea. However, there is no association between depressive symptoms and less frequent green tea consumption in this population (111023).
• Diabetes. It is unclear if drinking green tea or taking green tea extract is beneficial for the prevention of diabetes or the improvement of glycemic control. Details: Epidemiological research has found that Japanese adults who consume 6 or more cups of green tea daily have a 33% lower risk of developing type 2 diabetes when compared to those who consume one cup or less daily. The risk reduction appears to be more pronounced in females when compared with males (14313). Also, epidemiological research has found that Chinese adults who consume at least one cup of green tea per week have a 59% to 77% lower risk of impaired fasting glucose when compared to those who consume less than one cup per week (90149). Other epidemiological research has found that consumption of any amount of green tea daily by Chinese adults is associated with an 8% reduced risk of developing type 2 diabetes when compared with never drinking green tea (107165). In contrast, some epidemiological research in Chinese adults has found that green tea consumption is associated with a 20% increased risk of developing type 2 diabetes when compared with non-green tea drinkers. A dose-response relationship was found for both the amount and duration of tea consumed (107170). Also, clinical research in patients with prediabetes shows that drinking one cup of green tea three times daily for 14 weeks does not improve fasting blood glucose or glycated hemoglobin (HbA1c) when compared to control (90174). There is inconsistent evidence regarding the effects of green tea in patients with type 2 diabetes. Epidemiological research suggests that drinking at least 4 cups of green tea daily is associated with a 40% reduction in mortality risk when compared to not drinking green tea (104589). Other epidemiological research in patients with type 2 diabetes has found that consumption of any amount of green tea daily is associated with a 10% reduction in mortality risk when compared to never drinking green tea. However, there was no association between green tea intake and the incidence of developing macrovascular or microvascular complications (107165). Meta-analyses of clinical research show that green tea extract and green tea catechins reduce fasting blood glucose when compared to control when patients with type 2 diabetes, borderline diabetes, or normal blood glucose status are evaluated together (90154,90187). However, a meta-analysis of up to 15 mainly small clinical trials involving patients with type 2 diabetes shows that taking green tea does not affect fasting blood glucose or insulin or improve insulin resistance or glucose control when compared with placebo. Most included studies used green tea or its extract in doses of 400-10,000 mg daily for 8-16 weeks (104604). Also, clinical research shows that taking green tea extract daily for up to 16 weeks does not improve blood glucose, HbA1c, or insulin when compared with placebo in patients with type 2 diabetes or borderline diabetes (37678,37781,54035). Some research has evaluated the effect of green tea on other outcomes in patients with type 2 diabetes. One meta-analysis shows that taking green tea extract modestly reduces fasting triglyceride levels when compared with control. This benefit was seen with doses of at least 800 mg daily taken for longer than 8 weeks. This dose and duration reduces levels of total cholesterol, but not low-density lipoprotein (LDL) or high-density lipoprotein (HDL) cholesterol levels (102715). Another meta-analysis shows that taking green tea modestly reduces body weight, body mass index (BM), and body fat. A sub-analysis shows that these benefits occur in studies lasting more than 8 weeks, using doses of up to 800 mg daily, and in patients who were overweight. There was no effect on waist circumference. Most patients included in the analysis were overweight or had obesity (104610).
• Diabetic neuropathy. It is unclear if oral green tea is beneficial for improving diabetic neuropathy symptoms. Details: Clinical research in patients with mild-to-moderate diabetic peripheral neuropathy shows that taking decaffeinated green tea extract 500 mg three times daily for 16 weeks modestly reduces neural pain and dysfunction, as well as overall symptom severity, when compared with placebo (107159).
• Down syndrome. It is unclear if oral green tea is able to alter facial morphology in children with Down syndrome.
• Down syndrome. There was no effect in children aged 4-18 years (107167). This study is limited by its observational design. The dosage, time of onset, and duration of treatment differed between individuals.
• Dry eye. It is unclear if oral green tea is beneficial for improving dry eye symptoms. Details: In patients with mild to moderate dry eye and meibomian gland dysfunction, preliminary clinical research shows that applying green tea extract into the eyes three times daily for one month, in addition to artificial tears three times daily, improves symptoms of dry eye. Symptoms of itching, burning, foreign body sensation, and redness were improved by a moderate amount over artificial tears alone (104612).
• Dysmenorrhea. It is unclear if drinking green tea is beneficial for preventing dysmenorrhea symptoms. Details: Population research has found that drinking green tea is associated with a 37% reduced odds of experiencing dysmenorrhea and a 58% reduced odds of having moderate-to-severe dysmenorrhea when compared with not drinking green tea (102729).
• Esophageal cancer. It is unclear if drinking green tea is beneficial for preventing esophageal cancer; the available research is conflicting. Details: Although some epidemiological evidence and observational studies have found that drinking green tea is associated with a reduced risk of esophageal cancer, most meta-analyses do not support this finding in a mixed group of adults (1457,36542,90169,90185,90186,102004,102716,107154). Meta-analyses of epidemiological studies suggest that drinking green tea is associated with a 54% reduction in the risk of esophageal cancer, or a 21% reduced odds per cup of green tea consumed daily, only in females (90169,90185,102004,107154). Also, some epidemiological research found that drinking green tea that is very hot is associated with an increased risk of esophageal cancer (53828). In addition, drinking decaffeinated green tea 5 mg daily for 12 months does not seem to be an effective treatment for patients diagnosed with esophageal precancerous lesions (53702).
• Fractures. It is unclear if drinking green tea reduces fracture risk. Details: Population research has found that consumption of green tea is associated with a 12% lower risk of any fracture and 20% lower risk of hip fracture when compared with no tea consumption (99800).
• Gastric cancer. Evidence evaluating an association between green tea consumption and gastric cancer risk is conflicting. Details: Most meta-analyses of epidemiological studies suggest that green tea consumption is not associated with gastric cancer risk (53767,53813,90181,102716). Although the most recent meta-analysis of epidemiological research suggests that drinking green tea regularly is associated with up to a 9% reduced risk of gastric cancer when compared with non-regular consumption, sub-analyses suggest that there is no association between gastric cancer and intake of specific amounts of green tea up to at least 3 cups daily (111025). Also, other population research suggests that drinking 10 or more cups of green tea daily is associated with a reduced risk of gastric cancer (8903,9222,9225,9226,9227), while consuming less than 10 cups daily is not consistently associated with a reduced risk (7033,9223,54090). The association between drinking green tea and gastric cancer-related mortality has also been investigated, A large-scale population study in Japan suggests that drinking 5 or more cups of green tea daily is not associated with a reduced risk of gastric cancer-related mortality when compared to drinking less than one cup daily (14498). Discrepancies might be related to the temperature of the green tea. The most recent meta-analysis suggests that intake of cold or warm green tea, and not hot green tea, is associated with a modest reduction in gastric cancer risk (111025).
• Gingivitis. It is unclear if oral or topical green tea is beneficial for gingivitis. Details: A meta-analysis of clinical research shows that use of oral or topical products containing green tea modestly reduces gingivitis and gingival bleeding when compared with control products, including triclosan toothpaste, placebo, and chlorhexidine rinse. However, a sub-group analysis shows that a green tea rinse is no more effective than a chlorhexidine rinse. Green tea products used in these studies were heterogeneous and included mouth rinse, gel, paste, tea, strips, and capsules (107156). Many of these studies are limited by a lack of clear blinding. A more recent clinical study in children ages 10-14 years with plaque and gingivitis shows that using a mouthwash containing green tea extract 5% twice daily, alone or at half-strength with ginger extract, for 30 days reduces plaque and gingivitis severity. The mouthwash containing the combination of green tea and ginger extract was most effective, and the green tea extract alone was at least as effective as chlorhexidine (107163).
• Headache. Although there has been interest in using oral green tea for headache, there is insufficient reliable information about the clinical effects of green tea for this condition.
• Hypertension. The evidence is mixed as to whether drinking green tea reduces the risk of hypertension and whether oral green tea lowers blood pressure in patients with hypertension. Details: Some epidemiological research from China shows that drinking 120-599 mL of green tea or oolong tea daily is associated with a 46% lower risk of developing hypertension when compared with non-habitual tea drinkers; drinking more than 600 mL daily is associated with a 65% reduced risk (12518). In contrast, drinking green tea daily is associated with a 38% increased odds of having hypertension when compared with never drinking green tea in elderly Chinese males, but not females (107166). Green tea may help lower blood pressure in patients with or without hypertension; however, the evidence is mixed, and any reductions appear to be small. A meta-analysis of two clinical trials in patients with hypertension shows that drinking green tea for 4-16 weeks reduces systolic, but not diastolic, blood pressure by about 6 mmHg (104583). Meta-analyses in patients with or without hypertension, including overweight or obese adults, suggest that green tea reduces systolic and diastolic blood pressure by 1-3 mmHg (90146,90155,90161,98423,102726,111018). Some studies used green tea, made by boiling a 3 gram tea bag with 150 mL water and then waiting for 5 minutes and consuming three times daily approximately 2 hours after each meal for 4 weeks (90159), or green tea extract up to 1500 mg daily for up to 12 weeks (111018), including a specific product (Olimp Labs) 379 mg, taken daily with the morning meal for 3 months (54068).
• Hypotension. It is unclear if oral green tea is beneficial for postprandial hypotension in elderly adults. Details: Some research shows that consuming caffeinated beverages increases blood pressure in elderly people with postprandial hypotension (11834,11835). Also, preliminary clinical research shows that drinking 400 mL of green tea before lunch increases postprandial systolic and diastolic blood pressure by 15 mmHg and 6 mmHg, respectively, in older elderly people with postprandial hypotension (89482).
• Infertility. Oral green tea has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in females with a history of problems conceiving shows that taking three capsules daily of a proprietary blend of Vitex agnus-castus extract (standardized to 0.5% agnusides), green tea extract (standardized to 50% phenols), L-arginine, vitamins E, B6, and B12, folate, iron, magnesium, zinc, and selenium (FertilityBlend, The Daily Wellness Company) for three menstrual cycles increases the rate of pregnancy at three months by 61% when compared with placebo (41479).
• Influenza. It is unclear if oral green tea is beneficial for preventing the flu. Details: A meta-analysis of five clinical trials in individuals with or without prior influenza vaccination shows that use of green tea catechins, either in capsule form or as a gargled liquid, reduces the rate of influenza infections by 33% when compared with control. Also, a meta-analysis of observational research has found that gargling with or consuming green tea containing catechins is associated with a 48% reduced risk of influenza when compared with not taking green tea catechins. More information is needed to compare the efficacy of the different forms of green tea catechins (107152). Some epidemiological research not included in this meta-analysis has found that drinking at least 5 cups of green tea weekly is associated with a 32% reduced odds of developing confirmed influenza when compared with drinking less than one cup weekly. A sub-group analysis suggests that this association is only evident in individuals who had not received the influenza vaccination (104608). Conversely, other preliminary research shows that gargling with green tea at least three times daily for 90 days does not prevent influenza in high school students when compared with water (90150). Green tea has also been evaluated in combination with theanine. One small study shows that taking a combination of green tea catechins (THEA-FLAN 90S, Ito-en Co) 378 mg standardized to 270 mg of epigallocatechin gallate (EGCG) with theanine 210 mg daily for 5 months reduces the risk of developing clinically defined influenza, but not laboratory-confirmed influenza infection, when compared with placebo (54021). Other preliminary clinical research in healthy adults shows that taking two capsules of a specific formulation (ImmuneGuard, Nutraceutical Holdings LLC) containing L-theanine (Suntheanine, Taiyo International) plus EGCG (Sunphenon, Taiyo International) twice daily for 3 months reduces the number of subjects with cold or flu symptoms and the number of days with symptoms when compared with placebo (53754).
• Japanese cedar pollinosis. It is unclear if oral green tea is beneficial for preventing Japanese cedar pollinosis symptoms. Details: In patients with Japanese cedar pollinosis, clinical research shows that drinking Benifuuki green tea drink 350 mL containing O-methylated catechin 34-40 mg daily beginning 6-10 weeks before pollen exposure until the end of pollen season can reduce nasal and ocular symptoms. Clinical research compared the "benifuuki" drink enriched in O-methylated EGCG with that of another green tea "yabukita," containing no O-methylated EGCG (53884,90156).
• Kidney stones (nephrolithiasis). It is unclear if drinking green tea prevents kidney stones. Details: Population research suggests that drinking green tea is associated with a reduced risk of having kidney stones. This risk was 22% lower in males and 16% lower in females when compared with never or former green tea drinkers (104613).
• Leukemia. It is unclear if drinking green tea is beneficial for leukemia prevention. Details: Although some large epidemiological studies suggest that drinking green tea reduces the risk of leukemia by 51% to 80% (53799,90183,102723), a meta-analysis of generally low-quality population research shows a variable association between green tea intake and risk of leukemia (102716).
• Liver cancer. It is unclear if drinking green tea is beneficial for liver cancer prevention. Details: Two meta-analyses of epidemiological research suggest that green tea consumption is associated with a reduced risk of liver cancer (97132,111016). The most recent meta-analysis in approximately 1.5 million adults in Asia, North America, and Europe suggests that the highest intake of green tea is associated with a 20% reduced risk of liver cancer when compared with the lowest. The most benefit was associated with consumption of at least 4 cups daily (111016). Another meta-analysis that included studies conducted in Japan, China, or Singapore suggests that higher green tea consumption is associated with a 12% reduced incidence of liver cancer when compared with the lowest consumption of green tea. However, the benefit appears to be limited to females; green tea consumption was not associated with a reduced risk of liver cancer in males (97132). A large epidemiological study in Chinese females also suggests that green tea consumption is associated with a reduced risk of liver cancer. Consuming a cumulative intake of 30 kg dried green tea leaves is associated with a 46% reduced risk of primary liver cancer over a median of 18 years when compared with never drinking green tea (111030). In contrast, some individual epidemiological studies suggest that green tea consumption is not associated with a reduced risk of liver cancer in Japanese individuals (90181,102716).
• Lung cancer. It is unclear if drinking green tea is beneficial for lung cancer prevention. Details: Individual observational studies and meta-analyses of population research have yielded conflicting evidence about the effects of green tea on lung cancer risk (13190,14498,53829,90177,102716). Although one meta-analysis of population research suggests that the highest intake of green tea does not reduce lung cancer risk when compared to the lowest intakes (102716), other analyses suggest that increasing green tea consumption by two cups daily is associated with an 18% decreased risk of lung cancer, and that drinking 7-10 cups of green tea daily is associated with an 18% to 33% reduced risk of lung cancer when compared with drinking less than one cup daily (53829,90177).
• Mental alertness. It is unclear if oral green tea is beneficial for mental alertness. Details: Green tea contains caffeine. Consumption of caffeinated beverages seems to prevent a decline in alertness and cognitive capacity when consumed throughout the day (4221,4224). Also, combining caffeine with glucose as an "energy drink" seems to improve mental performance better than placebo or either caffeine or glucose alone (13732). However, there is mixed evidence regarding the effects of green tea on mental alertness.
• Metabolic syndrome. It is unclear if oral green tea is beneficial for improving metabolic parameters in people with this condition. Details: Preliminary clinical research shows that taking green tea extract 1000 mg daily or drinking four cups of green tea daily for 8 weeks does not improve metabolic syndrome features, including waist circumference, blood pressure, cholesterol levels, or blood sugar in obese patients with metabolic syndrome when compared to control (53995).
• Multiple myeloma. It is unclear if drinking green tea is beneficial for multiple myeloma prevention. Details: Population research suggests that drinking at least 5 cups of green tea each day is not associated with a reduced risk of multiple myeloma when compared with never drinking green tea (102723).
• Myocardial infarction (MI). It is unclear if drinking green tea prevents MI or if drinking green tea prevents mortality in patients with a previous MI. Details: When compared with drinking less than one cup of green tea daily, epidemiological research in a population at high risk of coronary artery disease has found that drinking more than three cups of green tea daily is associated with a 49% reduced odds of having a past MI as determined by a coronary angiography. A sub-group analysis found that these odds only occurred in individuals consuming both fruits and vegetables more than four times weekly and not in individuals consuming fruits or vegetables less often (104588). In addition, observational research has found that drinking either 1-3 cups or at least 4 cups of green tea daily is associated with 19% and 32% lower odds of MI, respectively, when compared to drinking less than 1 cup daily (97134). In patients with a previous MI, drinking at least 7 cups of green tea daily is associated with a 53% reduced odds of all-cause mortality over a median of 18.5 years when compared with not drinking green tea (107160).
• Nasopharyngeal cancer. It is unclear if drinking green tea is beneficial for nasopharyngeal cancer prevention. Details: A meta-analysis of epidemiological research has found that the highest intake of green tea is associated with a 51% reduced risk of nasopharyngeal cancer when compared with the lowest intake (102716).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral green tea is beneficial for NAFLD. Details: Clinical research shows that drinking green tea 700 mL containing 1080 mg of catechins daily for 12 weeks does not affect body weight or body mass index (BMI), but does reduce body fat percentage from 34% to 32%, when compared with drinking either green tea 700 mL containing 200 mg of catechins or a control tea. Also, the liver-to-spleen attenuation ratio increased by 11% when compared with baseline (90168). Meta-analyses of four studies in patients with NAFLD show that taking green tea extract 500-1000 mg daily or green tea catechins 600 mg daily improves liver function tests when compared with placebo (98459,102720). One meta-analysis also shows that these doses improve BMI, total cholesterol, and low-density lipoprotein (LDL) cholesterol when compared with placebo (98459).
• Non-Hodgkin lymphoma. It is unclear if drinking green tea is beneficial for non-Hodgkin lymphoma prevention. Details: Population research has found that drinking at least 3.5 cups of green tea daily is not associated with a reduced risk of non-Hodgkin lymphoma when compared with never drinking or drinking less than 1 cup of green tea daily (102005,102723).
• Obesity. Evidence for the use of green tea products for weight loss is conflicting. The conflicting findings may be related to the caffeine and catechin content of the studied products, as well as the physical activity level of the individual. Details: Many clinical studies show that drinking green tea or taking green tea extract that contains caffeine (about 70-200 mg) and high levels of catechins (about 576-886 mg) daily for 12-24 weeks modestly improves weight loss when compared to control in overweight individuals or patients with obesity (8114,37725,53906,90184). A meta-analysis of 25 randomized clinical trials shows that taking green tea extract containing caffeine results in an additional weight loss of 1.8 kg when compared with a control group not taking green tea extract (102719). In addition, a meta-analysis of clinical trials shows that taking green tea reduces body weight by 0.4 kg in mainly overweight individuals with type 2 diabetes (104610). Some research also shows that drinking green tea or taking green tea extract containing high levels of catechins but no caffeine reduces weight and visceral fat in overweight individuals or patients with obesity when used for up to 12 weeks (53994,54039,90184). In these clinical trials, the following doses have been used: two capsules of green tea extract daily standardized to containing 870 mg of catechins (460 mg EGCG) or 4 cups of green tea daily standardized to contain 928 mg of catechins (440 mg EGCG) for 8 weeks (53994); a specific decaffeinated green tea extract (Sunphenon 90LB, Taiyo Kagaku Ltd.) 530 mg twice daily for 6 weeks (54039); catechin-enriched green tea beverages providing 234-886 mg of catechins once or twice daily for approximately 3 months (37705,53906,90184); a specific green tea extract (AR25, Exolise, Arkopharma), taken as four capsules standardized to contain 375 mg of catechins (epigallocatechin gallate 270 mg) in two divided doses daily for 12 weeks (8114). Some research has also shown weight loss benefits of multi-ingredient products or diets containing green tea. Multi-ingredient products have included an herbal mixture of garcinia extract 650 mg, green tea extract 100 mg, coffee extract 75 mg, and banaba extract 25 mg per tablet (IQP-GC-101, InQpharm Europe Ltd.) 30 minutes before meals twice daily for 12 weeks (90137) and a specific product (Sanavita Industry, Piracicaba) containing powdered green tea (40 mg of caffeine), orange pulp, vitamin C, zinc, and selenium, taken as 20 grams in two divided doses daily for 8 weeks (90134). Drinking green tea has also been used as part of a Mediterranean diet also including Wolffia globose (109888). However, many studies show conflicting results (37715,37753,54035,98419,98420,98422). Reasons for these inconsistent findings are not entirely clear, but may relate to the use of decaffeinated green tea products, the use of green tea products containing low catechin amounts, or the presence and type of concomitant exercise. Some research shows that green tea extract containing a lower catechin amount (491 mg daily) or decaffeinated green tea products do not improve weight loss when compared with placebo in patients with obesity (37753,54035,98419). One meta-analysis of 15 clinical studies including about 1240 patients with obesity shows that using green tea products that are decaffeinated does not improve body weight, body mass index, or waist circumference when compared with control, while green tea products containing catechins 576-714 mg daily and caffeine do improve these outcomes (16892). Taking green tea after weight loss does not seem to improve weight maintenance when compared with control (14428,54076). Other clinical research shows that green tea does not improve weight loss in individuals with obesity who are already participating in exercise, such as walking and interval sprinting (37715,98420). In contrast, another small clinical study shows that taking green tea 500 mg daily for 10 weeks while participating in HIIT improves weight, body fat percentage, triglycerides, and low-density lipoprotein (LDL) cholesterol levels when compared with either green tea or HIIT alone. However, it appears that the majority of these improvements are due to participation in HIIT (100201). There is also some limited research in children. One small clinical trial in obese children ages 6-16 years shows that taking green tea providing 576 mg catechins daily for 24 weeks modestly reduces waist circumference, as well as systolic blood pressure and low-density lipoprotein (LDL) cholesterol, when compared with taking green tea providing 75 mg catechins daily. However, there were no significant difference between groups for other anthropometric measures or cardiovascular risk factors (37743). Another clinical trial in obese females ages 6-10 years who were also given diet and exercise advice shows that taking decaffeinated green tea polyphenols 400 mg daily for 12 weeks modestly reduces fat mass, but does not affect other anthropometric measures, when compared with placebo. Also, taking green tea polyphenols modestly reduces ovary volume, but has no effect on other measures of early puberty, such as breast development, uterine volume, or levels of sex hormones (107162).
• Oral cancer. It is unclear if oral green tea is beneficial for oral cancer prevention. Details: Meta-analyses of epidemiological research suggest that the highest intake of green tea is associated with a 20% to 29% reduction in risk of oral cancer when compared with the lowest intake (90180,102716). Also, preliminary clinical research in patients with high-risk oral premalignant lesions shows that taking a green tea extract 500-1000 mg/m2 three times daily after meals for 12 weeks increases the rate of clinical and histological response when compared with placebo (53936).
• Oral leukoplakia. It is unclear if drinking green tea and concomitantly applying topical green tea to lesions is beneficial for oral leukoplakia. Details: Preliminary clinical research in patients with oral leukoplakia shows that drinking 3 grams of a mixed tea product containing green tea daily for 6 months, while also topically applying a 10% mixed tea product in the mouth three times daily, reduces oral lesion size by about 38%, compared with a 3% increase in those taking placebo. It is not clear if this effect is due to green tea, the other ingredients, or the combination (4213).
• Osteopenia. It is unclear if oral green tea is beneficial for preventing osteopenia. Details: Population research suggests that drinking green tea for 10 years is associated with increased bone mineral density (8116). Other population research suggests that drinking less than one cup of green tea daily is associated with an 81% to 85% increased odds of having osteopenia when compared with drinking green tea 1-3 times daily (111026). Preliminary clinical research in postmenopausal adults with osteopenia shows that taking capsules containing green tea polyphenols 500 mg (233 mg as epigallocatechin-3-gallate or EGCG) daily, possibly while practicing tai chi 60 minutes three times weekly, for 24 weeks improves serum markers of bone turnover and muscle strength when compared to baseline (54040). However, the results from this study are limited by a lack of control group and the fact that diagnostic measures of bone health, such as T-score or Z-score, were not assessed.
• Osteoporosis. It is unclear if oral green tea is beneficial for preventing osteoporosis. Details: Population research suggests that drinking green tea for 10 years is associated with increased bone mineral density (8116). Other population research suggests that drinking less than one cup of green tea daily is associated with up to a 91% increased odds of having osteoporosis when compared with drinking green tea 1-3 times daily (111026). More recent clinical research shows that taking decaffeinated green tea extract supplying approximately 1315 mg of catechins (843 mg as EGCG) daily does not improve bone mineral density, T-score, or Z-score in postmenopausal adults (98419).
• Overall mortality. Some population research suggests that drinking green tea may reduce the risk of overall mortality by a small amount. Details: A meta-analysis of population research in Japanese adults found that drinking at least 5 cups of green tea daily is associated with reduced risk of all-cause mortality when compared with drinking less than 1 cup daily (102002). Another meta-analysis of population research found that each one cup per day increase in green tea consumption is associated with a 3% reduced risk of all-cause mortality (102728). However, more recent population research has found that although drinking green tea is associated with reduced risk of all-cause mortality in patients with a previous MI and stroke, drinking as much as 7 cups of green tea daily is not associated with a reduced odds of all-cause mortality over a median of 18.5 years in individuals with no history of stroke or MI when compared with not drinking green tea (107160).
• Pancreatic cancer. It is unclear if drinking green tea is beneficial for pancreatic cancer prevention. Details: A meta-analysis of population research suggests that the highest intake of green tea is not associated with a reduced risk of pancreatic cancer when compared with the lowest intake (102716). However, one epidemiological study suggests that drinking green tea is associated with a reduced risk of pancreatic cancer (54096).
• Parkinson disease. Although consuming caffeinated beverages might reduce the risk of developing Parkinson disease, it is unclear if oral green tea prevents or improves symptoms in people with this condition. Details: There is some evidence from large-scale epidemiological studies that the incidence of Parkinson disease decreases with increased consumption of caffeinated beverages such as coffee, tea, and cola. For men, the effects seem to be dose related. Men consuming a total of 421-2716 mg of caffeine (approximately 5-33 cups of tea) from any source daily seem to have the greatest reduction in risk. However, there seems to be a significant reduction in risk even with consumption of as little as 124-208 mg caffeine daily (approximately one to three cups tea) (6022). In females, the effects do not seem to be dose related. Moderate consumption of approximately 1-4 cups daily seems to provide the most reduction in risk (1238). It is unclear if consuming green tea is more or less effective than other caffeinated beverages for reducing Parkinson disease risk.
• Periodontitis. It is unclear if oral or topical green tea is beneficial for improving oral health or improving periodontal disease. Details: Epidemiological research has found that intake of green tea is inversely associated with symptoms of periodontal disease, including probing depth, attachment loss, and bleeding on probing (53844). A small clinical trial shows that taking green tea extract 1.55% by weight in chewable candy for 28 days appears to reduce plaque accumulation and gingival inflammation (7594). A small clinical trial in patients with chronic periodontitis shows that applying a gel containing green tea extract 1 gram/100 mL into the periodontal pocket as an adjunct to scaling improves gingivitis, periodontal disease, and clinical attachment by 7%, 112%, and 116%, respectively, when compared with placebo gel (90135). A meta-analysis of low-quality clinical research also shows that use of oral or topical products containing green tea modestly improve clinical attachment when compared with control products, including triclosan toothpaste and placebo. Green tea products included gel, paste, and tea (107156).
• Pneumonia. It is unclear if drinking green tea is beneficial for pneumonia prevention. Details: Epidemiological research in Japanese females has found that consuming green tea is associated with a lower risk of death from pneumonia when compared to those who do not drink green tea (53897). However, other epidemiological research in hospitalized elderly Japanese adults has found that there is no association between green tea consumption during the past month and prevalence of pneumonia at time of hospitalization (107161).
• Polycystic ovary syndrome (PCOS). It is unclear if oral green tea is beneficial for PCOS. Details: A meta-analysis of 4 small clinical trials shows that taking green tea modestly reduces weight in patients with PCOS when compared with placebo. However, there was no effect on other endpoints including body mass index (BMI), percent body fat, or waist or hip circumference. Three studies in the meta-analysis used green tea 1000-2000 mg/daily in tablets or capsules; the other study used green tea powder providing epigallocatechin gallate 1620 mg daily (111019). However, the included studies were small and utilized heterogeneous dosing regimens.
• Postoperative pain. It is unclear if rinsing the mouth with green tea is beneficial for postoperative pain associated with molar removal. Details: In patients undergoing third molar extraction, a small clinical trial shows that using 15 mL of a mouthwash containing green tea extract 5 grams/100 mL twice daily, beginning the day after surgical removal of impacted molars and continuing for 7 days thereafter, reduces pain by 60% and analgesic use during the first three days when compared with using a mouthwash that does not contain green tea (90141).
• Prostate cancer. It is unclear if drinking green tea or taking green tea catechins by mouth is beneficial for prostate cancer treatment or prevention. Details: Green tea catechins have been evaluated for reducing prostate cancer risk in high-risk patients (14127,98421,102716). A meta-analysis of results from three clinical trials shows that taking green tea catechins 400-600 mg daily for 12-30 months reduces the risk of prostate cancer by approximately 62% when compared with placebo in high-risk patients (98421). However, another meta-analysis including two of these studies plus one additional does not show that taking green tea catechins reduces the incidence of prostate cancer in high-risk patients (102716). Most population research has found that drinking higher amounts of green tea is not associated with a reduced risk for prostate cancer when compared with those who never or rarely drink green tea (14128,54036,53741,53753,90153,90181,98421). However, one meta-analysis of population research found that people who drink very high amounts of green tea (7-15 cups daily) have a 19% to 44% reduced risk of prostate cancer (98421). Another population study found that higher green tea intake is associated with a reduced risk of advanced, but not overall, prostate cancer risk (53753). In April 2012, the US Food and Drug Administration (FDA) determined that it would allow a qualified health claim stating that consuming green tea may reduce the risk of prostate cancer, although the FDA has concluded that there is very little scientific evidence to support this claim (102106). Additionally, most clinical research shows that drinking large amounts of green tea or taking green tea extract does not reduce disease progression in patients with prostate cancer (11366,53726). Green tea and green tea catechins have also been evaluated for reducing prostate specific antigen (PSA) levels. A meta-analysis of clinical research in patients with or at risk of prostate cancer shows that taking green tea or green tea extract for 3 weeks to 12 months does not modify PSA levels when compared with water or placebo. However, sub-analyses suggest that there is significant heterogeneity with respect to findings between geographical locations, with some evidence of benefit in studies conducted in the US (107155).
• Radiation dermatitis. It is unclear if topical green tea is beneficial for preventing radiation dermatitis. Details: Preliminary clinical research in patients undergoing radiotherapy after breast cancer surgery shows that spraying epigallocatechin gallate (EGCG) over the radiation field prevents the development of at least moderate severity radiation dermatitis by 30% when compared with saline as placebo. Also, occurrence of symptoms was delayed by about 2.7 days and symptom severity was reduced. EGCG 660 mcmol/L was sprayed 3 times daily from the first day of radiation until 2 weeks after completion at 0.05 mL per squared cm (111031). The interpretation of these results is limited by the unbalanced treatment groups.
• Radiation-induced diarrhea. It is unclear if oral green tea is beneficial for reducing diarrhea associated with radiotherapy. Details: A small clinical trial shows that taking a green tea tablet (Camgreen, Iran Giahessence Pharmacy Co.) 450 mg daily for 5 weeks during pelvic irradiation reduces the frequency of diarrhea in patients undergoing radiotherapy treatment. In the fifth week of treatment, 19% of patients taking green tea had diarrhea, compared with approximately 62% of those taking placebo (104614).
• Radiation-induced nausea and vomiting. It is unclear if oral green tea is beneficial for reducing vomiting associated with radiotherapy. Details: A small clinical trial shows that taking a green tea tablet (Camgreen, Iran Giahessence Pharmacy Co.) 450 mg daily for 5 weeks during pelvic irradiation does not reduce the frequency of vomiting when compared with placebo in patients undergoing radiotherapy treatment (104614).
• Renal cell carcinoma. It is unclear if oral green tea is beneficial for preventing kidney cancer. Details: Epidemiological research suggests that green tea intake is not associated with risk of kidney cancer over a mean of 19 years in Japanese adults. However, in females, consuming at least 5 cups of green tea daily, but not lesser amounts, is associated with a 55% reduced risk of kidney cancer when compared with rare intake (111022).
• Skin cancer. Although there has been interest in using oral or topical green tea for skin cancer, there is insufficient reliable information about the clinical effects of green tea for this condition.
• Stress. It is unclear if oral green tea is beneficial for stress reduction. Details: Preliminary clinical research shows that taking a specific brand of green tea extract (Teavigo, DSM) 300 mg orally for 7 days reduces stress and increases calmness when compared with placebo in healthy individuals (54055).
• Stroke. It is unclear if consumption of green tea is associated with a reduced risk of stroke or with reduced all-cause mortality in patients with a previous stroke. Details: Large-scale population research in Japanese individuals suggests that consuming at least 3-5 cups of green tea daily is associated with a reduced risk of cerebrovascular mortality when compared with drinking less than 1 cup daily. This association appears to be primarily related to a decrease in risk for cerebral infarction or hemorrhage (14498,54080,102002). Other population research suggests that drinking 1-3 cups of green tea daily is associated with a 36% reduced odds of stroke when compared with drinking less than 1 cup daily, while drinking 4 or more cups daily has no effect. Also, green tea consumption was not associated with reduced incidence of cerebral hemorrhage or infarction in this study (97134). Meta-analyses of population research suggest that an increase of 1 cup per day in green tea consumption is associated with a 6% reduced risk of stroke or cerebral hemorrhage (102728,111021). A prospective, observational study also suggests that higher intake of tea, including green and black tea, of at least 2 cups daily is associated with a 16% reduced risk of stroke when compared with not drinking tea. This study also found that drinking 2-3 cups daily of each tea and coffee is associated with a 38% reduced risk of stroke when compared with not drinking tea and coffee. The combination of 0.5-1 cups of coffee and 2-3 cups of tea daily, but not tea alone, was associated with a 50% reduced risk of post-stroke dementia when compared with not drinking tea and coffee (107204). In patients with a previous stroke, drinking at least 3 cups of green tea daily is associated with a 48% to 62% reduced odds of all-cause mortality over a median of 18.5 years when compared with not drinking green tea (107160).
• Sunburn. It is unclear if oral or topical green tea is beneficial for preventing ultraviolet radiation-induced erythema. Details: A meta-analysis of three small clinical trials shows that taking green tea catechins 540-1402 mg daily for 6 to 12 weeks has a small to moderate protective effect against ultraviolet radiation-induced erythema when compared with placebo, especially at lower doses of ultraviolet radiation. A single topical dose of green tea ingredients may also be beneficial, but data is limited (107153).
• Systemic lupus erythematosus (SLE). It is unclear if oral green tea is beneficial for SLE. Details: Preliminary clinical research shows that taking green tea extract 500 mg (containing 22% polyphenols) twice daily for 3 months modestly improves disease activity, general health, and vitality when compared with placebo (97136).
• Tinea pedis. It is unclear if a topical green tea footbath is beneficial for athlete's foot. Details: In bedridden, elderly patients with cognitive deficiency, use of a footbath containing a 0.1% green tea extract for 15 minutes once daily for 12 weeks does not improve symptoms of athlete's foot, but does improve skin condition, when compared with a footbath not containing green tea. The green tea extract Sunphenon BG-3 (Taiyo Kagaku Co. Ltd., Yokkaichi), prepared by dissolving 5 grams of the Sunphenon BG-3 product in 5 liters of water to create a 0.1% green tea solution, was used (90151).
• Ulcerative colitis. It is unclear if oral green tea is beneficial for ulcerative colitis. Details: Preliminary clinical research in patients with mild to moderate ulcerative colitis shows that taking a specific green tea product (Polyphenon E, Mitsui-Norin) 200 mg or 400 mg twice daily for 8 weeks may increase the number of people who respond to therapy and achieve remission when compared with placebo. After treatment, 10 of 15 patients in the green tea extract group responded to therapy and 8 of 15 patients achieved remission, compared with 0 in the placebo group (90140).
• Upper respiratory tract infection (URTI). It is unclear if gargling and swallowing green tea is beneficial for reducing URTI symptoms. Details: Preliminary clinical research shows that gargling and swallowing green tea (Morgentau, Ronnefeld KG) 100 mL daily over 4 days is less effective than proprietary labdanum lozenges (CYSTUS052, Dr Pandalis Urheimische Medizin GmbH & Co.) for upper respiratory tract symptoms in patients with URTIs (53867).
• Urinary tract infections (UTIs). It is unclear if oral green tea is beneficial for reducing UTI symptoms. Details: A small clinical study in females with acute uncomplicated cystitis shows that adding green tea 2000 mg daily for 3 days to treatment with trimethoprim-sulfamethoxazole reduces symptoms of cystitis when compared with placebo (99799). This study is limited by its small size and the lack of information on antibiotic resistance in each treatment group.
• Wrinkled skin. It is unclear if oral or topical green tea is beneficial for wrinkles. Details: Some preliminary clinical research shows that taking green tea catechins 175 mg twice daily for two years does not reduce signs of photo-aging of the skin in females with facial photo-aging when compared with placebo (53873). However, using a combination of topical green tea 10% cream and oral green tea extract 300 mg twice daily for 8 weeks seems to improve skin elasticity in females with moderate photo-aging based on microscopic analysis, although the clinical appearance of the skin does not seem to significantly improve (53731). Other preliminary clinical research shows that consuming one liter of a beverage with green tea polyphenols for 12 weeks improves skin elasticity, roughness, and hydration in middle-aged females when compared with placebo (54030). More evidence is needed to rate green tea for these uses.

