Green Propolis Extract by CATALO

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Athletic performance. Preliminary clinical research shows that taking chrysin orally, in combination with androgen precursors, does not enhance resistance training outcomes in athletes. Taking a combination of chrysin 625 mg with androstenedione, dehydroepiandrosterone (DHEA), tribulus, indole-3-carbinole, and saw palmetto daily for 8 weeks does not affect testosterone concentrations, body composition, or strength in response to resistance training (7514). More evidence is needed to rate chrysin for this use.

(Read more about CHRYSIN)

POSSIBLY EFFECTIVE

• Diabetes. Oral propolis seems to improve glycemic control in patients with type 2 diabetes; however, some conflicting evidence exists. Details: A meta-analysis of six clinical trials including 374 patients with type 2 diabetes shows that taking propolis for 8 weeks to 6 months reduces glycated hemoglobin (HbA1c) by 0.5% and fasting plasma glucose by 14 mg/dL when compared with placebo. However, significant improvements in insulin levels or measures of insulin resistance were lacking (102520). While this pooled analysis suggests that propolis is modestly effective for improving glycemic control, individual study results are mixed. Three of the trials in the analysis failed to demonstrate significant improvements in HbA1c or glucose levels; however, all of these studies were small and likely underpowered to detect meaningful improvements in glycemic control (102523,102524,102525). Other studies showed positive results, with reductions in HbA1c ranging from 0.9% to 1.1% and reductions in fasting plasma glucose ranging from 21 mg/dL to 26 mg/dL. The doses and durations of propolis therapy in these studies included 400 mg daily for 6 months (99173), 900 mg daily for 12 weeks (95883), and 500 mg three times daily for 8 weeks (102521).
• Herpes labialis (cold sores). Topical propolis ointment or cream, applied five times daily, may improve lesion healing and reduce symptoms in patients with cold sores. Details: One small clinical study in patients with cold sores shows that applying a specific propolis 3% ointment (Herstat or ColdSore-FX by Afexa), five times daily at the start of symptoms, reduces cold sore duration by about 3-4 days and may reduce cold sore-related pain when compared with placebo (17664,17665). Larger clinical studies in patients with cold sores in the papular or vesicular stages show that applying a lip cream containing a specific propolis extract (GH2002) 0.5% five times daily for 5-10 days reduces the time to complete encrustation/epithelialization by about 1 day and improves symptoms of pain, burning, itching, tension, and swelling when compared with acyclovir 5% cream (95875,102519).
• Oral mucositis. Most clinical research shows that oral propolis or propolis-containing mouthwash can reduce the risk for severe, chemotherapy-induced oral mucositis. Details: A meta-analysis of five clinical trials including 209 patients shows that using mouthwash containing propolis reduces the odds of severe chemotherapy-induced oral mucositis by 65% when compared with placebo in cancer patients (99171). Rinsing with 5-10 mL of a propolis mouth rinse for 1 minute three times daily, alone or in addition to chlorhexidine mouthwash and fluconazole for 7-14 days, improves mucositis and redness when compared to control in patients receiving chemotherapy (92793,95877). A small clinical study in patients receiving chemotherapy for breast cancer also shows that taking tablets of propolis (Natur Farma S.A.S.) 80 mg two or three times daily for 3 weeks, in addition to rinsing with sodium bicarbonate solution, decreases the development of mucositis when compared with only rinsing with sodium bicarbonate solution (95882). However, at least one high quality clinical study shows that rinsing with 7 mL of a specific product (Faringel, Cadigroup) containing propolis extract 6% and other ingredients three times daily for 6 weeks does not prevent the development of mucositis due to chemotherapy when compared with placebo in patients with head and neck cancer (95879).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Athletic performance. It is unclear if oral propolis is beneficial for improving athletic performance. Details: A small clinical study in healthy male military cadets shows that taking propolis 450 mg twice daily for 4 weeks does not improve measures of aerobic or anaerobic performance during exercise testing when compared with placebo (108519).
• Atopic disease. It is unclear if oral propolis can prevent atopic disease in lactating adults or their infants. Details: A small clinical study in lactating adults shows that taking propolis 300 mg daily for 4-10 months does not appear to reduce the risk for developing atopic disease in either the mothers or their infants when compared with placebo (102518). However, due to the small sample size, this study may have been inadequately powered to detect a difference between groups.
• Breast cancer. It is unclear if oral propolis is beneficial in patients with breast cancer. Details: A small clinical study in patients with stage II or III breast cancer receiving chemotherapy shows that taking propolis 250 mg twice daily for 3 months improves quality of life and nutritional status when compared with placebo (108518). It is unknown if propolis can increase the likelihood of survival or remission in patients with breast cancer.
• Burns. It is unclear if topical propolis is beneficial in patients with minor burns. Details: One small clinical study in patients with minor burns shows that application of propolis cream to burn wounds every 3 days improves healing and reduces inflammation when compared with silver sulfadiazine. Propolis cream seems to be as effective for preventing infection as silver sulfadiazine in these patients (8663).
• Canker sores. It is unclear if oral propolis is beneficial in patients with canker sores. Details: A very small clinical study in patients with recurrent canker sores shows that taking propolis 500 mg daily for 6-13 months significantly reduces canker sore outbreaks and improves quality of life when compared with placebo. A 50% or greater reduction in cold sore outbreaks was reported in 60% and 11% of patients taking propolis or placebo, respectively (17629).
• Catheter-related infections. It is unclear if topical propolis is beneficial for the prevention of catheter-related infections. Details: One small clinical study in patients with peritoneal dialysis catheters shows that cleaning the exit site after dialysis with a normal saline wash and propolis 10% ointment for 6 months does not reduce the rate of catheter site infections when compared with using normal saline wash plus mupirocin 2% ointment or normal saline wash alone (109985).
• Chronic kidney disease (CKD). It is unclear if oral propolis is beneficial in patients with CKD. Details: A small clinical study in patients with CKD shows that taking Brazilian green propolis extract (EPP-AF) 250 mg twice daily for 12 months reduces proteinuria, but does not increase estimated glomerular filtration rate (eGFR), when compared with placebo (105785).
• Chronic obstructive pulmonary disease (COPD). Oral propolis has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with frequent exacerbations of COPD shows that taking a combination of N-acetylcysteine (NAC) 1200 mg and propolis 160 mg orally once daily for 3 months reduces the incidence of acute exacerbations during 1 year of follow-up when compared with placebo or a lower dose combination of NAC 600mg and propolis 80 mg (109984). Further research shows that using the higher dose combination for 6 months reduces acute exacerbations, cough, and overall COPD severity, and increases dyspnea-free walking distance, when compared with placebo or the lower dose combination (109986).
• Common cold. It is unclear if oral propolis is beneficial in patients with the common cold. Details: One small clinical study in patients with rhinovirus infection shows that taking propolis (dose and duration unknown) might decrease the duration of cold symptoms 2.5-fold when compared with placebo (6602).
• Coronavirus disease 2019 (COVID-19). It is unclear if oral propolis is beneficial for the prevention or treatment of COVID-19. Details: A small observational study in healthcare professionals working in an emergency department shows that taking a 30% Anatolian propolis solution as 20 drops twice daily for one month reduces the occurrence of COVID-19 positivity to 2 of 102 subjects, compared with 14 of 102 in an untreated control group (109983). The validity of this study is limited by the lack of blinding and randomization. A small, open-label clinical study in hospitalized adults with COVID-19 shows that taking a standardized green propolis extract (EPP-AF) 100 mg or 200 mg four times daily for 7 days, along with conventional therapy, reduces length of hospital stay by around 5-6 days, but does not affect the need for supplemental oxygen, odds of intubation, or admission to the intensive care unit, when compared with conventional therapy alone (108514).
• Dengue fever. It is unclear if oral propolis is beneficial in patients with dengue fever. Details: A small clinical study in patients with dengue hemorrhagic fever shows that taking propolis extract (Propoelix) 400 mg three times daily for 7 days reduces the length of hospital stay by about 18 hours when compared with placebo. This was based on being deemed technically fit for discharge because of a recovery of platelet counts. The effect of propolis on other symptoms of dengue fever was not investigated in this study (99168).
• Dental caries. It is unclear if topical propolis, used either as a chewing gum or mouthwash, can prevent dental caries in children. Details: One small clinical trial in children 6-8 years of age at high risk of dental caries shows that chewing propolis gum twice daily for 20 minutes or rinsing with 10 mL of propolis 2% mouthwash for 1 minute twice daily for 2 weeks reduces plaque and Streptococcus mutans count when compared to baseline. There were no differences between the two propolis formulations; however, children preferred the chewing gum over the mouthwash (105790). The validity of these findings is limited by a lack of control group.
• Denture stomatitis. Small clinical studies suggest that topical propolis may speed recovery in patients with denture stomatitis. Details: One very small clinical study in denture-bearing patients with prosthesis stomatitis candidiasis shows that applying Brazilian green propolis 20% ethanol extract topically four times daily for 7 days can cause regression of candidiasis lesions. After 7 days, 58% of patients treated with propolis and 67% of patients treated with nystatin had total lesion remission. After 15 days, all patients in both groups saw total lesion remission (70070). Also, two small clinical studies in patients with denture-induced oral mucositis show that applying propolis 2% to 3% gel (EPP-AF) to dentures three to four times daily for 7-14 days improves the cure rate and reduces erythema. In these studies, propolis appeared to be comparable to applying miconazole to dentures (95881,95884).
• Depression. It is unclear if oral propolis is beneficial as adjunct therapy in patients with depression. Details: A small clinical study in patients with moderate to severe depression inadequately managed with selective serotonin reuptake inhibitors (SSRIs) shows that taking propolis 1000 mg daily for 6 weeks, in addition to SSRI therapy, reduces symptoms of depression, as measured on the 17-item Hamilton Depression Scale (HAMD-17) and Beck Depression Inventory (BDI), when compared with placebo (108523).
• Diabetic foot ulcers. It is unclear if topical propolis is beneficial in patients with diabetic foot ulcers. Details: A small clinical study in patients with diabetic foot ulcers shows that topical application of propolis 5% ointment in addition to routine care for 4 weeks reduces ulcer size about 2.5-fold more than routine care alone (99172).
