Re-Built Mass Chocolate Brownie [Discontinued] by GNC Beyond Raw

POSSIBLY EFFECTIVE

• Chronic kidney disease (CKD). Oral alpha-ketoglutarate appears to improve markers of amino acid metabolism and prevent secondary hyperparathyroidism in patients with CKD on hemodialysis. Details: Several small clinical studies in patients on hemodialysis show that taking calcium alpha-ketoglutarate seems to improve biochemical markers, including blood levels of urea and phosphate, when compared with pre-treatment (5311,30784,30785). Furthermore, one small clinical study shows that taking calcium alpha-ketoglutarate 4.5 grams daily for 36 months decreases serum levels of parathyroid hormone in these patients, suggesting that calcium alpha-ketoglutarate might decrease the risk of secondary hyperparathyroidism (30785).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aging. It is unclear if oral alpha-ketoglutarate can prevent signs and symptoms of aging. Details: A small observational study in healthy adults has found that taking a specific product (Rejuvant, Ponce De Leon Health Inc.), providing calcium alpha-ketoglutarate 2 grams and vitamin A 900 mg (males) or vitamin D 25 mg (females), daily for 4-10 months is associated with an 8-year reduction in biological age, as measured by DNA methylation testing (111124). The validity of these findings is limited by a lack of randomization and placebo control.
• Aging skin. It is unclear if topical alpha-ketoglutarate is beneficial in patients with aging skin. Details: A small clinical study in healthy Chinese females shows that applying alpha-ketoglutarate cream to the face daily for 8 weeks improves skin firmness and reduces the severity of crow's feet wrinkles, nasolabial folds, and forehead skin wrinkles when compared to baseline (111125). The validity of these findings is limited by a lack of control group.
• Athletic performance. It is unclear if oral alpha-ketoglutarate improves athletic performance. Details: A small clinical trial in adults shows that taking alpha-ketoglutarate (Evonik Rexim SAS) 0.2 grams/kg daily for 5 weeks increases exercise tolerance, power output, and muscle torque when compared with placebo (18113). Another small clinical study in middle-distance runners 14-17 years of age shows that taking a specific L-arginine alpha-ketoglutarate product (AAKG 1250 Extreme Mega Caps, Olimp Laboratories) 2.5-3.75 grams, combined with a calcium hydroxymethylbutyrate product (HMB 1250 Mega Caps, Olimp Laboratories) 2.5 grams, 3 times daily attenuates reductions in countermovement jump height during a 12-day intensive training camp when compared with placebo. Markers of muscle damage and stress were similar in both groups (106032). It is unclear if the findings from this study are due to alpha-ketoglutarate, other ingredients, or the combination.
• Bariatric surgery complications. Although there has been interest in using oral alpha-ketoglutarate for bariatric surgery complications, there is insufficient reliable information about the clinical effects of alpha-ketoglutarate for this purpose.
• Idiopathic interstitial pneumonia. Although there has been interest in using oral alpha-ketoglutarate for idiopathic interstitial pneumonia, there is insufficient reliable information about the clinical effects of alpha-ketoglutarate for this purpose.
• Inflammatory bowel disease (IBD). Although there has been interest in using oral alpha-ketoglutarate for IBD, there is insufficient reliable information about the clinical effects of alpha-ketoglutarate for this purpose.
• Ischemia-reperfusion injury. It is unclear if intravenous alpha-ketoglutarate can prevent ischemia-reperfusion injury during or after heart surgery. Details: A small clinical study in male patients undergoing heart surgery shows that intravenous administration of alpha-ketoglutarate 28 grams with blood cardioplegia reduces several markers of ischemia when compared with a control group, suggesting that alpha-ketoglutarate might prevent ischemic injury during heart surgery (5312,5313).
• Liver disease. Although there has been interest in using oral alpha-ketoglutarate for liver disease, there is insufficient reliable information about the clinical effects of alpha-ketoglutarate for this purpose.
• Osteoarthritis. Although there has been interest in using oral alpha-ketoglutarate for osteoarthritis, there is insufficient reliable information about the clinical effects of alpha-ketoglutarate for this purpose.
• Osteoporosis. Although there has been interest in using oral alpha-ketoglutarate for osteoporosis, there is insufficient reliable information about the clinical effects of alpha-ketoglutarate for this purpose.
• Rheumatoid arthritis (RA). Although there has been interest in using oral alpha-ketoglutarate for RA, there is insufficient reliable information about the clinical effects of alpha-ketoglutarate for this purpose.
• Small intestinal bacterial overgrowth (SIBO). Although there has been interest in using oral alpha-ketoglutarate for SIBO, there is insufficient reliable information about the clinical effects of alpha-ketoglutarate for this purpose.
• Tendinopathy. Oral alpha-ketoglutarate has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with insertional Achilles tendinopathy shows that taking two sachets of a specific combination product (Tenosan, Agave s.r.l.), each containing methylsulfonylmethane 550 mg, arginine-L-alpha-ketoglutarate 500 mg, hydrolyzed collagen type I 300 mg, Vinitrox 125 mg, bromelain 50 mg, and vitamin C 60 mg, in addition to extracorporeal shock wave therapy (ESWT) improves pain and function when compared with ESWT alone (19321). It is unclear if these findings are due to alpha-ketoglutarate, other ingredients, or the combination. More evidence is needed to rate alpha-ketoglutarate for these uses.

(Read more about ALPHA-KETOGLUTARATE (AKG))

EFFECTIVE

• Homocystinuria. Oral betaine anhydrous is effective at reducing plasma homocysteine levels in patients with homocystinuria associated with cystathionine beta-synthase (CBS) deficiency, 5,10-methylenetetrahydrofolate reductase (MTHFR) deficiency, or cobalamin cofactor metabolism (cbl) defect. Details: Clinical research shows that taking oral betaine anhydrous reduces plasma homocysteine levels by 20% to 30% when compared with placebo in adults and children with several types of homocystinuria, including CBS deficiency, MTHFR deficiency, and cbl defect (698). Observational studies have also found that betaine anhydrous reduces plasma homocysteine levels as monotherapy, in combination with other treatments, such as pyridoxine, folate, and cobalamin, and in patients refractory to pyridoxine treatment (145,698,34956). A specific betaine anhydrous product (Cystadane, Recordati Rare Diseases Inc.) is approved by the US FDA for homocystinuria. Oral betaine anhydrous is initiated at a dose of 100 mg/kg daily in children under 3 years of age and a dose of 3 grams twice daily in children 3 years and older, then titrated to effect. Although some patients have taken up to 20 grams daily, some clinical research suggests that doses above 150 mg/kg daily do not provide additional benefit (698).