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INSUFFICIENT RELIABLE EVIDENCE to RATE

• Atopic dermatitis (eczema). It is unclear if oral hemp seed oil is beneficial in patients with eczema. Details: A small preliminary clinical trial in patients with eczema shows that taking hemp seed oil 30 mL daily for 8 weeks improves skin dryness, itchiness, and use of dermal medication when compared with baseline, but not when compared with an olive oil control (101125).
• Constipation. Oral hemp seed has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in patients with functional constipation shows that taking a proprietary Chinese herbal medicine (Hemp Seed Pill) containing hemp seed, rhubarb root, peony root, apricot kernel, bitter orange fruit, and magnolia bark twice daily for 8 weeks results in a response rate to 43%, compared with 8% in those taking placebo. The response rate was defined as an increase of at least 1 complete spontaneous bowel movement per week. This combination product also improved the responder rate in the 2 weeks after treatment, as well as the overall use of rescue therapy, when compared with placebo (101127). Data from this study pooled with data from another larger study in adults with functional constipation shows that this same product increases the likelihood of complete response, defined as at least 3 complete spontaneous bowel movements per week or an increase over baseline of at least 1 weekly, by 1.43 times when compared with placebo. Complete spontaneous bowel movements per week also increased by 1 when compared with placebo (107319). It is unclear if these effects are due to hemp seed, other ingredients, or the combination.
• Dysmenorrhea. Although there is interest in using oral hemp for dysmenorrhea, there is insufficient reliable information about the clinical effects of oral hemp for this condition.
• Familial hypercholesterolemia. It is unclear if oral hemp seed oil is beneficial in children with this condition. Details: A small preliminary clinical trial shows that taking hemp seed oil (AlfaLife, Freia Farmaceutici Srl) 3 grams daily for 8 weeks does not improve levels of total or low-density lipoprotein (LDL) cholesterol when compared with no treatment in hyperlipidemic children aged 6-16 years who are also following a low-fat diet with high fruit and vegetable intake (101144).
• Joint pain. Although there is interest in using oral hemp for joint pain, there is insufficient reliable information about the clinical effects of oral hemp for this condition.
• Multiple sclerosis (MS). Oral hemp seed has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with relapsing-remitting MS shows that taking a combination of hemp seed oil 5.4-6.3 grams and evening primrose oil three times daily for 6 months seems to improve disability scores and relapse rate when compared to baseline. However, the control group in this study ingested olive oil and also experienced notable improvements in disability and relapse rates (88183). This study is limited due to high dropout rate and because there was no statistical comparison between treatment and control groups.
• Obesity. It is unclear if an oral cannabidiol-rich hemp oil extract helps to improve weight loss. Details: A small clinical study in healthy overweight adults shows that taking a specific hemp oil extract (PlusCBD Extra Strength Hemp Extract, CV Sciences) as 60 mg, providing 15 mg cannabidiol, daily for 6 weeks, does not reduce weight or body mass index when compared with placebo (103805). The validity of this study is limited due to its exploratory nature and lack of control for voluntary dietary changes.
• Osteoarthritis. It is unclear if oral hemp seed is beneficial in patients with osteoarthritis. Details: A clinical study in 18 older adults with osteoarthritis undergoing in-hospital rehabilitation following knee or hip arthroplasty shows that consuming pasta enriched with hemp seed flour for 6 weeks improves pain scores by about 3 points, compared with only 1 point in those consuming a regular pasta control (107320).
• Psychological well-being. Although there is interest in using oral hemp for psychological well-being, there is insufficient reliable information about the clinical effects of oral hemp for this condition. More evidence is needed to rate hemp for these uses.

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EFFECTIVE

• Anemia of chronic disease. Oral and intravenous iron in combination with erythropoiesis-stimulating agents (ESAs) are effective for treating anemia of chronic disease. Details: Iron supplementation with ESAs is effective for treating anemia associated with chronic kidney disease (CKD) or chemotherapy. During therapy with ESAs, iron levels should be monitored and supplementation provided as needed to ensure that the response is not limited by lack of iron for erythropoiesis (1087,1091,20110,20111,110192). Research shows that intravenous iron appears to be more effective than oral supplements for this purpose (20112,20113). In patients with CKD, intravenous iron at total doses from 2232 mg over 6 months to 1020 mg over one week increases hemoglobin levels more than oral doses of 4-6 mg/kg daily or 325 mg daily for up to 6 months (20112). Some research has evaluated the effect of intravenous or oral iron in patients not treated with ESAs. In patients with cancer or CKD, oral iron supplements have been shown to improve iron status (110184,110192). However, overall benefits of iron alone remain unclear in treated or untreated patients with cancer and more research is needed to rule out an increase in mortality and to determine any effect on blood transfusion requirements (110192). Preliminary clinical research shows that children aged 6 months to 10 years with HIV and anemia who take elemental iron 3 mg/kg daily along with a multivitamin for 3 months have a 41% lower chance of having persistent anemia at 3 months when compared with multivitamins alone (95432).
• Iron deficiency anemia. Oral and intravenous iron are effective for treating or preventing iron deficiency anemia. The benefits of iron supplementation in people with iron deficiency without anemia are unclear. Details: Oral iron supplements, mainly as ferrous sulfate, are effective for treating and preventing iron deficiency anemia in adults, children, and infants (1089,7135,17495,17496,17497,103806,20114,20115,91183,96621)(104680,104681,112601). Other forms are also effective, including sodium iron ethylenediaminetetra-acetate (NaFeEDTA), iron(III)-hydroxide polymaltose complex (IPC), iron protein succinylate, iron bisglycinate, and lactoferrin with iron (20117,20118,110189). Treatment with iron supplements should increase hemoglobin levels by 1 gram/dL every 2-3 weeks. However, even after hemoglobin has normalized, it may take up to 4 months for iron stores to be replenished (17497). Historically, treatment of iron deficiency anemia with oral iron supplements has typically consisted of a daily dosing regimen, often taken in divided doses to reduce adverse effects. In more recent years, however, intermittent iron supplementation (1-3 doses/week) has become preferred for some patients, particularly those with mild anemia, due to better absorption and a possible reduction in side effects compared to daily dosing. One small clinical study shows that taking ferrous sulfate 60 mg on alternate days in single doses improves iron absorption when compared to once daily dosing (96630). Another small clinical study in females with iron-deficiency anemia shows that fractional iron absorption is 40% to 50% higher with alternate-day dosing compared with daily dosing. Furthermore, total iron absorption was shown to be similar for alternate day dosing of elemental iron 200 mg compared with daily dosing of 100 mg, but the incidence of gastrointestinal adverse effects may be lower for the alternate day dosing regimen (101514). A meta-analysis of 25 clinical trials, including 10,996 menstruating females with or without pre-existing iron deficiency and/or anemia, shows that intermittent iron reduces the risk of anemia and increases hemoglobin and serum ferritin when compared with placebo or no intervention. This meta-analysis did not identify differences in the risk of anemia, hemoglobin, or serum ferritin between intermittent and daily iron supplementation. However, it did show that females receiving intermittent dosing had a 59% reduction in the risk for adverse effects. The validity of these findings is limited by significant heterogeneity in the enrolled populations and selected dosing strategies, including frequency of intermittent dosing, total weekly dose, and duration of follow-up. In addition, the subgroup analyses performed by baseline anemia, hemoglobin, and serum ferritin, as well as duration of follow-up, showed differing overall conclusions when comparing intermittent and daily iron supplementation. While intermittent dosing appears to be beneficial when compared with daily dosing for some patients with iron deficiency anemia, intermittent dosing may be less effective than daily iron supplementation in some patients (103806). For patients with severe anemia, twice daily dosing may be preferred to alternate day dosing due to faster response. A small clinical study in patients with iron deficiency anemia shows that taking ferrous sulfate 200 mg twice daily is more effective at increasing hemoglobin levels by 3 weeks when compared with ferrous sulfate 400 mg taken on alternate days in single doses (102864). Intermittent iron supplementation has also been investigated in children. A meta-analysis of clinical research in children and adolescents with or without pre-existing iron deficiency and/or anemia shows that taking iron supplements 1-2 times weekly is similarly effective as 3-7 times weekly for decreasing iron deficiency and iron deficiency anemia. However, ferritin and hemoglobin levels increased to a greater extent with 3-7 times weekly supplementation (112601). Blood transfusion may be required for some patients with severe iron deficiency anemia who have symptoms such as dyspnea and fatigue (17497). Intravenous iron should be considered in patients who cannot tolerate oral iron or in patients with chronic bleeding or intestinal malabsorption (17497). Guidelines from the British Society of Gastroenterology recommend treatment with iron while awaiting investigations to rule out gastrointestinal issues in adults in the absence of an alternative explanation. The guidelines recommend ferrous sulfate, fumarate, or gluconate as one tablet daily. If adverse effects occur, intake can be reduced to once every other day, or alternative oral or parenteral sources of iron can be used. Parenteral sources should be used if oral sources are contraindicated or ineffective. Treatment should be monitored and continued after hemoglobin levels are normalized (110193). Iron supplementation may also be beneficial in patients with iron deficiency without anemia, which can cause fatigue and reduced well-being, although guidelines are lacking. A meta-analysis of randomized controlled trials in adults with iron deficiency but not anemia shows that supplemental iron improves iron stores and hemoglobin levels. In addition, iron moderately reduces self-reported fatigue, but not physical capacity, when compared with placebo. Oral ferrous sulfate was used in most studies included in the analysis; however, intravenous or intramuscular iron were also used (104684).
• Pregnancy-related iron deficiency. Oral iron is effective for preventing pregnancy-related iron deficiency. Details: Clinical research shows that taking iron orally at an average daily dose of 20-225 mg of elemental iron increases maternal hemoglobin levels by up to 1 gram/dL when compared with placebo and reduces the risk of maternal anemia by 62% to 100% (20122,20123,20124,110180,110188). Some clinicians may recommend alternating days of iron administration to reduce gastrointestinal adverse effects. A pooled analysis shows that taking iron supplements on alternating days during pregnancy maintains adequate iron intake and reduces gastrointestinal adverse effects when compared with taking iron daily (96625). Various forms of oral iron seem to be equally effective for raising hemoglobin levels (110185,110188). However, in patients with anemia during pregnancy, a meta-analysis of clinical research shows that intravenous iron sucrose and ferric carboxymaltose were more effective than oral ferrous sulfate for improving hemoglobin levels (110185).

POSSIBLY EFFECTIVE

• Breath-holding attacks. Oral iron seems to be effective for reducing the frequency of breath-holding attacks in children with iron deficiency. Details: The incidence of breath-holding attacks is increased in children with iron deficiency or iron deficiency anemia. Most research shows that oral supplementation with ferrous sulfate 3-6 mg/kg daily for 4-16 weeks reduces the frequency of breath-holding attacks in children aged 1-72 months (20128,104682,104683). The best evidence comes from a meta-analysis of one randomized controlled trial and 11 observational single arm studies (104682). In this analysis, approximately 84% of children experienced at least a 50% decreased frequency of breath-holding attacks (104682). Some preliminary clinical research also shows that administering intramuscular iron reduces the frequency of breath-holding attacks and increases remission in children with iron deficiency anemia (20128).
• Cognitive function. Oral iron seems to be effective for improving cognitive function in children and adolescents with iron deficiency. Details: Taking iron orally seems to improve cognitive function in iron-deficient children and adolescents (20121,112600). For example, ferrous sulfate 650 mg twice daily for 8 weeks improved verbal learning and memory in non-anemic iron-deficient adolescent females (1095). Ferrous sulfate 50 mg twice weekly for 16 weeks appeared to improve attention measures in adolescent females with possible anemia (91186). Iron also appears to reverse developmental and learning deficits caused by iron-deficiency in anemic infants (1104). Some clinical research is focused on children and adolescents from low- and middle-income countries. In children aged 5-19 years with or without iron-deficiency anemia, a meta-analysis of clinical research shows that iron supplementation for 3-8 months dose-dependently improves measured intelligence by a modest amount. However, there was no effect on other measures of cognition, including attention or memory (110181). Another meta-analysis of clinical research in school age children shows that taking iron for 2-12 months modestly improves intelligence, attention, and memory, but not educational achievement, when compared with placebo or no intervention. However, sub-analyses show that any benefits are limited to children with anemia (112600).
• Heart failure. Intravenous iron seems to be effective for improving recovery in patients with heart failure and iron deficiency. It is unclear if oral iron is effective. Details: Iron deficiency is common in patients with heart failure (17499,112597,112598,112599). Individual clinical trials and meta-analyses of clinical research in patients with heart failure show that administering intravenous iron, as ferric carboxymaltose, iron dextran, iron isomaltoside, or iron sucrose, for at least 12 weeks modestly improves quality of life, increases exercise capacity, and reduces hospitalizations when compared with placebo or standard care. However, there was no effect on all-cause mortality or cardiovascular mortality (17498,91179,110176,110187,112597,112598,112599). Some individual clinical trials have used intravenous ferric carboxymaltose 200 mg or iron sucrose 200 mg in patients with mild or moderate heart failure and iron deficiency (17498,91179). Guidelines from the British Society of Gastroenterology suggest that treatment with parenteral iron improves symptoms and quality of life in patients with functional iron deficiency related to CHF (110193). Limited research has investigated the effect of oral iron in this population. A small meta-analysis of clinical research shows with low certainty that taking iron orally has beneficial effects on serum ferritin and left ventricular ejection fraction (110178). Most research shows that taking oral iron does not improve hemoglobin levels, quality of life, or exercise capacity when compared with placebo (100970,110178). However, one small clinical trial shows that taking oral iron modestly improves iron status and overall symptoms and increases the 6-minute walking distance by about 46 meters, compared with a reduction of only 14 meters in those taking placebo (110183). Some doses used in individual clinical studies have included iron polysaccharide 150 mg twice daily for 16 weeks and ferrous sulfate 200 mg three times daily for 12 weeks (100970,110183).
• Restless legs syndrome (RLS). Oral and intravenous iron seem to be beneficial for RLS. The American Academy of Neurology recommends a combination of oral ferrous sulfate and vitamin C or intravenous ferric carboxymaltose for patients with RLS. Details: RLS is commonly associated with iron deficiency anemia. Some clinical research shows that taking iron in the form of ferrous sulfate 325 mg twice daily for 12 weeks reduces RLS symptoms comparably to pramipexole. Symptoms such as leg discomfort, need to move, and sleep disturbances improved considerably in about half of the patients taking either treatment (91181). Additional clinical research shows that taking ferrous sulfate 325 mg twice daily along with vitamin C 100 mg twice daily for 12 weeks reduces symptoms of RLS when compared with vitamin C alone in patients with RLS and low-normal serum ferritin levels (94189). Based on these results, clinical practice guidelines by the American Academy of Neurology report that taking this combination of oral ferrous sulfate and vitamin C is likely to improve symptoms in patients with RLS and low-normal serum ferritin (93587). Intravenous iron may also reduce symptoms of RLS. Clinical practice guidelines by the American Academy of Neurology report that two doses of intravenous ferric carboxymaltose 500 mg given 5 days apart are likely to improve symptoms and quality of life within 28 days in patients with moderate to severe RLS, regardless of serum ferritin levels. Intravenous iron sucrose has also been evaluated in patients with RLS, but there is currently insufficient available evidence to support or refute the use of this form of iron for treating RLS (93587).

POSSIBLY INEFFECTIVE

• Athletic performance. Oral iron does not seem to improve athletic performance. Details: A meta-analysis of clinical research in adults of childbearing age shows that iron supplementation improves some exercise performance measures, such as maximal oxygen uptake capacity, but not others, such as time until exhaustion and energy consumption, when compared with control (91184). Another meta-analysis of clinical research in patients with iron deficiency without anemia shows that iron supplementation improves subjective measures of fatigue, but does not improve exercise time to exhaustion or other measures of physical capacity (104684). A small clinical study in healthy children shows that taking iron supplements or consuming food providing iron 30-200 mg daily for 1-2 months improves running performance when compared with placebo. This was demonstrated by reductions of heart rate of 6.6 to 8 beats per minute during the running exercise. One preliminary study included in this analysis also showed that iron supplementation improved treadmill endurance time (20140).
• Child growth. Oral iron does not seem to be beneficial for child growth. Details: Meta-analyses of mainly preliminary clinical research show that oral iron supplementation, at doses averaging 2-80 mg or 1-10 mg/kg elemental iron daily for up to 52 weeks, does not increase growth rate in children (20131,20132,20133,95434).
• Preterm labor. Oral iron does not seem to prevent preterm labor and may actually increase the risk in malaria-endemic regions. Details: A meta-analysis of results from five clinical studies shows that maternal intake of iron as ferrous sulfate 20-60 mg daily for 14-26 weeks starting in the second trimester of pregnancy does not affect the length of gestation or increase birthweight of the infant (95434). In females from a malaria-endemic area who have never been pregnant before, another clinical study shows that taking ferrous gluconate 60 mg and folic acid 2.8 mg weekly, starting before conception and continuing to the first antenatal visit, may more than double the risk of preterm birth, defined as a delivery under 37 weeks gestation, when compared with folic acid alone (100969). Some research suggests that the adverse outcome in this latter study may be explained by a rise in hepcidin levels in pregnant patients with malaria. Hepcidin is a hormone that regulates iron absorption and distribution, and malaria can upregulate hepcidin. High levels of hepcidin can decrease iron absorption, stimulate inflammatory processes, and cause progesterone withdrawal, leading to preterm labor (102863).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• ACE inhibitor-induced cough. It is unclear if oral iron is beneficial in patients with this condition. Details: A small clinical trial shows that taking ferrous sulfate 256 mg daily reduces or eliminates cough induced by ACE inhibitors such as captopril (Capoten), enalapril (Vasotec), lisinopril (Prinivil, Zestril), and others, when compared with placebo (7307).
• Androgenic alopecia. Oral iron has only been evaluated in combination with other ingredients, its effect when used alone is unclear. Details: A moderate-sized clinical study in adults with androgenic alopecia or telogen effluvium shows that taking one tablet daily of a specific product (GFM Oral, Cantabria Labs), providing an unknown dose of iron in combination with selenium, taurine, cysteine, methionine, and hydrolyzed collagen, along with conventional therapy, consisting primarily of finasteride or minoxidil, for 12 weeks improves hair loss when compared with conventional therapy alone (111636). It is unclear if this effect is due to iron, other ingredients, or the combination.
• Attention deficit-hyperactivity disorder (ADHD). It is unclear if oral iron is beneficial in children with ADHD. Details: Three small clinical studies in children with ADHD and iron deficiency shows that taking oral iron improves some measures of ADHD after 1-3 months of treatment when compared with baseline or placebo. These studies used ferrous sulfate 5 mg/kg daily, ferrous sulfate 80 mg daily, ferrous fumarate 200 mg daily for children weighing up to 30 kg, or ferrous fumarate 400 mg daily for children weighing more than 30 kg (1093,16013,110191).
• Child development. It is unclear if oral iron is beneficial for improving development in non-anemic children. Details: Some observational research has found that iron deficiency in infancy is associated with poor verbal performance and social skills in childhood (102862). It is unknown whether iron supplementation can ameliorate these developmental issues. In non-anemic infants and children, preliminary clinical research shows that iron does not improve cognitive performance; the evidence for the benefits of iron on psychomotor development is conflicting (20129,20130,91315,96616,96626).
• Esophageal cancer. It is unclear if oral iron is beneficial for esophageal cancer prevention. Details: Population research has found that taking iron supplements is associated with a 32% lower risk of esophageal adenocarcinoma when compared to never taking iron supplements. However, use of iron supplements is not associated with a lower risk of esophageal squamous cell carcinoma (95435).
• Fatigue. It is unclear if oral iron is beneficial in patients with fatigue due to iron deficiency without anemia. Details: A meta-analysis of mainly preliminary clinical research in adults with iron deficiency without anemia shows that iron reduces self-reported fatigue moderately more than placebo (104684). A specific ferrous sulfate supplement (Tardyferon; Pierre Fabre Médicament) providing 80 mg of elemental iron daily for 4-12 weeks was used in two studies included in this analysis (11406,91188).
• Inflammatory bowel disease (IBD). In patients with active IBD, intravenous iron may be more beneficial than oral iron due to impaired absorption. However, it may also increase the risk of infection in these patients. Details: Since the absorption of oral iron may be impaired in patients with active symptoms of IBD, guidelines from the British Society of Gastroenterology suggest that treatment with parenteral iron may be needed in patients with IBD who have moderate to severe iron-deficiency anemia (110193). However, a meta-analysis of clinical research in this population shows that administering IV iron, usually as iron sucrose or ferric carboxymaltose, increases the risk of infection by 73% when compared with oral iron or no iron (110186).
• Postoperative recovery. It is unclear if intravenous iron is beneficial for recovery following cardiac surgery. Details: A meta-analysis of low- to moderate-quality clinical research in patients with preoperative iron-deficiency anemia shows that treatment with intravenous iron before cardiac surgery does not improve the rate of transfusions or the length of stay in the intensive care unit or hospital when compared with control groups, including placebo, oral iron, or no treatment. Also, a meta-analysis of clinical research shows that intravenous iron does not reduce postoperative mortality rates (110182).
• Postpartum depression. Although there has been interest in using iron for postpartum depression, there is insufficient reliable information about the clinical effects of iron for this condition.
• Prematurity. Enteral iron seems to be beneficial for some measures of development in preterm infants. Details: A meta-analysis of clinical research in preterm or low birthweight infants fed human milk shows that enteral iron supplementation increases linear growth and reduces the risk of anemia when compared with control groups receiving no iron supplementation. However, there was no effect on serum ferritin, weight, head circumference, cognitive development, risk of infection, or risk of necrotising enterocolitis (110177). Additional clinical research in infants born at 24-28 weeks' gestation shows that a higher average enteral iron dose by 60 days of age is positively associated with cognitive performance at 2 years of corrected age. However, this association was not present for iron doses received at 90 days of age (110190). More evidence is needed to rate iron for these uses.

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EFFECTIVE

• Lactose intolerance. Lactase is effective for reducing gastrointestinal symptoms from consuming lactose in lactose intolerant individuals. Details: Multiple clinical trials show that taking lactase orally is effective for reducing GI symptoms in lactose-intolerant people when used before the consumption of lactose or when added to milk prior to consumption (2371,2372,2373,106669).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Colic. It is unclear if oral lactase is beneficial in infants with colic. Details: Preliminary clinical research in infants with colic shows that supplementing human milk or formula with lactase (Crosscare Ltd) for 10 days reduces breath hydrogen levels, but not time spent crying, when compared with placebo. However, approximately 30% of infants in this study were considered to be noncompliant. When only infants considered to be compliant were included in the analysis, time spent crying during the 10-day treatment period was reduced by about 6 hours in the lactase group when compared with placebo (96347). In two other small trials, giving 5 drops of a specific lactase formulation (Colibid, RG Pharmaceutica or Yamoo, Walter Bushnell) to infants aged 0-6 months with colic before each feed, or 4 times a day, for 2-4 weeks significantly reduces crying time and fussing time when compared with placebo (104107,112190). However, measures of crying time were based on subjective parent recall only.
• Prematurity. It is unclear if oral lactase is beneficial in premature patients. Details: Clinical research shows that giving fortified human milk or preterm formula treated with lactase drops (Lactaid, McNeil Consumer Products Company) to preterm infants does not improve weight gain, feeding tolerance, weekly length gain, or gain in head circumference by 36 weeks' gestational age or discharge from the hospital (whichever comes first) when compared with giving untreated milk or formula (96346). More evidence is needed to rate lactase for these uses.

(Read more about LACTASE)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Antibiotic-associated diarrhea. Oral Lacticaseibacillus casei has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking a specific L. casei-containing combination product (Bio-K+ CI1285) may be beneficial for preventing antibiotic-associated diarrhea. This combination product provides L. casei LBC80R, Lactobacillus acidophilus CL1285 and Lacticaseibacillus rhamnosus CLR2 as 100 billion colony-forming units (CFUs) daily (25494,95402,95403) However, taking L. casei might not help with the treatment of antibiotic-associated diarrhea. Clinical research in hospitalized patients with antibiotic-associated diarrhea shows that taking a combination of L. casei 20 million CFUs and Bifidobacterium breve 50 million CFUs 3 times daily does not reduce the average duration of diarrhea, the frequency of healing, or relapse rates, when compared with taking placebo (111006).
• Atopic dermatitis (eczema). Oral Lacticaseibacillus casei has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In children under two years of age with atopic dermatitis who are on a cow's milk protein elimination diet, clinical research shows that taking a specific mixture (Latopic, Biomed S.A.) providing 1 billion colony-forming units (CFUs) of L. casei ôOCK 0919 50%, Lacticaseibacillus rhamnosus ŁOCK 0900 25%, and L. rhamnosus ôOCK 0908 25% for 3 months increases the odds of a 30% or greater improvement in symptom scores by about 2.6-fold when compared with placebo. However, there was no difference in the absolute symptom scores between groups. Beneficial effects of this combination were greater in children confirmed to have allergen sensitization (107510). Other clinical research in children ages 4-17 years shows that taking 1 billion CFUs of a 1:1:1 combination of L. casei CECT 9104, Bifidobacterium lactis CECT 8145, and Bifidobacterium longum CECT 7347 for 12 weeks modestly reduces symptom severity and the need for topical corticosteroids when compared with placebo (107531).
• Cancer. Although there has been interest in using oral Lacticaseibacillus casei for cancer prevention or treatment, there is insufficient reliable information about the clinical effects of L. casei for this condition.
• Clostridioides difficile infection. Some early research suggests that oral Lacticaseibacillus casei may be beneficial for preventing a first C. difficile infection. However, the quality of evidence is generally poor, and taking oral L. casei does not seem to be beneficial for the prevention of C. difficile recurrence. Details: Evidence from clinical and observational research investigating the effect of L. casei on C. difficile occurrence or recurrence is weak. Most studies use this species in combination with one or more additional probiotic species, including a specific product (Bio-K+ Cl1285) providing L. casei LBC80R and Lactobacillus acidophilus CL1285 and a specific product (Bio-K+ 50 Billion; Bio-K Plus International) providing L. casei LBC80R, L. acidophilus CL1285, and Lacticaseibacillus rhamnosus CLR2 as 50 or 100 billion CFUs daily (25494,90231,90934,95369,95403,107529). Observational research has found that providing a specific combination (Bio-K+ 50 Billion; Bio-K Plus International) of L. casei LBC80R, L. rhamnosus CLR2, and L. acidophilus CL1285 as 50-100 billion colony-forming units (CFUs) daily for 5 days to patients who are on antibiotics for at least 2 days reduces the hospital-wide incidence of C. difficile by approximately 40%. The incidence rate was decreased by at least 50% in the highest risk individuals taking this combination (107529). Current guidelines from the Infectious Diseases Society of America (IDSA) state that there is insufficient information to recommend administration of probiotics for the primary prevention of C. difficile-associated diarrhea (107538).
• Constipation. Oral Lacticaseibacillus casei has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Combinations of probiotics containing L. casei appear to increase stool frequency and improve symptoms of functional constipation in adults. These combinations include Hexbio, containing L. casei, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. lactis, Bifidobacterium bifidum, Bifidobacterium longum, and Bifidobacterium longum subsp. infantis 30 billion CFUs twice daily for 7 days (90266), and ID-HWS1000, containing L. casei IDCC 3451, Lactiplantibacillus plantarum IDCC 3501, Lacticaseibacillus rhamnosus IDCC 3201, Bifidobacterium animalis subsp. lactis IDCC 4301, Bifidobacterium breve IDCC 4401, Lactococcus lactis IDCC 2301, xylooligosaccharide, and dietary fiber as nondigestible maltodextrin, oat fiber, and psyllium husk fiber (107517).
• Depression. Oral Lacticaseibacillus casei has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with major depression shows that taking L. casei, Lactobacillus acidophilus, and Bifidobacterium bifidum daily for 8 weeks reduces symptoms of depression measured on the Beck Depression Inventory (BDI) when compared with placebo (99780). However, the validity of the results from this study is limited by incomplete reporting. For example, patient baseline BDI scores were not reported.
• Diabetes. It is unclear if oral Lacticaseibacillus casei is beneficial for treatment of type 2 or gestational diabetes. Details: In patients with gestational diabetes, clinical research shows that taking a combination of freeze-dried L. casei, Lactobacillus acidophilus, and Bifidobacterium bifidum each as 2 billion colony-forming units (CFUs) per gram daily for 6 weeks improves fasting blood glucose levels and glycemic control when compared with placebo (95416,98430). Furthermore, a sub-analysis of a meta-analysis of clinical research investigating the effects of L. casei as part of multi-ingredient probiotic and prebiotic products shows that taking products containing L. casei modestly reduces fasting insulin levels and improves insulin resistance in this population. There were also modest reductions in triglyceride levels; however, the effects on fasting blood glucose were not significant (111796). It is unclear from these studies if any beneficial effects are related to L. casei, L. acidophilus, Bifidobacterium bifidum, or the combination. Limited evidence from mainly small clinical trials has also assessed the effects of L. casei for type 2 diabetes. In one study, taking L. casei 100 million CFUs daily for 8 weeks reduces fasting blood glucose by about 28 mg/dL when compared with placebo. There was no effect on glycated hemoglobin; however, the duration was inadequate to demonstrate an effect (99786). In another study, taking a specific product (Familact) containing L. casei and six other probiotic strains daily for 6 weeks reduces fasting blood glucose, but does not affect plasma insulin, when compared with placebo (99790).
• Diarrhea. Oral Lacticaseibacillus casei has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in children with dysentery being treated with ceftriaxone shows that taking a specific combination probiotic sachet (Kidilact, Zisttakhmir Company) containing L. casei, Lactobacillus acidophilus, Lacticaseibacillus rhamnosus, Lactobacillus delbrueckii subsp. bulgaricus, Bifidobacterium longum subsp. infantis, Bifidobacterium breve, and Streptococcus thermophilus daily for 5 days modestly reduces the duration of diarrhea, hospitalization, and blood in diarrhea when compared with control (102417). Although The European Society for Pediatric Infectious Diseases recommends probiotics in hospitalized children with diarrhea (98469) and the Infectious Disease Society of America (IDSA) recommends probiotics for the outpatient treatment of acute diarrhea (95388), both guidelines note that most evidence is low quality.
• Helicobacter pylori. It is unclear if oral Lacticaseibacillus casei is beneficial for H. pylori eradication in adults or children. Details: Clinical research in adults shows that taking L. casei along with six other probiotics in conjunction with bismuth quadruple therapy does not seem to improve H. pylori eradication rates when compared with placebo and bismuth quadruple therapy (90291). Also, taking a combination of L. casei and Lactobacillus acidophilus without any standard H. pylori therapies does not improve H. pylori eradication rates (12766). However, a clinical study in children shows that taking a fermented milk product containing L. casei DN-114 001 for 14 days along with triple therapy comprised of omeprazole, amoxicillin, and clarithromycin for 7 days improves the H. pylori eradication rate to approximately 85%, compared with 61% of those given triple therapy alone (107544).
• HIV/AIDS. Although there has been interest in using oral Lacticaseibacillus casei for HIV/AIDS, there is insufficient reliable information about the clinical effects of lactobacillus for this condition.
• Hyperlipidemia. It is unclear if oral Lacticaseibacillus casei is beneficial for hyperlipidemia. Details: In patients with primary hyperlipidemia, clinical research shows that taking L. casei 200 million colony-forming units in combination with red yeast rice twice daily for 8 weeks does not have beneficial effects on low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, or triglyceride levels, when compared with taking red yeast rice alone. Taking L. casei seems to modestly reduce diastolic blood pressure in this population; however, it is unclear if these changes are clinically significant (112517).
• Hypertension. It is unclear if oral Lacticaseibacillus casei is beneficial for lowering blood pressure. Details: A meta-analysis of 18 clinical trials shows that taking various species of lactobacilli as 100 million to 1.5 trillion colony-forming units daily for 3-24 weeks reduces systolic and diastolic blood pressure by 3 mmHg and 1.5 mmHg, respectively, when compared with placebo in various populations. However, sub-group analyses of three clinical trials show that these benefits do not occur in clinical research investigating the effects of L. casei, specifically (105135).
• Irritable bowel syndrome (IBS). Oral Lacticaseibacillus casei has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A clinical study in patients with diarrhea-predominant IBS shows that taking a specific multi-species probiotic (NordBiotic, MBM Biotix) containing L. casei LC130, Lacticaseibacillus rhamnosus LR110, Lacticaseibacillus paracasei LPC100, Lactobacillus acidophilus LA120, Lactiplantibacillus plantarum LP140, Bifidobacterium breve BB010, Bifidobacterium longum BL020, Bifidobacterium bifidum BF030, Bifidobacterium animalis subsp. lactis BL040, and Streptococcus thermophilus ST250 as 2.5 billion colony-forming units (CFUs) total twice daily for 8 weeks improves overall symptom severity, as well as pain severity, pain frequency, and quality of life, when compared with placebo. Symptom severity was rated as mild by approximately 60% of those taking the probiotic mixture, compared with 30% of those taking placebo (107516). However, clinical research shows that taking another multi-species combination of L. casei LBC80R, L. acidophilus CL1285, and L. rhamnosus CLR2 50 billion CFUs each daily for 3 months does not improve symptoms in patients with IBS when compared with placebo (99789).
• Lyme disease. Although there has been interest in using oral Lacticaseibacillus casei for Lyme disease, there is insufficient reliable information about the clinical effects of lactobacillus for this condition.
• Necrotizing enterocolitis (NEC). It is unclear if oral Lacticaseibacillus casei is beneficial or safe for NEC prevention. Details: Most meta-analyses of clinical research show that giving lactobacilli enterally reduces the risk of NEC and/or severe NEC in preterm, mainly very low birth weight (VLBW), infants. Some meta-analyses support the use of lactobacilli in combination with bifidobacteria, as opposed to lactobacilli alone for reducing the risk of NEC. However, the effects of L. casei specifically are unclear (95344,95351,103437,103445,104157,105162,105164). Also, guidance among regulatory agencies and clinical organizations varies with respect to the use of probiotics in very low birth weight infants under 1000 grams. The US Food and Drug Administration (FDA) warns that preterm infants given probiotics are at risk of serious infections caused by the bacteria or fungi contained in probiotics due to cases reported in this group of infants (111610). Also, The American Academy of Pediatrics does not support the routine administration of probiotics to preterm infants, particularly those with a birth weight below 1000 grams, due to conflicting data on safety and efficacy and potential for harm in this vulnerable population (111608). The Canadian Paediatric Society, the American Gastroenterological Association, and the European Society for Paediatric Gastroenterology, Hepatology and Nutrition state that probiotic combinations may be of benefit in reducing the incidence of NEC in preterm neonates over 1000 grams. However, L. casei is not specifically recommended (103003,111609,111611).
• Nonalcoholic fatty liver disease (NAFLD). Oral Lacticaseibacillus casei has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in adults with NAFLD shows that taking a combination of L. casei BCMC 12,313, Lactobacillus acidophilus BCMC 12,130, Lactobacillus delbrueckii subsp. lactis BCMC 12,451, Bifidobacterium bifidum BCMC 02290, Bifidobacterium longum subsp. infantis BCMC 02129, and Bifidobacterium longum BCMC 02120 as 30 billion colony-forming units twice daily for 6 months has no beneficial effects on hepatic steatosis or fibrosis or on levels of liver enzymes, blood lipids, or fasting blood glucose, when compared with placebo (107523).
• Polycystic ovary syndrome (PCOS). Oral Lacticaseibacillus casei has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In patients with PCOS, clinical research shows that taking a combination of L. casei T2 (IBRC-M10783), Lactobacillus acidophilus T16 (IBRC-M10785), and Bifidobacterium bifidum T1 (IBRC-M10771) as 2 billion colony-forming units (CFUs) each, plus inulin 800 mg, daily for 12 weeks modestly reduces serum insulin and triglyceride levels and improves insulin resistance and insulin sensitivity when compared with placebo. However, it does not alter cholesterol or fasting blood glucose levels (105159). Clinical research also shows that 31.3% of patients with PCOS taking L. casei in combination with other probiotics daily for 6 months had regular menstrual cycles compared with 12.5% of those taking placebo. There were also modest improvements in testosterone levels and waist circumference, but not other hormones, insulin resistance, body weight, or most measures of quality of life. The product provided L. casei UBLC-42 1 billion CFUs, along with Lactiplantibacillus plantarum UBLP-40, Lactobacillus acidophilus UBLA-34, Lacticaseibacillus casei UBLC-42, Limosilactobacillus fermentum UBLF-31, Lacticaseibacillus rhamnosus UBLR-58, Limosilactobacillus reuteri UBLRu-87, Bifidobacterium bifidum UBBB-55, and fructo-oligosaccharides (FOS) daily for 2 months and then twice daily for 4 months. All patients also underwent dietary and lifestyle changes (110974).
• Pregnancy-induced nausea and vomiting. Oral Lacticaseibacillus casei has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small preliminary clinical trial shows that taking probiotics during pregnancy reduces the severity and duration of nausea and vomiting by 16% to 54%. There was also a small benefit on stool hardness. A specific probiotic (Probiotics 10, Nature's Bounty) was taken as 2 capsules daily for two back-to-back cycles comprised of six days with probiotics and two days without. Each capsule contained a total of 10 billion colony-forming units (CFUs) of L. casei Lc-11, Lactiplantibacillus plantarum 299v and DSM 15312, Lactobacillus delbrueckii subsp. bulgaricus Lb-87, Lacticaseibacillus paracasei DSM 13434 and Lpc-37, Ligilactobacillus salivarius Ls-33, Levilactobacillus brevis Lbr-35, Lactobacillus acidophilus La-14, and Bifidobacterium animalis subsp. lactis Bl-04, along with inulin 200 mg (107199).
• Rheumatoid arthritis (RA). Small clinical studies suggest that taking Lacticaseibacillus casei might be beneficial for RA. Details: Two small clinical studies in patients with RA show that taking L. casei 01 as 100 million colony-forming units daily for 8 weeks reduces tender and swollen joints and increases the number of patients who experience moderate symptom improvement when compared with placebo (90230,90297). However, one small clinical study in patients with moderate-to-severe RA shows that taking capsules containing freeze-dried strains of L. casei, Lactobacillus acidophilus, and Bifidobacterium bifidum daily for 8 weeks does not reduce RA severity, the number of tender or swollen joints, or joint pain when compared with placebo (95418).
• Rotaviral diarrhea. It is unclear if Lacticaseibacillus casei is beneficial for rotaviral diarrhea. Details: Although the World Gastroenterology Organization has not made a recommendation (98471), the European Society for Pediatric Infectious Diseases recommends probiotics in hospitalized children with diarrhea (98469) and the Infectious Disease Society of America (IDSA) recommends probiotics for the outpatient treatment of acute diarrhea (95388). However, these guidelines note that most evidence is low quality and is not specific to rotavirus infection. Furthermore, these guidelines were released prior to the publication of the most recent, high-quality studies showing no benefit with the use of certain probiotics (98427,98428). Research on the use of L. casei, specifically, for this purpose is lacking.
• Short bowel syndrome. Although there has been interest in using oral Lacticaseibacillus casei for short bowel syndrome, there is insufficient reliable information about the clinical effects of L. casei for this condition.
• Small intestinal bacterial overgrowth (SIBO). It is unclear if oral Lacticaseibacillus casei is beneficial for the treatment of SIBO. Details: A small clinical study in children with chronic diarrhea due to SIBO shows that taking a combination of lyophilized L. casei 1.5 grams and Lactobacillus acidophilus 1.5 grams by mouth twice daily for 21 days decreases average daily stools by 1.5, but does not improve other symptoms, when compared with placebo (91143). Disparate study findings may be due to many factors, including differences in patient populations evaluated and use of different probiotic formulations. More evidence is needed to rate Lacticaseibacillus casei for these uses.