• Genital herpes. It is unclear if topical propolis is beneficial in patients with genital herpes. Details: A small clinical study in patients with recurrent genital herpes caused by herpes simplex virus type 2 (HSV-2) shows that applying propolis 3% ointment (Herstat or ColdSore-FX by Afexa) four times daily for 10 days reduces healing time and increases the relative rate of complete healing by 1.7- and 2-fold when compared with acyclovir 5% ointment and placebo, respectively (1926).
• Gingivitis. Small clinical studies suggest that topical propolis may modestly improve symptoms in patients with gingivitis. Details: A small clinical study shows that rinsing with a propolis 2% solution 20 mL twice daily for 21 days is as effective as a rinse containing sodium fluoride 0.05% plus cetylpyridinium chloride 0.05% for the prevention of induced gingival redness and bleeding (99169). Another small clinical study in patients with gingivitis shows that rinsing with a propolis solution twice daily for 4 weeks reduces gingival bleeding, but does not improve plaque index, when compared with placebo (108513). Propolis has also been evaluated in combination with other ingredients. One small clinical study in patients with plaque-induced gingivitis shows that adjuvant therapy with a topical gel containing propolis and other ingredients (Oralsan NBF gel, IDS SpA) for 15 days following scaling and root planing is as effective as a chlorhexidine-based gel for improving bleeding, plaque, and probing depth (99170). Another small clinical study in patients with generalized or localized gingivitis or stage I periodontitis shows that taking 194 mg of a product containing propolis and mangosteen improves the modified gingival index by 31% or 40% at weeks 4 or 8, respectively, compared with 16% or 25% in those receiving placebo. No changes in probing depth, clinical attachment, plaque index, bleeding, or gingival recession were observed (106789).
• Helicobacter pylori. It is unclear if oral propolis is beneficial in patients with H. pylori infection. Details: One very small, uncontrolled clinical study in patients with H. pylori infection shows that taking 60 drops of an alcoholic preparation of Brazilian green propolis daily for 7 days does not reduce H. pylori infection when compared to baseline (70107).
• HIV/AIDS. Although there has been interest in using oral propolis as an adjunct to antiretroviral therapy for HIV/AIDS, there is insufficient reliable information about the clinical effects of propolis for this purpose.
• Intestinal parasite infection. It is unclear if oral propolis is beneficial in patients with giardiasis. Details: One small clinical study in adults with giardia infection shows that taking a specific propolis 30% extract (Propolisina, Apis Flora) for 5 days increases cure rates when compared with tinidazole. The cure rate was 60% with propolis extract, compared to only 40% with tinidazole. In children with giardiasis, taking propolis 10% extract showed a 52% cure rate; however, the rate of cure with tinidazole was not available (70121).
• Malnutrition. It is unclear if oral red propolis is beneficial in malnourished children with frequent respiratory tract infections. Details: A small clinical study in children aged 1-5 years with frequent respiratory tract infections and growth failure associated with malnutrition shows that giving 3% red propolis in 8 mL (10 grams) of honey once daily in addition to adequate nutrition does not improve weight gain or reduce the frequency of respiratory infections when compared with honey plus adequate nutrition (109987).
• Muscle fatigue. It is unclear if oral propolis is beneficial for speeding recovery from muscle fatigue. Details: One small study in young, healthy males shows that taking Brazilian green propolis 1575 mg before meals three times daily for one week, followed by exercise to induce muscle fatigue, reduces the time to regain maximal contraction torque after stopping when compared with placebo or a 100-mg dose of propolis. There was no difference in average peak power between the groups (109989).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral propolis is beneficial in patients with NAFLD. Details: One small clinical study in patients with NAFLD shows that taking propolis extract 250 mg twice daily for 4 months improves markers of hepatic steatosis and fibrosis, but does not improve liver function, when compared with placebo (105786). Another small study in adults with obesity and NAFLD shows that taking propolis 510 mg daily for 8 weeks with a calorie-restricted diet reduces liver fibrosis, fasting blood glucose levels, serum insulin levels, and homeostasis model assessment of insulin resistance (HOMA-IR) when compared with placebo. However, it does not affect the severity of fatty liver, anthropometric measurements, lipid profile, or levels of inflammatory markers (109988).
• Peptic ulcers. Although there has been interest in using oral propolis for peptic ulcers, there is insufficient reliable information about the clinical effects of propolis for this purpose.
• Periodontitis. It is unclear if oral propolis or propolis extract rinse is beneficial in patients with periodontitis. Details: One small clinical study in patients with type 2 diabetes and chronic periodontitis also receiving scaling and root planing shows that taking propolis 400 mg daily for 6 months reduces probing depth and improves clinical attachment by a small amount when compared with scaling and planing alone. There was no additional benefit with propolis on measures of gingivitis, plaque, or bleeding when compared with scaling and planing alone (99173). Another very small clinical study in patients with chronic periodontitis shows that irrigation of the gums with an ethanol solution containing propolis extract 20% twice weekly for 2 weeks reduces gum bleeding when compared with irrigation with ethanol 14% solution (95876). Propolis has also been evaluated in combination with other ingredients. A small clinical study in patients with generalized or localized gingivitis or stage I periodontitis shows that taking 194 mg of a product containing propolis and mangosteen improves the modified gingival index by 31% or 40% at weeks 4 or 8, respectively, compared with 16% or 25% in those receiving placebo. No changes in probing depth, clinical attachment, plaque index, bleeding, or gingival recession were observed (106789).
• Rheumatoid arthritis (RA). It is unclear if oral propolis is beneficial in patients with RA. Details: A small clinical study in females with RA shows that taking Brazilian propolis 508.5 mg daily for 24 weeks does not improve measures of disease activity, quality of life, or activities of daily living when compared with placebo (108515).
• Sepsis. It is unclear if oral propolis is beneficial in patients with sepsis. Details: A small clinical study in patients with pneumosepsis shows that taking propolis 1000 mg daily along with conventional therapy does not improve survival rates or disease severity, as measured using APACHE II and SOFA scores, when compared with placebo. The combination of propolis 1000 mg plus melatonin 20 mg daily did improve disease severity scores but had no effect on survival (108524).
• Tinea pedis. It is unclear if topical propolis is beneficial in patients with tinea pedis. Details: A case series involving students with athlete's foot found that topical treatment with a 100 mg/mL ethanolic extract of Brazilian green propolis results in less skin itching, peeling, and redness when compared with petroleum jelly placebo, but not when compared with miconazole (95880).
• Tuberculosis. Although there has been interest in using oral propolis for tuberculosis, there is insufficient reliable information about the clinical effects of propolis for this purpose.
• Upper respiratory tract infection (URTI). It is unclear if oral propolis spray is beneficial in patients with URTI. Details: One small clinical study in patients reporting mild URTI symptoms shows that use of a propolis oral spray (M.E.D. Propolis, B Natural srl), 2-4 sprays daily, providing 6 mg of polyphenols per spray, for 5 days reduces the time to complete resolution of symptoms by 2 days when compared with placebo (105787). Propolis has also been evaluated in combination with other ingredients. A large clinical study in children 1-5 years of age shows that taking 5-7.5 mL of a specific combination product (Chizukit, Hadas Corp Ltd.) containing propolis 50 mg/mL, echinacea extract 50 mg/mL, and vitamin C 10 mg/mL for 12 weeks reduces the number of children who experience one or more upper respiratory tract illnesses, as well as the number and duration of illnesses, when compared with placebo (48551). It is unclear if these findings are due to propolis, other ingredients, or the combination.
• Urinary tract infections (UTIs). Oral propolis has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of 3 small clinical studies in adults with uncomplicated UTIs shows that taking combination products containing propolis, Hibiscus sabdariffa, and gelatin or xyloglucan daily for 5-10 days, then daily for two weeks each month for two months, reduces the odds of UTI recurrence by 87% when compared with control (108520). One of these studies used a specific product (Utipro Plus, Noventure) containing propolis 100 mg, xyloglucan extract 100 mg, Hibiscus sabdariffa extract 100 mg, and gelatin 50 mg once daily for 15 consecutive days each month for 6 months (101734). A small clinical study in females with recurrent UTIs shows that taking two capsules of a specific combination product (DUAB, Nutrivercell) containing propolis, cranberry, and zinc daily for 6 months reduces the number of recurrent UTIs by around 0.8 and delays the time to first recurrent UTI by around 26 days when compared with placebo (102522).
• Vaginitis. It is unclear if topical propolis is beneficial in patients with vaginitis. Details: A small clinical study in patients with chronic vaginitis shows that applying 50 mL of a specific aqueous solution containing propolis 5% (Melprotect, Melbrosin International) to the vagina for 7 days can reduce symptoms and improve quality of life when compared to baseline (70068). The validity of these findings is limited by a lack of control group.
• Warts. It is unclear if oral propolis is beneficial in patients with warts. Details: One small clinical study in adults and children with common and plane warts shows that taking propolis (Bee Propolis, Pollen) 500 mg orally daily for up to 3 months increases wart cure rates when compared with echinacea or placebo. Common warts were cured in 73% of patients taking propolis, compared to 20% taking echinacea and 8% taking placebo. Plane warts were cured in 75% of patients taking propolis, compared with 36% taking echinacea and 21% taking placebo. Neither propolis nor echinacea were effective for treating plantar warts (92800).
• Wound healing. It is unclear if topical propolis or propolis mouth rinse improves wound healing. Details: One small clinical study shows that using an aqueous alcohol mouth rinse containing propolis 5% five times daily for 1 week following sulcoplasty improves healing and reduces pain and inflammation (799). Another small clinical study in males recovering from surgery for sacrococcygeal pilonidal disease shows that using 1 mL of propolis 15% solution on the wound dressing daily for 28 days accelerates wound healing when compared with normal saline (108516) However, another small clinical trial in patients undergoing dental surgery shows that using a propolis 20% solution in a dressing is no more effective than the dressing alone for improving wound healing and reducing pain associated with the wound (99167). More evidence is needed to rate propolis for these uses.