POSSIBLY EFFECTIVE

• Hyperhomocysteinemia. Oral betaine anhydrous decreases plasma homocysteine levels in people with hyperhomocysteinemia; however, any effects on cardiovascular sequela and other clinical outcomes are unclear. Details: Most clinical research in adults with normal or mildly elevated plasma homocysteine levels (<25 micromol/L) shows that taking betaine anhydrous 3-6 grams daily orally for up to 12 weeks can modestly decrease plasma homocysteine levels by 5.5% to 15% when compared with control (6810,16451,16452,34894,34896,34902,34904,34925,34936). Some research indicates that oral doses of betaine anhydrous up to 4 grams daily can lower plasma homocysteine levels without an adverse effect on lipid levels (105813). However, it is not clear whether any reduction in plasma levels of homocysteine results in a decreased risk for cardiovascular disease. In patients with kidney failure, clinical research shows that taking betaine anhydrous 4 grams daily lowers levels of plasma homocysteine after methionine loading, but does not affect fasting levels, when compared with control (16455). However, taking this dose of betaine anhydrous in combination with folate 5 mg daily does not seem to have additive homocysteine-lowering effects in patients with kidney failure when compared with folate alone (34885,34957,34963). A very small clinical study in children with hyperhomocysteinemia secondary to pyridoxine non-responsive cystathionine beta-synthase (pnrCBS) or cobalamin C (cblC) deficiencies shows that taking betaine anhydrous 100 or 250 mg/kg daily in divided doses for one month leads to similar reductions in total plasma homocysteine concentrations, suggesting that an increased dose is not beneficial in the setting of pediatric pnrCBS and cblC deficiencies. The researchers noted that increased doses of betaine anhydrous cause proportional increases in methionine concentrations, which can induce severe hypermethioninemia in patients with pnrCBS, possibly leading to increased intracranial pressure and cerebral edema. In contrast, increases in methionine and S-adenosylmethionine concentrations are desirable in patients with cblC deficiency since low concentrations of both are implicated in the pathology of cblC deficiency (111374).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Angelman syndrome. Oral betaine anhydrous has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in children with Angelman syndrome shows that taking betaine anhydrous (Cystadane, Recordati Rare Diseases, Inc.) 100-200 mg/kg daily or betaine anhydrous 6-12 grams daily for 12 months, in combination with folate, folic acid derivatives, creatine, and/or vitamin B12, does not prevent seizures or improve cognitive, motor, or language development, when compared with placebo or baseline (34932,34945).
• Athletic performance. It is unclear if oral betaine anhydrous improves athletic performance; small clinical trials have yielded conflicting findings that may be related to age, training status, and biological sex. Details: Small clinical trials in males with and without strength training experience shows that taking betaine anhydrous 2-2.5 grams daily for 10-15 days, either alone or in combination with resistance training or blood flow restriction, does not improve muscle power, strength, or performance on bench press, leg press, or squat exercises when compared with placebo (34940,34941,34947,34954,111373). In aerobic exercise training, a small clinical study in healthy untrained males shows that taking betaine anhydrous 1.25 grams twice daily with 300 mL of a sports beverage for 2 weeks does not improve aerobic capacity or performance during exhaustive endurance exercise when compared with placebo (105550). Similarly, a small clinical study in trained male runners shows that taking betaine anhydrous 5 grams once with 1000 mL of a sports beverage after becoming dehydrated does not improve long-distance running or sprinting after rehydration when compared with placebo (34916). Additional clinical research in males and females who have undergone at least 6 months of CrossFit training shows that taking betaine anhydrous 1.25 grams twice daily for 6 weeks while continuing to train does not improve muscle strength, body composition, aerobic capacity, or anaerobic performance when compared with placebo (105549). However, other research shows that betaine anhydrous benefits certain aspects of athletic performance in particular subgroups. One small clinical study in healthy, active males shows that taking betaine anhydrous 2.5 grams daily for 2 weeks improves subjective fatigue scores during exercise when compared with placebo (34941). Another small clinical study in active but untrained young females shows that taking betaine anhydrous (BetaPower, Finnfeeds) 2.5 grams daily for 8 weeks in combination with a structured resistance training program reduces body fat percentage and body fat mass, but does not improve muscle strength, when compared with placebo (98525). Another small clinical study in active females shows that taking betaine anhydrous 1.2 grams twice daily for 2 weeks improves power output during sprinting, but not oxygen uptake, when compared with placebo (107950). Betaine anhydrous has also been studied in adolescents. Preliminary clinical research in trained adolescent soccer players shows that taking betaine 1 gram twice daily orally with 300 mL water for 14 weeks improves muscle power, agility, and sprint time, but not muscle strength, when compared with placebo (108654).
• Colorectal adenoma. It is unclear if oral betaine anhydrous reduces the risk of colorectal adenoma. Details: Preliminary population research has found that high dietary betaine intake is not associated with a reduced risk of colorectal adenoma when compared with low dietary betaine intake (14845).
• Depression. Oral betaine anhydrous has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with major depression shows that taking a specific combination product (DDM Metile, Omeopiacenza) containing betaine anhydrous 125 mg and S-adenosyl-L-methionine (SAMe) 250 mg orally twice daily for 12 months improves depression symptoms when compared with amitriptyline 75 mg daily. After 12 months, patients treated with the combination product showed an average improvement in depression scores of 38%, compared with 18% in patients treated with amitriptyline (90107). It is unclear if this effect is due to betaine anhydrous, SAMe, or the combination.
• Dry mouth. It is unclear if topical betaine anhydrous is beneficial in patients with dry mouth. Details: Applying betaine anhydrous 4% topically twice daily in a toothpaste for 2 weeks reduces symptoms of dry mouth when compared with baseline (6812). Other preliminary clinical research in adults with dry mouth shows that using a specific mouthwash product (Xeros Dentaid) that contains betaine anhydrous 1.33%, xylitol 3.3%, and sodium fluoride 0.05%, each evening for 4 weeks improves dry mouth symptoms when compared with baseline (34944). It is unclear if this effect is due to betaine anhydrous, other ingredients, or the combination. Additionally, the validity of the findings from these studies is limited by the lack of a comparator group.
• Fibrocystic breast disease. Although there has been interest in using oral betaine anhydrous for fibrocystic breast disease, there is insufficient reliable information about the clinical effects of betaine anhydrous for this purpose.
• Gastroesophageal reflux disease (GERD). Oral betaine anhydrous 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 betaine anhydrous 100 mg, melatonin 6 mg, L-tryptophan 200 mg, vitamin B6 25 mg, folic acid 10 mg, vitamin B12 50 mcg, and methionine 100 mg daily for 40 days reduces symptoms of GERD in more patients when compared with omeprazole 20 mg daily. Symptom improvement occurred in 100% of patients who took this combination supplement, compared with only 66% of patients taking omeprazole (16011). It is unclear if this effect is due to betaine anhydrous, other ingredients, or the combination.
• Gingivitis. Topical betaine anhydrous has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study of patients with gingivitis shows that brushing with a toothpaste containing a combination of extra virgin olive oil, xylitol, and betaine anhydrous daily for 4 months decreases gingival bleeding and improves markers associated with gingival health when compared with placebo and commercial toothpaste (111372).
• Hepatitis C. Oral betaine anhydrous has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking pegylated interferon alpha and ribavirin in combination with betaine anhydrous (Cystadane, Recordati Rare Diseases, Inc.) and S-adenosyl-L-methionine (SAMe) daily for 12 months induces early virological response in approximately 60% of patients with hepatitis C who were previously unresponsive to treatment with pegylated interferon alpha and ribavirin. However, sustained virological response only occurred in 10% of these patients (20465). The validity of this study is limited by the lack of a comparator group. Also, it is unclear if this effect is due to betaine anhydrous, SAMe, or the combination.
• Metabolic Syndrome. It is unclear if oral betaine anhydrous is beneficial in patients with metabolic syndrome. Details: A large observational study in older adults with overweight or obesity and metabolic syndrome has found that increased dietary intake of betaine for 1 year is associated with reduced body weight, waist circumference, glycated hemoglobin (HbA1c), body weight, and triglycerides and increased levels of high-density lipoprotein (HDL) cholesterol (111375).
• Nonalcoholic steatohepatitis (NASH). It is unclear if oral betaine anhydrous is beneficial in patients with NASH. Details: Preliminary clinical research shows that taking betaine anhydrous 10 grams twice daily orally for 12 months improves NASH scores when compared with placebo (34928). Taking betaine anhydrous also normalizes liver enzyme levels and reduces inflammation and fibrosis when compared with baseline (10631,34928).
• Obesity. It is unclear if oral betaine anhydrous is beneficial in patients with obesity. Details: Preliminary clinic research in obese adults on a reduced-calorie diet shows that taking betaine anhydrous 3 grams orally twice daily for 12 weeks does not reduce body weight or fat mass or improve resting energy expenditure when compared with placebo (16452). A meta-analysis of small randomized controlled trials that studied the effects of betaine anhydrous on body composition also shows that taking betaine 1.5-20 grams daily for 2-52 weeks does not reduce body mass, fat mass, or fat-free mass when compared with control. However, the validity of this study is limited by inclusion of obese, non-obese, and healthy patients (108653).
• Osteoarthritis. Although there has been interest in using oral betaine anhydrous for osteoarthritis, there is insufficient reliable information about the clinical effects of betaine anhydrous for this purpose.
• Rett syndrome. Oral betaine anhydrous has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in female children with Rett syndrome shows that taking a combination of folate 15 mg and betaine anhydrous 6-12 grams orally daily for 12 months does not improve motor function, growth, or development when compared with placebo. In addition, one subgroup analysis suggests that taking the combination product may reduce head circumference growth rate (34922).
• Sunburn. Topical betaine anhydrous has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in healthy adults shows that applying a specific cream (Physiogel AI), which contains betaine anhydrous 0.36%, N-palmitoylethanolamine 0.3%, N-acetylethanolamine 0.21%, and sarcosine 0.24%, daily for one month prior to ultraviolet (UV) light exposure can reduce UV-induced redness when compared with placebo. However, application of this cream only once 20 minutes prior to UV exposure does not have any effect (34905). It is unclear if any benefits are due to betaine anhydrous, other ingredients, or the combination. More evidence is needed to rate betaine anhydrous for these uses.