(Read more about LACTICASEIBACILLUS CASEI)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Celiac disease. Although there has been interest in using oral lipase for celiac disease, there is insufficient reliable information about the clinical effects of lipase for this purpose.
• Dyspepsia. It is unclear if oral lipase is beneficial for improving symptoms of postprandial distress syndrome. Details: A small clinical trial shows that taking a specific acid-resistant lipase (Amano Enzyme USA) 280 mg immediately before a high-fat meal does not reduce postprandial bloating and nausea when compared with placebo in individuals with postprandial distress syndrome (101900).
• Inflammatory bowel disease (IBD). Although there has been interest in using oral lipase for IBD, there is insufficient reliable information about the clinical effects of lipase for this purpose.
• Prematurity. It is unclear if adding a specific form of lipase, recombinant human bile salt-stimulated lipase (rhBSSL), to infant formula improves outcomes in premature infants. Some research suggests a potential increased risk for adverse effects. Details: Human breast milk contains rhBSSL, but it is inactivated when breast milk is pasteurized for donation. Clinical research in infants born before 32 weeks' gestation shows that adding rhBSSL as 8700 units per 100 mL formula or pasteurized breast milk, for 4 weeks does not increase growth velocity, body length, or head circumference over the next 12 months when compared with formula or pasteurized breast milk devoid of lipase. However, the infants who were small for gestational age (SGA), which made up approximately 15% of the study population, grew by an additional 1.9 grams/kg daily on average when compared with placebo (101940). More evidence is needed to rate lipase for these uses.

(Read more about LIPASE)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Cardiovascular disease (CVD). Although there has been interest in using oral Monterey pine for preventing CVD, there is insufficient reliable information about the clinical effects of Monterey pine for this condition.
• Cognitive function. It is unclear if oral Monterey pine bark extract improves cognition. Details: Preliminary clinical research shows that taking vitamin C 120 mg daily along with a specific product containing Monterey pine bark extract (Enzogenol, ENZO Nutraceuticals) 960 mg daily for 5 weeks improves response speed related to working memory tasks and immediate recognition tasks in middle-aged and elderly males when compared with baseline. Improvements in memory do not appear to occur with vitamin C alone (63620).
• Migraine headache. Although there has been interest in using oral Monterey pine for preventing migraine headache, there is insufficient reliable information about the clinical effects of Monterey pine for this condition.
• Neurological trauma. It is unclear if oral Monterey pine bark extract is beneficial in patients with neurological trauma. Details: A small clinical study in patients 3-12 months post-traumatic brain injury shows that taking a specific Monterey pine bark extract (Enzogenol, ENZO Nutraceuticals) 1000 mg daily for 12 weeks improves cognitive function scores when compared with placebo. However, measures of working memory, episodic memory, anxiety, and depression were not improved (105777). Another small clinical study in college students suffering from chronic concussion symptoms shows that taking a specific Monterey pine bark extract (Enzogenol, ENZO Nutraceuticals) 1000 mg daily for 6 weeks improves mental fatigue when compared with placebo (105779). More evidence is needed to rate Monterey pine for these uses.

(Read more about MONTEREY PINE)

EFFECTIVE

• Acetaminophen poisoning. Oral and intravenous N-acetyl cysteine, as prescription drug products, are effective for treating acetaminophen poisoning. Details: Administering prescription N-acetyl cysteine orally or intravenously is effective in decreasing mortality rate and preventing the permanent sequelae of acetaminophen poisoning (17,64513,64745,64746). N-acetyl cysteine injection and oral effervescent tablets are approved by the US FDA for this use (102147,104164).
• Atelectasis. When inhaled, N-acetyl cysteine is effective for treating atelectasis. Details: N-acetyl cysteine solution for inhalation is effective for atelectasis caused by mucus obstruction (15,91650) and is approved by the US FDA for this use (102147).
• Bronchial diagnostic studies. When inhaled, N-acetyl cysteine is effective for bronchial diagnostic study preparation. Details: N-acetyl cysteine solution for inhalation is helpful when used to prepare people for bronchial diagnostic studies (15,91650), and is approved by the US FDA for this use (102147).
• Tracheostomy care. When inhaled and used as adjunct therapy, N-acetyl cysteine is effective for preventing endotracheal crusting in patients with a tracheostomy. Details: N-acetyl cysteine solution for inhalation is effective when used as an adjunct for preventing endotracheal crusting in tracheostomy care (15), and is approved by the US FDA for this use (102147).

POSSIBLY EFFECTIVE

• Angina. Oral or intravenous N-acetyl cysteine may reduce nitroglycerin tolerance in patients with angina. However, some studies suggest that N-acetyl cysteine might increase the risk for severe headaches and hypotension when used with intravenous or transdermal nitroglycerin. Details: Administering N-acetyl cysteine orally or intravenously, in combination with nitroglycerin, seems to improve unstable angina pectoris (2245,2246). There is also some clinical research showing that concurrent intravenous or oral administration of N-acetyl cysteine reduces the development of nitroglycerin tolerance (832,2245,64546). However, other research shows that taking N-acetyl cysteine orally does not reduce the development of nitroglycerin tolerance in angina patients (2281,2282). Additionally, severe headache and hypotension can occur when oral N-acetyl cysteine and nitroglycerin are administered together, which may limit the feasibility of concomitant use (2245).
• Autism spectrum disorder. Oral N-acetyl cysteine may improve irritability, but not other symptoms, associated with autism spectrum disorder. Details: One small clinical study in children with autism shows that taking N-acetyl cysteine 900 mg daily for 4 weeks followed by 900 mg twice daily for 4 weeks and then 900 mg three times daily for 4 weeks improves symptoms of irritability when compared with placebo (91241). Another small clinical study in children and adolescents with autism shows that taking N-acetyl cysteine 1200 mg daily plus risperidone for 8 weeks is more effective than risperidone alone for reducing irritability (91239). However, it does not seem to improve other symptoms, such as hyperactivity, social withdrawal, lethargy, repetitive behaviors, and inappropriate speech (91239,91241,97047).
• Bronchitis. Via inhalation, N-acetyl cysteine is FDA-approved for managing acute episodes of bronchitis. Oral N-acetyl cysteine may help to reduce the occurrence of acute exacerbations of chronic bronchitis when used for 3-36 months. Details: N-acetyl cysteine solution for inhalation is FDA-approved for the management of acute bronchopulmonary disease, including bronchitis (102147). Taking N-acetyl cysteine 1200-1500 mg daily orally for 4 months seems to reduce shortness of breath and coughing, and improve lung capacity, in patients with sulfur mustard-induced bronchitis (64586,64614). Also, taking N-acetyl cysteine orally, usually 400-600 mg daily, seems to reduce the risk of acute exacerbations of chronic bronchitis by a moderate amount when used for 3-36 months (6176,64419,102660). Symptom improvement has been shown to occur in 61% of patients taking N-acetyl cysteine, compared with 34% of those taking placebo (102660). However, oral N-acetyl cysteine does not seem to have a beneficial effect on chronic bronchitis when administered for shorter durations (64685,64696,64737,64818).
• Chronic obstructive pulmonary disease (COPD). Taking N-acetyl cysteine orally seems to decrease the exacerbation rate and improve symptoms in patients with moderate to severe COPD, particularly those who are not taking inhaled corticosteroids. Also, taking N-acetyl cysteine along with standard therapy appears to improve recovery in patients hospitalized due to an acute exacerbation. Details: N-acetyl cysteine solution for inhalation is FDA-approved for the management of chronic bronchopulmonary disease, such as COPD (102147). A meta-analysis of 12 clinical studies involving 2,691 patients shows that N-acetyl cysteine, given as 257-1800 mg daily for at least 6 months, decreases the number of patients experiencing at least one COPD exacerbation by 15% when compared with placebo; however, it is not associated with a reduction in COPD exacerbation rate or improvement in measures of lung function (97046). Some smaller studies have shown a higher improvement rate of 23% to 40%, with the greatest efficacy seen in patients who are not already taking inhaled corticosteroids (10429,64552). While some studies have failed to show any benefit of N-acetyl cysteine, the lack of benefit appears to correlate with a treatment duration of less than 6 months (64704,97039,97046). The 2015 guidelines from the American College of Chest Physicians and Canadian Thoracic Society (AECOPD) recommend that N-acetyl cysteine be considered as an adjunctive treatment option for patients with moderate to severe COPD and a history of 2 or more exacerbations in the previous 2 years (97043). The 2017 Global Initiative for Chronic Obstructive Lung Disease (GOLD) guideline also states that N-acetyl cysteine may be an appropriate treatment option for patients who are not able to use inhaled corticosteroids (97050). In hospitalized patients with an acute exacerbation of COPD, preliminary clinical research shows that adding N-acetyl cysteine 1200 mg daily to regular treatment has a moderate effect on wheeze and the need for oxygen over a 7-day period when compared with regular treatment alone (102653).
• Contrast induced nephropathy. Oral or intravenous administration of N-acetyl cysteine seems to prevent contrast induced nephropathy in patients with kidney dysfunction. However, it is not beneficial in those with normal kidney function or diabetes. Details: Large meta-analyses of over 150 clinical studies in patients with reduced kidney function (serum creatinine of 1.2-2.4 mg/dL) show that oral N-acetyl cysteine is more effective than either sodium bicarbonate or saline hydration alone in preventing contrast agent-induced kidney damage after coronary angiography, computed tomography, left heart catheterization, and/or percutaneous coronary intervention. N-acetyl cysteine in combination with sodium bicarbonate appears to have similar efficacy to N-acetyl cysteine monotherapy, with an odds ratio of 0.62-0.67, when compared with hydration alone. Pretreatment with high-dose statin, prostaglandin, or theophylline appears to be more effective than N-acetyl cysteine, with odds ratios of 0.37, 0.37, and 0.48, respectively, when compared with hydration alone. However, combination treatment with N-acetyl cysteine and a high-dose statin appears to provide the greatest benefit of all treatments studied, with an odds ratio of 0.31, when compared with hydration alone. No treatments demonstrate significant efficacy in reducing the risk of contrast induced nephropathy in patients with diabetes (97036,97038). Some evidence also suggests that N-acetyl cysteine may have similar effects to fenoldopam in reducing the risk of contrast induced nephropathy in patients with reduced kidney function (64489,97036,97038). N-acetyl cysteine does not reduce the risk of contrast induced nephropathy in patients with normal kidney function (mean serum creatinine less than 1.2 mg/dL) when compared with control (64538,64573,64617). Although many individual studies have failed to show a significant benefit (11430,64514,64543,64561,64581,64623,64639,91232,91236,106884), pooled evidence from these and many additional studies provide a benchmark for the place for N-acetyl cysteine in reducing the risk of contrast induced kidney damage in people with reduced kidney function.
• Hyperhomocysteinemia. Oral N-acetyl cysteine seems to reduce homocysteine levels. Details: Taking N-acetyl cysteine orally seems to reduce homocysteine levels in patients with elevated homocysteine levels, including those with kidney failure requiring dialysis (2258,64542,64596).
• Hyperlipidemia. Oral N-acetyl cysteine seems to reduce lipoprotein(a) levels. Details: Taking N-acetyl cysteine orally seems to modestly reduce lipoprotein(a) levels in patients with hyperlipidemia (2256,2257,64516).
• Ifosfamide (Ifex) toxicity. Oral N-acetyl cysteine may be beneficial for reducing ifosfamide toxicity, although it does not appear to be as effective as mesna. Details: Taking N-acetyl cysteine orally seems to reduce ifosfamide-induced bladder toxicity (5808,10270,64730). However, mesna seems to be more effective for preventing ifosfamide toxicity than N-acetyl cysteine (10748).
• Influenza. Oral N-acetyl cysteine may reduce the risk for symptomatic influenza. Details: One multi-center clinical trial conducted in Italy shows that taking N-acetyl cysteine 600 mg twice daily for 6 months does not prevent influenza infection, but reduces the risk for clinically apparent disease by 68%, when compared with placebo (2260).
• Kidney failure. Oral N-acetyl cysteine may reduce the risk for cardiovascular events in patients with kidney failure. Details: One clinical study in adults with kidney failure who have been on dialysis for at least 3 months shows that taking N-acetyl cysteine 600 mg twice daily reduces the incidence of cardiovascular events, such as ischemic stroke and myocardial infarction, by about 40% when compared with placebo. There was no effect on total mortality or mortality from cardiovascular causes, although the study may have been inadequately powered to detect a difference in these outcomes (10430).
• Myocardial infarction (MI). Intravenous N-acetyl cysteine, along with standard therapy, seems to improve outcomes in patients with MI. Oral N-acetyl cysteine has not been evaluated for this use. Details: Clinical research in adults undergoing percutaneous coronary intervention (PCI) for ST-segment elevation MI shows that administering N-acetyl cysteine with nitroglycerin as a continuous intravenous infusion for 48 hours reduces myocardial infarct size by 5.5%, doubles the extent of myocardial salvage, and shortens the time to chest pain resolution when compared with nitroglycerin plus placebo (97044). Additional preliminary clinical research shows that intravenous N-acetyl cysteine, when given with nitroglycerin and streptokinase in patients with evolving MI, may preserve left ventricular function and reduce oxidative stress (7872,64502,64778).

POSSIBLY INEFFECTIVE

• Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease). Subcutaneous administration of N-acetyl cysteine does not seem to improve survival or disease progression in patients with ALS. Details: One clinical trial in patients with ALS shows that administering N-acetyl cysteine 50 mg/kg daily for 12 months via subcutaneous injection does not improve survival or slow disease progression when compared with placebo (2254).
• Anthracycline cardiotoxicity. Oral N-acetyl cysteine does not seem to prevent or treat doxorubicin-induced cardiac toxicity. Details: Small clinical studies show that taking N-acetyl cysteine orally does not seem to prevent or reverse doxorubicin-induced cardiac toxicity when compared with placebo or a control group (2252,2253,64712).
• Bronchopulmonary dysplasia. Intratracheal N-acetyl cysteine does not seem to prevent bronchopulmonary dysplasia in premature infants. Details: Clinical research in premature infants shows that intratracheal N-acetyl cysteine does not seem to improve symptoms, hasten recovery of chronic lung disease, or reduce the risk of bronchopulmonary dysplasia when compared with placebo (64460,64490).
• Cannabis use disorder. Oral N-acetyl cysteine does not seem to improve abstinence rates in patients with cannabis use disorder. Details: Most clinical research in adolescents and adults with cannabis use disorder shows that taking N-acetyl cysteine 1200 mg twice daily for 8-12 weeks as an adjunct to counseling and other interventions does not reduce symptoms of depression or help with cannabis abstinence (99531,102663,102666,102668). Although a single study shows that taking N-acetyl cysteine more than doubles the odds of a negative urine cannabinoid test over an 8-week period in adolescents aged 15-21 when compared with placebo, there was no significant difference in the time to first negative urine cannabinoid test or end of treatment abstinence (102666).
• Cystic fibrosis. Oral or inhaled N-acetyl cysteine does not seem to improve lung function in patients with cystic fibrosis. Details: Most clinical research shows that taking oral or nebulized N-acetyl cysteine does not significantly improve lung function or lung capacity in patients with cystic fibrosis when compared with a control (22735,64406,64671,64743). However, one preliminary clinical study shows that high-dose oral N-acetyl cysteine reduces the number and activity of airway neutrophils in these patients when compared with placebo (64510).
• Erythropoietic protoporphyria (EPP). Oral N-acetyl cysteine does not seem to improve photosensitivity in patients with EPP. Details: Small clinical studies show that taking N-acetyl cysteine 1800 mg daily orally for 4 weeks does not improve photosensitivity in patients with EPP when compared with placebo or baseline (64448,64756).
• Helicobacter pylori. Adding oral N-acetyl cysteine to conventional Helicobacter pylori (H. pylori) eradication regimens does not seem to increase eradication rates. Details: Despite conflicting findings from individual, small clinical studies (64497,97042), meta-analyses of clinical research show that adding N-acetyl cysteine to a standard antibiotic eradication regimen does not improve eradication when compared with standard eradication therapy alone (99530,106901). N-acetyl cysteine has also been evaluated in combination with other ingredients. Preliminary clinical research shows that taking N-acetyl cysteine 600 mg orally twice daily in combination with curcumin 30 mg, bovine lactoferrin 100 mg, and pantoprazole 20 mg, all taken twice daily for one week, without antibiotic therapy does not eradicate H. pylori infection, although it might improve dyspeptic symptoms and gastrointestinal inflammation (64559).
• Hepatitis. Oral N-acetyl cysteine does not appear to improve treatment response in patients with hepatitis. However, when taken with interferon, it might lengthen the time to relapse. Details: Taking N-acetyl cysteine orally does not seem to benefit patients with acute viral hepatitis (64462). Also, adding N-acetyl cysteine to conventional interferon therapy does not seem to improve treatment response in patients with hepatitis C when compared with interferon therapy alone (64418,64799,64825). However, some clinical research shows that adding N-acetyl cysteine to interferon therapy delays relapse in hepatitis C patients when compared with interferon treatment alone (64424).
• HIV/AIDS. Oral N-acetyl cysteine does not seem to increase CD4+ cell count in patients with HIV. Details: Small clinical studies show that taking N-acetyl cysteine 400 mg orally twice daily or 600 mg once daily for 4-6 months does not improve CD4+ cell counts or viral load in patients with HIV when compared with placebo (64482,64779). In addition, taking N-acetyl cysteine 600 mg orally three times daily in combination with sodium selenite 500 mcg daily for up to 24 weeks does not affect the percentage of CD4+ lymphocytes or viral load in HIV patients when compared with a control (64798).
• Hypotension. Oral N-acetyl cysteine does not seem to improve renal outcomes in patients with prolonged hypotension. Details: One clinical trial in patients with prolonged hypotension shows that taking N-acetyl cysteine orally for 7 days does not reduce the risk of acute kidney failure when compared with placebo (64545).
• Infertility. Oral N-acetyl cysteine does not seem to improve fertility in females with unexplained infertility. Details: One clinical trial in females with unexplained infertility shows that taking oral N-acetyl cysteine 1200 mg daily in addition to clomiphene citrate 50 mg twice daily for 5 days, beginning on the second day of the cycle, does not improve pregnancy rate or reduce miscarriage rate when compared with clomiphene citrate alone (64528).
• Liver transplant. Intravenous N-acetyl cysteine during liver donor operation does not seem to improve liver transplant outcomes. Oral N-acetyl cysteine has not been evaluated for this use. Details: One clinical trial shows that administering N-acetyl cysteine intravenously during a liver donor operation and preserving the liver in cold solution containing N-acetyl cysteine does not reduce the risk of ischemia reperfusion injury or acute cellular rejection in liver transplant recipients when compared with control (64486).
• Pancreatitis. Oral N-acetyl cysteine does not seem to prevent pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP). Additionally, intravenous N-acetyl cysteine does not seem to reduce the risk of organ dysfunction in patients being treated for severe acute pancreatitis. Details: Two clinical trials show that taking oral N-acetyl cysteine 1200 mg once before undergoing ERCP does not reduce the risk of post-ERCP pancreatitis when compared with placebo (64522,109939). One of these trials also evaluated oral N-acetyl cysteine in combination with rectal indomethacin, but the incidence of post-ERCP pancreatitis did not appear to be lower when compared with taking indomethacin alone. However, the study may have been inadequately powered to detect a difference between those groups (109939). In patients with severe acute pancreatitis, intravenous N-acetyl cysteine, in combination with selenium and vitamin C, also does not seem to reduce the risk of organ dysfunction (64551).
• Postoperative recovery. Oral or intravenous N-acetyl cysteine does not seem to improve survival, prevent complications, or reduce length of hospital stay in patients undergoing cardiac or liver surgery. Details: N-acetyl cysteine, taken orally or intravenously, does not seem to reduce the risk of myocardial infarction, stroke, kidney injury, or mortality or reduce the length of hospital stay following cardiac surgery (64610,64624,64628,64635,91233,91240). While some meta-analyses of clinical research show that taking N-acetyl cysteine orally or intravenously reduces the odds of postoperative atrial fibrillation by 36% to 44% when compared with placebo in patients undergoing cardiac surgery (64635,91233,91240), conflicting results exist (64624). In patients undergoing liver resection, intravenous N-acetyl cysteine does not reduce complication rate, risk of liver failure, length of hospital stay, or mortality when compared with a control group. In fact, patients receiving N-acetyl cysteine were more likely to experience delirium and its associated complications (99532).

LIKELY INEFFECTIVE

• Head and neck cancer. Oral N-acetyl cysteine does not seem to reduce mortality, improve event-free survival, or prevent additional tumors in patients with head and neck cancer. Details: Taking N-acetyl cysteine orally does not prevent second primary tumors in patients with head and neck cancer (1710). Also, N-acetyl cysteine alone, or in combination with retinyl palmitate, has no effect on mortality or event-free survival in these patients (1710).
• Lung cancer. Oral N-acetyl cysteine does not seem to reduce mortality, improve event-free survival, or prevent additional tumors in patients with lung cancer. Details: Taking N-acetyl cysteine orally does not prevent second primary tumors in patients with lung cancer (1710). Also, N-acetyl cysteine alone, or in combination with retinyl palmitate, has no effect on mortality or event-free survival in these patients (1705,1710).
• Multisystem organ failure. Administering intravenous N-acetyl cysteine might increase the risk of mortality due to multisystem organ failure. Oral N-acetyl cysteine has not been evaluated for this use. Details: Administering N-acetyl cysteine intravenously, greater than 24 hours after hospital admission, might increase mortality rate due to multisystem organ failure. The effect of N-acetyl cysteine given within 24 hours of hospital admission requires further study (7871).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acute respiratory distress syndrome (ARDS). Research on the use of intravenous N-acetyl cysteine in patients with ARDS is conflicting. Oral N-acetyl cysteine has not been evaluated for this purpose. Details: Some clinical research shows that N-acetyl cysteine might reduce mortality and improve oxygenation in patients with acute lung injury/ARDS when compared with a control (64619). These patients were administered intravenous N-acetyl cysteine 150 mg/kg on the first day followed by 50 mg/kg for 3 more days. However, other clinical research shows that administering intravenous N-acetyl cysteine 40 mg/kg daily for 3 days does not reduce the risk of ARDS development in patients with acute lung injury (64771). Also, some clinical research shows that intravenous N-acetyl cysteine for up to 6 days does not reduce the time for improvement in patients with ARDS (64492). These discrepancies may be due to variations in genes involved in glutathione-S-transferase (GST) expression (64619).
• Adrenoleukodystrophy (ALD). It is unclear if oral or intravenous N-acetyl cysteine is beneficial in patients with ALD. Details: A case series of three male children with this rare condition suggests that administering N-acetyl cysteine orally and intravenously might improve overall survival and stabilize neurologic status after hematopoietic stem cell transplantation when compared with historical controls (64547).
• Aging. Oral N-acetyl cysteine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in older adults shows that taking a combination product containing N-acetyl cysteine 100 mg/kg, glycerine 100 mg/kg, and alanine 200 mg/kg orally daily for 16 weeks modestly improved waist circumference, systolic blood pressure, and some serum markers of oxidative stress, but not body-mass index or diastolic blood pressure, when compared with placebo (110624). It is unclear if this effect is due to N-acetyl cysteine, other ingredients, or the combination.
• Alcohol-related liver disease. Although there has been interest in using oral N-acetyl cysteine for preventing alcohol-related liver damage, there is insufficient reliable information about the clinical effects of N-acetyl cysteine for this purpose.
• Allergic rhinitis (hay fever). Although there has been interest in using oral N-acetyl cysteine for allergic rhinitis, there is insufficient reliable information about the clinical effects of N-acetyl cysteine for this condition.
• Altitude sickness. It is unclear if oral N-acetyl cysteine can treat or prevent altitude sickness. Details: One very small clinical trial shows that taking N-acetyl cysteine 400 mg daily does not reduce altitude-associated anorexia or improve food intake in individuals exposed to high altitudes when compared with either placebo or vitamin E 400 mg daily (64599).
• Alzheimer disease. It is unclear if oral N-acetyl cysteine is beneficial for Alzheimer disease. Details: One clinical trial in a small number of patients with Alzheimer disease shows that taking N-acetyl cysteine 50 mg/kg daily for 6 months does not improve most cognitive symptoms of Alzheimer disease when compared with placebo (7870). However, preliminary clinical research in adults with mild to moderate Alzheimer disease also shows that taking a combination product containing N-acetyl cysteine 2.55 grams, L-serine 12.35 grams, nicotinamide riboside 1 gram, and L-carnitine tartrate 3.73 grams orally once daily for 28 days followed by twice daily for 56 more days improves cognitive functioning scores by 14% to 29% when compared with placebo (110623). It is unclear if this effect is due to N-acetyl cysteine, other ingredients, or the combination.
• Aminoglycoside ototoxicity. Small clinical studies suggest that oral N-acetyl cysteine may modestly reduce the risk of ototoxicity caused by aminoglycoside therapy. Details: A meta-analysis of available clinical research in adults with kidney failure receiving aminoglycosides for bloodstream infections shows that taking N-acetyl cysteine 600 mg twice daily for a total of 14 days, or for up to 7 days after completion of aminoglycoside therapy, reduces the risk of hearing loss by 33% when compared with placebo. The findings of this analysis are limited by the small sample sizes and high risk of bias of the included studies (97049).
• Asthma. It is unclear if inhaling N-acetyl cysteine is beneficial in patients with asthma. Details: Preliminary clinical research shows that, when administered as an aerosol daily for one week in combination with isoproterenol, N-acetyl cysteine 10% improves lung capacity and decreases sputum viscosity when compared with placebo in patients with asthma (64674).
• Athletic performance. It is unclear if oral N-acetyl cysteine can improve athletic performance. Details: Some small clinical studies shows that N-acetyl cysteine might be beneficial if taken orally at a dose of 1200 mg daily for 9 days leading up to exercise or when administered intravenously both before and during exercise (64529,91248), but that it might not improve performance when taken as a single 20 mg/kg oral dose 60 minutes prior to exercise (102028).
• Biliary disorders. It is unclear if intravenous N-acetyl cysteine is beneficial in patients with biliary disorders. Oral N-acetyl cysteine has not been evaluated for this use. Details: Preliminary clinical research in patients undergoing surgical bypass for obstructive jaundice shows that postoperative intravenous N-acetyl cysteine for 48 hours reduces levels of some liver enzymes, but not bilirubin levels or mean hospital stay, when compared with a control group. Although all liver enzyme levels had not returned to normal by 30 days after surgery, they were more improved in the group using N-acetylcysteine (102654).
• Bipolar disorder. The effects of oral N-acetyl cysteine in patients with bipolar disorder are conflicting. Oral N-acetyl cysteine might reduce symptoms of depression and increase remission rates, but it does not appear to be beneficial for reducing symptoms of mania or for maintaining remission. Details: One clinical study in patients with bipolar disorder shows that taking N-acetyl cysteine 1000 mg twice daily as adjunct to usual therapy for 24 weeks reduces symptoms of depression when compared with placebo (64608). A subgroup analysis of patients from this study who were diagnosed with bipolar II disorder shows that this dose of N-acetyl cysteine can increase the number of patients who achieve remission of both depression and mania, but not the number achieving remission of only one of these, when compared with placebo (91243). However, other research shows that taking N-acetyl cysteine 3 grams daily in addition to standard therapy for 20 weeks does not improve depression when compared with placebo in patients with bipolar depression experiencing a depressive episode for at least 4 weeks. A limitation of this study is the high (56%) placebo response rate, which might have limited the ability to detect between-group differences in symptoms improvements (99529). Taking N-acetyl cysteine as an adjunct to usual therapy does not appear to be beneficial for maintaining remission. A clinical study in patients with bipolar disorder shows that, although taking N-acetyl cysteine 1000 mg twice daily for 8 weeks improves symptoms of bipolar disorder when compared to baseline, maintenance therapy with N-acetyl cysteine for an additional 6 months does not improve depression symptoms or prevent recurrence when compared with placebo (91234).
• Bronchiectasis. Oral N-acetyl cysteine has been evaluated in patients with bronchiectasis, with promising results. Details: Preliminary clinical research in Chinese adults with bronchiectasis shows that taking N-acetyl cysteine 600 mg twice daily for 12 months reduces the risk of exacerbation by 59% when compared with a control group receiving on-demand treatment only. For every eight patients treated with N-acetyl cysteine, one additional patient was free of exacerbations at 12 months when compared with on-demand treatment only (102027).
• Canker sores. It is unclear if rinsing the mouth with N-acetyl cysteine solution is beneficial in patients with canker sores. Details: Preliminary clinical research in patients with recurrent canker sores shows that rinsing the mouth with N-acetyl cysteine (ACC, HEXAL AG) 200 mg dissolved in water for 30 seconds is no more effective than 0.12% chlorhexidine digluconate for canker sore healing time or level of pain. However, pain was reduced by 50% to 90% more over baseline 2-4 days after use of N-acetyl cysteine when compared with 0.12% chlorhexidine digluconate (102659).
• Chemotherapy-induced hepatotoxicity. It is unclear if intravenous N-acetyl cysteine is beneficial in patients with chemotherapy-induced hepatotoxicity. Oral N-acetyl cysteine has not been evaluated for this use. Details: Some observational research in children aged 2-17 years with chemotherapy-induced hepatotoxicity has found that intravenous N-acetyl cysteine 3 mcg/kg over 24 hours is associated with day-to-day improvement in liver injury, based on liver function enzyme levels, when compared with no N-acetyl cysteine therapy. Decreases in liver enzymes also occurred earlier in patients using N-acetyl cysteine (102664).
• Chemotherapy-induced peripheral neuropathy. Small clinical studies suggest that oral N-acetyl cysteine may reduce the risk for peripheral neuropathy in patients receiving oxaliplatin. Details: One preliminary clinical study in patients with colon cancer shows that taking N-acetyl cysteine 1200 mg orally at 1.5 hours prior to oxaliplatin therapy reduces the incidence of oxaliplatin-induced neuropathy when compared with placebo (64505). Another small clinical trial in patients with gastric or colorectal cancers shows that taking N-acetyl cysteine (Osveh Pharmaceutical Company) 1200 mg one hour before receiving oxaliplatin during eight courses of chemotherapy reduces the incidence and severity of neurotoxicity symptoms when compared with placebo. In patients taking N-acetyl cysteine, 31% had no signs of neurotoxicity after oxaliplatin chemotherapy, compared with 0% of those taking placebo. Also, 44% had mild symptoms, compared with 6% of those taking placebo. However, there were no significant differences in electrophysiological sensory results (102665).
• Chronic fatigue syndrome (CFS). Although there has been interest in using oral N-acetyl cysteine for CFS, there is insufficient reliable information about the clinical effects of N-acetyl cysteine for this purpose.
• Chronic kidney disease (CKD). Oral N-acetyl cysteine does not seem to improve kidney function in patients with CKD or reduce the risk of kidney injury or other complications after cardiac surgery in patients with CKD. However, intravenous N-acetyl cysteine might offer some benefit in patients with CKD undergoing cardiac surgery. Details: Clinical research shows that taking N-acetyl cysteine 1200 mg orally daily in combination with standard antihypertensive drugs does not reduce proteinuria or other markers of kidney injury in patients with CKD (64627). N-acetyl cysteine has also been evaluated for the prevention of acute kidney injury following cardiac surgery in patients with CKD, with conflicting results. Several meta-analyses have shown that N-acetyl cysteine does not reduce the incidence of acute kidney injury, postoperative complications, postoperative interventions, length of hospitalization, or mortality after cardiac surgery in adults with CKD (95766,95767,95768). However, these meta-analyses found that intravenous, but not oral, N-acetyl cysteine might be beneficial (95767,95768). A more recent meta-analysis shows that intravenous N-acetyl cysteine reduces the risk of postoperative acute kidney injury by 23% and reduces the risk of cardiac adverse events by 17% (99533). However, most of the studies included in this latter meta-analysis were small and the definition of cardiac events varied among the included studies. Higher quality research is needed to determine the benefit, if any, of N-acetyl cysteine in reducing acute kidney injury after cardiac surgery in patients with CKD.
• Cocaine dependence. It is unclear if oral N-acetyl cysteine is effective for reducing cravings or withdrawal symptoms in people trying to stop cocaine use. Details: Some preliminary clinical research shows that taking N-acetyl cysteine 600 mg twice daily for 2 days reduces the desire to use cocaine when compared with placebo in individuals with cocaine dependence (64563). However, other preliminary clinical research shows that taking oral N-acetyl cysteine 600 mg twice daily for 2 days does not reduce cravings or withdrawal symptoms when compared with placebo in patients hospitalized for cocaine dependency (64504).
• Colorectal cancer. It is unclear if oral N-acetyl cysteine is effective for preventing colorectal cancer. Details: Clinical research in a small group of patients with a history of adenomatous colonic polyps shows that taking N-acetyl cysteine 800 mg daily for 12 weeks reduces the proliferative index of colonic crypts, suggesting that N-acetyl cysteine might decrease the likelihood of colorectal cancer (7873).
• Coronary artery bypass graft (CABG) surgery. It is unclear if oral or intravenous N-acetyl cysteine is beneficial in patients undergoing CABG surgery. Details: A small clinical study shows that taking N-acetyl cysteine 300 mg orally in addition to intermittent blood cardioplegia does not affect postoperative outcomes or the risk of mortality when compared with control in patients undergoing elective CABG surgery (64638). Another small clinical study shows that giving N-acetyl cysteine 100 mg/kg by intravenous infusion, for two doses during CABG surgery and one postoperative dose, seems to reduce serum creatinine levels at 4 and 48 hours after surgery and reduce the incidence of acute kidney injury when compared with placebo. However, serum creatinine levels were within the normal range in all patients (106886).
• Coronavirus disease 2019 (COVID-19). Small clinical trials suggest that intravenous N-acetyl cysteine is not beneficial in patients at risk for respiratory failure from severe COVID-19. It is unclear if oral use is beneficial. Details: A small single-center clinical trial of patients presenting to the emergency room with COVID-19 pneumonia in Brazil shows that receiving intravenous N-acetyl cysteine 21 grams in dextrose 5% over 20 hours in conjunction with institutional standard care, including empiric antibiotics, does not reduce the need for mechanical ventilation, length of intensive care unit (ICU) stay, or mortality when compared with dextrose 5% (105560). Another small single-center clinical trial in patients with COVID-19 and acute respiratory distress syndrome (ARDS) in Iran shows that receiving a continuous intravenous infusion of N-acetyl cysteine 40 mg/kg in dextrose 5% daily for 3 days in conjunction with institutional standard care, including corticosteroids, vitamin C, vitamin D, and zinc, also does not reduce the need for mechanical ventilation, length of ICU stay, or mortality when compared with dextrose 5% (105561). Similarly, a retrospective study of patients hospitalized in Italy for COVID-19 pneumonia shows that receiving intravenous N-acetyl cysteine 300 mg three times daily, switched to 600 mg twice daily if the patient was clinically stable, for a duration of least 5 days, does not improve inpatient mortality, ICU admission, length of ICU stay, or the incidence of atelectasis, when compared with no supplementation. At a 6-month follow-up, treatment with N-acetyl cysteine also did not appear to impact long-term outcomes in these patients (108449). In contrast, a small, retrospective study in hospitalized patients with moderate to severe COVID-19 pneumonia shows that taking oral N-acetyl cysteine, 600 mg twice daily for 10 days in addition to standard care, including empiric antibiotics, corticosteroids, and remdesivir, reduces the risk for severe respiratory failure requiring ventilator support and reduces mortality at 14 days in those with severe pneumonia when compared with standard care alone (106885). Prospective, randomized, double-blind trials are needed to confirm these findings.
• Dental plaque. It is unclear if mouthwash solutions containing N-acetyl cysteine can reduce dental plaque; higher concentrations may be more effective than lower concentrations. Details: Preliminary clinical research shows that using a mouthwash solution containing N-acetyl cysteine 10% four times daily for 7 days reduces dental plaque (64687). However, other clinical research shows that rinsing twice daily for 3 weeks with N-acetyl cysteine 1.25% does not reduce the development of plaque. In addition, N-acetyl cysteine 1.25% was not beneficial when used for 2 weeks as a treatment for experimental plaque (102662).
• Dry eye. Small clinical studies suggest that eye drops containing N-acetyl cysteine, with or without chitosan, might improve objective measures of dry eye. Details: Preliminary clinical research in patients with dry eye shows that using tear solution containing 20% N-acetyl cysteine every two hours for 2 months improves objective, but not subjective, symptoms of dry eye syndrome when compared with artificial tears (64705). A small clinical study in patients with moderate to severe dry eye disease shows that applying a specific product (Lacrimera) containing chitosan-N-acetyl cysteine as one drop once or twice daily improves tear film thickness (TFT) after 10 minutes of application, and is maintained for 24 hours, when compared with placebo. Once or twice daily application does not seem to alter the level of benefit (97710). It is unclear if the benefit of this combination product is due to N-acetyl cysteine, chitosan, or the combination.
• Endometriosis. Oral N-acetyl cysteine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with endometriosis-associated pelvic pain shows that taking a combination product containing N-acetyl cysteine 1200 mg, alpha lipoic acid 400 mg, bromelain 50 mg, and zinc 20 mg daily for 6 months improves pain and reduces analgesic intake when compared to baseline (99535). This study was limited by a lack of comparator group.
• Esophagogastroduodenoscopy (EGD). It is unclear if N-acetyl cysteine (NAC) can improve visualization when used as a premedication for EGD. Details: Clinical research shows that giving NAC orally, 600 mg in 90 mL of an emulsion formulation, 20 minutes prior to EGD reduces foaming and mucus, allowing better visualization of the mucosa. The percentage of patients with no bubbles affecting visualization is about 51% with NAC, compared with 34% with placebo. The percentage not requiring suction or endoscopic flushes is 50% with NAC and 27% with placebo. Giving simethicone 150 mg in combination with NAC further improves visualization (108941).
• Exercise-induced muscle damage. It is unclear if oral N-acetyl cysteine is effective for preventing or treating exercise-induced muscle damage. Details: One small clinical study shows that taking N-acetyl cysteine 20 mg/kg daily in three divided doses after muscle-damaging exercise does not improve muscle repair or inflammatory response in healthy patients taking part in a specific resistance training program (91244).
• Fibrocystic breast disease. It is unclear if oral N-acetyl cysteine is effective for fibrocystic beast disease. Details: Preliminary clinical research in adult females with fibrocystic breast disease and cyclical mastalgia shows that taking N-acetyl cysteine (Osvah Pharmaceutical Company) 600 mg orally once daily for 12 weeks modestly improves pain scores when compared with placebo (109938).
• Gingivitis. It is unclear if mouthwash containing N-acetyl cysteine is effective for the prevention or treatment of gingivitis. Details: Clinical research shows that rinsing twice daily for 3 weeks with N-acetyl cysteine 1.25% is slightly more effective than placebo for reducing the development of gingivitis. However, there was no effect on plaque. In addition, N-acetyl cysteine is not as effective as chlorhexidine 0.2% and had no benefit when used for 2 weeks as a treatment for experimental gingivitis (102662).
• Hangover. Although there has been interest in using oral N-acetyl cysteine for treating hangovers, there is insufficient reliable information about the clinical effects of N-acetyl cysteine for this purpose.
• Hearing loss. It is unclear if oral N-acetyl cysteine is effective for preventing or treating hearing loss. Details: A meta-analysis of clinical trials in adults shows that taking N-acetyl cysteine 900-2700 mg orally daily for up to 42 days modestly protects against noise-induced hearing loss in middle to high hearing thresholds (0 to 4 kHz and 0 to 6 kHz), but not low hearing thresholds (0 to 2 kHz), when compared with control. However, the validity of this study is limited by high heterogeneity (109937). Another meta-analysis of 2 clinical trials in adults with sudden hearing loss shows that taking N-acetyl cysteine 1200 mg orally daily for 2 weeks to 3 months moderately improves pure tone threshold hearing when compared with control (109940).
• Hepatorenal syndrome. It is unclear if intravenous N-acetyl cysteine is beneficial in patients with hepatorenal syndrome. Oral N-acetyl cysteine has not been evaluated for this use. Details: A case series of 12 patients with hepatorenal syndrome reported that intravenous N-acetyl cysteine, starting with a 150 mg/kg loading dose over 2 hours, followed by a continuous infusion of 100 mg/kg daily for 5 days, modestly improved kidney function, but not liver function or blood pressure. When compared with historical controls, N-acetyl cysteine administration was also associated with an improvement in total survival time (1752). Prospective clinical studies are needed to confirm these findings.
• Hereditary hemorrhagic telangiectasia (HHT). It is unclear if oral N-acetyl cysteine is beneficial in patients with HHT. Details: One small clinical study shows that taking N-acetyl cysteine 600 mg three times daily orally for 12 weeks decreases the frequency and severity of daytime nosebleeds, but not nighttime nosebleeds, when compared to baseline in individuals with HHT (64643). The validity of these findings is limited by the lack of a comparator group.
• Idiopathic interstitial pneumonia. It is unclear if oral or inhaled N-acetyl cysteine is beneficial for the management of various forms of interstitial pneumonia. Details: A very small clinical study in patients with idiopathic interstitial pneumonia shows that taking N-acetyl cysteine 600 mg three times daily for 12 weeks seems to improve pulmonary function tests and decrease biochemical markers of disease when compared with baseline (7868). However, a meta-analysis of clinical research in patients with idiopathic pulmonary fibrosis, a specific type of interstitial pneumonia, shows that oral or inhaled N-acetyl cysteine does not reduce the risk of acute exacerbations or attenuate decline of lung function as measured by forced vital capacity (FVC), when compared with placebo (99538).
• Lead toxicity. Although there has been interest in using oral N-acetyl cysteine for lead toxicity, there is insufficient reliable information about the clinical effects of N-acetyl cysteine for this purpose.
• Malaria. It is unclear if intravenous N-acetyl cysteine is beneficial as an adjunct in treating malaria. Oral N-acetyl cysteine has not been evaluated for this use. Details: One small clinical study shows that intravenous N-acetyl cysteine, in combination with intravenous artesunate, does not reduce symptoms or the risk of mortality in patients with severe malaria when compared with artesunate alone (64630).
• Male infertility. It is unclear of oral N-acetyl cysteine is beneficial for male infertility. Details: Clinical research in adults with idiopathic oligoasthenoteratospermia shows that taking N-acetyl cysteine 600 mg orally daily for 26 weeks improves sperm concentration, but not sperm motility, when compared with placebo (64626). Additionally, a preliminary clinical study in adults with asthenoteratozoospermia shows that taking N-acetyl cysteine 600 mg daily for 3 months improves sperm motility and concentration, increases protamine, and improves hormone levels and sperm morphology when compared to baseline (99534). The validity of this study is limited by the lack of a comparator group. There is also interest in using N-acetyl cysteine to attenuate the infertility effects observed after COVID-19 infection. A large clinical study in males who had normal sperm analysis prior to COVID-19, but with significantly lower sperm parameters within 6 weeks after infection, shows that taking oral N-acetyl cysteine 600 mg daily for 3 months improves sperm volume, concentration, morphology, and total motility when compared with baseline post-COVID-19 levels (108447). Although the study enrolled a control group, the investigators did not provide a statistical comparison of outcomes between groups, limiting the validity of this finding.
• Mercury toxicity. Although there has been interest in using oral N-acetyl cysteine for mercury toxicity, there is insufficient reliable information about the clinical effects of N-acetyl cysteine for this purpose.
• Miscarriage. Oral N-acetyl cysteine has only been evaluated in combination with other ingredients; its benefit when used alone is unclear. Details: One small clinical trial shows that taking oral N-acetyl cysteine 600 mg daily with folic acid 500 mcg daily improves the likelihood of maintaining pregnancy past 20 weeks when compared with folic acid alone in adults with a history of recurrent pregnancy loss (64616).
• Multiple sclerosis (MS). It is unclear if oral and intravenous N-acetyl cysteine are beneficial in patients with MS. Details: One clinical trial in a small group of patients with MS shows that intravenous and oral N-acetyl cysteine in addition to standard care for 2 months improves self-reported cognition by a moderate amount when compared with standard care alone. Self-reported attention also seems to improve (102657).
• Nitrate tolerance. Intravenous N-acetyl cysteine seems to reduce the development of nitrate tolerance. Oral N-acetyl cysteine has shown mixed results for this use. Details: Some clinical research shows that concurrent intravenous or oral administration of N-acetyl cysteine reduces the development of nitroglycerin tolerance (832,2245,64546). However, other research suggests that oral N-acetyl cysteine does not reduce the development of nitroglycerin tolerance in patients with angina (2281,2282).
• Nonalcoholic steatohepatitis (NASH). It is unclear if oral N-acetyl cysteine is beneficial in patients with NASH. Details: One small clinical study in patients with NASH shows that taking N-acetyl cysteine 1.2 grams with metformin 850-1500 mg daily for 48 weeks reduces NASH activity scores and measures of steatosis and hepatocellular ballooning, but not inflammation or fibrosis, when compared to baseline. However, taking the same dose of N-acetyl cysteine and metformin along with ursodeoxycholic acid 15 mg/kg daily does not improve these outcomes, or improve liver enzyme levels, when compared with baseline (102026). The reasons for these disparate findings are unclear. Inadequate statistical power and the lack of a comparator group limit the validity of these findings.
• Obsessive-compulsive disorder (OCD). Oral N-acetyl cysteine might improve some symptoms of OCD when used with fluvoxamine in adults. Its effects when used in combination with other psychiatric medications or as monotherapy in children and adults is unclear. Details: Preliminary clinical research in adults shows that taking N-acetyl cysteine 1000 mg twice daily along with fluvoxamine 200 mg daily for 10 weeks modestly reduces overall symptoms of OCD and symptoms of obsession when compared with fluvoxamine alone. However, the addition of N-acetyl cysteine is not associated with an improvement in symptoms of compulsion, nor with a statistically significant increase in partial or complete responders, when compared with fluvoxamine alone (97048). A clinical trial in adults with OCD who are taking various psychiatric medications shows that adding oral N-acetyl cysteine 2000-4000 mg daily for 20 weeks does not reduce symptoms of OCD, or improve secondary outcomes such as anxiety, mood, functioning, or quality of life, when compared with placebo (108450). Over half (63%) of patients had a comorbid psychiatric diagnosis, limiting the applicability of these findings. Other preliminary clinical research in adults with moderate to severe OCD who are taking various psychiatric medications shows that taking N-acetyl cysteine 3000 mg daily for 16 weeks does not improve OCD symptoms when compared with placebo (97045). A very small preliminary clinical trial in children aged 8-17 years, most of whom are not taking psychiatric medications, shows some benefit for symptom reduction when N-acetyl cysteine 2700 mg daily for 12 weeks is compared with placebo (102656).
• Otitis media. Although there has been interest in using ear drops containing N-acetyl cysteine for otitis media, there is insufficient reliable information about the clinical effects of N-acetyl cysteine for this purpose.
• Polycystic ovary syndrome (PCOS). Oral N-acetyl cysteine might improve pregnancy-related outcomes in PCOS, although it appears to be less effective than metformin. Evidence on its benefits for other symptoms of PCOS is conflicting. Details: Some research in patients with PCOS shows that N-acetyl cysteine can increase insulin sensitivity, improve hirsutism, and improve menstrual irregularity (64435,64550,91245,102121). It may also improve fasting insulin levels, but results are conflicting (64435,64550,91245). Other research shows that N-acetyl cysteine, alone or as a specific combination product (Ovaric HP, Just Pharma), increases ovulation rates in some, but not all, patients with PCOS (64480,64550,64553,91246,91247,102121). A meta-analysis of clinical research suggests that N-acetyl cysteine increases the odds of having a live birth, getting pregnant, and/or ovulating by about 3-fold when compared with placebo. Its effects on the odds of pregnancy and ovulation appear to be greater in those resistant to clomiphene citrate. However, when compared with metformin, N-acetyl cysteine appears to decrease the odds of getting pregnant by about 60% and decrease the odds of ovulation by about 87%. N-acetyl cysteine also does not appear to reduce the rate of miscarriage, menstrual irregularity, or the severity of acne or hirsutism in people with PCOS (93057). Another meta-analysis shows that N-acetyl cysteine in various doses is associated with an insignificant improvement in ovulation and pregnancy rate, multiple pregnancy rate, and miscarriage rate, and is less efficacious than metformin for all of these outcomes (106888).
• Post-traumatic stress disorder (PTSD). It is unclear if oral N-acetyl cysteine is beneficial in veterans with PTSD. Details: A small clinical study in veterans with PTSD and a history of substance use disorders shows that taking N-acetyl cysteine 1200 mg orally twice daily for 8 weeks while receiving cognitive behavioral therapy reduces depressive symptoms and the rate of self-reported PTSD symptoms when compared with cognitive behavioral therapy plus placebo. Additionally, receiving N-acetyl cysteine reduces the amount and frequency of cravings by 81% and 72%, respectively, compared to a reduction of 32% and 29% for those receiving cognitive behavioral therapy with placebo. The use of N-acetyl cysteine did not impact the intensity of cravings or the actual rate of substance use during the study, which was low for all patients (97037).
• Postmenopausal conditions. It is unclear if oral N-acetyl cysteine is beneficial for preventing postmenopausal bone loss. Details: One small clinical trial shows that taking N-acetyl cysteine 2 grams daily for 3 months does not reduce postmenopausal bone loss when compared with placebo (64576).
• Preterm labor. It is unclear if oral N-acetyl cysteine is beneficial for reducing the risk for preterm labor. Details: Some clinical research shows that taking N-acetyl cysteine 0.6 grams daily orally in combination with 17-hydroxyprogesterone caproate (17-OHPC), beginning at 16 to 18 weeks gestation and continuing until active labor, increases the likelihood of reaching 36 weeks gestation and increases gestational age at delivery in adults with previous preterm labor and bacterial vaginosis when compared with 17-OHPC alone (64615). However, taking oral N-acetyl cysteine 0.6 grams every 8 hours, beginning at 25 to 33 weeks gestation and continuing until delivery, does not improve the treatment-to-delivery interval when compared with placebo in adults with early onset severe pre-eclampsia and/or HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome (64493).
• Radiation-induced sialadenitis. It is unclear if mouthwash containing N-acetyl cysteine is beneficial for reducing dry mouth during chemoradiotherapy. Details: One clinical trial in a small group of patients undergoing chemoradiotherapy for head and neck cancer shows that using a mouth rinse containing N-acetyl cysteine 500 mg five times daily during radiotherapy and 2 weeks postradiotherapy improves daytime and total sticky saliva and feelings of dry mouth by up to 38% when compared with placebo. However, N-acetyl cysteine does not seem to improve nighttime symptoms (102661).
• Schizophrenia. Oral N-acetyl cysteine seems to improve negative symptoms of schizophrenia. The benefits of N-acetyl cysteine on positive symptoms of schizophrenia are less clear. Details: A meta-analysis of clinical research shows that taking N-acetyl cysteine for at least 6 months has a small to moderate effect on negative symptoms when compared with placebo. However, taking N-acetyl cysteine for only 8 weeks does not reduce negative symptoms, suggesting that a longer duration of treatment may be necessary (102658). Individual clinical studies show that N-acetyl cysteine does not improve positive symptoms, social function, cognition, and clinical global impression when compared with placebo (64605,99528). However, a meta-analysis of available research shows that taking N-acetyl cysteine for any duration has a small effect on positive symptoms, a moderate effect on working memory, and a large effect on overall symptoms (102658). It is possible that many individual studies were underpowered to detect a difference.
• Sepsis. Small clinical studies suggest that intravenous N-acetyl cysteine may improve respiratory function and tissue oxygenation, but not mortality, in patients with septic shock. Details: Two small clinical studies show that intravenous N-acetyl cysteine might improve respiratory function and tissue oxygenation, but not mortality, in some patients with recently diagnosed septic shock when compared with placebo (64760,64797).
• Sjogren syndrome. Small clinical studies suggest that oral N-acetyl cysteine may improve ocular and oral manifestations of this condition. Details: Two small clinical studies in adults with Sjogren syndrome show that taking oral N-acetyl cysteine 200 mg three times daily for 4 weeks reduces eye soreness and irritability, bad breath, and daytime thirst when compared with a control group; however, objective signs of dry eye were not improved (64673,64812).
• Systemic lupus erythematosus (SLE). It is unclear if oral N-acetyl cysteine is beneficial in patients with SLE. Details: One small clinical trial shows that taking N-acetyl cysteine orally 2.4-4.8 grams daily for 3 months significantly reduces disease activity and fatigue when compared with placebo in patients with SLE (91242).
• Thrombocytopenia. Oral N-acetyl cysteine has only been evaluated in combination with other ingredients, its effect when used alone is unclear. Details: A very small clinical study in adults with primary immune thrombocytopenia resistant or refractory to steroid therapy shows taking N-acetyl cysteine 400 mg every 8 hours with atorvastatin daily for at least one month at least doubles platelet count or increases it above 30 × 109/L compared to baseline in 60% of participants. However, 40% of participants did not respond to treatment (111572). It is unclear if this effect is due to N-acetyl cysteine, atorvastatin, or the combination. The validity of these findings is limited by the very small sample size, insufficient randomization, lack of a comparator group, and low retention rate, especially in the non-responder group.
• Tourette syndrome. It is unclear if oral N-acetyl cysteine is beneficial in patients with this condition. Details: One small clinical trial in children 8-17 years of age with Tourette syndrome shows that taking N-acetyl cysteine 600 mg twice daily for 2 weeks, followed by 1200 mg twice daily for the next 10 weeks, does not improve tic symptoms, premonitory urges, or the comorbid symptoms of obsessive-compulsive disorder (OCD), attention deficit-hyperactivity disorder (ADHD), anxiety, or depression when compared with placebo (97040).
• Trichotillomania. Oral N-acetyl cysteine might offer some benefit to adults, but not children, with trichotillomania. Details: One small clinical trial in adults shows that taking N-acetyl cysteine orally, in doses up to 2400 mg daily, significantly decreases the urge to pull hair, the amount of hair pulled, and patients' perception of their control over hair pulling as measured by a self-rating scale. After 12 weeks of treatment, scores decreased by 40% (16840). However, in children, taking N-acetyl cysteine in doses up to 2400 mg daily for 12 weeks does not seem to improve hair pulling when compared with placebo (91235).
• Ulcerative colitis. It is unclear if oral N-acetyl cysteine is beneficial in patients with ulcerative colitis. Details: One small clinical trial shows that oral N-acetyl cysteine 0.8 grams daily in combination with mesalamine 2.4 grams daily for 4 weeks does not improve the rate of clinical remission in individuals with ulcerative colitis when compared with mesalamine alone (64606).
• Urinary tract infections (UTIs). Oral N-acetyl cysteine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Observational research in female breast cancer survivors has found that taking the combination of D-mannose 500 mg, N-acetyl cysteine 100 mg, and Morinda citrifolia fruit extract 200 mg daily for 2 months in addition to antibiotic therapy is associated with reduced recurrence of UTIs and urinary discomfort when compared with antibiotics alone (97360).
• Uterine fibroids. It is unclear if oral N-acetyl cysteine is beneficial in patients with uterine fibroids. Details: Preliminary clinical research shows that taking N-acetyl cysteine 600 mg daily for 12 weeks reduces the volume of uterine fibroids by about 25%, compared with a reduction of about 1% with placebo. N-acetyl cysteine also reduces painful and heavy menstrual bleeding when compared with placebo (106889).
• Wound healing. It is unclear if postoperative intravenous N-acetyl cysteine is beneficial in patients undergoing lower extremity amputation. Details: A clinical study in patients undergoing lower extremity amputation due to critical limb-threatening ischemia shows that receiving postoperative intravenous N-acetyl cysteine 1200 mg twice daily for 5 days, beginning within 3 hours after surgery, improves tissue perfusion from days 3 to 5 and amputation stump healing at day 30 in patients that are defined as high-risk, but not in the intent-to-treat population, when compared with placebo (108448). The validity of these findings is limited due to the short duration of treatment and the inclusion of both above-the-knee and below-the-knee amputations. More evidence is needed to rate N-acetyl cysteine for these uses.