(Read more about PROPOLIS)

POSSIBLY INEFFECTIVE

• Athletic performance. Oral quercetin does not seem to improve athletic performance. Details: A pooled analysis of data from seven clinical trials shows that intake of quercetin does not improve maximal oxygen consumption or capacity to perform prolonged exercise in trained or untrained athletes when compared with placebo (91577). Additionally, one small clinical study in male soldiers shows that taking quercetin 500 mg twice daily for 8.5 days before a loaded treadmill marching test and a cycling time trial test does not affect ratings of perceived exertion, cycling time, or peak oxygen consumption during treadmill testing when compared with placebo (91578).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Age-related cognitive decline. It is unclear if oral quercetin is beneficial in older adults with age-related cognitive decline. Details: Preliminary research in healthy adults aged 60 to 80 years with age-related forgetfulness shows that drinking 500 mL of a barley-based beverage containing 110 mg quercetin glycoside calculated as isoquercitrin, daily for 40 weeks seems to improve reaction times when compared with placebo. However, increase in score on the mini-mental state examination (MMSE), reduction in accumulation of amyloid beta in the brain, and prevention of reduction in cerebral blood flow occur to a similar extent with quercetin and placebo (110008).
• Allergic rhinitis (hay fever). It is unclear if oral quercetin is beneficial in patients with allergic rhinitis. Details: A small clinical study in Japanese adults with allergic rhinitis shows that taking a specific quercetin product (Quercetin Phytosome, Indena SpA) 100 mg twice daily for 4 weeks does not improve scores related to quality of life, activities of daily living, nasal symptoms, or ocular symptoms on the Japanese Rhino-conjunctivitis Quality of Life Questionnaire (JRQLQ). However, scores related to fatigue and sleep quality improved when compared with placebo. Additionally, sneezing, rhinorrhea, and activities of daily living scores improved when another scale was used to assess the severity of allergic rhinitis (109620). Quercetin has also been evaluated in combination with other ingredients. A small clinical study in children aged 6-12 years with allergic rhinitis who had gone through a treatment phase with antihistamines and a specific combination of quercetin, perilla, and vitamin D3 (Lertal) 1 tablet daily for 4 weeks shows that taking this specific combination for an additional 4-12 weeks reduces the chance of having symptom exacerbations by approximately 50% when compared with no further treatment past the first 4 weeks. The number of days requiring rescue medication was also reduced from 28.5 days to an average of 9.6 days (104676).
• Alzheimer disease. Although there has been interest in using oral quercetin for Alzheimer disease, there is insufficient reliable information about the clinical effects of quercetin for this condition.
• Asthma. It is unclear if oral quercetin is beneficial in patients with asthma. Details: Preliminary clinical research in patients with mild-to-moderate asthma shows that taking a specific quercetin product (QFit, Indena SpA) 250 mg or 500 mg daily for 30 days along with conventional therapy reduces daytime and nighttime asthma symptoms, improves spirometry measures, and decreases the use of rescue inhalers when compared to baseline. Significant improvements in these outcomes were lacking in patients receiving conventional therapy alone (102540).
• Atherosclerosis. Although there has been interest in using oral quercetin for atherosclerosis, there is insufficient reliable information about the clinical effects of quercetin for this condition.
• Autism spectrum disorder. Oral quercetin has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in children aged 4-10 years with autism shows that taking a combination of luteolin 10 mg/kg, quercetin 7 mg/kg, and rutin 3 mg/kg in olive oil for 26 weeks improves hyperactivity, irritability, and lethargy by a moderate to large amount, and improves some indices of functioning, such as daily living and social behavior, by a small amount when compared with baseline. The validity of these findings is limited by the lack of a comparator group (96765).
• Benign prostatic hyperplasia (BPH). Oral quercetin has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking one tablet of a specific combination product (Difaprost) containing quercetin, beta-sitosterol, and saw palmetto daily for 3 months does not improve general symptoms of BPH when compared to baseline (96784). The validity of these findings is limited by the lack of a comparator group.
• Beta-thalassemia. It is unclear if oral quercetin is beneficial in patients with beta-thalassemia. Details: Preliminary clinical research in transfusion-dependent patients with beta-thalassemia shows that taking quercetin 500 mg daily for 12 weeks reduces iron and ferritin levels, increases transferrin levels, and decreases transferrin saturation when compared with placebo. However, total iron binding capacity was not improved. These results suggest that quercetin might reduce iron overload, which is a complication of frequent blood transfusions in these patients (102541).
• Cancer. Although there has been interest in using intravenous or intraperitoneal quercetin for cancer, there is insufficient reliable information about the clinical effects of quercetin for this condition.
• Canker sores. Topical quercetin has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that applying a cream containing quercetin, glycol, zinc, and Myristica (Rootage skin cream, Elsi-Si) three times daily results in complete healing of minor canker sores and reduces pain in 100% of patients within 7-10 days, compared with only 60% of patients using a benzydamine hydrochloride mouthwash three times daily (104677).
• Cardiovascular disease (CVD). It is unclear if oral quercetin is beneficial for CVD prevention. Details: Population research has found that increasing dietary intake of quercetin from food sources such as tea, onions, and apples is associated with a significantly reduced risk of heart disease-related mortality in elderly males (7726). However, preliminary clinical research shows that quercetin 1 gram daily for 28 days does not significantly improve platelet aggregation, thromboxane B2 production, blood pressure, heart rate, or serum lipid levels when compared with placebo in healthy people (1998).
• Cataracts. Although there has been interest in using oral quercetin for cataracts, there is insufficient reliable information about the clinical effects of quercetin for this condition.
• Chemotherapy-induced cystitis. Oral quercetin has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with bladder cancer undergoing intravesical chemotherapy shows that taking a specific combination product (Ialuril, IBSA Farmaceutici) containing quercetin 400 mg, hyaluronic acid 40 mg, chondroitin sulfate 400 mg, and curcumin 400 mg every morning, starting 7 days before the first instillation and ending 30 days after the last instillation, improves lower urinary tract symptoms as measured using a visual analog scale and the International Prostate Symptom Score (IPSS) at 13 months when compared with placebo (109622).
• Chronic fatigue syndrome (CFS). Although there has been interest in using oral quercetin for CFS, there is insufficient reliable information about the clinical effects of quercetin for this condition.
• Chronic venous insufficiency (CVI). Although there has been interest in using oral quercetin for CVI, there is insufficient reliable information about the clinical effects of quercetin for this condition.
• Colorectal cancer. Although there has been interest in using oral quercetin for colorectal cancer prevention, there is insufficient reliable information about the clinical effects of quercetin for this condition.
• Contrast induced nephropathy. It is unclear if oral quercetin is beneficial for the prevention of contrast induced nephropathy. Details: Preliminary clinical research in patients undergoing coronary catheterization shows that taking quercetin 500 mg every 8 hours, starting two days prior to contrast imaging and continuing for two days after, does not appear to prevent contrast induced nephropathy when compared with a control group not receiving quercetin (102539). Given its small size, this study may have been inadequately powered to detect significant differences for this outcome.
• Coronavirus disease 2019 (COVID-19). Analysis of several small, open-label clinical studies suggest that oral quercetin may modestly reduce hospitalizations and intensive care unit (ICU) admissions in patients with COVID-19. Whether quercetin is beneficial in patients with severe COVID-19 is unclear. Details: A meta-analysis of 6 open-label clinical studies in patients with COVID-19 shows that taking quercetin 260-1000 mg daily for 7-30 days along with standard therapy with analgesics, antipyretics, antibiotics, remdesivir, or favipiravir reduces the odds of intensive care unit (ICU) admission by 69% and the odds of hospitalization by 75% but does not decrease the rate of all-cause mortality or the rate of recovery upon follow-up when compared with standard care (111412). However, the interpretation of these findings is limited by differences in the severity of COVID-19, doses and durations of quercetin therapy, and standard of care regimens used across the included studies. In outpatients in the early stages of COVID-19, two small, open-label clinical studies included in the meta-analysis above show that taking quercetin 200 mg two or three times daily for 14-30 days along with standard care reduces time to symptom resolution when compared with standard care alone. However, these studies show mixed results with respect to prevention of hospitalization, ICU admission, and death (106498,106499). More recent research in patients with early-stage, mild to moderate COVID-19 symptoms shows that taking quercetin 500 mg three times daily for 1 week, followed by 500 mg twice daily for 1 week, increases the rate of symptom resolution and achieving a negative COVID-19 test at 1 week by 116% and 183%, respectively, when compared with placebo (110009). Quercetin has also been evaluated in patients with severe COVID-19. A small, open-label clinical study of patients with severe COVID-19 who have not been admitted to the ICU shows that taking quercetin 500 mg twice daily for 7 days along with remdesivir or favipiravir shortens the time to discharge by around 1.5 days and improves symptoms of weakness and lethargy, but does not improve other symptoms of COVID-19 or reduce the risk of ICU admission or death, when compared with remdesivir or favipiravir alone (107450).
• Depression. It is unclear if oral quercetin is beneficial for depression in patients with a recent myocardial infarction (MI). Details: A moderate-sized clinical study in adults 6-8 weeks post-MI conducted in Iran shows that taking quercetin 500 mg daily for 8 weeks does not improve self-reported depression scores when compared with placebo (112228). However, the severity of patients' depression was minimal at baseline, which limits the power to detect a difference between groups.