(Read more about BETAINE ANHYDROUS)

POSSIBLY EFFECTIVE

• Hepatic encephalopathy. Oral and intravenous BCAAs improve symptoms and nutritional status in patients with hepatic encephalopathy, especially in those not tolerating protein supplementation. Details: Taking BCAAs 240 mg/kg (up to 25 grams) daily in 3 divided doses for up to 3 months can improve symptoms, liver function tests, and nitrogen balance in patients with chronic hepatic encephalopathy (68,69,82,690,92643,97531). Oral BCAAs are recommended for malnourished patients with chronic hepatic encephalopathy who cannot tolerate protein supplementation (69,4274). When the enteral route is unavailable and when patients cannot tolerate general purpose amino acid solutions, intravenous solutions with BCAAs can be used for nutritional support; however, most patients can tolerate standard amino acid mixtures (4274). Some clinical research also suggests that taking BCAAs orally improves psychomotor function, attention, intelligence, and driving ability in patients with latent hepatic encephalopathy (684,685,37131,97531). However, not all studies show a positive effect of BCAAs on psychometric outcomes (37135). There is also some preliminary evidence that intravenous BCAAs might be helpful for reversing coma in acute hepatic encephalopathy, although findings are conflicting (66,81,686,687,688,689,4274,37134). BCAAs do not appear to reduce the risk of mortality or improve quality of life in patients with hepatic encephalopathy (92643,97531).
• Tardive dyskinesia. Oral BCAAs might reduce symptoms of tardive dyskinesia precipitated by antipsychotic drugs. Details: Taking BCAAs orally seems to reduce symptoms of tardive dyskinesia (72,10146,13307). Clinical research in adult and pediatric patients who are taking antipsychotic drugs shows that taking a drink containing BCAAs 222 mg/kg three times daily for 3 weeks reduces tardive dyskinesia movements by 30% to 60% when compared with placebo (10146,13307).

POSSIBLY INEFFECTIVE

• Liver cancer. Oral BCAAs do not seem to improve outcomes or reduce the risk for recurrence in patients with liver cancer. Details: A meta-analysis of the available clinical research, as well as individual clinical studies, in patients with hepatocellular carcinoma show that consuming up to 50 grams of BCAAs twice daily for up to 4 years does not improve survival, reduce tumor recurrence, or reduce the risk of complications such as ascites following liver resection when compared with a control group receiving no intervention (37143,92646,97532,105578). However, one small clinical study suggests that BCAAs may be beneficial in patients recently diagnosed with hepatocellular carcinoma that does not require surgery. Taking two packets of a specific supplement (Aminoleban EN) daily containing a total of L-leucine 4 grams, L-isoleucine 3.8 grams, and L-valine 3.2 grams, starting two weeks before receiving transcatheter arterial chemoembolization and radiofrequency ablation and continuing for up to 5 years, reduces recurrence of liver cancer and increases event-free survival when compared with placebo (97533). However, the validity of these findings is limited by the high withdrawal rate in this study.