(Read more about N-ACETYL CYSTEINE (NAC))

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Melasma. Preliminary clinical research in adults with melasma shows that applying a brewed parsley water to the face with a cotton ball on 6 days of each week for 8 weeks is as effective as hydroquinone 4% cream for improving dark spots (96828). More evidence is needed to rate parsley for this use.

(Read more about PARSLEY)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Diabetes. Although there has been interest in using oral pea protein for diabetes, there is insufficient reliable information about the clinical effects of pea protein for this purpose.
• Exercise-induced muscle damage. It is unclear if oral pea protein is beneficial for exercise-induced muscle damage. Details: A small clinical study in healthy, untrained males shows that taking a specific type of pea protein (Nutralys S85 Plus, Roquette) 0.3 grams/kg 3 times daily for 5 days after a 90-minute whole-body high-intensity eccentric exercise bout does not reduce surrogate markers of exercise-induced muscle damage, including creatine kinase, lactate dehydrogenase, and myoglobin, when compared with whey protein or water (104758). However, the study may have been inadequately powered to detect a difference between groups and is further limited by double-blinding restricted only to the protein supplements. The water control did not match the taste, texture, or calorie content of the protein supplements. Another small clinical trial in healthy, physically active older adults shows that taking pea protein 25 grams daily for 10 days prior to and 3 days after a single 20-30 km endurance walk does not improve markers of muscle damage when compared with placebo and may be less effective when compared with whey protein (111729).
• Exercise-induced muscle soreness. It is unclear if oral pea protein is beneficial for exercise-induced muscle soreness. Details: A small clinical study in healthy, untrained males shows that taking a specific type of pea protein (Nutralys S85 Plus, Roquette) 0.3 grams/kg 3 times daily for 5 days after a 90-minute whole-body high-intensity eccentric exercise bout does not reduce exercise-induced muscle soreness when compared with whey protein or water (104758). However, the study may have been inadequately powered to detect a difference between groups and is further limited by double-blinding restricted only to the protein supplements. The water control did not match the taste, texture, or calorie content of the protein supplements. Another small clinical trial in healthy, physically active older adults shows that taking pea protein 25 grams daily for 10 days prior to and 3 days after a single 20-30 km endurance walk does not improve muscle soreness when compared with whey protein or placebo (111729).
• Hyperlipidemia. Although there has been interest in using oral pea protein for hyperlipidemia, there is insufficient reliable information about the clinical effects of pea protein for this purpose.
• Hypertension. It is unclear if oral pea protein hydrolysate is beneficial for hypertension. Details: A small clinical study in adults with elevated blood pressure shows that taking a pea protein hydrolysate 3 grams daily for 3 weeks reduces systolic blood pressure by 6 mmHg when compared with placebo. Taking the same product at a dose of 1.5 grams daily does not reduce blood pressure (94973).
• Irritable bowel syndrome (IBS). Oral pea protein has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small open-label study in patients with diarrhea-predominant IBS shows that taking two tablets of a specific product (Gelsectan, Noventure) containing pea protein, grape seed extract tannins, xyloglucan, and xylo-oligosaccharides (doses unknown) before breakfast and dinner daily for 6 months improves IBS-related symptoms, including diarrhea, pain, bloating, defecatory frequency, stool consistency, and defecatory urgency when compared to baseline (108881). The validity of this study is limited by a lack of placebo control group.
• Muscle strength. Clinical research on the impact of oral pea protein on muscle strength is mixed. Its effects might be similar to whey protein. Pea protein may be more effective in individuals with lower baseline muscle strength. Details: A clinical trial in physically active, but non-resistance trained, young male adults participating in a 12-week upper body resistance training program shows that taking a specific type of pea protein isolate (Nutralys, Roquette) 25 grams twice daily over the training program does not augment training-induced increases in muscle thickness or strength when compared with whey protein or isocaloric placebo. However, a post hoc analysis of participants with the lowest muscle strength at baseline shows that pea protein supplementation increases bicep muscle thickness more than placebo and to a similar degree as whey protein (95426). Additionally, a very small clinical study in trained adults shows that taking pea protein 24 grams twice daily during an 8-week high-intensity functional training program improves muscle strength to a similar degree as whey protein, while neither supplement appears to impact muscle thickness or body mass (102013). The small study size and lack of an isocaloric, protein-free control limits conclusions that can be drawn from this study.
• Obesity. Although there has been interest in using oral pea protein for obesity, there is insufficient reliable information about the clinical effects of pea protein for this purpose.
• Postoperative recovery. Oral pea protein has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults undergoing gastrointestinal resection due to cancer shows that consuming a beverage (Providextra, Fresenius Kabi) containing pea protein hydrolysate 11% and carbohydrates 89% the night before (400 mL) and the morning of surgery (200 mL) reduces postoperative hospital stay by almost 2-fold when compared with conventional preoperative fasting (94933). It is unclear if these findings are due to pea protein, carbohydrates, or the combination. More evidence is needed to rate pea protein for these uses.

(Read more about PEA PROTEIN)

Proteolytic enzymes represent a wide group of enzymes that are used alone or in combination. See specific monographs for effectiveness information.

(Read more about PROTEOLYTIC ENZYMES (PROTEASES))

POSSIBLY EFFECTIVE

• Dyslipidemia. Taking full-fat rice bran, reduced-fat rice bran, or rice bran oil daily appears to modestly reduce lipoprotein (LDL) cholesterol levels. The effects of rice bran on other types of cholesterol are unclear. Details: Clinical research in adults with hypercholesterolemia shows that taking full-fat rice bran 85 grams daily for 6 weeks lowers total cholesterol by 8% and LDL cholesterol by 14% when compared with placebo. Rice bran does not seem to affect triglycerides or high-density lipoprotein (HDL) cholesterol (865). Conversely, a meta-analysis of 8 small clinical studies in patients with hypercholesterolemia, type 2 diabetes, or who have survived colorectal cancer shows that taking rice bran 20 to 100 grams/day does not improve total cholesterol, LDL, HDL, or triglycerides when compared with control (112092). However, the interpretation of these findings is limited by the heterogeneity of patients, dosages, and study designs included in the analysis. The oil from rice bran has also been shown to affect the lipid profile (1354,97524,100481,106591). Multiple meta-analyses of small clinical studies show that taking rice bran oil for 2.5-13 weeks reduces LDL cholesterol levels by 7-8 mg/dL when compared with control. However, rice bran oil does not appear to affect HDL cholesterol levels. Rice bran oil may also modestly lower triglyceride levels; however, results are conflicting between meta-analyses (97524,106591). The validity of these findings is limited by inclusion of low-quality studies and the inclusion of patients without hypercholesterolemia at baseline. The effectiveness of rice bran oil may also depend on the content of gamma-oryzanol. A small clinical study in patients with hyperlipidemia shows that taking rice brain oil 30 mL containing 4000, 8000, and 11000 ppm gamma-oryzanol daily for 4 weeks decreases LDL-C levels when compared with control. The greatest effects occurred in the patients receiving higher gamma-oryzanol content (8000 and 11000 ppm) (100481).

POSSIBLY INEFFECTIVE

• Colorectal cancer. Clinical and population research suggest that consuming dietary cereal fiber, including rice bran, doesn't seem to reduce the risk of colorectal cancer. Details: Clinical research in adults with colorectal adenomas shows that increasing dietary fiber, including rice bran, for up to 4 years does not reduce the risk of recurrent adenomas (4820). Observational research in females has also found that increasing dietary fiber consumption, including rice bran, for up to 16 years is not associated with colorectal cancer risk (4821). However, the validity of these studies is limited by the use of multiple sources of dietary fiber.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alcohol use disorder. Although there has been interest in using oral rice bran for alcohol use disorder, there is insufficient reliable information about the clinical effects of rice bran for this purpose.
• Alopecia areata. Although there has been interest in using topical rice bran for alopecia areata, there is insufficient reliable information about the clinical effects of rice bran for this purpose.
• Androgenic alopecia. It is unclear if topical rice bran is beneficial in patients with androgenic alopecia. Details: One small clinical study shows that applying dermal rice bran 5% supercritical CO2 extract (RB-SCE) 4 mL to the scalp twice daily for 16 weeks improves hair density and visual ratings of hair growth in males, but not females, with androgenic alopecia when compared with placebo (97523).
• Athletic performance. Although there has been interest in using oral rice bran for athletic performance, there is insufficient reliable information about the clinical effects of rice bran for this purpose.
• Atopic dermatitis (eczema). It is unclear if topical rice bran is beneficial in patients with atopic dermatitis. Details: Low-quality observational research has found that using a topical rice bran broth bath for 2-5 months reduces skin symptoms in approximately 69% to 94% of patients with atopic dermatitis when compared with baseline. However, the validity of this study is limited by the lack of a comparator group (872).
• Cardiovascular disease (CVD). There is limited evidence on the oral use of rice bran oil in coronary artery disease (CAD). Details: Preliminary clinical research in adult males who recently underwent angioplasty for CAD shows that taking oral rice bran oil 30 grams daily for 8 weeks improves left ventricular ejection fraction by 35% more when compared with taking sunflower oil 30 grams daily. Taking rice bran oil also improves triglyceride and low-density lipoprotein cholesterol levels, but not high-density lipoprotein cholesterol levels, when compared with placebo (106590).
• Diabetes. It is unclear if oral rice bran is beneficial in patients with type 2 diabetes. Details: A small clinical study in adults with type 2 diabetes shows that ingesting stabilized rice bran 20 grams once daily for 12 weeks does not reduce fasting blood glucose, postprandial glucose, or glycated hemoglobin (HbA1c) when compared with ingesting a placebo of 20 grams milled rice flour (97522). However, this study may not have been adequately powered to identify a difference between groups.
• Gastric cancer. Although there has been interest in using oral rice bran to prevent gastric cancer, there is insufficient reliable information about the clinical effects of rice bran for this purpose.
• Halitosis. It is unclear if oral rice bran is beneficial in patients with halitosis. Details: Preliminary clinical research shows that swishing with 15 mL of rice bran oil for 10 minutes and spitting it out, also referred to as "oil pulling", once daily for 14 days, improves halitosis scores when compared with baseline in pregnant adults with halitosis. Rice bran oil was similarly effective to sesame oil or chlorhexidine for reducing halitosis (97526).
• HIV/AIDS. Although there has been interest in using oral rice bran for HIV/AIDS, there is insufficient reliable information about the clinical effects of rice bran for this purpose.
• Hypercalciuria. It is unclear if oral rice bran is beneficial in patients with hypercalciuria. Details: Preliminary observational research in adults with idiopathic hypercalciuria shows that taking oral defatted rice bran 10 grams twice daily for up to 3 years reduces annual kidney stone recurrence by 83% when compared with baseline (876). The validity of this study is limited by the lack of a comparator group.
• Hypertension. Although there has been interest in using oral rice bran for hypertension, there is insufficient reliable information about the clinical effects of rice bran for this purpose.
• Insomnia. It is unclear if oral rice bran is beneficial in patients with insomnia. Details: A small clinical study in patients with disturbed sleep shows that taking a specific rice bran extract (S&D Co.) 1000 mg daily for 2 weeks improves total sleep time by about 20 minutes when compared with placebo. Taking rice bran extract also modestly improves sleep efficiency and sleep quality scores when compared with placebo (103760).
• Obesity. Although there has been interest in using oral rice bran for obesity, there is insufficient reliable information about the clinical effects of rice bran for this purpose. More evidence is needed to rate rice bran for these uses.

(Read more about RICE BRAN)

POSSIBLY EFFECTIVE

• Food allergies. Clinical research in infants 1 month of age and older with IgE-mediated allergy to cow's milk protein shows that administering either a partially hydrolyzed rice protein formula supplemented with lysine and threonine or a hydrolyzed cow's milk formula until age 24 months results in similar overall growth. Hydrolyzed rice protein formula is also similarly effective to hydrolyzed cow's milk formula for improving the rate of tolerance to cow's milk (97798).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Exercise-induced muscle soreness. Preliminary clinical research shows that taking rice protein isolate (Oryzatein rice protein, Axiom Foods) 48 grams in water immediately after resistance training three times weekly for 8 weeks is as effective for reducing muscle soreness and increasing perceived recovery as taking whey protein isolate 48 hours after each individual session (95674). The validity of this finding is limited by the lack of a placebo comparator group.
• Muscle strength. Preliminary clinical research shows that taking rice protein isolate (Oryzatein rice protein, Axiom Foods) 48 grams in water immediately after resistance training three times weekly for 8 weeks is as effective for increasing muscle mass and muscle strength as taking whey protein isolate 48 hours after each individual session (95674). The validity of this finding is limited by the lack of a placebo comparator group.

(Read more about RICE PROTEIN)

LIKELY EFFECTIVE

• Cystic fibrosis. Long-term nebulized hypertonic sodium chloride improves lung function and reduces pulmonary exacerbations in patients with cystic fibrosis. Details: Meta-analyses of clinical research in adults with cystic fibrosis show that, when taken along with a bronchodilator and other standard therapies, nebulized hypertonic sodium chloride in concentrations of 3% to 7%, up to 10 mL twice daily for 4 weeks, increases forced expiratory volume at one second (FEV1) when compared with isotonic saline (sodium chloride 0.9%) (26230,26230). This benefit was not seen at 48 weeks. Other clinical research in adults with cystic fibrosis shows that inhaling sodium chloride 7%, 4 mL twice daily for 48 weeks, does not improve FEV1 when compared with isotonic saline. However, chronic treatment with hypertonic saline does reduce the number of pulmonary exacerbations and increase the number of patients without pulmonary exacerbations when compared with isotonic saline (29402). It is not clear if this benefit occurs in children with cystic fibrosis. The Pulmonary Clinical Practice Guidelines Committee of the Cystic Fibrosis Foundation recommends that individuals with cystic fibrosis aged 6 years or older use nebulized hypertonic saline long-term to improve lung function, reduce the number of exacerbations, and improve quality of life (29403).

POSSIBLY EFFECTIVE

• Amphotericin B nephrotoxicity. Oral sodium chloride seems to prevent nephrotoxicity associated with use of amphotericin B. Details: Clinical research shows that administering oral or intravenous sodium chloride 150 mEq daily during treatment with amphotericin B can attenuate the rise in serum creatinine levels and preserve renal function when compared to treatment with amphotericin B alone (26226).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Bipolar disorder. It is unclear if oral sodium is beneficial in preventing lithium level fluctuations in patients with bipolar disorder. Details: A moderate-sized open-label clinical study in adults with type I bipolar disorder receiving lithium carbonate shows that taking sodium chloride 1 gram daily for 12 weeks along with dietary salt restriction of 1 gram daily reduces the percentage of patients with lithium level fluctuations above 0.8 mEq/L, but does not significantly affect serum sodium, potassium, aldosterone, or creatinine levels when compared with controls who were not salt restricted, but were advised not to consume additional salt at the table (112909). However, the interpretation of these findings is limited by missing data in both groups.
• Canker sores. Although there is interest in using topical sodium chloride for canker sores, there is insufficient reliable information about the clinical effects of sodium chloride for this condition.
• Congestive heart failure. It is unclear if oral sodium is beneficial in patients with acute decompensated heart failure requiring decongestive therapy with diuretics. Details: A moderate-sized clinical study in adults hospitalized with acute decompensated heart failure requiring high-dose intravenous furosemide shows that taking sodium chloride 2 grams three times daily for up to 96 hours does not affect patient weight or serum creatinine levels when compared with placebo (112911). However, the clinical relevance of this study is unclear and it may have been inadequately powered to detect a difference between groups.
• Conjunctivitis. Although there is interest in using ophthalmic sodium chloride for conjunctivitis, there is insufficient reliable information about the clinical effects of sodium chloride for this condition.
• Hyponatremia. Although there is interest in using oral sodium chloride for hyponatremia, there is insufficient reliable information about the clinical effects of oral sodium chloride for this condition.
• Pharyngitis. Although there is interest in using topical sodium chloride for pharyngitis, there is insufficient reliable information about the clinical effects of sodium chloride for this condition.
• Prematurity. It is unclear if oral sodium is beneficial for premature infants. Details: Preliminary clinical research in infants born at less than 32 weeks' gestation shows that adding sodium 4 mEq/kg daily to enteral feedings, starting from the 7th day after birth and continuing through the 35th day, reduces the risk of developing hyponatremia and improves weight gain when compared with adding water (98180). A small, open-label clinical study in newborns less than 35 weeks gestation shows that high sodium intake, defined as an average of 0.25% sodium in maintenance fluids, for 48 hours on day 2 and 3 after birth results in less weight loss within the first 72 hours of life when compared with control, but does not improve mortality, length of hospital stay, or complications from prematurity (112908). However, interpretation of these findings is limited by varied concentrations of sodium as an intervention. More evidence is needed to rate sodium for these uses.