• Diabetes. Oral quercetin has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with type 2 diabetes who are not using hypoglycemic agents shows that taking a specific combination of quercetin, myricetin, and chlorogenic acid (Emulin, Anderson Global Group LLC) 250 mg daily for 7 days reduces levels of fasting and postprandial glucose by about 5% when compared to baseline. These changes were significantly different than the slight increases seen in the placebo group. In patients taking metformin along with the combination supplement, fasting blood glucose levels decreased by about 20%, compared with a decrease of less than 1% with metformin alone (96779).
• Exercise-induced muscle damage. It is unclear if oral quercetin is beneficial for preventing muscle damage associated with exercise. Details: Some clinical research shows that taking quercetin 500 mg twice daily for 3 weeks prior to and during an endurance run or cycling event does not attenuate exercise-induced muscle damage, soreness, or inflammation (16429,16431). However, a series of two small clinical trials show that taking quercetin 1000 mg daily for 14 days prior to eccentric exercise modestly attenuates the decline in the maximal intensity of a contraction when compared with placebo (99236,104226). Additionally, this dosing regimen appears to modestly accelerate the recovery of muscle strength and neuromuscular function after exercise when compared with placebo (104226).
• Exercise-induced respiratory infections. It is unclear if oral quercetin is beneficial for prevention of respiratory infections induced by exercise. Details: Preliminary clinical research shows that taking quercetin 500 mg twice daily for 3 weeks before, and continuing during 3 days of prolonged, intense cycling, reduces the incidence of upper respiratory infections in the 14 days following the heavy exercise (16430).
• Gout. Although there has been interest in using oral quercetin for gout, there is insufficient reliable information about the clinical effects of quercetin for this condition.
• Herpes labialis (cold sores). Although there has been interest in using oral quercetin for herpes labialis, there is insufficient reliable information about the clinical effects of quercetin for this condition.
• Hypercholesterolemia. It is unclear if oral quercetin is beneficial for improving cholesterol levels. Details: Multiple meta-analyses show that taking quercetin does not affect total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, or triglycerides (TG) when compared with placebo (96783,104229). However, a subgroup analysis shows that taking quercetin for at least 8 weeks seems to reduce TG levels by 13 mg/dL and increase HDL levels by 3 mg/dL, compared with no change in patients who took quercetin for less than 8 weeks (104229). It is unclear these patients had elevated cholesterol levels at baseline.
• Hypertension. It is unclear if oral quercetin is beneficial for reducing blood pressure. Details: Three meta-analyses show that taking quercetin 100-1000 mg daily for 4-12 weeks decreases systolic and diastolic blood pressure by 2-4 mmHg and 2-3 mmHg, respectively, when compared with placebo. However, only two of the studies included in these analyses evaluated patients with hypertension (16424,96775,104229,109617). Additional clinical research in patients with mild hypertension shows that taking a single dose of quercetin 1095 mg can lower systolic and diastolic blood pressure by 7 mmHg and 3 mmHg, respectively, when measured 10 hours later (96780). Overall, the benefit of quercetin on blood pressure seems modest; it is unclear whether the improvement is clinically significant for patients with hypertension.
• Kidney transplant. Oral quercetin has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that a specific product containing a combination of quercetin 20 mg and curcumin 480 mg (Oxy-Q, Farr Labs) taken once or twice daily in combination with anti-rejection medications, starting within 24 hours of a kidney transplant and continuing for one month, improves early function of the graft and reduces serum creatinine when compared with taking placebo in combination with anti-rejection medications (16420).
• Lung cancer. It is unclear if oral quercetin is beneficial in lung cancer prevention. Details: Epidemiologic research has found that increasing dietary intake of quercetin is associated with a reduced risk of lung cancer in smokers (96778).
• Metabolic syndrome. It is unclear if oral quercetin is beneficial in patients with metabolic syndrome. Details: A meta-analysis of small clinical studies shows that taking quercetin 100-1000 mg daily for 4-12 weeks does not improve fasting blood glucose, glycated hemoglobin, or insulin levels when compared with placebo in patients with risk factors for metabolic syndrome, such as type 2 diabetes, prehypertension, polycystic ovary syndrome, and/or obesity (100967). Additional research is needed to determine if quercetin is beneficial in patients with existing metabolic syndrome.
• Niacin-induced flushing. Although there has been interest in using oral quercetin for niacin-induced flushing, there is insufficient reliable information about the clinical effects of quercetin for this condition.
• Obesity. Oral quercetin has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking quercetin 500 or 1000 mg daily for 12 weeks, in addition to niacin 5 mg or 10 mg and vitamin C 125 mg or 250 mg, does not reduce body weight or fat mass when compared with placebo in adults considered overweight or obese based on body mass index (BMI) (104678).
• Oral mucositis. It is unclear if oral quercetin is beneficial in patients with oral mucositis. Details: One small clinical study shows that taking quercetin 250 mg twice daily for 4 weeks does not prevent oral mucositis associated with chemotherapy when compared with placebo (96776).
• Ovarian cancer. It is unclear if oral quercetin is beneficial for ovarian cancer prevention. Details: One epidemiologic study found no association between dietary intake of quercetin and related flavonols and the risk of ovarian cancer (16428).
• Pancreatic cancer. It is unclear if oral quercetin is beneficial for pancreatic cancer prevention. Details: Epidemiologic studies have found that a high dietary intake of quercetin and related flavonols might reduce the risk of pancreatic cancer, especially in male smokers (16426,16427).
• Peptic ulcers. Although there has been interest in using oral quercetin for peptic ulcers, there is insufficient reliable information about the clinical effects of quercetin for this condition.
• Physical performance. It is unclear if oral quercetin is effective for improving physical performance in older adults. Details: A small clinical study in Japanese individuals 50-74 years of age shows that taking quercetin glycosides 200 mg or 500 mg daily along with low-intensity resistance training 3 days weekly for 24 weeks does not improve muscle size or lean body mass, but may reduce muscle stiffness, when compared with placebo (109621).
• Polycystic ovary syndrome (PCOS). It is unclear if oral quercetin is beneficial for improving hormone levels or pregnancy rates in patients with PCOS. Details: Clinical research in patients with PCOS shows that taking quercetin 1000 mg daily for 12 weeks reduces testosterone and luteinizing hormone (LH) levels by 9% and 3%, respectively, when compared to baseline; both of these improvements were significant when compared with placebo. Insulin resistance also improved by 18% when compared to baseline, which was significant when compared with placebo (96782). In a similar group of patients with higher levels of insulin resistance at baseline, taking the same dose of quercetin modestly reduced testosterone and LH levels when compared with placebo; however, there was no improvement in insulin resistance (99237). These disparate outcomes might be due to different baseline levels of insulin resistance. Also, it is unclear if these changes are associated with an improvement in the clinical symptoms of PCOS. Quercetin has also been evaluated for improving pregnancy rates in adults with PCOS and infertility. A small clinical study shows that taking quercetin 500 mg daily for 40 days increases pregnancy rates when compared with placebo. Quercetin supplementation also improves the grading of oocytes, but not the quality of embryos, in those undergoing in vitro fertilization (IVF). Nearly 84% of patients taking quercetin became pregnant spontaneously or via IVF in the 6 months following initiation of quercetin supplementation. Only 11% of patients taking placebo became pregnant during the study, all through IVF (109618). Due to a short duration of follow-up, it is unclear whether quercetin improves live birth rates.
• Prostatitis. It is unclear if oral quercetin is beneficial in patients with prostatitis. Details: Preliminary clinical research shows that taking quercetin 500 mg twice daily for one month reduces pain and improves quality of life, but does not seem to affect voiding dysfunction, in patients with chronic, nonbacterial prostatitis when compared with placebo (481).
• Rheumatoid arthritis (RA). It is unclear if oral quercetin is beneficial in patients with RA. Details: In patients with RA, clinical research shows that taking quercetin 500 mg daily for 8 weeks improves morning stiffness, morning pain, and after-activity pain when compared with placebo. However, taking quercetin does not seem to improve the number of swollen or tender joints or the disease activity score when compared with placebo (96774).
• Schizophrenia. Although there has been interest in using oral quercetin for schizophrenia, there is insufficient reliable information about the clinical effects of quercetin for this condition.
• Upper respiratory tract infection (URTI). Oral quercetin has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking quercetin 500 mg or 1000 mg daily for 12 weeks, in combination with vitamin C 500 mg or 1000 mg daily or niacin 20 mg or 40 mg daily, does not reduce the frequency or severity of URTIs. However, in a subgroup analysis of physically fit individuals 40 years and older, the severity of URTIs and the number of sick days related to URTIs were reduced by 36% and 31%, respectively, when quercetin 1000 mg was compared with placebo (104679).
• Urethral syndrome. Oral quercetin has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking one tablet daily of a specific formulation containing quercetin, bromelain, chondroitin sulfate, gotu kola, rhodiola, and barbed skullcap (Cistiquer, Deakos) for 7 weeks reduces urinary urgency by 91% when compared with baseline. Also, 55% of patients reported no discomfort associated with urination. This combination product was reported to be at least as effective as intravesical administration of betamethasone 8 mg plus gentamicin 80 mg twice weekly (96777).
• Urinary tract infections (UTIs). Oral quercetin has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking 1-2 capsules of a combination of hyaluronic acid, chondroitin sulfate, curcumin, and quercetin daily for 15 days each month, in combination with the use of local topical estrogen therapy (0.005% estriol vaginal gel) for up to 12 months, increases the number of women cured of recurrent UTIs to 66%, compared with only 34% of those taking the oral combination product or the vaginal estrogen product alone (96781). More evidence is needed to rate quercetin for these uses.