LIKELY INEFFECTIVE

• Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease). Overall, oral BCAAs are not beneficial and might even lead to worsened outcomes in patients with ALS. Details: Although early studies have indicated that taking BCAAs might be beneficial in ALS, more recent studies show no benefit and a possible increased loss of pulmonary function and higher rate of mortality among patients using BCAAs (678,679,680,681,37154).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alzheimer disease. It is unclear if dietary BCAAs prevent Alzheimer disease. Details: Observational research has found that higher blood levels of BCAAs are associated with an 11% to 13% lower risk of Alzheimer disease; however, when research was adjusted for mortality, body mass index, and concomitant cholesterol-lowering medications, the association was no longer significant (100469).
• Athletic performance. Small clinical trials suggest that although oral BCAAs may not enhance athletic performance, they may modestly reduce perceived exertion and fatigue with some forms of exercise. Details: In most studies, taking BCAAs orally does not enhance athletic performance (692,1135,37080,37094,37106,37123,37141,37142,37151,92641). For instance, BCAAs do not appear to improve strength or work power or to reduce completion times for long-distance running or cycling trials (692,37106,37112,37141,37142,92641). However, most research shows that BCAAs are beneficial for reducing exercise-induced fatigue and perceived exertion after prolonged or intense exercise, exercise in the heat, or exercise following glycogen depletion (692,37112,37124,37144,92642,92644,92645,92648,97529,97530)(97535,105582). In many cases, this improvement is observed when BCAAs are taken in combination with arginine, citrulline, or green tea powder (37124,92642,92645,92648,97529,100462). However, some conflicting evidence exists (1135,37080,37094). Overall, the validity of these findings is limited because most studies differ widely in the amount and type of product consumed. For example, studied doses included BCAAs 0.17-0.3 mg/kg daily; or valine 0.5-1.7 grams, leucine 1-3.5 grams, and isoleucine 0.48-2.1 grams given before and/or after exercise (37108,37123,92642,92644,92645). Other limitations include variability in the studied endpoints and control comparisons used.
• Bipolar disorder. It is unclear if oral BCAAs are beneficial in patients with bipolar disorder. Details: One small clinical study shows that consuming a tyrosine-free amino acid drink containing 60 grams of the BCAAs leucine, isoleucine, and valine in a ratio of 3:3:4, reduces acute manic symptoms within 6 hours when compared with placebo. When taken daily for 7 days, it seems to continue to improve symptoms over a 2-week period (10117).
• Cachexia. Small clinical studies suggest that oral BCAAs are beneficial in patients with cachexia from various causes. Details: Preliminary clinical research in elderly malnourished patients receiving hemodialysis shows that taking a combination of BCAAs 4 grams three times daily improves appetite and caloric intake and increases plasma albumin levels and anthropometric measurements when compared with placebo (10147). Also, small clinical studies in adults with cachexia due to cancer or cirrhosis show that taking oral BCAAs 2.4 grams twice daily for 1 year or 4.8 grams 3 times daily for 1 week might be helpful when compared to baseline (71,37090). This finding is limited by the lack of a comparator group. A small clinical study in adults with congestive heart failure who have lost at least 7.5% of dry weight over the past 6 months or have a body mass index below 20 kg/m² shows that taking BCAAs 10 grams every evening at bedtime for 8 weeks improves physical and emotional quality of life scores, appetite, and fatigue when compared with placebo. Patients taking melatonin 20 mg nightly in addition to BCAA supplementation observed greater improvements in appetite and fatigue when compared with placebo (108478). However, a statistical comparison of outcomes between the groups taking BCAA alone or BCAA with melatonin was not provided.
• Cancer. It is unclear if dietary BCAA consumption improves cancer-related mortality. Details: Observational research in adults has found that consuming BCAAs 19 grams or more daily as part of the diet is not associated with a reduced risk of cancer-related mortality when compared with a lower dietary BCAA intake of less than 7.8 grams daily (108467). The validity of this finding is limited due to unclear reporting; additionally, dietary intake was recorded from a single survey.
• Cardiovascular disease (CVD). It is unclear if dietary BCAA consumption reduces the risk of CVD-related mortality. Details: Observational research in adults has found that CVD-related mortality is not associated with dietary BCAA intake or with individual leucine, isoleucine, or valine intake (108467). The validity of this meta-analysis is limited due to unclear reporting; additionally dietary intake was recorded from a single survey.
• Chronic obstructive pulmonary disease (COPD). It is unclear if oral BCAAs can improve physical performance in adults with COPD. Details: A clinical study in adults with stable, stage 2 or 3 COPD undergoing a pulmonary rehabilitation program shows that taking a BCAA powder 4.3 grams, diluted in water and consumed once daily for 4 weeks, may improve recovery after exercise, but does not impact maximal exercise capacity, functional and muscular performance, or quality of life when compared with placebo (108464). The validity of these findings is limited due to the short duration of treatment.
• Cirrhosis. Most small studies suggest that BCAAs may modestly improve certain measures in some patients with liver cirrhosis. Details: One small clinical study shows that although taking BCAAs 14.4 grams daily for 12 months does not improve survival or liver function in patients with advanced liver cirrhosis, the number of hospitalizations and prevalence of cachexia are reduced and quality of life is improved when compared with control or whey protein (37090). A clinical study in patients with sarcopenia and liver cirrhosis shows that taking BCAAs 7.2 grams for 6 months decreases bilirubin levels and improves Child-Turcotte-Pugh and model for end-stage liver disease (MELD) scores when compared with baseline (108468). Although the study enrolled a control group (whey protein), the investigators did not provide a statistical comparison of outcomes between groups. In addition, a small study in Japanese patients with cirrhosis shows that taking BCAAs 12.45 grams daily for at least 12 months improves liver function and reduces liver complications by 50% to 60% over 3-5 years when compared with control (37120). Also, taking a specific product (Livact, Samil Pharmaceutical) providing the same dose for 11-22 months improves liver function by a small to moderate amount over a 24-month period when compared with not taking BCAAs. There was also a moderate reduction in the rate of developing or worsening major complications such as ascites or hepatic encephalopathy (103351). However, some research providing BCAAs as part of a late evening snack has found no benefit. In one small study, consuming BCAAs as part of a late evening snack in an undefined dose for 3 months does not seem to improve quality of life when compared with a late evening snack without BCAAs (37101). Also, a very small clinical study in patients with abnormal glucose metabolism related to cirrhosis shows that consuming BCAAs in an undefined dose as part of a late evening snack for 1 week does not improve glycemic control when compared with baseline. Instead, glucose levels increased in some patients (103348). It is possible that the doses provided in these latter studies were lower than those used in the studies showing benefit. Additionally, these very small studies may not have been adequately powered to detect a difference between groups.
• Colorectal cancer. It is unclear if dietary BCAAs are beneficial or harmful in patients with colorectal cancer. Details: An observational study in Italy has found that increased dietary intake of BCAAs is associated with a lower risk of developing sigmoid colon cancer, but not overall colorectal cancer risk, when compared with lower intake (105584). However, there's some concern that increased dietary BCAAs may have negative effects in patients who have been diagnosed with colorectal cancer. Observational research in patients living in the US has found that higher dietary intake of BCAAs is associated with a slightly higher risk of all-cause mortality when compared with lower intake (105581).