(Read more about SODIUM)

POSSIBLY INEFFECTIVE

• Bladder cancer. Consuming tomatoes and tomato-based products does not appear to reduce the risk of bladder cancer. Details: Observational studies have found no association between tomato and tomato-based product intake and the risk of bladder cancer (2407).
• Breast cancer. Consuming tomatoes and tomato-based products does not appear to reduce the risk of breast cancer. Details: Observational studies have found no association between tomato or tomato-based product intake and risk of breast cancer (15747).
• Diabetes. Consuming tomatoes and tomato-based products does not appear to prevent the development of type 2 diabetes or improve glycemic control in patients with type 2 diabetes. Details: Observational studies have found that increasing intake of tomato or tomato-based products does not significantly decrease the risk of developing type 2 diabetes (14004,14361). Additionally, a small clinical study in non-smoking male patients with type 2 diabetes shows that consuming raw tomato 200 grams daily for 8 weeks does not improve plasma glucose levels when compared to baseline (102477). The validity of this finding is limited by the lack of comparator group.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aging skin. It is unclear if tomato improves skin appearance. Details: A small study of females aged 35-55 shows that taking a certain tomato pulp product (Lumenato, Lycored) 1 capsule daily for 12 weeks improves patient reported skin appearance scores when compared to baseline (110523). The interpretation of this result is limited by the lack of a placebo group.
• Benign prostatic hyperplasia (BPH). Oral tomato powder has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in patients with BPH shows that taking 5 grams of a whole tomato food supplement consisting of tomato powder and polyphenols extracted from olives daily for 2 months improves quality of life and reduces lower urinary tract symptoms including urinary frequency, urinary urgency, and nocturia when compared to baseline. No improvements in these symptoms were reported with placebo (106656). It is unclear if these findings are due to tomato, olive polyphenols, or the combination.
• Cardiovascular disease (CVD). It is unclear if consuming tomato-based foods reduces the risk of cardiovascular events. Details: Observational research has found that increased consumption of tomato-based foods is associated with an insignificant trend towards a reduced risk of myocardial infarction, stroke, and other cardiovascular events (10418,102178).
• Cataracts. It is unclear if consuming tomatoes reduces the risk of cataracts. Details: Observational research has found that eating more than 3 servings of tomatoes each week may decrease the risk of developing cataracts (9439).
• Cervical cancer. It is unclear if consuming tomatoes reduces the risk of cervical cancer. Details: Observational research has found that increased tomato intake is associated with a decreased risk of cervical cancer (2407).
• Colorectal cancer. Research on the benefits of consuming tomatoes or tomato-based products for the prevention of colorectal cancer is conflicting and limited to observational studies only. Details: Some observational research has found that increasing tomato or tomato-based product intake is associated with a reduced risk of colorectal cancer (2404,2407). However, higher quality observational research has found that tomato-based product intake is not associated with risk of colorectal cancer (15747).
• Exercise-induced asthma. It is unclear if oral tomato extract is beneficial in patients with exercise-induced asthma. Details: A small clinical study in patients with exercise-induced asthma shows that taking a specific tomato extract (Lyc-O-Mato, LycoRed Ltd) 30 mg daily for 1 week seems to reduce exercise-induced asthma when compared with placebo. The tomato extract seems to prevent decreases in forced expiratory volume (FEV1) in response to exercise (7898).
• Gastric cancer. Research on the benefits of consuming tomatoes or tomato-based products for the prevention of gastric cancer is conflicting and limited to observational studies only. Details: Some observational studies have found that increasing tomato or tomato-based product intake is associated with a reduced risk of gastric cancer in some subgroups of patients (2407,15747,102480). However, other observational research has found that tomato-based product intake is not associated with risk of gastric cancer (15747). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim regarding tomatoes and gastric cancer risk. However, the FDA concludes that it is highly unlikely that tomatoes reduce the risk of gastric cancer (102375).
• Hyperlipidemia. Small clinical studies suggest that consuming tomato sauce or semi-dried tomatoes may modestly reduce low-density lipoprotein (LDL) cholesterol levels in patients with hyperlipidemia. Details: One small, open-label clinical trial in patients with hyperlipidemia shows that consuming a specific vine-ripened tomato sauce (OsteoCol, C.G. Food, SRL) 150 mL daily for 6 weeks reduces total cholesterol and LDL cholesterol levels when compared to baseline. Patients adherent to the tomato sauce regimen showed an 11 mg/dL and 12 mg/dL reduction in total and LDL cholesterol, respectively, while those consuming a sterol-enriched yogurt saw total and LDL cholesterol levels decrease by 18 mg/dL and 16 mg/dL, respectively. Patients with a baseline LDL cholesterol level of greater than 152 mg/dL saw the greatest benefit from this tomato sauce (106653). Another small clinical study in Japanese patients with borderline high cholesterol shows that taking 50 grams of a semi-dried tomato containing lycopene 22-27.8 mg daily for 12 weeks modestly reduces LDL cholesterol levels but does not affect high-density lipoprotein (HDL) cholesterol levels when compared with taking 50 grams of a tomato without lycopene (102180). This suggests that any benefit of tomato on blood lipid levels is likely due to its lycopene content.
• Hypertension. Small clinical studies suggest that oral tomato extract may modestly reduce blood pressure in patients with hypertension. Details: Several small clinical trials in patients with hypertension show that taking a specific tomato extract product (Lyc-O-Mato, LycoRed, Ltd.), providing lycopene 15-30 mg daily, for 6-8 weeks, reduces systolic blood pressure by around 7-13 mmHg and diastolic blood pressure by around 4-6 mmHg when compared to baseline (14287,60415,102182). The validity of these findings is limited by the lack of a comparator group. Evidence on the use of tomato in patients with pre-hypertension is mixed. One small clinical study in patients with pre-hypertension shows that taking a specific tomato extract (Fruitflow, Provexis Plc, UK.) 150 mg as a single dose seems to modestly reduce blood pressure over a 24-hour period when compared with placebo (102478). This study is limited by its small size and short duration. Another small clinical study in pre-hypertensive patients shows that taking a specific tomato extract (Lyc-o-Mato, LycoRed Ltd) containing lycopene 15 mg daily for 8 weeks does not reduce blood pressure when compared with placebo (42079). The impact of dietary tomato consumption on preventing hypertension has also been evaluated. A large prospective observational study in Chinese adults without a history of smoking or myocardial infarction suggests moderate dietary intake of tomatoes (i.e. up to 33.3 grams daily) is associated with a 49-58% reduction in the risk of developing new onset hypertension when compared with no consumption after about 6 years' follow up. However, the associated risk reduction was less with higher consumption (110525). These results may not apply to patients in countries where dietary trends are different, and the validity of these findings is limited by the potential for confounding.
• Lung cancer. It is unclear if consuming tomatoes reduces the risk of lung cancer; the available research is conflicting. Details: Some observational studies have found an association between increased tomato and tomato-based product consumption and a reduced risk of lung cancer; however, many of these studies were not stratified based on the patient's smoking status. Higher quality, large-scale observational studies have not found any association between tomato product intake and lung cancer risk (15747).
• Muscle strength. It is unclear if consuming tomatoes improves muscle strength or attenuates declines in muscle strength. Details: A small observational study in Japanese adults 22-68 years of age found that more frequent tomato consumption (2 or more times weekly) is associated with an attenuated rate of handgrip strength decline over 3 years when compared with less frequent tomato consumption (102473).
• Ovarian cancer. Research on the benefits of consuming tomatoes or tomato-based products for the prevention of ovarian cancer is conflicting and limited to observational studies only. Details: Some observational research has found that increased tomato or tomato juice intake is not associated with risk of ovarian cancer; however, consuming tomato sauce two or more times weekly is associated with a decreased risk (2407). Other observational research has found that increased dietary intake of lycopene, particularly from tomato sauce, is associated with a reduced risk of ovarian cancer in premenopausal patients (10133). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim regarding tomato sauce and ovarian cancer risk. However, the FDA concludes that it is highly uncertain that tomato sauce reduces the risk of ovarian cancer (102375).
• Pancreatic cancer. Research on the benefits of consuming tomatoes or tomato-based products for the prevention of pancreatic cancer is conflicting and limited to observational studies only. Details: A large-scale observational study have found that that tomato or tomato-based product intake is not associated with a decreased risk of pancreatic cancer (15747). However, other observational studies have found that raw tomato intake, and high tomato intake in general, is associated with a reduced risk of pancreatic cancer (2407,15747,15750). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim regarding tomatoes and pancreatic cancer risk. However, the FDA concludes that it is highly unlikely that tomatoes reduce the risk of pancreatic cancer (102375).
• Prostate cancer. Consuming tomatoes or tomato-based products may slightly lower the risk of prostate cancer; however, observational research is mixed and high-quality clinical trials addressing tomato intake and prostate cancer risk are lacking. Details: Some observational studies have found that consuming tomato products, including tomatoes, tomato sauce, pizza, or tomato juice, one time or more per week, is associated with a modest reduction in the risk of prostate cancer (2406,7772,7895,12878,15747,102476). However, other observational research has found that tomato consumption is not associated with a reduced risk of prostate cancer (14125,15172,15747,92171). One small clinical study in patients with high-grade prostatic intraepithelial neoplasia shows that taking tomato extract capsules containing lycopene 30 mg daily for 6 months does not impact benign tissue endpoints when compared with placebo (102471). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim stating that one-half to one cup of tomatoes or tomato sauce weekly may reduce the risk of prostate cancer. However, the FDA concludes that there is little scientific evidence to support this claim (102375).
• Radiation dermatitis. It is unclear if drinking tomato juice is beneficial in patients with radiation dermatitis. Details: One small, uncontrolled clinical trial in patients undergoing radiotherapy for breast cancer shows that drinking tomato juice 160 mg daily for 6 months after radiotherapy improves the severity of dermatitis within 1 month of treatment when compared to baseline (106654). The lack of a comparator group limits the validity of these findings; it is unclear how tomato juice consumption compared with the natural resolution of radiation dermatitis. More evidence is needed to rate tomato for these uses.

(Read more about TOMATO)

POSSIBLY EFFECTIVE

• Allergic rhinitis (hay fever). Oral turmeric seems to improve symptoms in people with allergic rhinitis. Details: Clinical research shows that taking a specific curcumin product (Organika Health Products) 500 mg daily for 2 months reduces nasal symptoms, including sneezing, itching, runny nose, and congestion, when compared with placebo in people with allergic rhinitis (96138).
• Depression. Most research shows that oral curcumin, a constituent of turmeric, 1 gram daily improves symptoms of depression after 6 weeks when taken along with an antidepressant. However, it is unclear whether curcumin is beneficial when used for greater than 8 weeks. Details: Curcumin appears to be most beneficial for depression in middle aged patients compared to older patients, when taken for at least 6 weeks, and when used at a dose of at least 1 gram daily. In adults with major depressive disorder, a meta-analysis of data from six clinical studies, as well as individual studies not included in this analysis, show that taking curcumin 1 gram daily along with an antidepressant moderately improves depression symptoms when compared with placebo (96131,96139). Another meta-analysis of 10 studies shows symptom reductions in patients with major depression when combined with conventional antidepressants, but not when used alone in patients with milder depressive symptoms. However, the quality of the evidence is low (104971). When used alone, one clinical study shows that curcumin 1 gram daily for 6 weeks may be similarly effective to fluoxetine 20 mg daily. Taking both products together seems to be more effective than either product alone, increasing the response rate from 65% to 78% (89728). Guidelines from The World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety Treatments (CANMAT) Taskforce state that curcumin extract at doses of 500-1000 mg daily is provisionally recommended for monotherapy or adjunctive use in mild to moderate depression (110318).
• Dyspepsia. Oral turmeric may be modestly beneficial for some patients with dyspepsia. In patients with functional dyspepsia, small clinical studies show that oral curcumin, a constituent of turmeric, is similarly effective when compared with the proton-pump inhibitor omeprazole. Details: Clinical research shows that taking turmeric 500 mg four times daily for 7 days can relieve overall symptoms of dyspepsia in 64% more patients than taking placebo (11144). A small, unblinded clinical study in patients with a type of dyspepsia called postprandial distress syndrome shows that taking turmeric 250 mg or 500 mg orally three times daily after meals for 4 weeks is associated with reductions in symptom scores which are similar to those seen with simethicone 60 mg three times daily for 4 weeks. However, the recurrence rate upon stopping therapy was about 14% with simethicone, compared with 43% to 46% with turmeric (104963). In patients with functional dyspepsia, taking the constituent curcumin appears similarly effective when compared with omeprazole, but might not provide further symptom reduction in those also taking famotidine or omeprazole (106063,106801,111599). One small clinical study in Iran shows that taking curcuminoids (C3 Complex, Sami Labs) 500 mg with piperine (Bioperine) 5 mg daily in addition to famotidine 40 mg daily for 30 days is no more effective for reducing overall symptoms of dyspepsia, such as abdominal pain, heartburn, bloating, and nausea, when compared with famotidine alone (106063). Another small clinical study in Thailand shows that taking curcumin 500 mg four times daily for 4 weeks is similarly effective for reducing dyspepsia severity and improving satisfaction when compared with an unspecified dose of omeprazole and more effective when compared with placebo (106801). Similarly, a moderate-size clinical study in Thailand shows that taking curcumin 500 mg four times daily for 4 weeks is similarly effective for reducing dyspepsia severity when compared with omeprazole 20 mg daily. However, taking curcumin and omeprazole in combination did not provide further symptom reduction (111599). The validity of these results is limited by the high rate of study dropouts.
• Hyperlipidemia. Research is conflicting on whether oral turmeric, curcumin, or curcuminoids can reduce serum lipids. Any improvement in lipids is likely to be small. Reasons for the conflicting findings may relate to turmeric formulation, duration of treatment, and/or the baseline cholesterol status of the included patients. Details: Results from meta-analyses of clinical research show inconsistent and conflicting results. One large meta-analysis of over 50 clinical studies in healthy adults and those with a variety of conditions shows that supplementation with turmeric or curcumin 80-4000 mg daily for 4-24 weeks reduces total cholesterol by 4 mg/dL, low-density lipoprotein (LDL) cholesterol by 5 mg/dL, and triglycerides by 7 mg/dL and increases high-density lipoprotein (HDL) cholesterol by 2 mg/dL when compared with placebo (112119). Two other meta-analyses of 27 clinical studies agree that taking turmeric, curcumin, or curcuminoids moderately reduce triglyceride levels but suggest that turmeric does not improve total cholesterol when compared with placebo. However, the meta-analyses contradict one another on whether turmeric and its constituents reduce LDL cholesterol or increase HDL cholesterol. (96128,96135). Additionally, a third meta-analysis of 10 clinical trials shows that taking up to 2400 mg daily of curcumin or curcuminoids, from turmeric or isolated sources, for up to 12 weeks, does not significantly improve triglycerides, LDL cholesterol, HDL cholesterol, or total cholesterol (110220).
• Nonalcoholic fatty liver disease (NAFLD). Oral curcumin, a constituent of turmeric, seems to attenuate fat deposition and improve some metabolic parameters in adults with NAFLD. Details: Clinical research shows that taking curcumin daily reduces NAFLD severity in 30% to 79% of patients, compared to 5% to 27.5% of patients receiving placebo. Curcumin also reduces the quantity of additional fat deposition in the liver to 0% to 4.5%, compared to 17.5% to 26% in those taking placebo. Most research shows that taking curcumin also reduces liver enzyme levels, body mass index (BMI), blood glucose levels, glycated hemoglobin (HbA1c), and total cholesterol when compared with placebo. Although some clinical research shows that taking curcumin improves levels of low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides, a meta-analysis of clinical research shows that these lipid levels are not improved in patients with NAFLD, specifically (97430,97431,100258,102350,106062,107120,109279,111349). However, another meta-analysis of 14 small, heterogeneous clinical studies in adults with NAFLD, that included some of these studies, shows that taking various doses and forms of turmeric or curcumin modestly reduces liver enzyme levels, improves measures of insulin resistance, reduces waist circumference, and improves LDL, HDL, and triglyceride levels when compared with placebo (111348). A small clinical trial in patients with NAFLD given specific lifestyle recommendations shows that taking curcumin modestly reduces the frequency of metabolic syndrome and fatty liver but does not have beneficial effects on fatty liver-associated indices, adiposity, or the atherogenic index, when compared with placebo (109285). Findings for specific endpoints are mixed between individual studies and may depend on the formulation of curcumin used or the duration of treatment. These studies have used various doses and formulations. In one study, 500 mg of a dispersion formulation equivalent to 70 mg of curcumin daily for 8 weeks was used (97430). Also, 250 mg once daily or 500 mg twice daily of a specific phytosomal formulation (Meriva, Indena) containing curcumin and soy phosphatidylcholine in a 1:2 ratio and standardized to an overall curcuminoid content of 20% was taken for 8 weeks (97431,106062). Another study used 1 gram of powdered turmeric rhizome taken three times daily with meals for 12 weeks (102350). One study used a curcumin-piperine complex (Curcumin C3 complex 500 mg plus Bioperine 5 mg) daily for 8 weeks (107120). One study used curcumin (Arjuna Natural Extract) 500 mg three times daily for 12 weeks (109285). Despite positive results with curcumin in several small clinical studies of patients with NAFLD, there is some concern that curcumin might cause hepatotoxicity in rare cases, especially when highly bioavailable formulations are used in high doses (103633). There is also evidence that the risk for hepatotoxicity with curcumin may be increased in individuals with the HLAB*35:01 allele (109288). Curcumin-induced hepatotoxicity has not been reported in clinical trials of patients with NAFLD, and its potential mechanism is unclear. However, patients seeking to take curcumin for NAFLD should be advised to monitor for symptoms of hepatotoxicity, including abdominal pain, dark urine, fatigue, jaundice, nausea, and pruritus.
• Oral mucositis. Oral curcumin or curcumin-containing mouthwash seem to reduce the development of severe oral mucositis, as well as reduce the severity and pain of oral mucositis, associated with cancer treatment. Details: Clinical research in patients receiving radiotherapy following recent radical surgery for oral cancer shows that taking turmeric (BCM-95, Arjuna Natural Pvt. Ltd., India) during radiotherapy reduces the incidence of severe oral mucositis to 25% or 20% in those taking turmeric 500 mg two or three times daily, respectively, compared with 65% in those taking placebo. The incidences of severe oral pain, dysphagia, and dermatitis were also reduced by at least 50% (105398). A small clinical study in patients receiving chemotherapy with or without head and neck radiotherapy shows that taking a specific nanoparticle formulation of curcumin (SinaCurcumin, ExirNanoSina) 80 mg twice daily for 7 weeks improves severity of oral mucositis at weeks 1, 4, and 7 and reduces pain at week 7 when compared with placebo. Effects were more pronounced in those with chemotherapy-induced oral mucositis than radiotherapy-induced oral mucositis (106800). In patients with head and neck cancer receiving radiotherapy, preliminary clinical research shows that swishing with 10 mL of turmeric solution (prepared by dissolving turmeric 400 mg in 80 mL of water) six times daily for 6 weeks delays mucositis and reduces the number of cases of intolerable mucositis by 49% when compared to swishing with 10 mL of povidone-iodine solution twice daily for 6 weeks (89726). Another small clinical study shows that swishing with 10 mL of nanoparticulate curcumin 0.1% mouthwash three times daily for 6 weeks is associated with a 50% lower risk of developing oral mucositis, and a delay of 2 weeks in the onset of mucositis, when compared with benzydamine 0.15% mouthwash (104969). A small clinical study in patients with mucositis due to head and neck radiotherapy shows that taking curcumin nanoparticles (SinaCurcumin, ExirNanoSina) 40 mg daily or using 10 mL of a curcumin 0.1% mouthwash three times daily for up to 21 days improves scores related to pain, burning, ulceration, and erythema when compared with placebo. Results with either oral or topical curcumin were similar (111350).
• Osteoarthritis. Some oral turmeric extracts and combination products containing turmeric seem to improve certain symptoms of knee osteoarthritis. However, it is unclear how turmeric compares to the use of non-steroidal anti-inflammatory drugs (NSAIDs). Details: Several meta-analyses of clinical studies show that turmeric extracts and/or curcuminoid products reduce knee pain and stiffness, improve physical function, and reduce the need for rescue medication. when compared with placebo (104970,106792,109280,110222). However, a reduced effect was noted in patients with increasing age or body mass index (104790). The studies evaluated in these meta-analyses are heterogeneous, of low- to moderate-quality, and utilized a variety of products and/or dosing strategies (104970,106792,109280,110222). Small to moderate-sized clinical studies show that specific products (Meriva, Indena; Theracurmin, Theravalues Corp) containing curcumin 90-100 mg twice daily for up to 6 months, or specific turmeric extracts (Turmacin, Natural Remedies Pvt. Ltd.; Curcugen, DolCas Biotech, LLC) 500 mg twice daily for 6-12 weeks, reduce pain and analgesic use and improve functionality when compared with placebo (17953,80988,89721,97424,104148,107118). A specific turmeric extract (CuraMed, EuroPharma USA) 1500 mg daily for 12 weeks improves functionality, but not pain, when compared with placebo (96127). Also, a specific nanoparticle formulation of curcumin (SinaCurcumin, ExirNanoSina), 40 mg twice daily for 6 weeks, improves pain, stiffness, and physical activity scores and reduces intake of rescue acetaminophen by about 60% when compared with placebo (102349). However, not all turmeric products seem to be effective for improving symptoms of osteoarthritis. One small clinical study shows that taking a specific turmeric extract (B-Turmactive, PLAMECA S.A.) 500 mg daily for one week does not reduce knee pain when compared with placebo (104147). Also, a meta-analysis of clinical research shows that benefits are limited to bio-optimized forms of curcuminoids, and benefits related to pure extracts are lacking (110222). Turmeric has also been compared with conventional treatments for knee osteoarthritis in small meta-analyses and individual clinical research. However, the evidence is mixed as to whether turmeric is as effective or more effective than NSAIDs, such as ibuprofen 400 mg taken 2-3 times daily or diclofenac 25 mg daily (17952,89720,89722,106792,109280,110222). Individual studies are heterogenous with respect to comparator medication and dosing schedule. Doses included a non-commercial turmeric extract 500 mg 3-4 times daily for 4-6 weeks (17952,89720) or turmeric extract 500 mg twice daily for 3 months (89722). Topical turmeric has also been evaluated. One clinical study shows that applying curcumin topically as a 5% ointment in Vaseline twice daily for 6 weeks reduces pain associated with knee osteoarthritis by a mean of about 11 on a 100-point visual analog scale when compared with placebo (104964). Research also shows that taking specific combination products containing turmeric and other ingredients can improve pain and functionality in patients with osteoarthritis. These combination products have combined turmeric with chondroitin sulfate and glucosamine hydrochloride (CartiJoint Forte, Fidia Farmaceutici SpA); boswellic acid (Curamin, EuroPharma USA; Rhulief); Boswellia serrata (Rhulief); ashwagandha, Boswellia serrata, and zinc (Articulin-F, Eisen Pharmaceutical Co. Pvt. Ltd.); devil's claw and bromelain (AINAT, Laboratoire de Rhumatologie Appliquée); Boswellia serrata, guggul, and valerian (Phytoproflex, OPTM Healthcare); Boswellia serrata and terminalia (LI73014F2, Laila Nutraceuticals); ashwagandha, Boswellia serrata, and ginger (Artrex, Mendar); or extracts of ginger rhizome, devil's claw tuber, Boswellia serrata resin, and celery seed (Tregocel, Max Biocare) (19276,51950,81466,89717,89719,96127,97419,97421,97428,106078)(109280).
• Pruritus. Oral turmeric has been evaluated for the management of pruritus of various etiologies, with promising results. Details: Clinical research in patients with kidney failure shows that taking turmeric 500 mg orally three times daily for 8 weeks decreases symptoms of uremic pruritus by 1.9-fold when compared with placebo (89724). Also, a small clinical study in patients with sulfur mustard-induced chronic pruritus shows that taking a specific combination product (C3 Complex, Sami Labs LTD) containing curcumin 1 gram plus extract from black pepper or long pepper (Bioperine) daily for 4 weeks reduces pruritus severity and improves quality of life when compared with placebo (81120,81176).