(Read more about QUERCETIN)

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)

There is insufficient reliable information available about the safety of chrysin.

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

(Read more about CHRYSIN)

POSSIBLY SAFE ...when used orally and appropriately. Propolis has been used with apparent safety in clinical research at doses of up to 1500 mg daily (95883,99173,102520,102521). ...when used topically. Propolis as a 3% or 10% ointment, 0.5% cream, 30% mouth rinse, or 15% solution has been used with apparent safety in small clinical studies (799,1926,6602,8663,17629,17664,17665,92793,92800,95882)(99171,99173,102519,102521,105785,105786,108516,108523,109985).

PREGNANCY:
Insufficient reliable information available; avoid using.

LACTATION: POSSIBLY SAFE
when used orally and appropriately during lactation. Propolis 300 mg daily has been used for 4-10 months in one clinical study with no apparent adverse effects to nursing infants (102518).

(Read more about PROPOLIS)

POSSIBLY SAFE ...when used orally and appropriately, short-term. Quercetin has been used with apparent safety in doses up to 1 gram daily for up to 12 weeks (481,1998,1999,16418,16429,16430,16431,96774,96775,96782)(99237,102539,102540,102541,104229,104679,106498,106499,107450,109620)(109621). ...when used intravenously and appropriately. Quercetin has been used with apparent safety in doses less than 945 mg/m2. Higher doses have been reported to cause nephrotoxicity (9564,16418). There is insufficient reliable information available about the safety of quercetin when used topically.

POSSIBLY UNSAFE ...when used intravenously in large amounts. Doses greater than 945 mg/m2 have been reported to cause nephrotoxicity (9564,16418).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

(Read more about QUERCETIN)

LIKELY SAFE ...when used orally and appropriately. Sodium is safe in amounts that do not exceed the Chronic Disease Risk Reduction (CDRR) intake level of 2.3 grams daily (100310). Higher doses can be safely used therapeutically with appropriate medical monitoring (26226,26227).