• Dementia. It is unclear if dietary BCAAs help to prevent dementia. Details: Observational research has found that higher blood levels of BCAAs are associated with a 13% to 17% lower risk of dementia. The lowered risk was maintained when research was adjusted for mortality, body mass index, and concomitant cholesterol-lowering medications (100469).
• Diabetes. It is unclear if dietary BCAAs reduce the risk for developing diabetes. Details: Some population research in Japanese females has found a decreased risk of diabetes associated with higher intake of BCAAs (97543). However, other observational research in people from the US has found that increased dietary intake of BCAAs is associated with an increased risk of diabetes (97536). Reasons for the conflicting finding are not entirely clear. Some evidence suggests that the dietary pattern of BCAA intake, rather than the total intake, may influence the risk of diabetes. Also, there is some speculation that differences in gut microbiota may attribute to the observed differences in diabetes risk associated with BCAA intake (100465). Prospective clinical research is needed to determine whether this association is causal or correlative.
• Exercise-induced muscle damage. Small studies suggest that BCAAs might reduce some, but not all, markers of muscle damage caused by exercise. Details: A meta-analysis of small clinical studies shows that supplementation with BCAAs reduces creatine kinase (CK) levels 24 hours post-exercise, but not 48 hours post-exercise. Additionally, this analysis shows that lactate dehydrogenase (LDH) levels are not affected by BCAA supplementation (97534). The validity of this analysis was limited because baseline dietary protein consumption was not taken into consideration as a potential confounder. A separate meta-analysis of clinical research in trained male athletes performing various resistance exercises shows that taking BCAAs 0.2-1.76 grams/kg for 1-28 days improves CK levels immediately following exercise, and at 24 and 48 hours post-exercise, but does not reduce LDH levels at any timepoint, when compared with placebo or control (108469). Most doses of BCAAs studied consisted of a 2:1:1 ratio of leucine, isoleucine, and valine, respectively. The validity of these findings is limited due to the short duration of treatment and various doses studied. Small individual clinical trials show that taking BCAAs does not affect urinary myoglobin after a marathon nor plasma myoglobin or CK levels after isotonic muscular exercise (37123,92641,100471). The benefits of BCAAs might depend on baseline protein consumption. A small clinical study in resistance trained males shows that adding BCAAs 0.22 grams/kg (MusclePharm BCAA) daily for 8 days to a high daily protein consumption of 1.2 grams/kg does not attenuate muscle damage or improve muscle recovery when compared with placebo (100471). Conversely, a meta-analysis of clinical research in adults completing various exercises shows that taking BCAAs consisting of any combination of valine, leucine, and isoleucine ratios modestly reduces CK, LDH, and myoglobin 24 and 48 hours post-exercise, but does not improve muscle recovery or muscle force after exercise, when compared with placebo (108471). The validity of these findings is limited due to unclear reporting.
• Exercise-induced muscle soreness. Limited evidence suggests that oral BCAAs may modestly attenuate exercise-induced muscle soreness. Details: One meta-analysis shows that taking BCAAs does not reduce delayed-onset muscle soreness after exercise when assessed at the individual time points of 24, 48, or 72 hours (97534). However, when results of all time points are pooled together in two separate meta-analyses, supplementation modestly reduces soreness after exercise (97534,103353). Most, but not all, individual trials also show that taking BCAAs in various doses, such as 0.087 grams/kg or 5-10 grams before and/or after exercise, modestly reduces muscle soreness after exercise (37108,37123,37124,92648,97530,97535,100467,100471,103346,108471). The validity of these individual trials is limited by their small sample sizes, variable dosing regimens, and enrolled populations, which were mainly limited to young untrained adult males (97534,103353). A separate meta-analysis of clinical research in trained male athletes performing various resistance exercises shows that taking BCAAs 0.2-1.76 grams/kg for 1-28 days may improve muscle soreness during the first 24 hours after exercise, but not at 24 or 48 hours post-exercise, when compared with placebo or control (108469). The validity of these findings is limited due to the short duration of treatment and various doses studied. Also, it is not clear whether taking BCAAs before or after a workout may be more beneficial. Some research found a nonsignificant trend toward reduced muscle soreness when consuming a specific product (Aminofeel, Seikatsu Bunkasya Co. Ltd.) containing BCAAs 3.2 grams three times daily starting 3 days before working out and continuing 3 days after, when compared to control (100467). More research is needed to determine the best dosing regimen and which populations, if any, may benefit.
• Heart failure. It is unclear if oral BCAAs are beneficial in patients with heart failure. Details: A small clinical study in patients with heart failure and hypoalbuminemia shows that taking a specific packet of BCAA granules (LIVACT, Ajinomoto Co) containing L-valine 1144 mg, L-leucine 1904 mg, and L-isoleucine 952 mg, three times daily for at least 7 days and stopping after discharge from the hospital, does not affect serum albumin or cardiothoracic ratio (CTR) when compared with placebo (100470). It is possible that this study was underpowered to detect differences between groups. Another small clinical study in adults with chronic heart failure participating in a cardiac rehabilitation program shows that taking a specific oral supplement (Meiji Mei Balance Rehasupport Mini; Meiji Group) containing BCAAs 2.5 grams and various vitamins, minerals, and whey protein, twice daily for 12 weeks increases fat mass, but has no effect on peak oxygen uptake, 6-minute walking distance, or strength parameters, when compared with no supplementation (108470). It is unclear if these effects are due to BCAAs, the other ingredients, or the combination.
• Hepatitis. It is unclear if oral BCAAs are beneficial in patients with hepatitis. Details: Preliminary clinical research in patients with alcoholic hepatitis shows that taking BCAAs 20 grams daily orally or enterally for 3 weeks or until discharge, in combination with a controlled diet, does not reduce the risk of mortality when compared with conventional protein or a controlled diet alone (37133).
• Inflammatory myopathies. It is unclear if oral BCAAs are beneficial in patients with polymyositis and dermatomyositis. Details: A small clinical study in adults with suspected or confirmed polymyositis or dermatomyositis who are receiving standard corticosteroid therapy shows that a BCAA-specific product containing L-isoleucine 952 mg, L-leucine 1904 mg, and L-valine 1144 mg for 12-28 weeks, taken as two packages three times daily for a total daily dose of 24 grams, does not improve manual muscle test scores or clinical response at 12 and 28 weeks when compared with placebo (108477).