POSSIBLY INEFFECTIVE

• Alzheimer disease. Neither oral turmeric nor its constituent curcumin appears to improve cognitive function or attenuate cognitive decline in adults with this condition. Details: A small clinical trial shows that taking the turmeric constituent, curcumin, 1-4 grams daily for 6 months does not improve mental state examination scores when compared with placebo (17096). Furthermore, a meta-analysis of this study and another small clinical study in patients with Alzheimer disease shows that the turmeric group experienced greater cognitive decline when compared with placebo (100261). While this research is limited by small study sizes and heterogeneous patient populations, the current evidence does not support the use of turmeric in patients with this condition.
• Peptic ulcers. Oral turmeric does not seem to improve the healing of peptic or gastric ulcers when compared with placebo or liquid antacids. Details: Some clinical research shows that taking turmeric 2 grams three times daily for 8 weeks does not improve the healing of peptic ulcers when compared with placebo in Vietnamese patients (81444). Also, taking powdered turmeric rhizome 250 mg four times daily for 6 weeks seems to be less effective than a liquid aluminum-magnesium-hydroxide antacid for promoting gastric ulcer healing (81284).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Although there has been interest in using topical turmeric for acne, there is insufficient reliable information about the clinical effects of turmeric for this purpose.
• Age-related cognitive decline. Some small clinical studies suggest that oral curcumin, a constituent of turmeric, may modestly improve cognition in elderly patients experiencing cognitive decline. Details: A meta-analysis of three small clinical trials shows that curcumin modestly improves cognition in the elderly (100261). One of these clinical trials shows that taking a specific brand of curcumin (Theracurmin, Theravalues Corp.) 90 mg twice daily for 18 months improves long-term memory and attention when compared with placebo in middle-aged and older adults with or without mild cognitive impairment (96161).
• Amenorrhea. Although there has been interest in using oral turmeric for amenorrhea, there is insufficient reliable information about the clinical effects of turmeric for this purpose.
• Ankylosing spondylitis. Although there has been interest in using oral turmeric for ankylosing spondylitis, there is insufficient reliable information about the clinical effects of turmeric for this purpose.
• Asthma. Some small clinical studies suggest that oral turmeric, as an adjunct to conventional asthma treatment, does not improve lung function or symptoms in adults and children with asthma. Details: One small clinical study in adults with mild to moderate asthma shows that adjuvant therapy with turmeric as curcumin 500 mg twice daily for 30 days does not improve lung function based on FEV1, or improve symptoms such as dyspnea, wheezing, cough, or tightness, when compared to standard treatment alone (99349). A small clinical trial in children 7-18 years of age with moderate to severe asthma shows that adding turmeric 500-1000 mg (containing 20-40 mg curcuminoids) daily for 6 months to standard therapy does not improve overall asthma symptoms when compared with placebo and standard therapy, although it may decrease the frequency of nighttime awakenings and the use of rescue inhalers (99348). Due to their small sizes and high drop-out rates, these studies may have been underpowered to detect a difference between groups.
• Athletic performance. It is unclear if oral curcumin, a constituent of turmeric, is beneficial for athletic performance. Details: Preliminary clinical research in middle-aged male long-distance runners shows that taking a turmeric extract providing 2 grams of curcumin 95% and piperine 5% daily for 6 weeks does not improve aerobic capacity when compared with placebo (109286).
• Benign prostatic hyperplasia (BPH). It is unclear if oral curcumin, a constituent of turmeric, is beneficial in BPH. Details: A clinical study in patients with BPH shows that taking curcumin 2250 mg once daily along with tamsulosin and finasteride for 6 months improves lower urinary tract symptoms related to storage, but not overall symptoms or symptoms related to voiding, by about 35%, compared with 25% in those receiving tamsulosin and finasteride alone. Periprostatic fat thickness, quality of life, and erectile function also were improved (106799).
• Beta-thalassemia. It is unclear if oral turmeric is beneficial for iron overload in patients with beta-thalassemia. Details: A small clinical study in patients with beta-thalassemia major and iron overload shows that taking turmeric extract containing curcumin 500 mg twice daily for 12 weeks modestly reduces non-transferrin bound iron (NTBI) by 0.6 micromol/L, but not hemoglobin, transferrin saturation, total iron binding capacity, ferritin, or hepcidin, when compared with placebo (99306). Another small clinical study in adult males with beta-thalassemia intermedia and iron overload shows that taking a higher dose of curcumin 500 mg three times daily for 12 weeks modestly reduces serum iron and ferritin levels and transferrin saturation when compared with placebo (108871).
• Bruises. Although there has been interest in using topical turmeric to alleviate bruising, there is insufficient reliable information about the clinical effects of turmeric for this purpose.
• Cachexia. It is unclear if oral curcumin, a constituent of turmeric, is beneficial for cancer cachexia. Details: A small clinical trial in patients with cancer anorexia-cachexia syndrome shows that taking curcumin 800 mg twice daily for 8 weeks does not reduce weight loss or improve body composition or handgrip strength when compared with placebo (109283).
• Canker sores. Some preliminary research suggests that topical curcumin, a constituent of turmeric, is beneficial for minor canker sores. Details: Preliminary clinical research in young adults with minor canker sores shows that applying a 2% curcumin oral gel for 6 months reduces ulcer size, pain, and recurrence rate and increases healing rate similarly to 0.1% triamcinolone oral paste (104962). The validity of the study is limited by a lack of investigator blinding and the lack of an intention to treat analysis. Another small clinical study shows that applying a 1% curcumin nanomicelle gel (SinaCurcumin Pharmaceuticals) on lesions three times daily for one week is modestly more effective than applying a 2% curcumin gel for reducing pain and ulcer size (109282). The validity of this finding is limited by the lack of a non-curcumin comparator group.
• Carpal tunnel syndrome. Oral turmeric has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A moderate-sized clinical study in adults with mild to moderate carpal tunnel syndrome shows that taking a combination product containing turmeric, alpha-lipoic acid, acetyl-L-carnitine, phosphatidylserine, and vitamins C, E, B1, B2, B6, and B12 twice daily for 60 days reduces symptom severity and pain but does not improve measures of hand and wrist function when compared with control (111702). The validity of these effects is limited by a lack of blinding. The study may also be inadequately powered to detect a difference between groups. Additionally, it is unclear if the effects are due to turmeric, other ingredients, or the combination.
• Chemotherapy-induced acral erythema. It is unclear if oral or topical turmeric reduces the risk for acral erythema from capecitabine. Details: A small clinical trial in adults with cancer shows that taking turmeric 4 grams daily for 6 weeks starting at the beginning of treatment with capecitabine does not reduce the incidence of acral erythema overall; however, it does seem to reduce acral erythema grade 2 or higher when compared with expected incidence rates (99309). Topical turmeric has also been evaluated. A clinical study in patients with colorectal, gastric, pancreatic, or breast cancer receiving capecitabine shows that applying a specific ointment (Alpha) standardized to contain curcumin extract 0.5% and henna extract 10% to the soles and palms twice daily, beginning on day 1 of chemotherapy and continued for 4 cycles, does not prevent acral erythema or improve World Health Organization severity scores when compared with placebo. A post-hoc analysis suggests that there may have been a trend toward delayed onset and progression; however, this study was not structured to assess these outcomes (108874).
• Chemotherapy-induced constipation. It is unclear if oral curcumin reduces symptoms of chemotherapy-induced constipation. Details: A small clinical study in patients with various forms of cancer receiving standard chemotherapy for that cancer type shows that taking curcuminoids (C3 Complex, Sami Labs) 500 mg with piperine (Bioperine) 5 mg twice daily for 9 weeks does not reduce symptoms of constipation when compared with placebo (107111).
• Chemotherapy-induced diarrhea. It is unclear if oral curcumin reduces symptoms of chemotherapy-induced diarrhea. Details: A small clinical study in patients with various forms of cancer receiving standard chemotherapy for that cancer type shows that taking curcuminoids (C3 Complex, Sami Labs) 500 mg with piperine (Bioperine) 5 mg twice daily for 9 weeks does not reduce symptoms of diarrhea when compared with placebo (107111).
• Chemotherapy-induced nausea and vomiting (CINV). It is unclear if oral curcumin reduces CINV. Details: A small clinical study in patients with various forms of cancer receiving standard chemotherapy for that cancer type shows that taking curcuminoids (C3 Complex, Sami Labs) 500 mg with piperine (Bioperine) 5 mg twice daily for 9 weeks modestly reduces symptoms of nausea, but not vomiting, in the second and third months after the start of treatment when compared with placebo (107111).
• Chemotherapy-induced peripheral neuropathy. It is unclear if oral curcumin reduces symptoms of chemotherapy-induced peripheral neuropathy. Details: A small clinical study in patients with various forms of cancer receiving standard chemotherapy for that cancer type shows that taking curcuminoids (C3 Complex, Sami Labs) 500 mg with piperine (Bioperine) 5 mg twice daily for 9 weeks modestly reduces symptoms of chemotherapy-induced peripheral neuropathy over a three-month period when compared with placebo (107111).
• Chronic kidney disease (CKD). It is unclear if oral turmeric is beneficial for CKD. Details: A meta-analysis of four small clinical trials in patients with CKD related to diabetic nephropathy or lupus nephritis shows that taking curcumin or turmeric for 0.5-4 months moderately reduces proteinuria when compared with placebo (109276). Also, a small clinical trial in children and young adults ages 6-25 years with vascular dysfunction related to autosomal dominant polycystic disease (PKD) shows that curcumin powder 25 mg/kg daily for 12 months does not improve vascular function or kidney function when compared with placebo (107117).
• Colorectal adenoma. It is unclear if oral turmeric is beneficial for managing colorectal adenoma. Details: Preliminary clinical research in adults with familial adenomatous polyposis shows that taking curcumin 1500 mg twice daily for 12 months does not reduce the quantity or size of lower intestinal adenomatous polyps when compared with placebo (97427). A very small clinical trial in patients with familial adenomatous polyposis shows that taking 8 capsules daily of a turmeric extract, in a formulation also containing pepper fruit, spirulina, seaweed, and ginger root, for 6 months does not affect total polyp number or burden when compared with placebo. However, both number and burden were modestly reduced in the left colon. Each capsule provided curcuminoids 123.65 mg and turmerones 26.79 mg (110223).
• Colorectal cancer. It is unclear if oral turmeric is beneficial for the prevention or treatment of colorectal cancer. Details: A small clinical trial in patients undergoing chemotherapy following colorectal cancer surgery shows that taking curcuminoids (C3 Complex, Sami Labs) 500 mg with piperine (Bioperine) 5 mg daily for 8 weeks modestly improves some measures of quality of life when compared with placebo (107109). In addition, a small clinical study in people at high risk for colorectal cancer, such as those who smoke, shows that taking the turmeric constituent, curcumin, 4 grams daily for 30 days can reduce the number of precancerous rectal aberrant crypt foci (18204). It is not clear if this results in a reduced risk for colorectal cancer.
• Coronary artery bypass graft (CABG) surgery. One small study suggests that oral turmeric may reduce the risk for myocardial infarction after CABG surgery. Details: Preliminary clinical research shows that taking the turmeric constituent, curcuminoids, 4 grams daily in four divided doses, beginning 3 days prior to surgery and continuing for 5 days post-surgery, decreases the relative risk of myocardial infarction following CABG by approximately 56% when compared with placebo (81143).
• Coronavirus disease 2019 (COVID-19). It is unclear if oral turmeric or its constituent, curcumin, is beneficial for reducing symptoms of COVID-19. Details: Small studies have evaluated curcumin as an adjunctive therapy in adults hospitalized with confirmed COVID-19. Patients in these studies also received treatments such as antimicrobials, anti-inflammatory medications, anticoagulants, antiretrovirals, and immunosuppressants (104966,105393,107119). One study shows that adding curcumin reduces the duration of shortness of breath by 6-9 days when compared with patients who received other treatments in combination with probiotics. However, there were no differences in the duration of other symptoms, including fever, cough, or sore throat. Subgroup analyses suggest that taking curcumin may improve oxygenation and reduce the need for supplemental oxygen or ventilation (105393). Another study shows that adding curcumin modestly reduces the time to resolution of COVID-19 symptoms, the length of supplemental oxygen use, and the likelihood for deterioration in the patients' condition when compared with patients who received other treatments alone (104966). A third study shows some benefit of curcumin on fever and cough when compared with baseline; however, it is unclear if any changes were significant when compared with placebo (107119). Doses of curcumin used in these studies include curcumin 525 mg with piperine 2.5 mg (C3 Complex, SamiDirect) twice daily, starting at admission and continuing for 14 days (105393), or a specific nanocurcumin product (SinaCurcumin, ExirNanoSina) 80 mg twice daily for 2 weeks or 240 mg daily in divided doses for 7 days (104966,107119). Limitations of these studies include the small number of patients with severe symptoms, the large number of outcomes evaluated, the inconsistencies in other treatments used, the lack of clarity related to presentation of some results, and, in most cases, a lack of blinding. Turmeric has also been evaluated in adults in the outpatient setting with suspected or confirmed mild to moderate COVID-19. One small clinical study shows that taking curcumin (SinaCurcumin, ExirNanoSina) 80 mg twice daily for 14 days in addition to other COVID-19 treatments (mainly hydroxychloroquine and azithromycin) reduces the duration of cough, chills, myalgia, and smell and taste disturbance, but not dyspnea, fever, sore throat, or others, by 1-2 days when compared with placebo with other treatments (106802). The validity of this study is limited by the lack of confirmatory diagnosis at baseline and lack of consistency with other treatments, as well as the unclear reporting of symptom duration in relation to the initiation of treatment. Another small clinical study in outpatients confirmed to have COVID-19 shows that taking curcumin 1000 mg plus piperine 10 mg (Sami Labs Limited) daily for 14 days modestly improves weakness, but not cough, pain, headache, difficulty breathing, or biochemical indices, when compared with placebo (109278). Some research has also examined the effect of turmeric as part of a polyherbal combination. Clinical research in patients hospitalized for moderate COVID-19 symptoms shows that using an Ayurvedic formulation 1776 mg twice daily containing turmeric, ashwagandha, ginger, and Boswellia serrata (BV-4051) for 14 days modestly reduces the duration of illness and reduces the severity of fever, cough, and smell and taste dysfunction when compared to placebo. There was no beneficial effect on other symptoms, including nasal congestion, breathing difficulty, headache, and gastrointestinal symptoms. More than half of the patients were also treated with remdesivir which did not impact the majority of these findings (109899).
• Crohn disease. It is unclear if oral turmeric is beneficial for improving symptoms of active Crohn disease. Details: Some clinical research shows that taking the turmeric constituent, curcumin, 1.08 grams daily for one month, then 1.44 grams daily for one month, can reduce bowel movements, diarrhea, and abdominal pain when compared to baseline in patients with Crohn disease (79730). The validity of these findings is limited by the lack of a comparator group.
• Denture stomatitis. Topical turmeric may be beneficial for treating denture stomatitis. Details: A small clinical study in patients with denture stomatitis shows that applying topical curcumin gel (Curenext, Abbott Laboratories) three times daily for 2 weeks resolves denture stomatitis lesions similarly to clotrimazole ointment (106797).
• Diabetes. Low-quality clinical studies suggest that oral curcumin, a constituent of turmeric, may modestly improve glycemic control in patients with diabetes. Details: A meta-analysis of small clinical trials in patients with diabetic kidney disease shows that curcumin reduces levels of fasting glucose by approximately 8.3 mg/dL when compared with placebo. Curcumin was used in doses of 66.3-1670 mg daily for 2-6 months (107114). Preliminary clinical research included in the analysis shows that taking a specific nanoparticle formulation of curcumin (SinaCurcumin, ExirNanoSina) 80 mg daily for 12 weeks reduces fasting blood glucose by about 20 mg/dL (104149). One small meta-analysis of studies in patients with type 2 diabetes shows that taking curcumin for 8-24 weeks improves glycated hemoglobin (HbA1c), but not insulin resistance, by 0.7% when compared with placebo or conventional treatment (106806). The validity of these findings is limited by the heterogeneity of the included studies. A meta-analysis of low- to moderate-quality clinical research in a variety of patient populations shows that taking turmeric extract, curcumin, or curcuminoids reduces fasting glucose by approximately 13 mg/dL and improves HbA1c by 0.4% in patients with type 2 diabetes, but not in patients without this condition, when compared with placebo (108877). The studies evaluated in this meta-analysis are heterogenous and provided curcuminoids in doses ranging from 46-1500 mg daily for 1-9 months. Conversely, another meta-analysis of 7 studies in patients with uncomplicated type 2 diabetes shows that curcumin reduces HbA1c when compared with baseline, but not when compared with placebo (104965).
• Diabetic foot ulcers. It is unclear if oral curcumin is beneficial in patients with diabetic foot ulcers. Details: Preliminary clinical research in patients with grade 3 diabetic foot ulcers shows that taking nanocurcumin 80 mg orally daily for 12 weeks does not improve glycated hemoglobin (HbA1c) or change the rate of ulcer healing when compared with placebo. Taking turmeric did result in modest decreases in fasting blood glucose, insulin levels, and insulin resistance (104972).
• Diabetic nephropathy. It is unclear if oral curcumin is beneficial in patients with diabetic nephropathy. Details: Meta-analyses of two to four small clinical trials in patients with diabetic kidney disease show that curcumin modestly improves serum levels of creatinine, total cholesterol, and fasting glucose, and reduces systolic blood pressure by 4 mmHg, when compared with placebo. However, there was no effect on diastolic blood pressure, proteinuria, or serum levels of other plasma lipids or blood urea nitrogen. Curcumin was used in doses of 66.3-1670 mg daily for 2-6 months (107114). One small study included in this analysis, which evaluated patients receiving hemodialysis, shows that taking a specific nanoparticle formulation of curcumin (SinaCurcumin, ExirNanoSina) 80 mg daily for 12 weeks reduces fasting blood glucose by about 20 mg/dL when compared with placebo (104149).
• Dysmenorrhea. It is unclear if oral curcumin is beneficial in patients with primary dysmenorrhea. Details: A clinical study in university students aged 18 to 24 in Iran with mild to severe primary dysmenorrhea and premenstrual syndrome (PMS) shows that taking a specific combination product containing curcumin 500 mg plus extract from black pepper 5 mg (C3 Complex, Sami Labs) daily, starting 7 days prior to menstruation and continuing for 3 days after menstruation for 3 consecutive menstrual cycles, does not improve the severity of symptoms when compared with placebo (106805).
• Erythema. Although there has been interest in using topical turmeric for reducing erythema, there is insufficient reliable information about the clinical effects of turmeric for this purpose.
• Exercise-induced muscle soreness. It is unclear if oral turmeric is beneficial for reducing muscle soreness from exercise. Details: A small clinical study in healthy males shows that taking turmeric capsules containing curcumin 2.5 grams twice daily for 5 days, starting 2.5 days before exercise, slightly reduces pain from certain movements when compared with placebo (98998). Another small crossover clinical study in professional male soccer players shows that taking curcumin 500 mg (Elite Opti-Turmeric, Health Span) immediately, 12 hours, and 36 hours after a match accelerates muscle recovery and reduces delayed-onset muscle soreness when compared with medium chain triglyceride oil 1000 mg (111356). Turmeric has also been examined in combination with other ingredients. Clinical research in healthy active adults with moderate to severe exercise-induced muscle pain shows that taking a single, 1000-mg dose of turmeric and Boswellia serrata extracts in black sesame oil (Rhuleave-K; Arjuna Natural Private Ltd.) improves pain relief when compared with placebo, with maximal benefits within about 3 hours. The number of people needed to treat to obtain pain relief of at least 50% over a 6-hour period was 1.1 (109277).
• Gingivitis. Small clinical studies suggest that oral turmeric and turmeric mouthwash may reduce the severity of gingivitis. Turmeric mouthwash appears to be similarly effective to chlorhexidine mouthwash. Details: A meta-analysis of generally preliminary clinical research shows that rinsing with a mouthwash containing curcumin for 3-4 weeks is as effective as rinsing with chlorhexidine for reducing the severity of gingivitis or plaque (106059). Mouthwashes in these studies contained 0.05% to 20% curcumin and were usually used twice daily for 3-4 weeks (81127,89723,106059). One mouthwash contained 0.05% turmeric extract and 0.005% eugenol (89723). Another small clinical trial shows that taking a specific nanoparticle formulation of curcumin (SinaCurcumin, ExirNanoSina) 80 mg daily by mouth after breakfast for 4 weeks reduces the severity of gingivitis and gingival bleeding, but not plaque, when compared with placebo in patients with gingivitis and mild periodontitis (104146).
• Gout. Although there is interest in using oral turmeric for gout, there is insufficient reliable information about the clinical effects of turmeric for this condition.
• Gulf war syndrome. It is unclear if oral curcumin is beneficial in patients with Gulf war syndrome. Details: A small preliminary clinical trial in patients with Gulf war syndrome shows that taking curcumin (Meriva, Indena, S.p.A.) 500 mg twice daily for 30 days reduces overall symptoms, including pain, fatigue, gastrointestinal distress, and others, by 19% when compared with baseline. Taking a higher dose of 2000 mg twice daily for an additional 30 days appears to be no more effective than the lower dose (105395).
• Helicobacter pylori. Small clinical studies suggest that oral turmeric is not beneficial for eradicating H. pylori when used alone or in combination with standard triple therapy or famotidine. Details: One small clinical study in patients with H. pylori gastritis shows that taking turmeric 2.1 grams daily for 4 weeks is less effective for eradicating H. pylori than taking an omeprazole-based triple regimen for one week (80957). Another small study in adults with peptic ulcers shows that taking a specific curcumin product (C3 Complex, Sami Labs LTD) 500 mg daily for 7 days, in conjunction with standard triple therapy, does not improve H. pylori eradication rates when compared with standard triple therapy alone. The addition of curcumin increased the resolution of dyspepsia symptoms by an additional 21%, but the clinical significance of this outcome is unclear (97420). In patients with dyspepsia, most of whom tested positive for fecal H. pylori antigen, clinical research shows that taking curcuminoids (C3 Complex, Sami Labs) 500 mg with piperine (Bioperine) 5 mg daily in addition to famotidine 40 mg daily for 30 days is no more effective for reducing fecal H. pylori antigen levels than taking famotidine alone (106063).
• Impaired glucose tolerance (prediabetes). Oral turmeric may modestly improve glucose control in some patients with prediabetes. Details: In overweight or obese individuals with prediabetes, clinical research shows that taking a turmeric extract (BCM95 or Cucugreen; M/s Arjuna Natural Pvt Ltd.) 500 mg daily, providing 95% curcuminoids and at least 65% curcumin, for 90 days, either alone or in combination with zinc 30 mg as zinc gluconate, results in a small reduction in fasting glucose and glycated hemoglobin when compared with placebo. There was also a small benefit in insulin sensitivity (105391). Also, preliminary clinical research shows that taking a turmeric extract containing curcumin 750 mg twice daily for 9 months reduces the percentage of prediabetic patients who develop type 2 diabetes when compared with placebo (81163).
• Irritable bowel syndrome (IBS). It is unclear if oral turmeric is beneficial for improving symptoms of IBS. Details: Preliminary clinical research in otherwise healthy adults with IBS shows that taking a turmeric extract (Cynara Turmeric, Lichtwer Pharma) 72-144 mg daily for 8 weeks reduces IBS symptoms by about 40% to 60% when compared to baseline (79565). The validity of this finding is limited by the lack of a comparator group. Taking a combination product (CU-FEO, Alfa Wasserman S.p.A.) containing curcumin 42 mg and fennel essential oil 25 mg per capsule twice daily for 60 days improves overall ratings of abdominal pain, abdominal distention, and quality of life by 24% when compared with placebo (97422). It is unclear if these effects are due to turmeric, fennel, or the combination.
• Joint pain. Oral turmeric has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking capsules of a specific combination product (Instaflex Joint Support, Direct Digital) containing glucosamine sulfate 1500 mg, methylsulfonylmethane 500 mg, white willow bark extract 250 mg, ginger root concentrate 50 mg, Boswellia extract 125 mg, turmeric root extract 50 mg, cayenne 40 m H.U. 50 mg, and hyaluronic acid 4 mg in three divided doses daily for 8 weeks reduces joint pain severity by 37% compared to only 16% with placebo. However, it does not improve joint stiffness or function when compared with placebo (89560). It is unclear if these effects are due to turmeric, other ingredients, or the combination.
• Juvenile idiopathic arthritis (JIA). Although there is interest in using oral turmeric for JIA, there is insufficient reliable information about the clinical effects of turmeric for this condition.
• Knee pain. It is unclear if oral turmeric is beneficial for knee pain. Details: Clinical research in individuals with knee pain not related to existing arthritis shows that taking turmeric extract (TurmXTRA 60N; Inventia Healthcare Ltd. and Laila Nutraceuticals) 250 mg, providing 60% curcuminoids, once daily for 90 days modestly reduces pain associated with walking 80 meters when compared with placebo. The time taken to walk 80 meters and to climb nine steps was reduced by 4-5 seconds (105396).
• Lichen planus. It is unclear if oral turmeric is beneficial for lichen planus. Details: A small clinical study shows that taking a specific turmeric extract (Curcumin C3 Complex, Sabinsa Corporation) containing curcuminoids 6000 mg daily in three divided doses for 12 days can reduce erythema and ulceration associated with lichen planus when compared with placebo (81109). Another small clinical study shows that taking a nanocurcumin product (SinaCurcumin, ExirNanoSina) 80 mg orally once daily for 1 month reduces oral lichen planus lesion size, pain, and burning similarly to prednisolone 10 mg taken orally once daily for 1 month (104961).
• Metabolic syndrome. It is unclear if oral turmeric is beneficial for metabolic syndrome. Details: Research is conflicting on how turmeric, curcumin, and other formulations affect various measures of metabolic syndrome. Some clinical research and a meta-analysis of 13 clinical studies in patients with metabolic syndrome show that taking turmeric or curcumin decreases low-density lipoprotein (LDL) cholesterol, waist circumference by 2 cm, fasting blood glucose by 9 mg/dL, and diastolic blood pressure by 3 mmHg and increases high-density lipoprotein (HDL) cholesterol by 5 mg/dL when compared with placebo. However, other research shows that turmeric or curcumin have no effect on body weight, lipids, blood pressure, or blood glucose when compared with placebo (98999,99311,105400,109284,111347,112118). The validity of these effects is limited by high heterogeneity within the included studies and incomplete information about randomization and blinding. Studies have used turmeric, curcumin, and curcumin extract 80-2400 mg, in divided doses, daily for 4-12 weeks, nano-curcumin 80 mg daily for 12 weeks, or calebin A (CurCousin, Sabinsa), which is a constituent of turmeric, 25 mg twice daily for 3 months (98999,99311,105400,109284,111347,112118). Also, taking crude or phosphorylated curcuminoids 1 gram daily for 6 weeks does not improve sleep or reduce weight in these patients (105397).
• Migraine headache. It is unclear if oral curcumin is beneficial for migraine headache. Details: A small clinical trial in females with regular migraines shows that taking curcumin 500 mg twice daily for 8 weeks reduces the severity and duration, but not the frequency, of migraine headaches when compared with placebo. In individuals taking curcumin, the duration of headache per month was reduced by approximately 10.3 hours from baseline (107116).
• Myocardial infarction (MI). It is unclear if oral curcumin is beneficial for reducing myocardial injury following a MI. Details: Clinical research in patients with an acute MI shows that taking curcuminoids 500 mg plus piperine (Bioperine) 5 mg daily (Sami Labs) for 8 weeks does not improve ejection fraction, serum levels of cardiac troponin 1, blood pressure, levels of fasting blood glucose, or kidney function parameters when compared to placebo. However, there were some modest benefits on levels of low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, glycated hemoglobin, and certain liver enzymes such as aspartate aminotransferase (AST) and alkaline phosphatase (ALP) (107115). The validity of this study is limited by its short duration and relatively small sample size.
• Obesity. Oral turmeric might modestly improve weight loss, although any effect is unlikely to be clinically significant. Details: Multiple meta-analyses of small, mostly low-quality clinical studies in adults with a variety of comorbid conditions show that taking various forms and doses of turmeric or curcumin results in an average weight loss of about 0.6-1 kg, a decrease in body mass index (BMI) of about 0.2-0.5 kg/m2, and a decrease in waist circumference of about 1.3 cm when compared with control (102345,111351,111352). A sub-analysis of dose and duration shows that a reduction in waist circumference only occurs with curcumin daily doses above 1000 mg, and duration of treatment longer than 8 weeks (102345).
• Oral submucous fibrosis. Small studies suggests that topical or oral curcumin might be beneficial for oral submucous fibrosis. However, the research is heterogenous with respect to outcomes, comparators, and the turmeric preparations, doses, and routes of administration utilized. Details: A meta-analysis of three clinical trials shows that turmeric modestly improves mouth opening when compared to control. In addition, a systematic review of 11 studies shows that turmeric improves overall symptoms, including mouth opening, tongue protrusion, burning sensation, and cheek flexibility. However, studies were small with short duration and used variable dosing strategies. Most trials have studied oral turmeric 300-400 mg, either alone or with black pepper 100 mg or piperine 5 mg, for 3-6 months. Less commonly, turmeric was provided in lozenge form (105399). Other preliminary clinical research shows that taking a specific oral product containing curcumin 300 mg and piperine 5 mg (Turmix tablets, Sanat Products), three times daily for 12 weeks, improves mouth opening, burning sensation, and tongue protrusion when compared with baseline, but not when compared with an antioxidant product containing alpha-lipoic acid, beta-carotene, copper, lycopene, selenium, and zinc. Mouth opening is further improved by concurrent use of a mouthwash (Turmix mouthwash, Sanat Products), containing 0.1% w/v turmeric extract (standardized to 95% curcumin), with thymol, eucalyptol, clove oil, mentha oil, and tea tree oil, twice daily for 12 weeks (102347). Finally, a small clinical study shows that applying topical curcumin gel (Curenext, Abbott Laboratories) 5 mg daily in 3-4 divided doses for 6 weeks, in combination with oral physical therapy, improves mouth opening similarly to using an aloe vera gel in combination with oral physical therapy. However, decreases in burning sensation are greater with aloe gel than curcumin gel (104967). It is not clear whether the gels, oral physical therapy, or the combination of both is responsible for the outcome.
• Pain (acute). Oral turmeric has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with acute musculoskeletal pain shows that taking a specific combination product containing turmeric and Boswellia serrata extracts in black sesame oil (Rhuleave-K; Arjuna Natural Private Ltd.) 1000 mg daily for 7 days is as effective as acetaminophen 1000 mg daily for pain relief, onset of pain relief, and onset of maximal pain relief (109287). This study is limited by its lack of blinding and placebo control. Additionally, the dose of acetaminophen used in this study is below the standard recommended daily dose.
• Periodontitis. There is limited evidence on the oral or topical use of turmeric or its constituent curcumin in patients with periodontitis. Details: A meta-analysis of heterogenous clinical studies in patients with chronic periodontitis suggests that use of local delivery gel products, usually turmeric 2% or a specific product containing curcumin (Curenext), modestly reduces pocket depth when compared with routine products, such as chlorhexidine. However, limited research suggests that curcumin products do not affect plaque or gingivitis measures, and curcumin irrigation does not affect pocket depth based on limited research (107108). A small preliminary clinical study in patients with severe chronic periodontitis shows that placing curcumin gel 2 mg on one side of the mouth along with scaling and root planing (SRP) reduces plaque and probing pocket depth, but not gingival index, when compared with SRP alone (101339). The use of oral curcumin has also been investigated. A small clinical trial in patients with gingivitis and mild periodontitis shows that taking a specific nanoparticle formulation of curcumin (SinaCurcumin, ExirNanoSina) 80 mg daily after breakfast for 4 weeks reduces the severity of gingivitis and gingival bleeding, but not plaque, when compared with placebo (104146).
• Physical performance. It is unclear if oral turmeric may be beneficial for improving physical performance in older adults. Details: A very small clinical study in moderately functioning, sedentary adults over age 65 with low-grade chronic inflammation shows that that taking a specific turmeric extract (Curcumin C3 Complex, Sabinsa Corporation) 500 mg twice daily for 12 weeks does not improve measures of physical function, walking speed, or muscle strength when compared with placebo (111357). However, this study may have been inadequately powered to detect any possible differences between groups.
• Polycystic ovary syndrome (PCOS). Small clinical studies suggest that oral curcumin may improve some metabolic parameters in patients with PCOS, but these improvements may not be considered clinically significant. Details: Clinical research in patients with PCOS shows that taking curcumin 500 mg one to three times daily for 6-12 weeks improves some metabolic parameters (104968,105394,106795). Conversely, a small clinical study in patients aged 18 to 45 with PCOS in Iran shows that taking curcumin 1000 mg daily for 12 weeks modestly reduces fasting glucose but does not improve other metabolic parameters when compared with placebo. Taking curcumin also did not improve testosterone levels or hirsutism scores (111355). Meta-analyses show that taking curcumin modestly decreases body mass index (BMI) and improves measures of glycemic control, including fasting glucose and insulin resistance, and levels of total cholesterol when compared with placebo or metformin alone. However, effects on high-density lipoprotein (HDL) cholesterol levels were mixed and there was no effect on low-density lipoprotein (LDL) cholesterol or triglyceride levels (105394,106795,110219). Other preliminary clinical research shows that taking curcumin decreases plasma dehydroepiandrosterone and fasting plasma glucose levels when compared with placebo (104968). Some clinical research also shows that taking nano-curcumin (SinaCurcumin, ExirNanoSina) 80 mg daily for 3 months is beneficial in patients already taking metformin 1500 mg daily. Taking curcumin had modest beneficial effects on fasting insulin and insulin resistance, as well as levels of testosterone, LDL cholesterol, HDL cholesterol, and triglycerides, when compared with metformin alone. There was no effect of curcumin on body weight, fasting blood glucose, or other hormones (106060).
• Postoperative pain. Small clinical studies suggest that oral curcumin, a constituent of turmeric, may modestly reduce pain in various postoperative recovery settings. Details: One small clinical study in patients undergoing laparoscopic cholecystectomy shows that taking curcumin 2 grams daily reduces postoperative pain, fatigue, and the need for analgesics by the second postoperative week when compared with placebo (81099). In patients undergoing surgery for inguinal hernia and/or hydrocele, taking curcumin 1.2 grams daily for 5 days reduces inflammation and tenderness by the sixth postoperative day when compared with placebo (81206). Curcumin was taken in 3-4 divided doses daily in these studies. Finally, taking a single dose of curcumin 200 mg after surgical removal of impacted third molars modestly reduces acute postoperative pain when compared with taking mefenamic acid 500 mg (99305).
• Premenstrual syndrome (PMS). It is unclear if oral turmeric may be beneficial for improving symptoms of PMS. Details: Some preliminary clinical research in patients with PMS shows that taking curcumin 100 mg twice daily, starting 7 days prior to menstruation and continuing for 3 days after menstruation, improves physical, behavioral, and mood symptoms, as well as overall severity of symptoms, when compared with placebo (97433). Conversely, in university students aged 18 to 24 in Iran with mild to severe PMS and primary dysmenorrhea, a clinical study shows that taking a specific combination product containing curcumin 500 mg plus extract from black pepper 5 mg (C3 Complex, Sami Labs) daily, starting 7 days prior to menstruation and continuing for 3 days after menstruation for 3 consecutive menstrual cycles, does not improve the severity of symptoms when compared with placebo (106805).
• Prostate cancer. It is unclear if oral turmeric is beneficial for the prevention or treatment of prostate cancer. Details: One small clinical study shows that taking curcumin 1.8 grams orally three times daily for 7 days, starting 4 days prior to docetaxel and prednisone treatment and continuing for up to 6 cycles, reduces PSA levels by at least half in 59% of patients when compared to baseline. Also, all patients with measurable lesions showed at least stable disease after treatment, and 40% of patients showed partial response when compared with baseline (96132). It is unclear if the addition of turmeric is beneficial when compared with docetaxel and prednisone alone. In contrast, an additional small clinical trial shows that taking curcumin 6 grams daily for 7 days every 3 weeks, starting four days before docetaxel, does not improve PSA levels or progression-free or overall survival when compared with docetaxel alone (105392).
• Psoriasis. Evidence is limited to one small study of topical use in patients with scalp psoriasis. Details: Preliminary clinical research in adults with scalp psoriasis shows that applying a tonic of turmeric to the scalp twice daily for 9 weeks modestly improves overall symptoms and quality of life when compared with a placebo tonic (97429).
• Quality of life. Some preliminary clinical research suggests that oral curcumin might improve quality of life in patients with various chronic conditions. Details: Small or low-quality clinical trials in various patient populations show that taking curcumin improves at least some measures of quality of life when compared with placebo. Research has been conducted in patients with cancer, sulfur mustard-induced chronic pruritus, benign prostatic hyperplasia (BPH), or irritable bowel syndrome (IBS). Studies have evaluated curcumin 2250 mg once daily for 6 months, a specific combination product (C3 Complex, Sami Labs LTD) containing curcumin 500-1000 mg plus piperine (Bioperine) daily for 4-9 weeks, or a combination product (CU-FEO, Alfa Wasserman S.p.A.) containing curcumin 42 mg and fennel essential oil 25 mg per capsule twice daily for 60 days (81120,81176,97422,106799,107109,107111). Also, in patients with scalp psoriasis, applying a tonic of turmeric to the scalp twice daily for 9 weeks modestly improves quality of life when compared with a placebo tonic (97429).
• Radiation dermatitis. It is unclear if oral or topical turmeric is beneficial for reducing the severity of radiation dermatitis. Details: A meta-analysis of 4 clinical studies in patients with breast cancer shows that taking curcumin 500-2000 mg three times daily for 3-7 weeks or applying curcumin gel 500 mg three times daily for 7 weeks reduces the radiation dermatitis severity score by about 0.5 points (on a 4-point scale) when compared with placebo or other control (111354). The validity of this analysis is limited by the heterogeneity of the included studies. However, a small clinical study in patients with breast cancer shows that taking nanocurcumin 80 mg twice daily during and for up to 2 weeks after treatment does not reduce skin reaction severity overall, but does modestly reduce pain, when compared with taking placebo. Also, there was a small reduction in skin reaction severity near the end of the study. All patients also used aloe vera leaf as part of the hospital protocol (109281). Another small preliminary clinical study in head and neck cancer patients shows that a specific cream (Vicco turmeric cream, Vicco Laboratories) containing turmeric and sandalwood oil, applied 5 times daily during radiation therapy, seems to reduce frequency and severity of radiation dermatitis when compared with baby oil (99307).
• Radiation proctopathy. It is unclear if oral turmeric is beneficial for preventing proctitis or cystitis in patients receiving radiotherapy for prostate cancer. Details: A small clinical study in patients with prostate cancer shows that taking a specific nanocurcumin product (SinaCurcumin, ExirNanoSina) 120 mg daily, for 3 days before and also during a course of radiotherapy, does not reduce the occurrence of proctitis or cystitis when compared with placebo (100259). This study may have been underpowered to detect small treatment effects.
• Respiratory tract infections. Although there is interest in using oral turmeric for various respiratory tract infections, including bronchitis and the common cold, it has not been clinically evaluated.
• Rheumatoid arthritis (RA). Small clinical studies suggest that oral curcumin, a constituent of turmeric, may modestly improve some symptoms of RA. Details: Meta-analyses of small clinical trials in patients with RA show that taking curcumin alone or with other treatments modestly reduces overall RA symptoms, pain, and markers of inflammation when compared with control groups, including placebo or other treatments. However, some research shows that there is no beneficial effect on tender or swollen joint count from the limited available clinical research (109280,111358), while other research shows that there is a benefit (112117). Clinical studies have evaluated curcumin 120-1200 mg daily for 2 weeks to 3 months (11149,18205,96129). The validity of these findings is limited by the small size of the studies, and in some cases, the lack of a comparator group.
• Sarcopenia. Oral turmeric has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in elderly patients with sarcopenia shows that taking a specific slow-release product containing turmeric, protein, carbohydrate, and fiber (Cureit, Aurea Biolabs), 500 mg orally daily for 3 months, increases handgrip strength by about 1% and distance walked before feeling tired by about 6% when compared with placebo. It also increases weightlifting capacity by about 6% from baseline, compared with a 5% decrease from baseline in those taking placebo (104973). It is unclear whether these small changes are clinically meaningful.
• Schizophrenia. Although there is interest in using oral turmeric for improving cognitive function in patients with schizophrenia, there is insufficient reliable information about the clinical effects of turmeric for this use.
• Sepsis. It is unclear if oral curcumin, a constituent of turmeric, is beneficial in patients with sepsis. Details: A small clinical trial in patients admitted to the intensive care unit (ICU) with sepsis shows that a specific nanoparticle formulation of curcumin (SinaCurcumin, ExirNanoSina), 80 mg dissolved in water and administered via gastric tube following lavage twice daily for 10 days does not affect length of ICU stay, Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, blood pressure, or heart rate when compared with placebo (108873).
• Stress. It is unclear if oral turmeric is beneficial for reducing occupational stress in healthy adults. Details: A small clinical trial in healthy adults with occupational stress-related anxiety and fatigue shows that taking a specific type of turmeric (CurQfen, Akay Flavours and Aromatics Pvt Ltd.) that contains fenugreek dietary fiber for improved bioavailability at a dose of 500 mg twice daily for 30 days reduces stress and fatigue and improves quality of life when compared with placebo, and also when compared with a standard curcumin supplement with lower bioavailability (99308).
• Systemic lupus erythematosus (SLE). There is limited evidence on the oral use of turmeric in adults with lupus nephritis. Details: Preliminary clinical research in adults with lupus nephritis shows that taking turmeric 1.5 grams daily in three divided doses for 3 months reduces systolic blood pressure and improves kidney function when compared to baseline (81104). The validity of this finding is limited by the lack of a comparator group.
• Tuberculosis. It is unclear if oral turmeric is beneficial in patients receiving treatment for tuberculosis. Details: A small clinical study in adults receiving antituberculosis treatment shows that taking a formulation containing turmeric 0.5 grams and Tinospora cordifolia 0.5 grams twice daily for 4 months can reduce levels of Mycobacterium tuberculosis in the sputum and improve lesion healing when compared with antituberculosis treatment alone. Also, liver toxicity associated with the antituberculosis treatment seems to be reduced when administered with this formulation (80424). It is unclear if these effects are due to turmeric, Tinospora cordifolia, or the combination.
• Ulcerative colitis. It is unclear if oral or rectal turmeric, or its constituent, curcumin, is beneficial in adults with ulcerative colitis. Details: Although two small clinical studies in adults with ulcerative colitis show that taking oral turmeric extract 2-3 grams daily for 1-6 months improves the rate of remission and reduces relapse rate (79966,97423), a meta-analysis of these studies, and one additional clinical study, show that turmeric does not improve remission rates when compared with placebo (99000). A specific product (Cur-Cure, Bara Herbs Inc) was used in some of these studies. Reasons for conflicting findings are unclear, but may be due to small patient populations, concerns about blinding, and the inclusion of patients who were also taking immunomodulating drugs. It may also be due to differences in how a study measures remission. A meta-analysis of small clinical studies in patients with mild to moderate ulcerative colitis shows that adding oral curcumin 0.5-3 grams daily to standard treatment for 1-6 months may improve clinical remission rates, but not endoscopic remission rates, when compared with placebo (108872). However, the validity of this finding is limited by the small number of studies that evaluated endoscopic remission. A small clinical study shows that administering an enema form of turmeric extract (NCB-02, Himalaya Drug Company) as 20 mL, containing turmeric extract 140 mg, daily for 8 weeks increases response rate from 50% to about 93% and increases remission rate from about 31% to 71% when compared with placebo in patients with active ulcerative colitis. However, patients using the turmeric extract enema for shorter durations did not improve when compared with placebo (89729).
• Uveitis. It is unclear if oral curcumin is beneficial for uveitis. Details: Observational research in patients with acute non-infectious uveitic macular edema shows that taking a specific hydrophilic curcumin product (Cucrcuwin, Diabec, Alfa Intes) 60 mg twice daily for 6 months, in conjunction with standard corticosteroid treatment, and then alone for an additional 6 months, modestly improves best corrected visual acuity, but not macular thickness or intraocular pressure, when compared with standard treatment alone for 6 months (107110).
• Wound healing. Although there is interest in using topical turmeric for wound healing, there is insufficient reliable information about the clinical effects of turmeric for this condition. More evidence is needed to rate turmeric for these uses.

(Read more about TURMERIC)

EFFECTIVE

• Vitamin C deficiency. Oral or intramuscular vitamin C is effective for preventing or treating vitamin C deficiency. Details: Administering vitamin C orally or intramuscularly prevents and treats vitamin C deficiency, including scurvy. Vitamin C administration can reverse complications of scurvy within 2 days to 3 weeks (4844). In newborns with transient tyrosinemia due to vitamin C deficiency, oral or intramuscular vitamin C can correct this condition (15).

POSSIBLY EFFECTIVE

• Anemia of chronic disease. Oral vitamin C seems to improve markers of anemia in patients on hemodialysis. Details: Meta-analyses of clinical research in hemodialysis patients with anemia shows that treatment with vitamin C 200-300 mg three times weekly for 3-6 months increases hemoglobin levels by approximately 0.9 grams/dL, increases transferrin saturation by about 8%, and decreases the required recombinant human erythropoietin dose by 17 U/kg weekly when compared with standard care (83447,83475).
• Atrial fibrillation. Oral and intravenous vitamin C seems to help prevent atrial fibrillation after cardiac surgeries. Details: Meta-analyses of clinical research show that taking vitamin C prior to and after cardiac surgery reduces the risk of postoperative atrial fibrillation by 27% to 53%. Most studies administered vitamin C at doses of 1-2 grams orally daily for 1-3 days prior to cardiac surgery, followed by 1-2 grams in two divided doses daily for 4-5 days after cardiac surgery. Some studies provided vitamin C intravenously at similar doses, but oral vitamin C seems to be more effective (91233,96703,96705). Despite these findings, a meta-analysis of clinical research conducted only in the U.S. does not support the benefit of vitamin C for reducing postoperative atrial fibrillation (96703). These differences may be related to lifestyle factors such as nutrition, as well as differences in hospital treatments. Vitamin C has also been studied in combination with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) with evidence of benefit (90701).
• Bowel preparation. Powdered vitamin C is approved for use as part of a polyethylene glycol-based bowel preparation for colonoscopy. Details: Clinical research shows that treatment with 2 liters of oral solution containing polyethylene glycol (PEG) plus vitamin C achieves a similar quality of bowel cleansing as treatment with 4 liters of PEG when administered on the evening prior to colonoscopy or when administered in a split-dose regimen. Patients given 2 liters of PEG plus vitamin C solution also have better adherence and experience fewer adverse events, such as nausea, vomiting, or abdominal bloating, compared to patients treated with 4 liters of PEG solution without vitamin C (90413,90415,90420,90424,90428). This treatment also appears to be effective and tolerable in elderly patients aged 60-79 years, including those with poor bowel habits and a high number of comorbidities (108085). Other clinical research in older adults undergoing bowel preparation for colonoscopy also shows that taking 1 liter of PEG plus vitamin C (CleanViewAL, Taejoon Pharm) results in similar quality of bowel cleansing overall and per segment with similar tolerability and adverse effects as sodium picosulfate 170 mL plus magnesium citrate or oral sulfate solution alone (111297,112476). The most common PEG plus vitamin C preparation used in clinical research is MoviPrep (Norgine BV), which contains macrogol 3350 100 grams, sodium sulfate 7.5 grams, sodium chloride 2.7 grams, potassium chloride 1 gram, vitamin C 4.7 grams, and sodium ascorbate 5.9 grams per liter of solution (90413,90415,90424). In the U.S., MoviPrep is approved by the Food and Drug Administration (FDA) for bowel preparation prior to a colonoscopy.
• Common cold. Oral high-dose vitamin C might modestly reduce cold symptoms; however, taking vitamin C prophylactically does not seem to prevent the development of a cold. Details: There is substantial controversy about the effectiveness of vitamin C for treating the common cold (1969,1989,7100,9835,9836). The majority of evidence shows that taking high doses of vitamin C orally might decrease the duration of cold symptoms by 1-1.5 days in some patients (1966,1967,1968,1987,6458,7102,9832,83487). However, other studies have found no effect with doses up to 3 grams daily (9833). A meta-analysis of clinical research suggests that vitamin C supplementation decreases the incidence of cold in individuals exposed to physical stress, but not in the general population (83487). Other research suggests vitamin C may be more effective for treating cold symptoms in children than in adults. Also, there may be a dose-dependent response; doses of at least 2 grams daily seem to work better than 1 gram doses (9834). Taking vitamin C supplements prophylactically does not decrease the risk of catching a cold (1966,1967,1968,1987,3042,6458,7101,9832). Dietary intake of vitamin C also does not seem to affect the risk of getting a cold (10780).
• Complex regional pain syndrome. Most research shows that taking oral vitamin C after a wrist or distal radius fracture or after orthopedic surgery seems to reduce the risk of developing complex regional pain. Details: Although some research has found no benefit in patients with distal radius (i.e. wrist) fractures (90411,96702), most clinical research shows that taking vitamin C 500 mg daily, and possibly doses of up to 1500 mg daily, for 45-50 days beginning immediately after fracture can reduce the risk of developing complex regional pain syndrome (2045,16302,96700,96706). Reasons for discrepancies are unclear but might relate to differences in diagnostic criteria for complex regional pain syndrome (96702). Research in patients undergoing orthopedic surgery has also shown benefit with the use of vitamin C for the prevention of complex regional pain syndrome (90422,108076,108087). One meta-analysis of clinical research in patients undergoing wrist, foot, or ankle surgery shows that taking vitamin C 500-1000 mg for 42-50 days following surgery reduces the rate of complex regional pain syndrome, and may improve pain following ankle or foot surgery, when compared with placebo (108076). The validity of these findings is limited by the high heterogeneity of included trials. Another meta-analysis of clinical research in patients undergoing orthopedic surgery (i.e. wrist, knee, ankle, foot, lumbar, rotator cuff) suggests that oral and intravenous vitamin C may have similar effectiveness; however, this evidence is low quality (108087).
• Exercise-induced respiratory infections. High-dose oral vitamin C seems to reduce the risk of respiratory infections associated with strenuous exercise. Details: Some preliminary clinical research suggests that prophylactic use of vitamin C in doses of 600 mg to 1 gram daily for 3-8 weeks before heavy physical exercise, such as a marathon, might prevent upper respiratory infections that sometimes follow heavy exercise (9831,83370). More recently, high doses of vitamin C have been studied. A large clinical study in army recruits undergoing basic military training shows that taking vitamin C 6 grams daily for one month reduces the odds of getting a cold by 20% when compared with placebo (102975).
• Hypercholesterolemia. Oral vitamin C seems to reduce lipid levels in patients with hypercholesterolemia. Details: A meta-analysis of clinical research in patients with hypercholesterolemia shows that taking vitamin C 500 mg daily for at least 4 weeks reduces low-density lipoprotein (LDL) cholesterol by about 8 mg/dL and reduces triglycerides by about 20 mg/dL when compared with control (83445).
• Hypertension. Oral vitamin C seems to modestly reduce blood pressure in patients with hypertension. Details: Vitamin C seems to modestly reduce systolic blood pressure, without meaningful effects on diastolic blood pressure (2044,9822,13162,83483,102974). A meta-analysis of 13 clinical trials in patients with hypertension, with or without other comorbidities, shows that taking a median dose of vitamin C 500 mg daily for 8 weeks reduces systolic, but not diastolic, blood pressure by about 5 mmHg. Some of the studies used vitamin C in combination with other supplements, such as vitamin E and magnesium. When studies assessing vitamin C alone were analyzed, the magnitude of reduction in systolic blood pressure decreased (83483). A newer meta-analysis of small clinical studies in patients with essential hypertension shows that taking vitamin C 200 mg or more daily reduces systolic blood pressure by about 4 mmHg and diastolic blood pressure by about 2 mmHg (102974). However, this newer analysis omitted numerous relevant studies and included studies with normotensive patients and those without an adequate control, limiting the validity of its findings.
• Laser skin resurfacing. Topical vitamin C seems to reduce erythema occurring after cosmetic laser skin resurfacing procedures intended to reduce scars and wrinkles. Details: There is some evidence that an aqueous formulation of topical vitamin C can decrease the degree and duration of erythema following cutaneous carbon dioxide laser resurfacing for scar and wrinkle removal (1959).
• Lead toxicity. Dietary vitamin C seems to lower concentrations of lead in the blood. Details: Observational research has found that consuming more vitamin C from dietary sources is associated with lower blood concentrations of lead. People who consumed at least 340 mg of vitamin C daily as part of the diet had lower blood lead levels than those who consumed less than 100 mg vitamin C daily (3097,3098,3099).
• Nitrate tolerance. Oral vitamin C might prevent nitrate tolerance in some patients. Details: Small clinical studies show that taking vitamin C orally seems to prevent the development of nitrate tolerance in patients taking sublingual nitroglycerin. There is some evidence that short-term vitamin C supplementation can prevent tolerance to the vasodilatory effects of nitrates (1441,1961).
• Postoperative pain. Oral or intravenous vitamin C might prevent acute postoperative pain following certain surgeries. It is unclear if vitamin C reduces chronic postoperative pain. Details: A meta-analysis of 7 small clinical studies in adults undergoing elective surgery shows that receiving perioperative vitamin C, either as 1 gram orally, 2-3 grams intravenously, or 50 mg/kg intravenously, modestly reduces acute pain and opioid requirements for up to 24 hours when compared with control (105457). Most surgeries were laparoscopic and included cholecystectomy, colectomy, hysterectomy; two non-laparoscopic surgeries included uvulopalatopharyngoplasty with tonsillectomy and major abdominal surgery (90418,99840,105457). A meta-analysis of clinical trials in adults undergoing noncardiac surgery (i.e., orthopedic, abdominal, gynecologic, kidney transplantation) shows that administering perioperative vitamin C, either orally or intravenously, reduces postoperative intravenous morphine requirements at 2, 24, and 48 hours after surgery and improves pain scores at 2, 6, and 24 hours after surgery when compared with placebo. The dose of vitamin C did not appear to impact outcomes. However, when only laparoscopic surgeries are included, perioperative vitamin C does not improve pain or morphine use when compared with placebo (108087). A moderate-sized clinical study in adults undergoing transurethral resection of a bladder tumor under general anesthesia shows that administering intravenous vitamin C 1 gram after induction of anesthesia reduces the incidence and severity of catheter-related bladder discomfort immediately after surgery and at 1 and 2 hours postoperatively, but not 6 hours, when compared with placebo. However, vitamin C does not reduce postoperative pain scores or analgesic requirements when compared with placebo (111645). Further research is needed to determine the effects of vitamin C for acute postoperative pain. Vitamin C has also been evaluated for reducing chronic pain after surgery. Clinical research in patients undergoing surgery for foot or ankle trauma shows that taking vitamin C 500 mg orally twice daily postoperatively for 6 weeks reduces pain scores when compared with placebo at 2 weeks and 6 weeks. The mean total amount of diclofenac used for pain relief over the 6-week period is also reduced, from 5.7 grams with placebo to 3.4 grams with vitamin C (102131).
• Wrinkled skin. Topical vitamin C might reduce the appearance of existing wrinkles. Details: Topical preparations containing vitamin C seem to improve the appearance of wrinkled skin. Some evidence shows that vitamin C 3% applied for 12 weeks might reduce facial wrinkles (14008). A small clinical study shows that applying a dissolving microneedle patch containing vitamin C 5.6% every 4 days for 12 weeks to crow's feet on one side of the face reduces wrinkles when compared to control treatment applied on the other side of the face (98780). Other clinical research in females aged 30-60 years shows that applying an oil-soluble cream containing the vitamin C derivative tetra-isopalmitoyl ascorbic acid 1%, 2%, or 3% to the periorbital area twice daily for 8 weeks reduces visual wrinkle grading when compared with placebo. A dose analysis shows greater improvements in wrinkle parameters, average wrinkle depth, and mean depth with the lower concentration, while greater improvements in maximum roughness and maximum depth are observed with the higher concentration (108072). This study only included individuals defined as having Fitzpatrick skin type III or IV; it effects on other skin types is unclear. Preparations containing vitamin C in combination with other ingredients have also been investigated. A small low-quality trial in females with moderately photodamaged and hyperpigmented facial skin shows that applying a moisturizer with vitamin C 30%, vitamin E, and coenzyme Q10 once daily in the morning, along with applying retinol 0.5% once daily or once every other day for 12 weeks, seems to improve skin tone, photodamage, and wrinkles when compared to baseline (99085). In another small trial, a topical preparation containing vitamin C 10% as L-ascorbic acid along with acetyl tyrosine, zinc sulfate, sodium hyaluronate, and bioflavonoids (Cellex-C High Potency Serum) applied to photo-aged facial skin for 3 months improves fine and coarse wrinkling, yellowing and sallowness, roughness, and skin tone when compared with placebo (6155). It is unclear if the beneficial effects of these products are due to vitamin C, other ingredients, or the combination.