POSSIBLY UNSAFE ...when used orally in high doses. Tell patients to avoid exceeding the CDRR intake level of 2.3 grams daily (100310). Higher intake can cause hypertension and increase the risk of cardiovascular disease (26229,98176,98177,98178,98181,98183,98184,100310,109395,109396,109398,109399). There is insufficient reliable information available about the safety of sodium when used topically.

CHILDREN: LIKELY SAFE
when used orally and appropriately (26229,100310). Sodium is safe in amounts that do not exceed the CDRR intake level of 1.2 grams daily for children 1 to 3 years, 1.5 grams daily for children 4 to 8 years, 1.8 grams daily for children 9 to 13 years, and 2.3 grams daily for adolescents (100310).

CHILDREN: POSSIBLY UNSAFE
when used orally in high doses. Tell patients to avoid prolonged use of doses exceeding the CDRR intake level of 1.2 grams daily for children 1 to 3 years, 1.5 grams daily for children 4 to 8 years, 1.8 grams daily for children 9 to 13 years, and 2.3 grams daily for adolescents (100310). Higher intake can cause hypertension (26229).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally and appropriately. Sodium is safe in amounts that do not exceed the CDRR intake level of 2.3 grams daily (100310).

PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used orally in higher doses. Higher intake can cause hypertension (100310). Also, both the highest and the lowest pre-pregnancy sodium quintile intakes are associated with an increased risk of hypertensive disorders of pregnancy, including gestational hypertension and pre-eclampsia, and the delivery of small for gestational age (SGA) infants when compared to the middle intake quintile (106264).

(Read more about SODIUM)

(Read more about CHRYSIN)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, propolis might increase the risk of bleeding when taken with antiplatelet or anticoagulant drugs.  Details In vitro research shows that propolis water extract and the propolis constituent, caffeic acid phenethyl ester, can inhibit platelet aggregation (50794,95885). Additionally, evidence from an animal model shows that taking propolis in addition to warfarin decreases INR, suggesting that propolis can decrease the effectiveness of warfarin (95874).

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, high doses of propolis might increase blood levels of drugs metabolized by CYP1A2.  Details In vitro research shows that propolis extract can inhibit CYP1A2 (92797,92799). However, animal research shows that propolis extract does not significantly affect CYP1A2 activity when administered to rats at doses up to 250 mg/kg. It is postulated that the constituents of propolis that inhibit CYP1A2 in vitro do not have significant effects in vivo due to low bioavailability and hepatic first-pass effect (92797). This effect has not been reported in humans.

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, high doses of propolis might increase blood levels of drugs metabolized by CYP2C19.  Details In vitro research shows that propolis extract can inhibit CYP2C19 (92797,92799). However, animal research shows that propolis extract does not significantly affect CYP2C19 activity when administered to rats at doses up to 250 mg/kg. It is postulated that the constituents of propolis that inhibit CYP2C19 in vitro do not have significant effects in vivo due to low bioavailability and hepatic first-pass effect (92797). This effect has not been reported in humans.

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, high doses of propolis might increase blood levels of drugs metabolized by CYP2C9.  Details In vitro research shows that propolis extract can inhibit CYP2C9 (92797,92799). However, animal research shows that propolis extract does not significantly affect CYP2C9 activity when administered to rats at doses up to 250 mg/kg. It is postulated that the constituents of propolis that inhibit CYP2C9 in vitro do not have significant effects in vivo due to low bioavailability and hepatic first-pass effect (92797). This effect has not been reported in humans.

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, high doses of propolis might increase blood levels of drugs metabolized by CYP2D6.  Details In vitro research shows that propolis extract can inhibit CYP2D6 (92797,92799). However, animal research shows that propolis extract does not significantly affect CYP2D6 activity when administered to rats at doses up to 250 mg/kg. It is postulated that the constituents of propolis that inhibit CYP2D6 in vitro do not have significant effects in vivo due to low bioavailability and hepatic first-pass effect (92797). This effect has not been reported in humans.

CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, propolis might increase levels of drugs metabolized by CYP2E1.  Details In vitro research shows that propolis can inhibit CYP2E1 (92799). This effect has not been reported in humans.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, high doses of propolis might increase blood levels of drugs metabolized by CYP3A4.  Details Some in vitro research shows that propolis extract can inhibit CYP3A4 (92797); however, other in vitro research shows that propolis has no effect on CYP3A4 activity (92799). Furthermore, animal research shows that propolis extract does not significantly affect CYP3A4 activity when administered to rats at doses up to 250 mg/kg. It is postulated that the constituents of propolis that might in inhibit CYP3A4 in vitro do not have significant effects in vivo due to low bioavailability and hepatic first-pass effect (92797). This effect has not been reported in humans.

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, propolis might decrease the effectiveness of warfarin.  Details Animal research shows that taking propolis in addition to warfarin decreases the international normalized ratio (INR) (95874). This effect has not been reported in humans.

(Read more about PROPOLIS)

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, concomitant use of quercetin and antidiabetes drugs might increase the risk of hypoglycemia.  Details Clinical research suggests that a combination of quercetin, myricetin, and chlorogenic acid reduce levels of fasting glucose in patients with type 2 diabetes, including those already taking antidiabetes agents (96779). The effect of quercetin alone is unknown.

ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, taking quercetin with antihypertensive drugs might increase the risk of hypotension.  Details Quercetin can modestly decrease blood pressure in people with mild hypertension (16424,96780). Theoretically, it might have additive blood pressure lowering effects when used with antihypertensive drugs.

CYCLOSPORINE (Neoral, Sandimmune) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, concomitant use might increase the levels and adverse effects of cyclosporine.  Details A small study in healthy volunteers shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of a single dose of cyclosporine, possibly due to inhibition of p-glycoprotein or cytochrome P450 3A4 (CYP3A4), which metabolizes cyclosporin (16434).

CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use might increase the levels and adverse effects of CYP2C8 substrates.  Details In vitro research shows that quercetin inhibits CYP2C8 (16432,16435). Inhibition of paclitaxel (Taxol) metabolism via CYP2C8 has been reported in vitro (16436). However, a small study in humans found no effect of quercetin on rosiglitazone (Avandia), which is also a CYP2C8 substrate (16432).

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, concomitant use might increase the levels and adverse effects of CYP2C9 substrates.  Details A small clinical study in healthy volunteers shows that taking quercetin 500 mg twice daily for 10 days prior to taking diclofenac, a CYP2C9 substrate, increases diclofenac plasma levels by 75% and prolongs the half-life by 32.5% (97931). Animal research also shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of losartan (Cozaar), a substrate of CYP2C9 (100968). Furthermore, laboratory research shows that quercetin inhibits CYP2C9 (15549,16433).

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use might increase the levels and adverse effects of CYP2D6 substrates.  Details In vitro research show that quercetin inhibits CYP2D6 (15549,16433). This effect has not been reported in humans.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use might alter the effects and adverse effects of CYP3A4 substrates.  Details A small clinical study in healthy volunteers shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of a single dose of cyclosporine (Neoral, Sandimmune), a substrate of CYP3A4 (16434). Animal research also shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of losartan (Cozaar) and quetiapine (Seroquel), substrates of CYP3A4 (100968,104228). Other laboratory research also shows that quercetin inhibits CYP3A4 (15549,16433,16435). However, one clinical study shows that quercetin can increase the metabolism of midazolam, a substrate of CYP3A4, and decrease serum concentrations of midazolam by about 24% in some healthy individuals, suggesting possible induction of CYP3A4 (91573).

DICLOFENAC (Voltaren, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Theoretically, concomitant use might increase the levels and adverse effects of diclofenac.  Details A small clinical study in healthy volunteers shows that taking quercetin 500 mg twice daily for 10 days prior to taking diclofenac increases diclofenac plasma levels by 75% and prolongs the half-life by 32.5%. This is thought to be due to inhibition of CYP2C9 by quercetin (97931).

LOSARTAN (Cozaar) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use might increase the effects and adverse effects of losartan and decrease the effects of its active metabolite.  Details Animal research shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of losartan (Cozaar) while decreasing plasma levels of losartan's active metabolite. This metabolite, which is around 10-fold more potent than losartan, is the result of cytochrome P450 (CYP) 2C9- and CYP3A4-mediated transformation of losartan. Additionally, in vitro research shows that quercetin may inhibit P-glycoprotein-mediated efflux of losartan from the intestines, resulting in increased absorption of losartan (100968). These results suggest that concomitant use of quercetin and losartan might increase systemic exposure to losartan while also decreasing plasma concentrations of losartan's active and more potent metabolite.