• Obesity. It is unclear of oral BCAAs can reduce the likelihood of developing obesity or improve weight loss in adults with overweight or obesity. Details: Some observational research has found that higher dietary intake of BCAAs is associated with lower odds of obesity when compared with a lower intake (100466). Conversely, a large observational study in adults in Iran, including those who are overweight or obese, has found that the highest dietary intake of BCAAs is associated with a 24% higher likelihood of general obesity in males, but not in females, when compared with the lowest dietary BCAA intake (108465). This study did not report ranges for highest and lowest BCAA intake, limiting the validity of this study. BCAAs have also been evaluated in adults with overweight or obesity. A small clinical study in obese females that underwent a 4-week calorie-restricted diet shows that taking 6 caplets daily containing a total of L-leucine 3 grams, L-isoleucine 1.5 grams, and L-valine 1.5 grams in addition to vitamin B6 40 mg daily for 4 weeks does not further reduce weight, but may slightly preserve lean body mass, when compared with placebo (100464). Another small clinical study in overweight and obese adults shows that taking BCAAs 0.1 gram/kg daily in addition to starting a low-calorie diet for 16 weeks does not improve weight loss, but may preserve lean muscle mass, when compared with taking placebo while following the low-calorie diet (105583).
• Overall mortality. It is unclear if dietary BCAA consumption reduces the risk of all-cause mortality. Details: Observational research in adults has found that total BCAA intake, as well as isoleucine intake, is associated with a reduced risk of all-cause mortality, particularly in those with higher serum triglyceride concentrations (108467). However, this association was not present for leucine or valine intake. The validity of this meta-analysis is limited due to unclear reporting; additionally dietary intake was recorded from a single survey.
• Pancreatic cancer. The association between dietary BCAA intake and pancreatic cancer risk is unclear. Details: Observational research in adults in Italy has found that consuming BCAAs as part of the diet in quantities greater than 18 grams daily is associated with a 2-fold increased risk of pancreatic cancer when compared with less than 12 grams daily. This relationship was stronger in younger males, those with higher body mass indexes, and in those who smoke or have high alcohol intake (108476). Dietary information was recorded from a single, weekly consumption questionnaire.
• Phenylketonuria (PKU). It is unclear if oral BCAAs are beneficial in patients with PKU. Details: A small clinical trial in adolescents and young adults with PKU shows that taking BCAAs, consisting of valine 150 mg/kg, isoleucine 150 mg/kg, and leucine 200 mg/kg, with meals and at bedtime for up to 6 months seems to improve attention and processing when compared with a control group (37127).
• Physical performance. It is unclear if oral BCAAs are beneficial for improving physical function and muscle strength in older adults. Details: In malnourished elderly individuals, preliminary clinical research shows that taking a supplement providing BCAAs 5000 mg daily, in addition to other amino acids, vitamin B6, and vitamin B1 (Aminotrofic) for 2 months, does not improve muscle mass, muscle strength, or physical function to a greater extent than dietary advice intended to maximize nutritional intake from food and drink (103349). Similarly, a clinical study in middle aged and elderly adults shows that a specific product (Sarcojoint; Orient Euro Pharma, Inc) containing leucine 1 gram, arginine, vitamin D3, glucosamine, chondroitin, and calcium, taken twice daily in addition to regular resistance exercise for 12 weeks, does not improve muscle strength, muscle mass, or physical performance when compared with taking an unspecified vitamin B supplement twice daily with regular exercise (108472). Conversely, one small clinical study in older adults who have had a hip replacement shows that taking BCAAs 1.2 grams and lysine 1.8 grams (Amino-aile, Ajinomoto Co., Inc.) daily for one month after undergoing exercise therapy sessions modestly increases the strength of both legs and arms when compared with taking starch. However, there was no effect on hip abductor strength of the operated leg or on grip strength or measures of independence (103347).
• Postoperative infection. There is limited evidence on the intravenous and oral use of BCAAs for reducing infection after oncologic surgery. Details: A meta-analysis of 6 small heterogeneous clinical trials in patients after oncologic surgery, mostly for liver cancer, suggests that receiving oral or intravenous BCAAs reduces the risk of postoperative infection by 38% when compared with control (105577).
• Postoperative recovery. There is limited evidence on the intravenous and oral use of BCAAs for improving postoperative recovery after oncologic surgery. Details: A meta-analysis of small heterogeneous clinical trials in patients after oncologic surgery, mostly for liver cancer, suggests that receiving oral or intravenous BCAAs reduces hospital stay by about 2 days, but does not reduce mortality or post-operative complications, when compared with control (105577).
• Psychological well-being. It is unclear if oral BCAAs are beneficial for psychological well-being. Details: A cross-sectional observational study has found that higher dietary consumption of BCAAs is associated with a lower risk of anxiety and depression when compared with lower consumption (105579).
• Sarcopenia. It is unclear if oral BCAAs are beneficial in patients with primary sarcopenia or in those with sarcopenia related to liver cirrhosis. Details: A small clinical study in postmenopausal adults at risk for sarcopenia shows that consuming BCAAs 9 grams daily for 8 weeks in addition to resistance training increases strength and muscle mass when compared with baseline, but is no different than resistance training plus a placebo (105576). Another small clinical study in adults 65 years or older with sarcopenia shows that taking a supplement containing BCAAs 2500 mg, vitamin D 500 IU, protein, and other vitamins daily for 8 weeks in addition to resistance training does not improve physical function when compared with resistance training alone. The supplement did seem to slightly improve handgrip strength and body mass when compared with no supplementation (100468). However, overall the study was inadequately powered to detect smaller effects on physical function and muscle mass. There is also interest in using BCCAs in patients with sarcopenia and liver cirrhosis. A clinical study in this population shows that taking BCAAs 7.2 grams (containing 1.2 grams of L-leucine, 600 mg of L-isoleucine, and 600 mg of L-valine) daily for 6 months improves handgrip strength, gait speed, and muscle mass when compared with baseline (108468). Although the study enrolled a control group (whey protein), the investigators did not provide a statistical comparison of outcomes between groups. A separate meta-analysis of low-quality clinical research in this population shows that taking BCAAs has no effect on handgrip strength when compared with no supplementation (108473). Although other outcomes were evaluated, results are inconclusive due to the limited number of studies available for each outcome.
• Spinocerebellar ataxia (SCA). It is unclear if oral BCAAs are beneficial in patients with SCA. Details: Although there is some preliminary clinical evidence that oral BCAAs might have a beneficial effect on symptoms of SCA (73), a small clinical crossover study shows that taking a particular BCAA compound (Livact) 4.5-18 grams daily for 4 weeks does not improve ataxia in patients with SCA when compared with placebo (37088).
• Stroke. It is unclear if oral BCAAs are beneficial in patients recovering from stroke. Details:A small nonblinded, clinical study in elderly patients with subacute stroke and sarcopenia currently undergoing intensive inpatient rehabilitation therapy shows that administering a specific product (Seniup; Enterogenomics Co) containing BCAAs 6 grams, given twice daily orally or by feeding tube for 1 month, modestly improves skeletal muscle index, dysphagia, gait, balance, and handgrip strength, and may attenuate muscle loss in affected upper and lower extremities, when compared with rehabilitation alone (108474). The validity of these findings is limited by the short duration of treatment. Other research has compared BCAA dosing regimens. A small study in stroke patients taking part in exercise sessions shows that taking BCAAs 3.5 grams (Hepas, Clinico Co. Ltd) daily for 2 months with breakfast is more effective for improving leg strength and balance than when taken post-exercise in the mid-afternoon. However, there were no differences in most measures of strength or in skeletal muscle mass (103352). More evidence is needed to rate BCAAs for these uses.