POSSIBLY INEFFECTIVE

• Acute bronchitis. Oral vitamin C doesn't seem to improve symptoms of acute bronchitis. Details: A clinical study in adults with acute bronchitis shows that taking vitamin C orally 500 mg on day 1, then 250 mg on days 2 through 5 (similar to an azithromycin regimen) doesn't seem to have any effect on quality of life or bronchitis duration when compared with azithromycin (9827).
• Asthma. Oral vitamin C doesn't seem to prevent asthma or improve lung function. Details: Although some observational research has found that some patients with asthma might have lower serum vitamin C levels (5873), other observational research found that increased dietary vitamin C intake is not associated with a reduced risk of asthma or improved lung function (15006,34567). In addition, clinical research shows that supplemental intake of vitamin C does not reduce asthma symptoms, improve lung function, or reduce the use of inhaled steroids in asthma patients (90409).
• Atherosclerosis. Oral vitamin C does not seem to reduce the progression of atherosclerosis. Details: A clinical study shows that taking a specific combination product containing slow-release vitamin C 250 mg and vitamin E 136 IU (CellaVie, Ferrosan A/S) twice daily modestly slows the 3-year progression of atherosclerosis of the carotid artery in males, but not females. This result persisted at a 6-year follow-up of this study (1918,10473). However, when this form of vitamin C is used alone, it does not slow the 3-year progression of atherosclerosis of the carotid artery (1918).
• Bladder cancer. Oral vitamin C does not reduce the risk of bladder cancer or mortality from bladder cancer. Details: Epidemiological research has found that supplemental vitamin C intake is not associated with mortality rate in patients with bladder cancer (9839). A secondary analysis of a large clinical trial, the Physicians' Health Study II, in healthy men aged at least 50 years also shows that taking vitamin C 500 mg daily alone or with vitamin E 400 IU daily for up to 10 years does not reduce the risk of developing bladder cancer or bladder cancer-related deaths when compared with placebo (90097).
• Cardiovascular disease (CVD). Oral vitamin C does not seem to be beneficial for either primary or secondary CVD prevention. Details: Vitamin C does not seem to be beneficial for primary prevention of CVD. Some population research has found that higher supplemental vitamin C or dietary vitamin C has been associated with a reduced risk of developing CVD (10358,14108,109779), while other observational research has found no benefit (34566,10358,14108). However, meta-analyses of clinical research in healthy patients show that vitamin C supplementation does not prevent CVD or coronary heart disease when compared with control (97308,104025). In 2004, the American Heart Association stated that current evidence does not justify use of antioxidants such as vitamin C for reducing the risk of CVD (12142). Evidence is also negative for secondary prevention in people with coronary heart disease. Population studies have found that higher serum vitamin C was associated with no effect or decreased CVD mortality from CVD (3910,5878). A meta-analysis of two large clinical trials shows that vitamin C supplementation does not reduce CVD events or CVD mortality when compared with control (97308).
• Colorectal cancer. Oral vitamin C does not seem to prevent colorectal cancer. Details: Population research has found that dietary vitamin C intake is not associated with a reduced risk of developing colon cancer. When total vitamin C intake from food and supplements is considered, there is a modest association (34600). However, most clinical trials show that supplemental vitamin C, alone or along with other antioxidants, does not reduce the risk of colorectal cancer development, colorectal cancer or adenoma recurrence, or colorectal cancer-related mortality (34580,34581,34594,90097,90089,92903).
• Coronavirus disease 2019 (COVID-19). Oral vitamin C, even at high doses, does not seem to speed recovery from COVID-19 in non-hospitalized patients. An analysis of clinical research suggests that oral or intravenous vitamin C might reduce mortality in patients hospitalized with COVID-19; however, given that nearly all individual studies are small and do not show benefit, larger and higher-quality studies are needed to confirm these findings. Details: A clinical study in adult outpatients with confirmed COVID-19 shows that taking oral vitamin C (ascorbic acid) 8000 mg in 2-3 divided doses daily, alone or with zinc gluconate 50 mg daily, for 10 days does not reduce symptom severity when compared with standard care (104450). The study was terminated prior to complete enrollment due to futility and apparent lack of effect from vitamin C and/or zinc supplementation. Limitations of this study include a lack of placebo control and blinding. Additionally, this study has been criticized for methodologic concerns (106624). Another small clinical trial in adult outpatients with confirmed COVID-19 shows that taking vitamin C 1000 mg daily for 14 days does not improve symptoms or quality of life when compared with placebo (109462). Vitamin C has also been evaluated in patients hospitalized with COVID-19. Individual prospective and retrospective studies in critically ill patients hospitalized with COVID-19 in various countries have found that administering vitamin C, either enterally as 500-1000 mg daily or intravenously as 8-24 grams daily or 50 mg/kg daily, does not significantly reduce in-hospital or short-term mortality, hospital length of stay, or end-organ failure when compared with control groups receiving standard care alone. Additionally, all but one study found no change in the need for mechanical ventilation (105458,105465,106937,106938,108075,108079,108081). One small study found a small improvement in survival rate when compared with standard care; however, the overall survival rate in this study was low (108075). Additionally, one clinical study in patients hospitalized in Turkey with COVID-19 shows that adding high-dose intravenous sodium ascorbate 50 mg/kg to a treatment regimen of hydroxychloroquine, azithromycin, and zinc may improve recovery time, with 57% and 39% of patients achieving total recovery at day 15 in the vitamin C and control groups, respectively (108071). However, the validity of this trial is limited due to unclear reporting. Additionally, these small studies were likely underpowered to detect differences between the vitamin C and control groups. A meta-analysis of 10 clinical trials and 9 observational studies in patients hospitalized with COVID-19 shows that receiving oral or intravenous vitamin C daily reduces the odds of in-hospital mortality by 41% when compared with control. When only clinical trials were considered, the odds of in-hospital mortality were decreased by 56%; however, this reduction was only identified in studies using vitamin C 10 grams daily or less. Conversely, supplementation with vitamin C increased the length of intensive care unit (ICU) stay by nearly 2 days and did not impact length of hospital stay or reduce the need for mechanical ventilation, liver injury, or cardiac injury (109955). Given that most individual studies in this analysis did not show improvements in mortality with vitamin C, larger and higher-quality prospective studies are needed to determine the role of vitamin C in hospitalized patients with COVID-19. Vitamin C has also been evaluated in patients with long COVID. Preliminary clinical research in adults with long COVID and persistent fatigue shows that taking a specific combination product containing vitamin C 500 mg and L-arginine 1.66 grams (Bioarginina C, Farmacetici Damor) for 28 days increases 6-minute walk test distance by 10% and reduces self-reported fatigue when compared with placebo (110390).
• Fetal and premature infant mortality. Oral vitamin C does not seem to prevent neonatal death. Details: Meta-analyses of clinical research show that taking vitamin C alone or with other supplements does not reduce the risk of neonatal death (83472,96707).
• Fractures. Oral vitamin C does not seem to improve fracture healing. Details: Clinical research shows that taking vitamin C 500 mg daily for 50 days following an acute distal radial fracture does not improve physical function, symptoms, or healing rates when compared with placebo (90411).
• Helicobacter pylori. Oral vitamin C does not seem to improve eradication of H. pylori. Details: Most clinical research shows that treatment with vitamin C, alone or in combination with vitamin E, does not improve the eradication rate of H. pylori when taken with a standard eradication regimen when compared with the eradication regimen alone (83476,90094).
• Hereditary motor and sensory neuropathy. Oral vitamin C does not seem to improve neuropathy in these patients. Details: In a meta-analysis of five studies in patients with Charcot-Marie-Tooth disease type 1A, taking vitamin C 1-4 grams orally daily for 1 year did not improve neuropathy when compared with placebo (99084). Continuing vitamin C 4 grams daily for 2 years also does not improve neuropathy in these patients (90419).
• Interferon-related retinopathy. Oral vitamin C does not seem to improve retinopathy associated with interferon therapy. Details: A small clinical study in patients with chronic hepatitis C receiving interferon therapy shows that taking vitamin C 600 daily orally does not seem to reduce the risk of retinopathy from interferon therapy when compared with control (10355).
• Leukemia. Oral vitamin C does not seem to reduce the risk of leukemia or mortality from leukemia. Details: A large clinical trial in men aged at least 50 years shows that taking vitamin C 500 mg daily, alone or along with vitamin E 400 IU daily, for up to 10 years does not reduce the risk of developing leukemia or leukemia-related deaths when compared with placebo (90097).
• Low birth weight. Oral vitamin C does not seem to reduce the risk of infants being born with a low birth weight. Details: Meta-analyses of clinical research show that maternal use of oral vitamin C alone or with other supplements does not reduce the risk of giving birth to infants with low birth weight when compared with control (83450,83472).
• Lung cancer. Oral vitamin C does not seem to reduce the risk of lung cancer. Details: Two meta-analyses of clinical research suggest that taking vitamin C, alone or in combination with vitamin E, does not reduce the incidence of lung cancer or lung cancer-related mortality (34528,34632). Also, a clinical study in females shows that taking supplemental vitamin C 500 mg daily, with or without vitamin E and beta carotene, is associated with an INCREASED risk of lung cancer when compared with placebo (34580).
• Melanoma. Oral vitamin C does not seem to reduce the risk of melanoma. Details: Clinical research shows that taking vitamin C 500 mg daily, alone or along with vitamin E 400 IU daily, for up to 10 years does not reduce the risk of developing melanoma or melanoma-related deaths when compared with placebo in men aged at least 50 years (90097).
• Miscarriage. Oral vitamin C does not seem to reduce the risk of miscarriage. Details: A meta-analysis of clinical research shows that taking vitamin C alone or with other supplements does not reduce the risk of miscarriage when compared with control (94820).
• Overall mortality. Oral vitamin C does not reduce overall mortality. Details: Although population research suggests that higher dietary intake and higher plasma vitamin C levels are associated with a reduced risk of mortality from all causes (3910,109779), vitamin C supplementation does not seem to affect overall mortality. Meta-analyses of clinical research show that taking vitamin C supplements does not reduce overall mortality when compared with control (34622,111641). Clinical studies of vitamin C used in combination with vitamin E, beta carotene, and/or selenium and zinc, also show no benefit for overall mortality (9817,14109).
• Pancreatic cancer. Oral vitamin C does not seem to prevent pancreatic cancer. Details: Observational research has found that increased dietary vitamin C intake is associated with up to a 30% reduced risk of pancreatic cancer (99083,99086). However, clinical research shows that supplemental vitamin C 500 mg daily does not reduce the risk of pancreatic cancer in females (34580). Also, taking vitamin C in combination with beta-carotene plus vitamin E does not reduce the risk of pancreatic cancer (12185,34581).
• Pre-eclampsia. Oral vitamin C does not seem to prevent pre-eclampsia. Details: Despite some early positive research in high-risk pregnancies, the majority of meta-analyses and clinical studies show that taking vitamin C alone or with vitamin E or other supplements does not reduce the risk of pre-eclampsia when compared with control. There is even some concern that vitamin C supplementation may increase the risk of gestational hypertension (3236,83450,83472,83474,96707).
• Preterm labor. Oral vitamin C does not seem to prevent preterm labor. Details: Meta-analyses of clinical research show that taking vitamin C alone or with other supplements does not reduce the risk of preterm labor when compared with control (83450,83472,96707).
• Prostate cancer. Oral vitamin C does not seem to prevent prostate cancer. Details: A large-scale clinical study (The SU.VI.MAX study) shows that a combination of vitamin C 120 mg, vitamin E (alpha-tocopherol) 30 mg, beta-carotene 6 mg, selenium 100 mcg, and zinc 20 mg, taken daily for an average of 8 years, does not reduce the risk of prostate cancer overall. However, it might reduce the risk of prostate cancer in those who have normal PSA levels. It does not seem to be beneficial for reducing the risk of prostate cancer in patients with PSA levels above 3 mcg/L (14135). Another large scale study (Physician's Health Study II) shows that taking vitamin C 500 mg daily for an average of 8 years does not significantly reduce the risk of prostate cancer when compared with placebo (16708). Similarly, results from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial seem to show that supplemental or dietary intake of vitamin C does not reduce the risk of prostate cancer when compared to individuals not taking vitamin C (14124).
• Radiation dermatitis. Topical vitamin C does not seem to prevent radiation dermatitis in cancer patients. Details: A small clinical study shows that applying a 10% vitamin C solution does not appear to protect from radiation dermatitis when applied to the scalps of patients treated with radiation for intracranial tumors (789).
• Small for gestational age (SGA). Oral vitamin C does not seem to reduce SGA. Details: Meta-analyses of clinical research show that taking vitamin C alone or with other supplements does not reduce the risk of small for gestational age birth when compared with control (83450,83472).
• Stillbirth. Oral vitamin C does not seem to prevent stillbirth. Details: Meta-analyses of clinical research show that maternal use of vitamin C alone or with other supplements does not reduce the risk of stillbirth when compared with control (83472,96707).

LIKELY INEFFECTIVE

• Sepsis. Intravenous vitamin C, alone or in combination with thiamine and/or hydrocortisone, does not prevent organ failure, reduce intensive care or hospital length of stay, or reduce mortality in sepsis or septic shock. Details: Observational research suggests that patients with septic shock are more likely to have low plasma levels of vitamin C (100317). However, two randomized clinical trials in patients with sepsis show no benefit with intravenous vitamin C, with or without thiamine, for improving organ function and preventing organ failure when compared with control treatment (102130,104027). A clinical study in patients with septic shock shows that administering an intravenous bolus of vitamin C 1000 mg followed by a continuous infusion of 250 mg/hour for 96 hours, starting within 24 hours of vasopressor initiation, does not improve 28-day or intensive care unit (ICU) mortality when compared with placebo. A subgroup analysis shows that the addition of corticosteroids does not affect outcomes in either group (108078). This study may have been inadequately powered to detect a difference between groups. Also, a larger clinical trial in adults with sepsis receiving vasopressor therapy in the ICU shows that intravenous administration of vitamin C 50 mg/kg every 6 hours for up to 4 days increases the risk of death or persistent organ dysfunction at day 28 by 14% to 21% when compared with placebo. There were no differences in mortality at 6 months (109459,111643). Vitamin C has also been frequently studied in patients with sepsis and septic shock in a specific combination regimen (HAT therapy) which includes intravenous vitamin C 1.5-2 grams with hydrocortisone 50 mg every 6 hours and thiamine 200 mg every 12 hours. While some retrospective research has found HAT therapy to be beneficial in sepsis (100315,102980), high quality, prospective clinical research has not confirmed these findings (105447,106620,109956). Several meta-analyses of randomized controlled trials and small clinical studies in patients with sepsis or septic shock show that intravenous vitamin C, either alone, as a component of HAT therapy, or in combination with thiamine, does not reduce short- or long-term mortality, ICU or hospital length of stay, kidney injury, or duration of mechanical ventilation, but modestly improves duration of vasopressor use and procalcitonin clearance, when compared with placebo or standard care. These analyses also show mixed results with respect to improvement in sequential organ failure assessment (SOFA) scores within 72 hours (105447,106620,106935,108073,109460,111298,111300,111301,111642,112479). Most studies included in the analyses administered HAT therapy for 2-10 days and compared it with normal saline control or with hydrocortisone alone (102129,102998,104027,104028,104032,105446). Although some subgroup analyses suggests that intravenous vitamin C alone in patients with sepsis may improve short-term mortality (106620,111298), other meta-analyses have not shown this benefit in subgroup analyses (111300). In addition, meta-analyses have identified significant publication bias (111298,111300). Long-term follow up from a study in patients with sepsis-induced respiratory and/or cardiovascular dysfunction shows that receiving HAT therapy does not improve cognitive, psychological, or functional status after 6 months and, for some domains, HAT therapy was worse when compared with placebo (111299). Studies evaluating intravenous vitamin C, either alone, as a component of HAT therapy, or in combination with thiamine, in mixed critically ill populations have also shown mixed findings. One such large meta-analysis of 27 randomized controlled trials and 21 observational studies shows that intravenous vitamin C reduces in-hospital mortality by 19% and ICU stay by about 1 day, but does not have a significant effect on hospital stay, mortality at 1 month, ICU mortality, or kidney injury, when compared with placebo or standard care. Also, effects on in-hospital mortality were no longer significant when data from randomized controlled trials were considered alone (106933). Other meta-analyses including 15-16 randomized controlled trials show that intravenous vitamin C, alone or as a component of HAT therapy, does not reduce overall, ICU, or in-hospital mortality when compared with control (106934,109957). A subgroup analysis in one of these analyses suggests that intravenous vitamin C as monotherapy, or in doses of at least 10 grams daily, may improve overall mortality (106934). Vitamin C also does not appear to benefit complications from sepsis, such as vasoplegic shock. A small clinical study in adults in the ICU with vasoplegic shock mostly secondary to sepsis and requiring moderate vasopressor support shows that administering intravenous vitamin C as sodium ascorbate 1.5 grams every 6 hours for 5 days or until cessation of vasoactive therapy does not reduce the duration of vasopressors, vasopressor dose, hospital or ICU length of stay, or mortality outcomes when compared with placebo (112475).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Atrophic acne scars. It is unclear if applying topical vitamin C after microblading improves atrophic acne scars. Details: A clinical study in adults with mild to severe atrophic acne scarring shows that applying a serum containing vitamin C 17% to the face after a once-monthly home microblade treatment for 4 months improves the appearance of acne scars at month 5 when compared with baseline (108086). Although this study enrolled a control group that used topical insulin in place of vitamin C, no between-group statistical comparisons were conducted, limiting the validity of this study.
• Age-related macular degeneration (AMD). Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Most clinical research shows that taking the antioxidants vitamin C 500 mg, vitamin E 400 IU, and beta-carotene 15 mg daily, with or without elemental zinc 80 mg, reduces the risk of visual acuity loss by 23% to 27% and reduces the risk of progression to advanced AMD at 5 years by 25% to 32% in patients at high risk for developing advanced AMD (7303,7304,11326,90069). The antioxidant plus zinc combination seems to reduce the risk of progression to advanced AMD in these patients more than taking the antioxidants without zinc (7303,90069). There is not enough evidence to know if taking the antioxidants or antioxidants plus zinc prevents progression to advanced AMD in patients with early stage AMD (7303,7304). The effect of vitamin C intake on developing AMD is unclear. Some population studies have found no association between dietary or supplemental vitamin C intake on risk of developing AMD (14007,14257). In one population study, vitamin C intake was associated with increased odds of developing age-related maculopathy (9823); however, in another population study, intake of vitamin C along with other antioxidants and zinc was associated with a reduced risk of AMD (14257). More evidence is needed to determine what role, if any, vitamin C intake has on the risk of developing AMD.
• Aging skin. Topical vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in females aged 30-65 years shows that applying a specific liquid (Antioxidant and Collagen Booster Serum, Max Biocare Pty Ltd.) containing vitamin C 20%, red raspberry leaf cell culture extract 0.0005%, and vitamin E 1% to the face nightly for 8 weeks, in addition to regular facial skin products, improves skin color, elasticity, radiance, smoothness, and appearance of wrinkles when compared with regular facial skin products alone (102355).
• Albuminuria. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study shows that taking vitamin C 1250 mg plus vitamin E 680 IU daily for 4 weeks can reduce the excretion of albumin by about 19% when compared with placebo in patients with type 2 diabetes (10434).
• Allergic rhinitis (hay fever). It is unclear if oral vitamin C is beneficial in patients with hay fever. Details: Epidemiological research has found that higher vitamin C plasma levels are not associated with a decreased risk of allergic rhinitis (15200). However, clinical research shows that some forms of vitamin C might help. In one small clinical study, intranasal vitamin C administered three times daily for 2 weeks reduces nasal secretions, nasal blockage, and edema in up to 74% of patients with perennial allergic rhinitis (15201). Another small clinical study in patients with seasonal allergic rhinitis shows that taking a single oral dose of vitamin C 2 grams reduces bronchial responsiveness to histamine at one hour after ingestion (15202). However, in another small study in patients with seasonal allergic rhinitis taking vitamin C orally in doses up to 4 grams daily for 3 days does not appear to suppress cutaneous or nasal response to histamine when compared to placebo (15203).
• Alzheimer disease. It is unclear if dietary vitamin C helps to prevent this condition. Details: Most epidemiological research has found that dietary intake of vitamin C is associated with a 17% reduced risk of developing Alzheimer disease (4636,9824,10131,13165,90082).
• Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease). It is unclear if oral vitamin C helps to prevent ALS. Details: Observational research has found that increased dietary or supplemental intake of vitamin C is not associated with risk of developing ALS (90412).
• Anthracycline cardiotoxicity. Although there is interest in using oral vitamin C for anthracycline-induced cardiac toxicity, there is insufficient reliable information about the clinical effects of vitamin C for this condition.
• Aspirin-associated gastric damage. It is unclear if oral vitamin C helps to prevent gastric damage caused by aspirin. Details: Some clinical research shows that vitamin C 480 mg might prevent gastric damage associated with taking aspirin 400 mg by decreasing blood loss and preventing decreased gastric blood flow (10357). However, a small clinical study in healthy patients shows that taking vitamin C 500 mg as ascorbic acid with aspirin 600 mg actually increases gastrointestinal permeability to a greater extent than either ingredient taken alone (98781).
• Athletic performance. It is unclear if oral vitamin C improves athletic performance. Details: Although some small preliminary clinical studies suggest that vitamin C might improve certain biomarkers during exercise (82922), a meta-analysis of small clinical trials in older and younger adults shows that taking vitamin C 500-1000 mg daily, with or without vitamin E, does not improve endurance, lean mass, or muscle strength when compared with placebo (102973). A more recent, small clinical study in recreationally trained males shows that taking vitamin C 1000 mg and vitamin E (as alpha-tocopherol) 235 mg daily for 10 weeks while participating in a resistance training program does not improve measures of muscle strength when compared with placebo (109959).
• Atopic disease. It is unclear if dietary vitamin C helps to prevent atopic disease. Details: Population research has found that higher intake of vitamin C is not associated with a reduced risk of eczema, wheeze, IgE-mediated food allergy, or allergic sensitization (90098).
• Attention deficit-hyperactivity disorder (ADHD). Small clinical studies suggest that high-dose oral vitamin C may not improve symptoms in patients with ADHD. Details: Some research suggests that taking megadose vitamins, including vitamin C, does not improve ADHD symptoms (9957,9958,9959). However, other preliminary clinical research shows that taking 25 mg of vitamin C in combination with flaxseed oil providing alpha-linolenic acid 200 mg twice daily might improve measures of attention, impulsivity, restlessness, and self-control in children with ADHD when compared with baseline (14443). It is not clear if these effects are due to vitamin C, flaxseed oil, or the combination.
• Autism spectrum disorder. It is unclear if oral vitamin C is beneficial in patients with autism spectrum disorder. Details: One small clinical study shows that taking vitamin C 8 grams per 70 kg daily for 10 weeks modestly reduces autism symptom severity in school children when compared with placebo (83604).
• Bleeding. It is unclear if intravenous vitamin C can reduce bleeding after total abdominal hysterectomy. Details: A small clinical study in patients undergoing total abdominal hysterectomy shows that administration of intravenous vitamin C 1 gram the night before surgery and 1 gram during surgery reduces postoperative hemorrhage volume by around 40 mL when compared with placebo (109465).
• Brain tumor. It is unclear if oral vitamin C helps to prevent brain tumors. Details: Population research has found that vitamin C intake is associated with a 14% reduced risk of glioma. This risk reduction was more prevalent in America compared to other geographic locations (98782).
• Breast cancer. It is unclear if oral vitamin C helps to prevent breast cancer, its recurrence, or breast cancer-related mortality. Details: Some epidemiological research has found that dietary vitamin C is associated with a reduced risk of breast cancer (1444,10823,10824). However, other epidemiological research has found no association with dietary or supplemental vitamin C (10825,10826,108080). One cohort study found no association between breast cancer risk and total, dietary, or supplemental vitamin C, regardless of dose, treatment duration, or formulation (single ingredient or combination product). Additionally, hormone and menopausal status did not appear to impact risk. Vitamin C intake might be associated with a reduced risk in individuals with a family history of breast cancer in first-degree relatives (108080). In patients with breast cancer, supplemental or dietary intake of vitamin C might be associated with a reduced risk of mortality. A meta-analysis of results from population research shows that vitamin C supplementation following breast cancer diagnosis is associated with a 15% lower risk of breast cancer-related mortality when compared with no supplementation (90416). A large, observational study in patients with breast cancer undergoing radiation therapy has found that vitamin C supplementation does not reduce the risk of breast cancer recurrence over a period of 5 years when compared with no supplementation. Although the vitamin C group had notably less aggressive tumor types, recurrence-free survival was similar in both vitamin C and control groups (108082). The validity of these findings is limited due to unknown doses of vitamin C and the inclusion of various breast cancer subtypes.
• Burns. Small studies suggest that intravenous vitamin C may modestly improve symptoms in patients with severe burns. Details: A small clinical study in patients with severe burns shows that administering vitamin C intravenously (IV) 66 mg/kg hourly over 24 hours, as part of fluid resuscitation using lactated ringer solution, reduces wound edema and the volume of fluid needed when compared with fluid resuscitation alone (83145). A retrospective review of adults hospitalized with severe burns has found that those who receive a continuous IV infusion of at least 10 grams of vitamin C within 2 days of admission have an in-hospital mortality rate of 46%, compared with 58% for those who do not receive vitamin C (102128).
• Cancer. It is unclear if oral or intravenous vitamin C helps to prevent cancer or cancer-related mortality. Details: Some population research has found that DIETARY intake of vitamin C is linked with a lower risk of cancer and cancer-related mortality (3910,5878,10819,109779). However, clinical research shows that taking vitamin C SUPPLEMENTS does not reduce the risk for cancer (10819,14109,34580,90097). In people with cancer, although some clinical research has shown that taking high-dose vitamin C supplements can improve survival rates (9809,96704), other clinical research has not shown this benefit (4842,4843). In 2003, the US Food and Drug Administration (FDA) determined that it would allow a qualified health claim stating that some scientific evidence suggests that antioxidant vitamins, such as vitamin C, may reduce the risk of certain forms of cancer. However, the FDA has determined that there is little scientific evidence supporting this claim (102334). Preliminary clinical research has also evaluated vitamin C supplements in patients with cancer. High-dose oral vitamin C, 10 grams daily, in patients with advanced cancer does not seem to improve survival or decrease disease progression (4842,4843,106617). However, preliminary clinical research suggests high doses of vitamin C, given intravenously, might have a beneficial effect on some outcomes, including survival rate in some patients with cancer (9809,96704,106617). However, there is no benefit to other patients studied in the case reports and this has not been tested in well-designed clinical trials (9809,96704).
• Carpal tunnel syndrome. Vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A clinical study in adults with mild to moderate carpal tunnel syndrome shows that taking a combination product containing vitamins C, E, B1, B2, B6, and B12, alpha-lipoic acid, acetyl-L-carnitine, phosphatidylserine, and turmeric twice daily for 60 days reduces symptom severity and pain but does not improve measures of hand and wrist function when compared with control (111702). The validity of these effects is limited by a lack of blinding. The study may also be inadequately powered to detect a difference between groups. Additionally, it is unclear if the effects are due to vitamin C, other ingredients, or the combination.
• Cataracts. It is unclear if oral vitamin C helps to prevent cataracts. Details: Population research has found that people with the highest total intake of vitamin C have about a 19% reduced risk of developing cataracts when compared with those with the lowest total intake. The greatest benefit is observed for nuclear cataracts (96711). A separate study found that higher supplemental intake of vitamin C for 10 years is associated with a 60% reduction in the incidence of nuclear and cortical cataracts (4208). Other population research has found that the highest blood levels of vitamin C are associated with a 33% reduced odds of developing age-related cataract, but any benefit seems to be limited to Asian populations (90944). One prospective clinical study shows that taking vitamin C plus vitamin E and beta-carotene does not prevent the development or progression of age-related loss of vision due to cataracts in well-nourished people taking the supplement for an average of 6.3 years (7304).
• Cervical cancer. It is unclear if oral vitamin C helps to prevent cervical cancer. Details: Observational research has found that higher vitamin C intake is associated with a 33% to 42% reduced odds of cervical neoplasm. Increasing vitamin C intake by 50 mg daily is associated with an 8% reduced odds of cervical neoplasm (34609,98771).
• Chronic fatigue syndrome (CFS). Although there is interest in using oral vitamin C for CFS, there is insufficient reliable information about the clinical effects of vitamin C for this condition.
• Colistin-induced nephrotoxicity. It is unclear if intravenous vitamin C helps to prevent nephrotoxicity from colistin. Details: A small clinical study shows that intravenous administration of vitamin C 2 grams every 12 hours along with colistin for around 9-10 days does not prevent nephrotoxicity when compared with colistin therapy alone (99839). However, this study was limited by a lack of statistical power to detect differences between the study groups.
• Contrast induced nephropathy. It is unclear if oral vitamin C helps to prevent contrast-induced nephropathy (CIN). Details: Some clinical research shows that taking vitamin C before and after coronary angiography reduces the risk of developing CIN by 33% to 55% when compared with placebo in patients with renal dysfunction (12234,90421). However, other clinical evidence published since 2012 suggests that vitamin C given orally and/or intravenously before and after angiography does not reduce the risk of CIN compared with control in high-risk patients with chronic renal insufficiency or diabetes (91232,91236,90410,90425). Reasons for the discrepancies are not entirely clear. However, it is possible that the lack of significant benefit from vitamin C in the latter studies results from the fact that incidences of CIN have become less common than in the past due to avoidance of dehydration, use of smaller catheters, and use of contrast agents with reduced nephrotoxicity (90429).
• Coronary artery bypass graft (CABG) surgery. It is unclear if intravenous vitamin C helps to improve patient outcomes after CABG surgery. Details: A small clinical study shows that giving vitamin C 5 grams intravenously (IV) before anesthesia induction and 5 grams in the cardioplegia solution used during surgery shortens the length of stay in the intensive care unit (ICU) by about 8 hours (102127). However, some limited research suggests that IV vitamin C does not resolve cardiac surgery complications. A small clinical study in patients with vasoplegia after receiving CABG and other cardiac surgeries shows that receiving IV vitamin C 1.5 grams every 6 hours after being admitted to the ICU does not improve vasoplegia when compared with control (102981).
• Delirium. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Observational research in adults with septic shock has found that receiving intravenous thiamine 400 mg daily with vitamin C 6 grams daily, both in divided doses, is not associated with reduced delirium when compared with control (103001).
• Dental plaque. It is unclear if vitamin C in a chewing gum helps to reduce dental plaque formation. Details: A small clinical study in patients with calculus shows that chewing 10 pieces of gum, each containing 60 mg of vitamin C, daily for 3 months reduces the formation of dental calculus, visible plaque, and the number of bleeding sites when compared not chewing gum (83303). The validity of this finding is limited by a lack of placebo group.
• Depression. It is unclear if oral vitamin C is beneficial for the treatment or prevention of depression. Details: A small clinical study in children and adolescents shows that taking vitamin C 500 mg orally twice daily in combination with fluoxetine 10-20 mg daily for 6 months reduces most symptoms of major depressive disorder when compared with taking fluoxetine alone (90404). However, a small clinical study in adults shows that taking vitamin C up to 1000 mg daily for 2 months does not improve the response rate or decrease symptoms of depression in adults also taking citalopram when compared with citalopram alone (96708). Reasons for these conflicting results may relate to the age of the patients, study duration, or differences in antidepressant medication being taken. One clinical guideline also provisionally recommends against the use of oral vitamin C to treat patients with depression based on low-quality evidence (110318). Some research has also evaluated vitamin C intake for the prevention of depression. A secondary analysis of pre- and peri-menopausal adults enrolled in the Study of Women's Health Across the Nation (SWAN) program suggests that vitamin C intake is inversely associated with depressive symptoms. This association persisted regardless of age, race, physical activity, body mass index, antidepressant use or menopausal status (108083). The validity of these findings is limited due to the secondary nature of this study; additionally, follow-up time is unclear.
• Diabetes. It is unclear if oral vitamin C prevents diabetes. Some low-quality research suggests that vitamin C might improve glycemic control in patients with diabetes. Details: Population research has not found a link between dietary vitamin C and the risk of developing type 2 diabetes (14004). However, low certainty clinical research has found some benefit of taking vitamin C supplements for glycemic control. Two meta-analyses of several small, heterogeneous clinical studies in patients with type 2 diabetes show that taking vitamin C 200-3000 mg daily for 2-48 weeks reduces fasting blood glucose by approximately 11 mg/dL (112478) and glycated hemoglobin (HbA1c) by an average of 0.5% when compared with placebo, standard treatment, or no treatment (105461,112478). Subgroup analyses suggest that durations of supplementation longer than 12 weeks show greater glycemic benefit, and although one meta-analysis suggests there is no dose-response relationship (105461), another meta-analysis suggests that doses of vitamin C 1000 mg and higher are most beneficial for improving glycemic indices (112478). Some research has evaluated the effects of vitamin C supplementation on the lipid profile in patients with diabetes, with mixed findings. One meta-analysis of 17 small clinical studies shows that taking vitamin C 200-3000 mg daily for 2 to 48 weeks improves levels of triglycerides and total cholesterol, but not low-density lipoprotein (LDL) or high-density lipoprotein (HDL) cholesterol. Subgroup analysis suggests that study durations of at least 12 weeks show greater benefit (106621). However, two other meta-analyses in patients with diabetes, one of 16 small heterogenous clinical studies and one of 11 small clinical studies, show no clinically important improvement in lipid levels after vitamin C supplementation (105461,105464).
• Dry mouth. Oral vitamin C has only been evaluated in combination with vitamin E; its effect when used alone is unclear. Details: A small clinical trial in patients receiving radiotherapy for head and neck cancer shows that taking vitamin E 100 IU and vitamin C 500 mg twice daily for an average of 3 months improves dry mouth when compared to baseline (99080). The validity of these results is limited by the lack of comparison with a control group.
• Endometrial cancer. Increased dietary vitamin C has been linked to reduced risk of endometrial cancer. Details: Population research has found that intake of vitamin C from dietary sources is associated with a slightly decreased risk of endometrial cancer when compared with control. However, this benefit is not observed when results from a prospective cohort study are assessed (34578).
• Endometriosis. Oral vitamin C has only been evaluated in combination with vitamin E; its effect when used alone is unclear. Details: A small clinical study in patients with endometriosis and pelvic pain shows that taking vitamin C 1000 mg and vitamin E 800 IU daily for 8 weeks improves dysmenorrhea, dyspareunia, and chronic pelvic pain scores when compared with placebo. Vitamin C and vitamin E supplementation also reduces some biochemical markers of oxidative stress when compared with placebo (106622).
• Endoscopy-associated adverse effects. It is unclear if a topical vitamin C spray reduces mucosal irritation in patients undergoing Lugol chromoendoscopy. Details: A small clinical trial in patients receiving a Lugol chromoendoscopy shows that spraying a vitamin C 2% solution after the application of the Lugol iodine 2% solution reduces the severity of mucosal irritation, heartburn, and pain when compared with using a normal saline spray after the Lugol iodine 2% solution (104030).
• Esophageal cancer. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Population research has found that higher dietary intake of vitamin C is associated with reduced odds of esophageal adenocarcinoma. A 50 gram increase in dietary vitamin C intake is associated with a 13% reduced odds of esophageal cancer (34551,98770). However, a meta-analysis of clinical research shows that taking a vitamin C supplement in combination with beta-carotene and vitamin E does not reduce the risk of esophageal cancer (34581).
• Exercise-induced asthma. Small clinical studies suggest that oral vitamin C may modestly improve symptoms in patients with exercise-induced asthma. Details: A meta-analysis of the available clinical research shows that vitamin C supplementation might reduce exercise-induced breathlessness when compared with placebo or control. However, the available research is of poor quality, and no clear conclusions can be drawn regarding its benefits for exercise-induced asthma (90409).
• Exercise-induced muscle damage. It is unclear if oral vitamin C is beneficial in exercise-induced muscle damage. Details: A small clinical study in healthy females shows that taking vitamin C 1000 mg before moderate intensity cycling does not prevent muscle damage when compared with placebo (99837). Another small clinical study in endurance-trained runners shows that taking vitamin C 1000 mg and vitamin E (as alpha-tocopherol) 235 mg 2 hours prior to an exercise protocol does not reduce delayed onset muscle soreness or improve other markers of exercise-induced muscle damage when compared with placebo (109961).
• Gallbladder disease. It is unclear if oral vitamin C reduces the risk of gallbladder disease. Details: Cross-sectional epidemiological evidence has found that vitamin C supplementation and increased vitamin C serum levels are associated with a decreased risk of developing gallbladder disease in females, but not males (5877).
• Gastric cancer. It is unclear if dietary or supplemental vitamin C reduces the risk of gastric cancer. Details: Most population research has not found an association between DIETARY intake of vitamin C and gastric cancer risk (9194,10822,10819,90083). Also, clinical research shows that taking vitamin C supplements in combination with other antioxidants does not reduce the risk of gastric cancer or precancerous gastric lesions (14447,34581,90085). However, some research suggests that it might be associated with a reduced risk for specific forms of gastric cancer (9838,90083). One clinical study shows that taking vitamin C orally 500 mg daily for 6 months after eradication of Helicobacter pylori infection decreases the incidence of precancerous changes in stomach tissue when compared with no treatment (10359). Also, other clinical research shows that taking vitamin C orally 1 gram daily helps promote the regression of precancerous gastric lesions in people at high risk for gastric cancer (2579). In 2009, the US Food and Drug Administration (FDA) determined that it would allow a qualified health claim stating that vitamin C supplements may reduce the risk of gastric cancer. However, the FDA has concluded that it is highly uncertain that vitamin C supplements actually reduce the risk of gastric cancer (102332).
• Gastritis. There is limited evidence on the oral use of vitamin C in omeprazole-induced corpus gastritis. Details: A small clinical study shows that taking vitamin C orally 1200 mg daily along with omeprazole decreases corpus gastritis associated with omeprazole therapy in patients with H. pylori infection (10360).
• Gout. It is unclear if oral vitamin C helps to prevent or manage gout. Details: Population research in men has found that taking vitamin C 500-1500 mg daily from the diet and/or supplements is associated with up to a 34% reduced risk of gout when compared with less than 250 mg daily (16755). Also, men who ingest over 500 mg of vitamin C daily from the diet and supplements have serum uric acid levels that are slightly lower than men who consume less than 90 mg daily (16820). However, taking supplemental vitamin C 500 mg daily for 8 weeks does not seem to lower serum uric acid levels in patients who already have gout (90423).
• Hearing loss. There is limited evidence on the intravenous use of vitamin C in idiopathic sudden sensorineural hearing loss. It is unclear if dietary vitamin C intake can affect the risk of hearing loss. Details: A small clinical study in patients with idiopathic sudden sensorineural hearing loss shows that receiving intravenous high-dose vitamin C 200 mg/kg daily in combination with steroid therapy for 10 days, followed by oral vitamin C 2000 mg daily for 30 days, increases recovery rate two-fold and modestly improves hearing threshold levels when compared with receiving steroid therapy only (90417). In addition, population research in females has found that high dietary intake of vitamin C is associated with a 22% increased risk of developing self-reported hearing loss over a 22-year period when compared with low intake (109807).
• Heart transplant complications. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial shows that a combination of vitamin C 500 mg and vitamin E 400 IU, taken twice daily for 1 year starting within the first 2 years after cardiac transplant, reduced the progression of vasculopathy as measured by intravascular ultrasonography (IVUS) when compared with placebo. This suggests that the combination may help slow the progression of CAV (82826).
• Hepatitis C. It is unclear if oral vitamin C is beneficial in patients with hepatitis C. Details: A small clinical study in patients with confirmed hepatitis C shows that taking vitamin C 1000 mg daily with conventional therapy (sofosbuvir plus daclatasvir) for 4 weeks improves serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, and albumin when compared with conventional therapy alone (109463).
• HIV/AIDS. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small, low-quality study in men with HIV shows that taking vitamin C 250 mg daily in combination with vitamin A, beta-carotene, vitamin E, selenium, and coenzyme Q10 does not improve viral load, although it seems to improve markers of oxidative stress when compared to baseline. However, a 1000 mg dose of vitamin C, as well as higher doses of the other antioxidants, do not seem to provide any additional effect (9830).
• HIV transmission. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A clinical study in HIV-positive mothers shows that taking vitamin B, vitamin C, and vitamin E daily during pregnancy and while breast-feeding for 20 weeks seems to reduce child mortality and HIV transmission through breast milk when compared with taking vitamin A (9801).
• Hyperphosphatemia. Intravenous vitamin C might be beneficial for reducing phosphate levels in patients with end-stage renal disease. Details: A small clinical study in hemodialysis patients with elevated phosphorus levels suggests that administering vitamin C 500 mg intravenously three times weekly for 8 weeks reduces phosphorus levels about seven-fold when compared with placebo (90414).
• Idiopathic interstitial pneumonia. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with idiopathic pulmonary fibrosis, a form of idiopathic interstitial pneumonia, shows that taking a combination of vitamin C 250 mg every other day, vitamin D 50,000 IU daily, and vitamin E 200 IU daily for 12 weeks improves some, but not all, measures of lung function and reduces markers of inflammation and oxidative stress when compared to baseline (109464). The validity of these findings is limited by a lack of placebo control group.
• Infertility. It is unclear if oral vitamin C is beneficial in anovulatory females. Details: A very small clinical study suggests that taking vitamin C 400-1000 mg daily might improve fertility, resulting in ovulation and pregnancy in some anovulatory females, when compared with baseline (14018). The validity of these findings is limited by the small study size and lack of a comparator group.
• Male infertility. It is unclear if oral or intravenous vitamin C is beneficial in males with infertility. Details: A meta-analysis of three small, low-quality clinical trials in males with infertility shows that taking vitamin C up to 1000 mg daily for up to 12 weeks can improve sperm count, motility, and vitality, but does not seem to increase semen volume or sperm concentration, when compared with control (109461). It is unclear if vitamin C can increase pregnancy rates, as these studies did not assess this outcome. A retrospective study in males with or without varicocele-related infertility has found that taking a specific combination product containing vitamin C 90 mg, zinc 10 mg, L-carnitine fumarate 1725 mg, acetyl-L-carnitine 500 mg, coenzyme Q10 20 mg, folic acid 0.2 mg, selenium 0.05 mg, and vitamin B12 0.015 mg (Proxeed Plus, Sigma-Tau) orally twice daily for 6 months improves sperm count, sperm concentration, and sperm motility when compared with baseline. Improvement in semen parameters were greatest in subjects with more severe varicoceles. The validity of this study is limited by the lack of a comparator group (111296).
• Mastalgia. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in patients with mastalgia shows that taking a combination of vitamin C 100 mg, vitamin B12, and gamma-linolenic acid daily for 12 weeks does not improve the proportion of patients with minimal or no pain when compared with placebo (111059).
• Melasma. It is unclear if topical vitamin C is beneficial in patients with melasma. Details: A small clinical study in patients with bilateral symmetrically distributed facial melasma shows that topical application of 0.5 mL of vitamin C (Cosmotech, Alpha Medical Cosmotech) following dermapen microneedling every 2 weeks for 6 weeks is similarly effective to tranexamic acid for improving melasma severity and pigmented, but not vascular, findings on dermoscopic examination (106939).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral vitamin C is beneficial in patients with NAFLD. Details: A clinical study in patients with NAFLD shows that taking vitamin C 250 mg, 1000 mg, or 2000 mg daily for 12 weeks improves some biochemical markers of liver health and glucose metabolism when compared with baseline. However, the improvement from baseline was similar between groups (106942).
• Nonalcoholic steatohepatitis (NASH). Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research suggests vitamin C in combination with vitamin E might improve hepatic fibrosis in patients with NASH. However, it does not seem to decrease liver inflammation (14005).
• Non-Hodgkin lymphoma. It is unclear if oral vitamin C reduces the risk of developing diffuse large B-cell lymphoma. Details: In one population study, higher dietary or supplemental intake of vitamin C was associated with a reduced risk of diffuse large B-cell lymphoma, a type of non-Hodgkin lymphoma, when compared with lower intake in postmenopausal adults (90945).
• Oral cancer. It is unclear if oral vitamin C reduces the risk of developing oral cancer. Details: Population research has found that higher dietary intake of vitamin C is associated with a reduced risk of oral cancer (10821). However, clinical research has not shown benefit with oral vitamin C supplements. A small clinical trial in Japanese adults with oral leukoplakia shows that taking vitamin C 500 mg and beta-carotene 10 mg daily for 12 months does not reduce the development of oral cancer over 5 years when compared with vitamin C 50 mg daily (91384).
• Oral leukoplakia. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in Japanese adults with oral leukoplakia shows that taking vitamin C 500 mg and beta-carotene 10 mg daily for 12 months does not improve leukoplakia symptoms or reduce the development of oral cancer over 5 years when compared with vitamin C 50 mg daily (91384).
• Osteoarthritis. It is unclear if dietary vitamin C reduces the risk of developing osteoarthritis. Details: Observational research has found that increased vitamin C from dietary sources is associated with a reduced risk of cartilage loss and disease progression in people with osteoarthritis (5881).
• Osteoporosis. It is unclear if dietary vitamin C improves bone density or reduces fracture risk in patients at risk for osteoporosis. Details: Some cross-sectional observational research in postmenopausal patients without a history of smoking or estrogen use has found that higher serum vitamin C levels are associated with lower bone mineral density (9828). However, other observational research in a larger population of adults at risk for osteoporosis has found that higher dietary vitamin C intake is not associated with fracture risk (104415).
• Ovarian cancer. Dietary vitamin C might not affect the risk of ovarian cancer. Details: Epidemiological research has found that dietary vitamin C intake is not linked with ovarian cancer risk (9193,102977).
• Pancreatitis. It is unclear if intravenous vitamin C is beneficial in patients with acute pancreatitis. Details: A small meta-analysis of clinical studies in patients with acute pancreatitis shows that intravenous vitamin C does not improve the odds of developing organ failure when compared with placebo or no intervention. Intravenous vitamin C seems to reduce hospital stay, but not in-hospital mortality (106941).
• Parkinson disease. Dietary vitamin C might not affect the risk of developing this condition. Details: Observational research has found that moderate or high dietary intake of vitamin C is not associated with a reduced risk of Parkinson disease (83316).
• Periodontitis. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. It is also unclear if dietary vitamin C reduces the risk of periodontitis. Details: A small clinical study in patients with moderate or advanced periodontitis shows that taking a supplement containing vitamin C 100 mg, alpha-lipoic acid, coenzyme Q10, cranberry extract, grapeseed extract, selenium, vitamin E, and zinc twice daily for 8 weeks in addition to standard nonsurgical therapy does not improve periodontal indices including bleeding on probing, gingival recession, plaque index, or inflammation, among others, when compared with placebo (111708). It is unclear if these effects are due to vitamin C, other ingredients, or the combination. There is also interest in whether dietary vitamin C intake impacts the risk of periodontitis. Observational research in US adults has found that individuals with dietary intake of vitamin C in the third quartile, but not the second or fourth quartiles, have lower odds of periodontitis when compared with vitamin C intake in the lowest quartile. Furthermore, the investigators identified a non-linear relationship between vitamin C intake and periodontitis risk, suggesting that individuals with intakes either much lower or much higher than 158 mg daily are at increased risk of developing periodontitis (109958).
• Peripheral arterial disease (PAD). It is unclear if dietary vitamin C helps to reduce the risk of developing PAD. Details: In females, epidemiological evidence has found that dietary intake of vitamin C of 142 mg daily or greater is associated with a 36% reduced risk of PAD when compared with lower intake levels of less than 80 mg daily (10130).
• Physical performance. It is unclear if oral vitamin C helps to improve physical performance and muscle strength in older people. Details: Population research has found that higher intake of dietary vitamin C is associated with improved physical performance and muscle strength in elderly people (14006). In contrast, a small clinical study in elderly men undergoing strength training shows that taking vitamin C 1000 mg and vitamin E 258IU daily for 12 weeks does not increase strength, and might even attenuate increases in muscle mass, when compared with strength training alone (96701).
• Pneumonia. It is unclear if oral vitamin C helps to prevent pneumonia. Details: A meta-analysis of two small, low-quality clinical studies in children shows that vitamin C does not seem to reduce the occurrence of pneumonia when compared to control (104033).
• Postoperative recovery. It is unclear if oral or intravenous vitamin C improves postoperative recovery. Details: Meta-analyses of clinical research show that oral or intravenous vitamin C can shorten the duration of hospitalization after cardiac surgery when compared with control (91233,96703). However, other research shows no decrease in intensive care or hospital stay with vitamin C supplementation (96705). A meta-analysis of 37 clinical trials in adults undergoing low- to high-risk noncardiac surgery (i.e., orthopedic, abdominal, gynecologic, or kidney transplantation), shows that receiving perioperative vitamin C, either orally or intravenously, does not improve duration of hospitalization or overall mortality when compared with control (108087). There's also some limited evidence that vitamin C might reduce postoperative pulmonary complications such as lung infection, pleural effusion, and pneumothorax. A small clinical trial in low-risk cardiac surgery patients shows that receiving intravenous vitamin C 1 gram 10 minutes after anesthesia might slightly reduce the rate of postoperative pulmonary complications when compared with receiving a saline injection (104034).
• Premature rupture of membranes (PROM). Oral vitamin C seems to reduce the risk of PROM in some patients; however, the addition of oral vitamin E seems to negate any benefit. Details: A meta-analysis of clinical research shows that taking vitamin C alone decreases the risk of both term and preterm PROM by 45% and 34%, respectively, when compared with placebo or control (96707). Also, a more recent clinical study in patients with a history of PROM shows that taking vitamin C 100 mg daily, starting at 14 weeks' gestation, increases the gestational age at recurrent PROM by around 1 week and increases the gestational age at birth by around 1.3 weeks when compared with placebo (109960). Taking vitamin C in combination with vitamin E, however, does not seem to reduce the risk of term or preterm PROM; some research suggests that it might even increase the risk of non-preterm PROM (83472,96707). However, other research shows that taking vitamin C 1000 mg plus vitamin E 400 IU daily, beginning at 24 to 34 weeks gestation and continuing until delivery, may help increase the latency period until delivery by 5 days and increase gestational age at delivery by almost 1 week when compared with placebo in patients with preterm PROM (90078).
• Pressure ulcers. It is unclear if oral vitamin C, when used alone or in combination with other ingredients, can improve the healing of pressure ulcers. Details: A small clinical study in institutionalized patients with pressure ulcers shows that taking vitamin C 500 mg twice daily for 12 weeks does not improve wound closure or increase healing rates when compared with vitamin C 10 mg twice daily (83617). Oral vitamin C has also been evaluated in combination with other ingredients for the treatment of grade II-IV pressure ulcers. Two small clinical studies in hospitalized patients with pressure ulcers shows that administering an oral nutritional supplement enriched with vitamin C, L-arginine, and zinc improves ulcer healing when compared with a standard diet (31953,87173). Also, clinical research in patients living in long-term care facilities shows that taking an oral nutritional supplement enriched in protein, vitamin C, L-arginine, and zinc daily for 9 weeks reduces ulcer area and decreases oozing when compared to baseline (32045). The validity of this finding is limited by the lack of a comparator group.
• Radiation proctopathy. Oral vitamin C has only been evaluated in combination with vitamin E; its effect when used alone is unclear. Details: A small clinical study in patients with chronic radiation proctitis shows that vitamin C 500 mg plus vitamin E 400 IU three times daily might improve symptoms when compared with baseline (9825). The validity of these findings is limited by the lack of a comparator group.
• Renal cell carcinoma. It is unclear if increased dietary intake of vitamin C helps to reduce the risk of renal cell carcinoma. Details: Population research has found that increased dietary intake of vitamin C is associated with a 12% reduced risk of renal cell carcinoma (98779).
• Respiratory tract infections. It is unclear if oral vitamin C is beneficial for preventing respiratory tract infections or reducing the duration of these infections. Details: A meta-analysis of clinical research in children and adults shows that, when compared with placebo, oral vitamin C supplementation reduces the average number of symptomatic days per individual, but does not reduce the average symptom days per respiratory episode. Also, vitamin C intake does not reduce the incidence or severity of respiratory disease or improve recovery in hospitalized patients with respiratory tract infections (108077). The validity of this trial is limited by the high heterogeneity of included studies, which evaluated various vitamin C regimens, ranging from 100 mg to 8 grams daily, as preventive therapy or as an adjuvant to active treatment. A clinical study in children aged 3-10 years shows that taking vitamin C 50 mg in combination with a specific product (Lab4) containing Lactobacillus acidophilus, Bifidobacterium bifidum, and Bifidobacterium animalis subsp. lactis daily for 6 months reduces the incidence of cough and sore throat by 16% and 20%, respectively, when compared with placebo. However, it did not improve total symptoms, nasal congestion, nasal discharge, or sneezing. Also, aside from a 33% reduction in the average number of days with a sore throat, daily supplementation does not reduce the duration of individual symptoms or total symptoms (106943). It is unclear if these effects are due to vitamin C, the probiotics, or the combination.
• Restless legs syndrome (RLS). It is unclear if oral vitamin C helps to reduce symptoms of stress. Details: A small clinical study in hemodialysis patients with RLS shows that taking vitamin C 200 mg daily, alone or in combination with vitamin E 400 mg, for 8 weeks reduces the severity of RLS when compared with placebo (90093). More research is needed to determine if vitamin C is beneficial in treating RLS that is not associated with hemodialysis.
• Sunburn. Topical and oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Taking vitamin C orally in combination with vitamin E seems to prevent ultraviolet (UV) radiation-induced erythema (sunburn) (4715,4716). Vitamin C in combination with high dose oral RRR-alpha-tocopherol (natural vitamin E) seems to protect against skin inflammation after exposure to UV radiation (4715). Also, applying topical vitamin C in combination with topical vitamin E and melatonin seems to provide modest photoprotective effects when used prior to UV exposure. However, it has no effect when used during or after UV exposure (4713,4714).
• Stress. It is unclear if oral vitamin C helps to reduce symptoms of stress. Details: A small clinical study in healthy adults shows that taking vitamin C 3000 mg daily for 14 days modestly reduces blood pressure and subjective stress response to psychological stress when compared with placebo (10353).
• Stroke. Observational research has found that although taking vitamin C supplements does not seem to be beneficial, eating more vitamin C-rich food is linked with reduced risk of stroke. Details: Lower plasma levels of vitamin C have been associated with increased stroke risk (90408). Additionally, population research has found that higher dietary intake of vitamin C is associated with a 8% to 19% reduction in stroke risk when compared to lower intake (90408,109779). This reduction appears to be dose-dependent, with each 100 mg/day increase in dietary vitamin C intake associated with about a 17% reduction (90408). However, taking vitamin C supplements has not been found to be associated with reduced stroke risk (1449,90408).
• Tetanus. It is unclear if intravenous vitamin C helps to reduce symptoms of tetanus. Details: A low quality clinical trial in children and young adults with tetanus shows that intravenous vitamin C 1 gram daily along with conventional treatment reduces fatality when compared to control (21539).
• Tooth extraction. It is unclear if oral vitamin C is beneficial for reducing pain or improving healing after tooth extraction. Details: A small clinical study in healthy patients aged 14-41 years who are undergoing bilateral premolar extraction shows that taking vitamin C 200 mg three times daily, beginning immediately after extraction and continued for 10 days, improves pain on days 1-3, and may reduce mesio-distal wound size between days 1 and 7, when compared with placebo, but not when compared with vitamin C 500 mg three times daily. A dose of 500 mg three times daily did not improve pain scores or extraction wound healing when compared with placebo (108084). The validity of this trial is limited by the short duration of treatment; additionally, this study did not report baseline vitamin C levels.
• Urinary tract infections (UTIs). Although there is interest in using oral vitamin C for UTIs, there is insufficient reliable information about the clinical effects of vitamin C for this condition.
• Vascular dementia. It is unclear if oral vitamin C reduces the risk of vascular dementia. Details: Population research has found that supplemental intake of vitamin C and vitamin E is associated with a reduced risk of vascular dementia in Japanese-American men (4636). However, when cases in which dementia was diagnosed prior to the study are excluded from data analysis, intake of vitamin C and vitamin E is not associated with a reduced risk of vascular dementia in these patients (9824).
• Wound healing. It is unclear if oral vitamin C improves the healing of chronic foot ulcers. It is also unclear if intravenous vitamin C improves healing of surgical wounds after total abdominal hysterectomy. Details: A very small clinical study in adults with chronic foot ulcers shows that taking slow-release vitamin C 500 mg daily for 8 weeks seems to result in a median of 100% ulcer healing, compared with a median of 14% ulcer healing in patients taking glucosamine 1000 mg daily (105456). This finding is limited due to the small and heterogeneous patient population, which included patients with diabetes, vascular disease, and/or vitamin C deficiency. Another small clinical study in patients undergoing total abdominal hysterectomy shows that administration of intravenous vitamin C 1 gram the night before surgery and 1 gram during surgery does not reduce the rate of surgical site infection or wound dehiscence when compared with placebo (109465). However, this study may not have been adequately powered to detect differences between groups. More evidence is needed to rate vitamin C for these uses.