MIDAZOLAM (Versed) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, concomitant use might decrease the levels and effects of midazolam.  Details A small clinical study in healthy volunteers shows that quercetin can increase the metabolism of midazolam, with a decrease in AUC of about 24% (91573).

MITOXANTRONE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, quercetin might increase the effects and adverse effects of mitoxantrone.  Details In vitro research shows that quercetin increases the intracellular accumulation and cytotoxicity of mitoxantrone, possibly through inhibition of breast cancer resistance protein (BCRP), of which mitoxantrone is a substrate (107897). So far, this interaction has not been reported in humans.

ORGANIC ANION TRANSPORTER 1 (OAT1) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use might increase the effects and adverse effects of OAT1 substrates.  Details In vitro research shows that quercetin is a strong non-competitive inhibitor of OAT1, with half-maximal inhibitory concentration (IC50) values less than 10 mcM (104454). So far, this interaction has not been reported in humans.

ORGANIC ANION TRANSPORTER 3 (OAT3) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use might increase the effects and adverse effects of OAT3 substrates.  Details In vitro research shows that quercetin is a strong non-competitive inhibitor of OAT3, with half-maximal inhibitory concentration (IC50) values as low as 0.75 mcM (104453,104454). So far, this interaction has not been reported in humans.

ORGANIC ANION-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, concomitant use might increase the effects and adverse effects of OATP substrates.  Details In vitro evidence shows that quercetin can inhibit organic anion-transporting peptide (OATP) 1B1-mediated uptake of estrone-3-sulfate and pravastatin (91581). Furthermore, clinical research in healthy males shows that intake of quercetin along with pravastatin increases the AUC of pravastatin by 24%, prolongs its half-life by 14%, and decreases its apparent clearance by 18%, suggesting that quercetin modestly inhibits the uptake of pravastatin in hepatic cells (91581).

P-GLYCOPROTEIN SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Theoretically, concomitant use might alter the effects and adverse effects of P-glycoprotein substrates.  Details There is preliminary evidence that quercetin inhibits the gastrointestinal P-glycoprotein efflux pump, which might increase the bioavailability and serum levels of drugs transported by the pump (16433,16434,16435,100968,104228). A small study in healthy volunteers reported that pretreatment with quercetin increased bioavailability and plasma levels after a single dose of cyclosporine (Neoral, Sandimmune) (16434). Also, two small studies have shown that quercetin might decrease the absorption of talinolol, a substrate transported by the gastrointestinal P-glycoprotein efflux pump (91579,91580). However, in another small study, several days of quercetin treatment did not significantly affect the pharmacokinetics of saquinavir (Invirase) (16433). The reason for these discrepancies is not entirely clear (91580). Until more is known, use quercetin cautiously in combination with P-glycoprotein substrates.

PRAVASTATIN (Pravachol) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, concomitant use might increase the effects and adverse effects of pravastatin.  Details In vitro evidence shows that quercetin can inhibit OATP 1B1-mediated uptake of pravastatin (91581). Also, preliminary clinical research in healthy males shows that intake of quercetin along with pravastatin increases the maximum concentration of pravastatin by 24%, prolongs its half-life by 14%, and decreases its apparent clearance by 18%, suggesting that quercetin modestly inhibits the uptake of pravastatin in hepatic cells (91581).

PRAZOSIN (Minipress) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, quercetin might increase the effects and adverse effects of prazosin.  Details In vitro research shows that quercetin inhibits the transcellular efflux of prazosin, possibly through inhibition of breast cancer resistance protein (BCRP), of which prazosin is a substrate. BCRP is an ATP-binding cassette efflux transporter in the intestines, kidneys, and liver (107897). So far, this interaction has not been reported in humans.

QUETIAPINE (Seroquel) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use might increase the effects and adverse effects of quetiapine.  Details Animal research shows that pretreatment with quercetin can increase plasma levels of quetiapine and prolong its clearance, possibly due to inhibition of cytochrome P450 3A4 (CYP3A4) by quercetin. Additionally, the brain-to-plasma ratio of quetiapine concentrations increased, possibly due to inhibition of P-glycoprotein at the blood-brain barrier (104228). This interaction has not been reported in humans.

QUINOLONE ANTIBIOTICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, concomitant use might inhibit the effects of quinolone antibiotics.  Details In vitro, quercetin binds to the DNA gyrase site on bacteria (481), which may interfere with the activity of quinolone antibiotics.

SULFASALAZINE (Azulfidine) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, quercetin might increase the effects and adverse effects of sulfasalazine.  Details Animal research shows that quercetin increases the maximum serum concentration (Cmax) and area under the curve (AUC) of sulfasalazine, possibly through inhibition of breast cancer resistance protein (BCRP), of which sulfasalazine is a substrate (107897). So far, this interaction has not been reported in humans.

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, quercetin may increase the risk of bleeding if used with warfarin.  Details Animal and in vitro studies show that quercetin might increase serum levels of warfarin (17213,109619). Quercetin and warfarin have the same human serum albumin (HSA) binding site, and in vitro research shows that quercetin has stronger affinity for the HSA binding site and can theoretically displace warfarin, causing higher serum levels of warfarin (17213). Animal research shows that taking quercetin for 2 weeks before initiating warfarin increases the maximum serum level of warfarin by 30%, the half-life by 10%, and the overall exposure by 63% when compared with control. Concomitant administration of quercetin and warfarin, without quercetin pre-treatment, also increased these measures, but to a lesser degree. Researchers theorize that inhibition of CYP3A4 by quercetin may explain these effects (109619). So far, this interaction has not been reported in humans.

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ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = A Theoretically, a high intake of dietary sodium might reduce the effectiveness of antihypertensive drugs.  Details High intake of dietary sodium can increase systolic and diastolic blood pressure (26222). Also, high intake of sodium may necessitate increased use of antihypertensive medications to achieve blood pressure control in some patients, such as those with chronic kidney disease (26223).

CORTICOSTEROIDS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Concomitant use of mineralocorticoids and some glucocorticoids with sodium supplements might increase the risk of hypernatremia.  Details Mineralocorticoids and some glucocorticoids (corticosteroids) cause sodium retention. This effect is dose-related and depends on mineralocorticoid potency. It is most common with hydrocortisone, cortisone, and fludrocortisone, followed by prednisone and prednisolone (4425).

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Altering dietary intake of sodium might alter the levels and clinical effects of lithium.  Details High sodium intake can reduce plasma concentrations of lithium by increasing lithium excretion (26225). Reducing sodium intake can significantly increase plasma concentrations of lithium and cause lithium toxicity in patients being treated with lithium carbonate (26224,26225). Stabilizing sodium intake is shown to reduce the percentage of patients with lithium level fluctuations above 0.8 mEq/L (112909). Patients taking lithium should avoid significant alterations in their dietary intake of sodium.

SODIUM-CONTAINING DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Concomitant use of sodium-containing drugs with additional sodium from dietary or supplemental sources may increase the risk of hypernatremia and long-term sodium-related complications.  Details The Chronic Disease Risk Reduction (CDRR) intake level of 2.3 grams of sodium daily indicates the intake at which it is believed that chronic disease risk increases for the apparently healthy population (100310). Some medications contain high quantities of sodium. When used in conjunction with sodium supplements or high-sodium diets, the CDRR may be exceeded. Additionally, concomitant use may increase the risk for hypernatremia; this risk is highest in the elderly and people with other risk factors for electrolyte disturbances.

TOLVAPTAN (Samsca) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = C Theoretically, concomitant use of tolvaptan with sodium might increase the risk of hypernatremia.  Details Tolvaptan is a vasopressin receptor 2 antagonist that is used to increase sodium levels in patients with hyponatremia (29406). Patients taking tolvaptan should use caution with the use of sodium salts such as sodium chloride.

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General ...There is currently a limited amount of information on the adverse effects of chrysin. No adverse effects have been reported in clinical trials (7514,42934).

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General ...Orally and topically, propolis seems to be well tolerated.
Most Common Adverse Effects:
Orally: Headache.
Topically: Contact cheilitis and contact dermatitis in sensitive individuals.
Serious Adverse Effects (Rare):
Orally: Severe allergic reactions in sensitive individuals.