(Read more about BRANCHED-CHAIN AMINO ACIDS (BCAA))

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 in adults with or without hypertension. However, it is unclear if this reduction is clinically significant. Details: Many clinical trials and observational studies, including a meta-analysis of 18 high-quality clinical trials, show that intake of calcium supplements or dietary calcium modestly reduces systolic 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 those who are salt-sensitive or have low baseline dietary calcium intake (945,972,974,976,984,1818,1819,1820,1821,6852)(13138,14406,38803,39063,39094,39221,113920,113925). 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 supplemental 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). Research evaluating the effect of calcium supplementation during pregnancy on the child's blood pressure has yielded conflicting findings. A systematic review of 2 clinical studies and 3 observational studies found that calcium intake during pregnancy is associated with a 1-2 mmHg reduction in the systolic blood pressure of the offspring between the ages of 1-7 years (38852). However, a separate meta-analysis of 3 clinical studies shows that calcium intake during pregnancy does not reduce systolic or diastolic blood pressure in the offspring (113923).
• 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, especially in high-risk individuals and those with low baseline dietary calcium intake. Details: Although there is some conflicting evidence (971,38756), most clinical research shows that taking calcium orally 1-2 grams daily reduces the risk of pre-eclampsia (973,1833,8828,39043,39319,39426,97348,113919). A large clinical trial of 11,000 pregnant individuals in India and Tanzania shows that supplementation with 500 mg daily is similarly effective to 1500 mg daily (113908). Multiple meta-analyses which include 16-30 clinical studies have found that varying doses of calcium supplementation reduce the relative risk of pre-eclampsia by 46% to 51% when compared with placebo (97348,113909,113919). One of these meta-analyses found that for every 19 females treated with calcium, one episode of pre-eclampsia would be avoided (97348). Additionally, one of these meta-analyses found that calcium reduces the relative risk of pre-eclampsia by 51%, regardless of whether it is taken at a dose above or below 1000 mg daily (113919). Some research suggests that calcium supplementation may have a greater effect in individuals at high risk of pre-eclampsia or with low baseline dietary calcium intake, and when taken at greater than or equal to 20 weeks of gestation (15029,38497,97348,99714,113919). However, another meta-analysis of 30 clinical studies found a similar benefit of calcium in both high- and low-risk individuals (113919). A separate meta-analysis of 6 clinical studies conducted in China evaluated the benefits of calcium carbonate 500-600 mg daily taken in conjunction with aspirin 50-75 mg daily during pregnancy. This combination was associated with an 80% lower relative risk of pre-eclampsia and an 83% lower relative risk of pre-eclampsia with gestational hypertension when compared with routine care (113913). 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 (102366). 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 1.5-2 grams daily during pregnancies at high risk of pre-eclampsia if dietary calcium intakes are low (97347).
• Pregnancy-induced hypertension. Oral calcium may reduce the risk of pregnancy-induced hypertension. Details: A meta-analysis of 17 clinical studies shows that calcium supplementation during pregnancy may reduce the relative risk of pregnancy-induced hypertension by 30% when compared with control (113909). A separate meta-analysis of 6 clinical studies conducted in China, which evaluated the benefits of calcium carbonate 500-600 mg daily taken in conjunction with aspirin 50-75 mg daily during pregnancy, shows that this combination reduces the relative risk of pregnancy-induced hypertension by 85% when compared with routine care (113913).
• 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, via supplementation or as part of the diet, does not seem to be beneficial for breast cancer prevention. Details: Although some studies disagree (15631,39041,95811,107237,113917), most population research suggests that increased calcium intake is not associated with overall breast cancer risk (15631,16715,98895,107236,107237,113917). However, one meta-analysis of observational studies shows that although higher total calcium intake is not associated with breast cancer risk, higher dietary calcium intake, specifically, may be associated with a slightly reduced risk (113917). Also, some analyses suggest that calcium intake may be associated with the risk for certain breast cancer sub-types. Some subgroup analyses suggest that calcium intake may reduce the risk of breast cancer in postmenopausal, but not pre-menopausal, adults (15631,107237) and that dietary calcium intake may reduce estrogen receptor(ER)-negative breast cancer, but not ER-positive breast cancer (107236). However, most 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: Robust meta-analyses of mostly large, high-quality clinical studies show that calcium supplementation 500-1600 mg daily for 0.5-7 years with or without vitamin D does not reduce total fractures, hip fractures, vertebral fractures, or non-vertebral fractures in older adults without osteoporosis (95822,112486). A large-scale study in postmenopausal females aged 50-79 years who were enrolled in the Women's Health Initiative (WHI) suggests that 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 WHI study found that, in older females with the lowest genetic susceptibility to low 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 in adults or children with overweight or obesity. 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 (12128,15397,14438,98905,113918), most clinical research has found that increased calcium intake does not increase weight loss (12052,13138,15396,15399,38985,39004,97356). A 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 (93533,97308,113584).