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POSSIBLY SAFE ...when acerola fruit is used orally and appropriately. Acerola fruit contains an average of 2000 mg vitamin C per 100 grams of fruit, although this content varies widely. Acerola fruit should be consumed in amounts that do not provide more vitamin C than the tolerable upper intake level (UL) of 2000 mg per day for adults (4844).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using in amounts greater than found in foods.

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LIKELY SAFE ...when aloe gel is used topically and appropriately. Aloe gel-containing formulations have been safely applied in clinical trials (101,11982,12096,12098,12159,12160,12163,12164,17418)(90123,90124,90127,90128,90129,90131,97320,98816,103305). When included in topical cosmetics, the Cosmetic Ingredient Review Expert Panel concluded that aloe-derived anthraquinone levels should not exceed 50 ppm (90122).

POSSIBLY SAFE ...when aloe gel is used orally and appropriately, short-term. Aloe gel has been safely used in a dose of 15 mL daily for up to 42 days or 100 mL of a 50% solution twice daily for up to 4 weeks (11984,12164). Also, a specific aloe gel complex (Aloe QDM complex, Univera Inc.) has been safely used at a dose of approximately 600 mg daily for up to 8 weeks (90121). ...when aloe extract is used orally and appropriately, short-term. Aloe extract has been used with apparent safety in a dose of 500 mg daily for one month (101579). Also, an aloe extract enriched in aloe sterols has been used with apparent safety in a dose of 500 mg daily for 12 weeks (101577).

POSSIBLY UNSAFE ...when aloe latex is used orally. There is some evidence that anthraquinones in aloe latex are carcinogenic or promote tumor growth, although data are conflicting (6138,16387,16388,91596,91597). In 2002, the US FDA banned the use of aloe latex in laxative products due to the lack of safety data (8229). ...when aloe whole-leaf extract is used orally. Aloe whole-leaf extract that has not been filtered over charcoal still contains anthraquinones. This type of aloe whole-leaf extract is referred to as being "nondecolorized". The International Agency for Research on Cancer has classified this type of aloe whole-leaf extract as a possible human carcinogen (91598,91908). Although filtering aloe whole-leaf extract over charcoal removes the anthraquinones, some animal research suggests that this filtered extract, which is referred to as being "decolorized", may still cause gene mutations (91598). This suggests that constituents besides anthraquinones may be responsible for the carcinogenicity of aloe whole-leaf extract. It should be noted that commercial products that contain aloe whole-leaf extract may be labeled as containing "whole leaf Aloe vera juice" or "aloe juice" (91908).

LIKELY UNSAFE ...when aloe latex is used orally in high doses. Ingesting aloe latex 1 gram daily for several days can cause nephritis, acute kidney failure, and death (8,8961).

CHILDREN: POSSIBLY SAFE
when aloe gel is used topically and appropriately. Aloe gel-containing formulations have been safely applied in clinical trials (90124,90131).

CHILDREN: POSSIBLY UNSAFE
when aloe latex and aloe whole leaf extracts are used orally in children. Children younger than 12 years may experience abdominal pain, cramps, and diarrhea (4).

PREGNANCY: POSSIBLY UNSAFE
when used orally. Anthraquinones present in aloe latex and aloe whole leaf extracts have irritant, cathartic, and possible mutagenic effects (4,16387,16388,90122). There are also anecdotal reports and evidence from animal research that anthraquinones or aloe whole leaf extracts might induce abortion and stimulate menstruation; avoid using (4,8,19,90122).

LACTATION: POSSIBLY UNSAFE
when aloe preparations are used orally. Cathartic and mutagenic anthraquinones present in aloe latex and aloe whole leaf extracts might pass into milk; avoid using (4,19).

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LIKELY SAFE ...when used orally and appropriately in food amounts (4819,4820,4821,5104,10166,10435,11134,11463,11986,92818). There is insufficient reliable information available about the safety of barley when used orally in medicinal amounts or when applied topically.

PREGNANCY: LIKELY SAFE
when used orally in amounts commonly found in foods (19).

PREGNANCY: POSSIBLY UNSAFE
when barley sprouts are consumed in relatively high doses. Excessive amounts of barley sprouts should not be consumed during pregnancy (19).

LACTATION:
Insufficient reliable information available; avoid using.

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LIKELY SAFE ...when used in amounts commonly found in foods.

POSSIBLY SAFE ...when used orally and appropriately for medicinal purposes, short term. Beetroot juice has been safely used in clinical trials in doses of up to 500 mL daily for up to 7 days and a beetroot-based nutritional gel has been used safely in doses of up to 100 grams daily for 8 days (94461,94462,94464,100149,100152,100153).

PREGNANCY AND LACTATION:
There is insufficient reliable information available about the safety of beets used medicinally during pregnancy and breast-feeding.

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LIKELY SAFE ...when used orally and appropriately. Bifidobacterium bifidum has been safely used alone or in combination with other probiotics in clinical trials lasting up to one year (1731,12775,14338,92255,107580,110972,110974,110978). There is insufficient reliable information available about the safety of non-viable, heat-killed B. bifidum formulations when used orally.

CHILDREN: LIKELY SAFE
when used orally and appropriately in children of most ages. Bifidobacterium bifidum has been safely used alone or in combination with other probiotics in clinical trials in infants and children for up to 18 months (161,90286,90602,98736,103436,110971,110976,110924). There is insufficient reliable information available about the safety of B. bifidum in preterm infants with a birth weight under 1000 grams. Cases of bacteremia have occurred rarely in preterm infants given other probiotics (102416,111610,111612,111613,111850,111852,111853). The US Food and Drug Administration (FDA) has issued a warning about cases of serious infections caused by probiotics reported in very preterm or very low birth weight infants under 1000 grams (111610). Similarly, the American Academy of Pediatrics does not support the routine administration of probiotics to these infants due to conflicting data on safety and efficacy (111608).

PREGNANCY: POSSIBLY SAFE
when Bifidobacterium bifidum is used orally and appropriately, short-term. A combination of B. bifidum, Lactobacillus acidophilus, and Lacticaseibacillus casei has been used with apparent safety for 6 weeks starting at 24-28 weeks' gestation (95416,98430).

LACTATION:
There is insufficient reliable information available about the safety of Bifidobacterium bifidum during lactation. However, there are currently no reasons to expect safety concerns when used appropriately.

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LIKELY SAFE ...when used orally and appropriately in amounts commonly found in foods. Bilberry has Generally Recognized As Safe status (GRAS) for use in foods in the US (4912).

POSSIBLY SAFE ...when used orally and appropriately for medicinal purposes. Bilberry fruit extracts have been used with apparent safety in clinical trials at a dose of up to 160 mg daily for up to 6 months (39,40,8139,9739,14280,35472,35510,35512,103190,104192,104195). A higher bilberry extract dose of 1.4 grams daily has been used with apparent safety for up to 4 weeks (104194). Whole bilberries or bilberry juice have also been consumed with apparent safety in quantities of 100-160 grams daily for up to 35 days (35463,91506).

POSSIBLY UNSAFE ...when the leaves are used orally in high doses or for a prolonged period. Death can occur with chronic use of 1.5 gram/kg daily (2).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in the amounts commonly found in foods. However, there is insufficient reliable information available about the safety of bilberry when used in medicinal amounts during pregnancy and lactation; avoid using.

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LIKELY SAFE ...when used orally and appropriately. Blueberry, as the whole fruit, juice, or in a powder formulation, is safe when consumed in amounts commonly found in foods (13533,92387,92388,92394,96467,97181,99139). There is insufficient reliable information available about the safety of blueberry when used topically or when the leaves are used orally.

CHILDREN: LIKELY SAFE
when used orally and appropriately in amounts commonly found in foods (13533,96465).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts commonly found in foods (13533,107281). There is insufficient reliable information available about the safety of blueberry for medicinal use; avoid using.

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POSSIBLY SAFE ...when non-contaminated species of spirulina blue-green algae are used orally and appropriately (91713). The blue-green algae species Arthrospira platensis has been used with apparent safety in doses up to 19 grams daily for 2 months, or 10 grams daily for 6 months (18296,18300,18306,75944,91705,99703,104567,109965). The blue-green algae species Arthrospira fusiformis has been used with apparent safety in doses up to 4 grams daily for 3 months, or 1 gram daily for 12 months (15782,91717). Another blue-green algae species, Arthrospira maxima, has been used with apparent safety in a dose of 4.5 grams daily for up to 12 weeks (18297,99654,99655,102688). ...when non-contaminated, non-toxin producing strains of blue-green algae from the Aphanizomenon flos-aquae species are used orally and appropriately. Doses up to 1.6 grams daily have been used with apparent safety for up to 6 months (14842,18310). Some blue-green algae species can produce toxins called microcystins. According to the World Health Organization (WHO), the tolerable daily intake of microcystins in adults is 0.04 mcg/kg (96549).

POSSIBLY UNSAFE ...when contaminated blue-green algae are used orally. Blue-green algae can be contaminated with heavy metals (including mercury, cadmium, lead, or arsenic), neurotoxins, and toxic microcystin-producing cyanobacteria such as Microcystis aeruginosa (9171,75966,91704,91711,96550). Microcystins are most commonly reported in the blue-green algae species Aphanizomenon flos-aquae harvested from Upper Klamath Lake in Oregon. The Oregon Department of Health has set a limit of 1 mcg of microcystin-LR equivalents per gram dry weight of blue-green algae, assuming consumption of about 2 grams/day by adults (91704,91713). However, many samples of Aphanizomenon flos-aquae have been reported to contain higher levels than this (9171,91704). According to the World Health Organization (WHO), the tolerable daily intake of microcystins in adults is 0.04 mcg/kg (96549). When consumed orally, microcystins accumulate in the liver, binding to and inhibiting protein phosphatases, causing hepatocyte damage and possible tumor promotion (9171). Aphanizomenon flos-aquae can also produce neurotoxic compounds that may be present in supplements containing this organism (91704).

CHILDREN: POSSIBLY UNSAFE
when blue-green algae products are used orally. Blue-green algae can accumulate heavy metals such as lead and mercury (91704,91711). They can also contain toxic microcystins produced by contaminating species of cyanobacteria such a Microcystis aeruginosa (91704). Children are more sensitive to poisoning by microcystins (3536). The Oregon Department of Health has set a limit for microcystins of 1 mcg per gram dry weight of blue-green algae, but some countries have set very low exposure limits of 0.2 mcg per day and 0.8 mcg per day for infants and children, respectively (91704).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using. Some blue-green algae products, specifically those of the species Aphanizomenon flos-aquae, have been found to contain low amounts of beta-methylamino-L-alanine (BMAA). BMAA is associated with neurodegenerative diseases, and breast milk has been shown to be a potential source of BMAA exposure in infants (96550).

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LIKELY SAFE ...when used orally or intravenously and appropriately. Calcium is safe when used in appropriate doses (7555,12928,12946,95817). However, excessive doses should be avoided. The Institute of Medicine sets the daily tolerable upper intake level (UL) for calcium according to age as follows: Age 0-6 months, 1000 mg; 6-12 months, 1500 mg; 1-8 years, 2500 mg; 9-18 years, 3000 mg; 19-50 years, 2500 mg; 51+ years, 2000 mg (17506). Doses over these levels can increase the risk of side effects such as kidney stone, hypercalciuria, hypercalcemia, and milk-alkali syndrome. There has also been concern that calcium intake may be associated with an increased risk of cardiovascular disease (CVD) and coronary heart disease (CHD), including myocardial infarction (MI). Some clinical research suggests that calcium intake, often in amounts over the recommended daily intake level of 1000-1300 mg daily for adults, is associated with an increased risk of CVD, CHD, and MI (16118,17482,91350,107233). However, these studies, particularly meta-analyses, have been criticized for excluding trials in which calcium was administered with vitamin D (94137). Many of these trials also only included postmenopausal females. Other analyses report conflicting results, and have not shown that calcium intake affects the risk of CVD, CHD, or MI (92994,93533,97308,107231). Advise patients not to consume more than the recommended daily intake of 1000-1200 mg per day and to consider total calcium intake from both dietary and supplemental sources (17484). Also, advise patients taking calcium supplements to take calcium along with vitamin D (93533).

POSSIBLY UNSAFE ...when used orally in excessive doses. The National Academy of Medicine sets the daily tolerable upper intake level (UL) for calcium according to age as follows: 19-50 years, 2500 mg; 51 years and older, 2000 mg (17506). Doses over these levels can increase the risk of side effects such as kidney stones, hypercalciuria, hypercalcemia, and milk-alkali syndrome. There has also been concern that calcium intake may be associated with an increased risk of cardiovascular disease (CVD) and coronary heart disease (CHD), including myocardial infarction (MI). Some clinical research suggests that calcium intake, often in amounts over the recommended daily intake level of 1000-1300 mg daily for adults, is associated with an increased risk of CVD, CHD, and MI (16118,17482,91350,107233). However, these studies, particularly meta-analyses, have been criticized for excluding trials in which calcium was administered with vitamin D (94137). Many of these trials also only included postmenopausal females. Other analyses report conflicting results, and have not shown that calcium intake affects the risk of CVD, CHD, or MI (92994,93533,97308,107231). Advise patients to not consume more than the recommended daily intake of 1000-1200 mg per day and to consider total calcium intake from both dietary and supplemental sources (17484). Also, advise patients taking calcium supplements to take calcium along with vitamin D (93533).

CHILDREN: LIKELY SAFE
when used orally and appropriately. Calcium is safe when used in appropriate doses (17506).

CHILDREN: POSSIBLY UNSAFE
when used orally in excessive doses. The Institute of Medicine sets the daily tolerable upper intake level (UL) for calcium according to age as follows: 0-6 months, 1000 mg; 6-12 months, 1500 mg; 1-8 years, 2500 mg; 9-18 years, 3000 mg (17506). Doses over these levels can increase the risk of side effects such as kidney stones, hypercalciuria, hypercalcemia, and milk-alkali syndrome.

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally and appropriately (945,1586,3263,3264,17506). The World Health Organization (WHO) recommends prescribing oral calcium supplementation 1.5-2 grams daily during pregnancy to those with low dietary calcium intake to prevent pre-eclampsia (97347).

PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used orally in excessive doses. The Institute of Medicine sets the same daily tolerable upper intake level (UL) for calcium according to age independent of pregnancy status: 9-18 years, 3000 mg; 19-50 years, 2500 mg (17506). Doses over these amounts might increase the risk of neonatal hypocalcemia-induced seizures possibly caused by transient neonatal hypoparathyroidism in the setting of excessive calcium supplementation during pregnancy, especially during the third trimester. Neonatal hypocalcemia is a risk factor for neonatal seizures (97345).

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LIKELY SAFE ...when used orally in amounts commonly found in foods. Carrot essential oil, extracts, and food additives have Generally Recognized as Safe (GRAS) status in the US (4912).

POSSIBLY SAFE ...when used orally in medicinal amounts, short-term. Carrot has been used safely in doses of approximately 100 grams three times daily for up to 4 weeks (96308). There is insufficient reliable information available about the safety of carrot when used topically.

CHILDREN: LIKELY SAFE
when used orally in amounts commonly found in foods (4912). Carrot essential oil, extracts, and food additives have Generally Recognized as Safe (GRAS) status in the US (4912).

CHILDREN: POSSIBLY UNSAFE
when carrot juices are used excessively in nursing bottles for small children. Excessive use of carrot juice may cause carotenemia and dental caries (25817).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts commonly found in food (4912). Carrot essential oil, extracts, and food additives have Generally Recognized as Safe (GRAS) status in the US (4912). There is insufficient reliable information available about the safety of carrot when used in medicinal amounts during pregnancy and lactation.

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LIKELY SAFE ...when used orally in amounts commonly found in foods. There is insufficient reliable information available about the safety of cauliflower when used in medicinal amounts.

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using in greater amounts than found in foods.

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LIKELY SAFE ...when used orally and appropriately, short-term. Tablets and liquids containing chlorella 3-10 grams or 60-100 mL daily have been safely used in clinical studies lasting 2-3 months (5890,92130,92131). Also, chlorella extract 200-1800 mg daily has been safely used in clinical research for 4-6 weeks (10388,92132). There is insufficient reliable information available about the safety of chlorella when used topically.

PREGNANCY: POSSIBLY SAFE
when used orally and appropriately in medicinal amounts for up to approximately 28 weeks. A commercially available chlorella supplement (Sun Chlorella A, Sun Chlorella Corp.) has been safely used in doses of 6 grams daily, starting during the 12-18th week of gestation and continuing until delivery (95013).

LACTATION:
Insufficient reliable information available; avoid using.

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LIKELY SAFE ...when used orally in amounts commonly found in foods. Grapes and grape skin extracts have Generally Recognized As Safe (GRAS) status for use in foods in the US (4912).

POSSIBLY SAFE ...when the whole fruit of the grape, or extracts of the fruit, seed, or leaf, are used orally and appropriately in medicinal amounts. Grape seed extracts have been used with apparent safety in doses up to 200 mg daily for up to 11 months (9182,53016) and in doses up to 2000 mg daily for up to 3 months (53149,53190). Specific grape fruit extracts (Stilvid, Actafarma; Cognigrape, Bionap srl) have been used with apparent safety in doses up to 250-350 mg daily for 3-12 months or 700 mg daily for 6 months (53254,53256,96198). A specific grape leaf extract (AS 195, Antistax, Boehringer Ingelheim) has been used with apparent safety in doses up to 720 mg daily for up to 3 months (2538,52985,53005,53206). A preparation of dehydrated whole grapes, equivalent to 250 grams of fresh grapes daily, has also been used with apparent safety for up to 30 days (18228). A specific grape seed extract (Enovita; Indena SpA) 150 mg twice daily, standardized to provide at least 95% oligomeric proanthocyanins, has been used with apparent safety for up to 16 weeks (108091) ...when used topically and appropriately. Creams and ointments containing grape seed extract 2% or 5% have been used topically with apparent safety for up to 3 weeks (91539,100955). There is insufficient reliable information available about the safety of other grape plant parts when used topically.

CHILDREN: LIKELY SAFE
when used orally in amounts commonly found in foods. Grapes and grape skin extracts have Generally Recognized As Safe (GRAS) status for use in foods in the US (4912). However, whole grapes should be eaten with caution in children aged 5 years and under. Whole grapes can be a choking hazard for young children (96193). To reduce the risk of choking, whole grapes should be cut in half or quartered before being given to children. There is insufficient reliable information available about the safety of grape when used in medicinal amounts in children.

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts commonly found in foods. There is insufficient reliable information available about the safety of medicinal amounts during pregnancy and breast-feeding; avoid using in amounts greater than what is commonly found in foods.

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LIKELY SAFE ...when green tea is consumed as a beverage in moderate amounts (733,6031,9222,9223,9225,9226,9227,9228,14136,90156)(90159,90168,90174,90184,95696). Green tea contains caffeine. According to a review by Health Canada, and a subsequent large meta-analysis conducted in the US, drinking up to 8 cups of green tea daily, or approximately 400 mg of caffeine, is not associated with significant adverse cardiovascular, bone, behavioral, or reproductive effects in healthy adults (11733,98806). The US Dietary Guidelines Advisory Committee states that there is strong and consistent evidence that consumption of caffeine 400 mg daily is not associated with increased risk of major chronic diseases, such as cardiovascular disease or cancer, in healthy adults (98806). ...when a specific green tea extract ointment is used topically and appropriately, short-term. The specific green tea extract ointment (Veregen, Bradley Pharmaceuticals) providing 15% kunecatechins is an FDA-approved prescription product. It has been safely used in trials lasting up to 16 weeks (15067). The safety of treatment beyond 16 weeks or multiple treatment courses is not known.