Dermatologic ...Propolis can cause allergic reactions and acute oral mucositis with ulceration from the use of the propolis-containing lozenges (2632).
Topically, propolis-containing products, including some cosmetics, can cause eczematous contact dermatitis, erythema multiforme-like contact dermatitis, or allergic contact cheilitis (2632,15647,92796,92798,95878,95882,102517).
Patients allergic to bees or bee products may be more likely to experience allergic reactions to propolis.

Genitourinary ...Vulvar eczema caused by propolis sensitization after topical therapy has been reported (70067).

Hepatic ...Orally, propolis may cause an increase in liver enzymes when used long-term at high doses. In one case, a 30-year-old male presented with persistent abnormal liver enzymes for six months. With other causes ruled out, the patient disclosed using more than 10 propolis lozenges per day for several months to treat a sore throat. Upon discontinuation of the propolis lozenges, liver enzymes returned to normal (105788). Despite concerns presented in this case, analyses of small clinical studies suggest that propolis may have hepatoprotective effects when used at doses of 500-1000 mg daily for up to one year (108521,108522).

Immunologic ...In one case report, a 36-year-old female developed severe erythematous papules and patches with edema of the face, neck, arms, abdomen, and thighs after consuming propolis solution for a few weeks. After symptom resolution, a patch test showed an extreme positive reaction to propolis (106443). In another case, laryngeal edema and severe anaphylactic reaction has been reported in a patient who used topical propolis for the treatment of acute pharyngitis. The patient died due to complications of hypoxia that resulted from the allergic reaction (70063).
Topically, propolis-containing products can cause allergic contact dermatitis, including cheilitis, when used on or near the lips or mouth (15647,92796,92798,102517). Propolis-containing lozenges can cause allergic reactions as well as acute oral mucositis with ulceration (2632).
Patients allergic to bees or bee products may be more likely to experience allergic reactions to propolis.

Neurologic/CNS ...Orally, propolis may cause headache in some patients. In one clinical trial, around 7% of patients taking propolis 250 mg twice daily for 4 months reported mild headache (105786).

Renal ...In one case report, a 59-year-old male with cholangiocarcinoma developed acute kidney failure requiring hemodialysis after taking a Brazilian preparation of propolis 5 mL three times daily for 2 weeks. Renal function improved when propolis was discontinued. The patient restarted taking propolis and symptoms developed again and the patient again required hemodialysis. Symptoms of renal failure improved when propolis was finally discontinued. This product was not screened for contaminants; however, family members of this patient used the same product without apparent adverse effects (14300).

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General ...Orally and intravenously, quercetin seems to be well tolerated in appropriate doses. Topically, no adverse effects have been reported. However, a thorough evaluation of safety outcomes has not been conducted.

Gastrointestinal ...Intravenous administration of quercetin is associated with nausea and vomiting (9564).

Neurologic/CNS ...Orally, quercetin may cause headache and tingling of the extremities (481,111500). Intravenously, quercetin may cause pain at the injection site. Injection pain can be minimized by premedicating patients with 10 mg of morphine and administering amounts greater than 945 mg/m² over 5 minutes (9564). In addition, intravenous administration of quercetin is associated with flushing and sweating (9564).

Pulmonary/Respiratory ...Intravenous administration of quercetin at doses as high as 2000 mg/m² is associated with dyspnea that may persist for up to 5 minutes (9564).

Renal ...Intravenously, nephrotoxicity has been reported with quercetin in amounts greater than 945 mg/m² (9563,9564,70304).

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General ...Orally, sodium is well tolerated when used in moderation at intakes up to the Chronic Disease Risk Reduction (CDRR) intake level. Topically, a thorough evaluation of safety outcomes has not been conducted.
Serious Adverse Effects (Rare):
Orally: Worsened cardiovascular disease, hypertension, kidney disease.

Cardiovascular ...Orally, intake of sodium above the CDRR intake level can exacerbate hypertension and hypertension-related cardiovascular disease (CVD) (26229,98176,100310,106263). A meta-analysis of observational research has found a linear association between increased sodium intake and increased hypertension risk (109398). Observational research has also found an association between increased sodium salt intake and increased risk of CVD, mortality, and cardiovascular mortality (98177,98178,98181,98183,98184,109395,109396,109399). However, the existing research is unable to confirm a causal relationship between sodium intake and increased cardiovascular morbidity and mortality; high-quality, prospective research is needed to clarify this relationship (100312). As there is no known benefit with increased salt intake that would outweigh the potential increased risk of CVD, advise patients to limit salt intake to no more than the CDRR intake level (100310).
A reduction in sodium intake can lower systolic blood pressure by a small amount in most individuals, and diastolic blood pressure in patients with hypertension (100310,100311,106261). However, post hoc analysis of a small crossover clinical study in White patients suggests that 24-hour blood pressure variability is not affected by high-salt intake compared with low-salt intake (112910). Additionally, the available research is insufficient to confirm that a further reduction in sodium intake below the CDRR intake level will lower the risk for chronic disease (100310,100311). A meta-analysis of clinical research shows that reducing sodium intake increases levels of total cholesterol and triglycerides, but not low-density lipoprotein (LDL) cholesterol, by a small amount (106261).
It is unclear whether there are safety concerns when sodium is consumed in amounts lower than the adequate intake (AI) levels. Some observational research has found that the lowest levels of sodium intake might be associated with increased risk of death and cardiovascular events (98181,98183). However, this finding has been criticized because some of the studies used inaccurate measures of sodium intake, such as the Kawasaki formula (98177,98178,101259). Some observational research has found that sodium intake based on a single 24-hour urinary measurement is inversely correlated with all-cause mortality (106260). The National Academies Consensus Study Report states that there is insufficient evidence from observational studies to conclude that there are harmful effects from low sodium intake (100310).

Endocrine ...Orally, a meta-analysis of observational research has found that higher sodium intake is associated with an average increase in body mass index (BMI) of 1. 24 kg/m2 and an approximate 5 cm increase in waist circumference (98182). It has been hypothesized that the increase in BMI is related to an increased thirst, resulting in an increased intake of sugary beverages and/or consumption of foods that are high in salt and also high in fat and energy (98182). One large observational study has found that the highest sodium intake is not associated with overweight or obesity when compared to the lowest intake in adolescents aged 12-19 years when intake of energy and sugar-sweetened beverages are considered (106265). However, in children aged 6-11 years, usual sodium intake is positively associated with increased weight and central obesity independently of the intake of energy and/or sugar-sweetened beverages (106265).

Gastrointestinal ...In one case report, severe gastritis and a deep antral ulcer occurred in a patient who consumed 16 grams of sodium chloride in one sitting (25759). Chronic use of high to moderately high amounts of sodium chloride has been associated with an increased risk of gastric cancer (29405).

Musculoskeletal ...Observational research has found that low sodium levels can increase the risk for osteoporosis. One study has found that low plasma sodium levels are associated with an increased risk for osteoporosis. Low levels, which are typically caused by certain disease states or chronic medications, are associated with a more than 2-fold increased odds for osteoporosis and bone fractures (101260).
Conversely, in healthy males on forced bed rest, a high intake of sodium chloride (7.7 mEq/kg daily) seems to exacerbate disuse-induced bone and muscle loss (25760,25761).

Oncologic ...Population research has found that high or moderately high intake of sodium chloride is associated with an increased risk of gastric cancer when compared with low sodium chloride intake (29405). Other population research in patients with gastric cancer has found that a high intake of sodium is associated with an approximate 65% increased risk of gastric cancer mortality when compared with a low intake. When zinc intake is taken into consideration, the increased risk of mortality only occurred in those with low zinc intake, but the risk was increased to approximately 2-fold in this sub-population (109400).

Pulmonary/Respiratory ...In patients with hypertension, population research has found that sodium excretion is modestly and positively associated with having moderate or severe obstructive sleep apnea. This association was not found in normotensive patients (106262).

Renal ...Increased sodium intake has been associated with impaired kidney function in healthy adults. This effect seems to be independent of blood pressure. Observational research has found that a high salt intake over approximately 5 years is associated with a 29% increased risk of developing impaired kidney function when compared with a lower salt intake. In this study, high salt intake was about 2-fold higher than low salt intake (101261).

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