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).
• Brain tumor. It is unclear if dietary calcium intake is associated with risk of brain tumor. Details: A meta-analysis of 4 case-control studies has found that higher dietary calcium intake is associated with a lower odds of brain tumor when compared with lower dietary intake (113922). The validity of this finding is limited by the exploratory nature of the included studies, which analyzed all dietary ingredients for any potential associations.
• 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 dietary calcium intake is associated with type 2 diabetes risk. Details: Some population research has found that a higher intake of calcium from the 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 (14265,16713,96473,113929). One meta-analysis of cohort and cross-sectional studies found that the highest level of dietary calcium intake is associated with an 18% relative reduction in risk of type 2 diabetes when compared with the lowest level of intake. A dose-response analysis suggests that each 300, 600, and 1000 mg per day increase in dietary calcium intake is associated with a 7%, 14%, and 23% reduced risk of type 2 diabetes, respectively (113929). However, population research is often limited by confounding variables. For example, one analysis suggests that any beneficial effect might be influenced by concomitant magnesium intake (96473,113929), while another suggests that any benefit from increased intake may be more pronounced in females, adults aged 50 years or older, and Asian populations (113929). 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 (95815).
• Dyslipidemia. It is unclear if oral calcium is beneficial for dyslipidemia. Details: One clinical study in adults with mild to moderate hypercholesterolemia shows that adding calcium carbonate 400 mg three times daily to a low-fat diet (American Heart Association Step 1) for 6 weeks reduces low-density lipoprotein (LDL) cholesterol levels by 4% and increases high-density lipoprotein (HDL) cholesterol levels by 4% when compared with the low-fat diet and placebo (2557). In contrast, a clinical study in females with dyslipidemia shows that taking calcium 800 mg daily for 2 years INCREASES total cholesterol levels and carotid intima-media thickness in postmenopausal, but not premenopausal, females when compared with placebo (97350). Calcium supplementation has also been evaluated in combination with vitamin D. A meta-analysis of randomized controlled trials including adults with normolipidemia and 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 most beneficial in patients with dyslipidemia at baseline (107227). The relationship between dietary calcium intake and serum lipid levels has also been evaluated in observational research. A meta-analysis of 7-11 observational studies found that dietary calcium intake is not associated with total cholesterol levels, although small differences in individual lipid parameters were identified. Additionally, a meta-analysis of 4-9 observational studies suggests that calcium intake is not associated with the risk of developing hypertriglyceridemia, hypercholesterolemia, or low HDL. A subgroup analysis found that higher calcium intake may be associated with lower triglyceride levels in Asian populations (113927). Overall, these findings are limited by significant heterogeneity and the cross-sectional nature of the included studies.
• 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).
• Exercise-induced muscle damage. It is unclear if oral calcium is beneficial for reducing exercise-induced muscle damage. Details: A very small clinical study in resistance-trained adults shows that taking calcium carbonate 500 mg 4 times daily for 3 weeks does not attenuate exercise-induced muscle damage from bench presses when compared with placebo (113933). This study may have been inadequately powered to detect a difference between groups.
• 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).
• 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).
• Prematurity. It is unclear if supplemental calcium is beneficial for the growth and development of preterm infants. Details: A small clinical study in preterm infants consuming human milk shows that supplementation with calcium 45 mg/kg daily and phosphorus 25 mg/kg daily does not affect infant weight, length, head circumference, or risk of osteopenia after 6 weeks when compared with human milk alone (113924). However, the duration and size of this study may have been too limited to detect any difference between groups.
• Preterm labor. It is unclear if oral calcium reduces the risk of preterm labor. Details: A meta-analysis of 10 clinical studies shows that taking calcium supplements during pregnancy does not reduce the risk of preterm labor when compared with placebo (113909). A separate meta-analysis of 7 clinical studies conducted in China, which evaluated the benefits of calcium carbonate 500-600 mg daily taken in conjunction with aspirin 50-75 mg daily during pregnancy, shows that this combination reduces the relative risk of preterm labor by 74% when compared with routine care (113913).
• 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)

LIKELY EFFECTIVE

• Atopic dermatitis (eczema). Consuming casein peptide as part of formula with or without breastmilk for up to 6 months reduces the risk of atopic dermatitis in infants. Details: Clinical research shows that feeding infants a casein peptide-based formula (Nutramigen or Progestimil, Mead Johnson), with or without breastmilk for 4-6 months, reduces the risk for atopic dermatitis during the first 9-24 months of life by 52% to 73% when compared to cow's milk formula (91655,91656,91658). The benefits of casein peptides appear to be most significant in infants with a family history of atopy (91655,91656). Additionally, the benefit of using a casein peptide-based formula during the first 4 months of life persists into childhood, with a 29% reduced risk of developing atopic dermatitis at 6 years of age when compared to cow's milk formula (91659,91660). Clinical research also shows that casein peptide formula is equally effective to hydrolyzed whey protein formula for reducing the risk for atopic dermatitis in infants (91657,91658,91659,91660,91661).
• Atopic disease. Consuming casein peptide as part of formula during the first 4 months of life reduces the risk of atopic disease in infants with a family history of atopy. The benefits of casein peptide in infants without a family history of atopy is unclear. Details: Clinical research in infants with a family history of atopy shows that taking a casein peptide-based formula (Nutramigen, Mead Johnson) during the first 4 months of life, or after weaning from breastmilk, reduces the risk for atopic manifestations during the first 12-18 months of life by 39% to 44% when compared with cow's milk formula (91656,91658). This benefit persists over time, with a 20% reduced risk for developing atopic disease at 6 years of age when compared to cow's milk formula (91660). However, it may not be beneficial in children without a family history of atopy. One large, ancillary clinical study in children at increased risk for development of type 1 diabetes, but not specifically at risk for atopy, shows that using an extensively hydrolyzed casein peptide formula (Nutramigen, Mead Johnson) in infancy for up to 6-8 months does not prevent persistent asthma, allergic rhinitis, or atopic dermatitis development when compared with using a conventional formula containing 80% intact cow's milk protein and 20% hydrolyzed milk protein (Enfamil, Mead Johnson). The validity of these findings is limited by the patient population and the unclear duration of follow up (106564).
• Food allergies. Consuming casein peptide formulas is a safe alternative to cow's milk in children with cow's milk allergy. Details: Clinical research shows that specific casein peptide formulas are a safe and well-tolerated alternative for children with documented allergy to cow's milk. Evaluated formulas include Alimentum (Abbot Laboratories), Damira 2000 (Nutrition & Sante S.L.), Frisolac Allergycare (Friesland Nutrition), and Nutramigen (Mead Johnson) (91663,91664,91665,111439). A cost-effective analysis in children with cow's milk allergy also suggests that using casein peptide-based formula is cost-effective dominant and reduces other allergic manifestations when compared with soy-based formula (111438).

POSSIBLY EFFECTIVE

• Colic. Clinical research shows that consuming casein peptides as part of formula reduces crying, short-term, in infants with colic. Details: Clinical research in infants with colic shows that replacing cow's milk formula with a specific casein peptide formula (Nutramigen, Mead Johnson) significantly reduces crying and colic when compared with cow's milk formula. However, this effect appears to diminish after more than four days of use (91262). Preliminary clinical research shows that consuming specific casein peptide formulas (Alimentum, Abbot Laboratories; Nutramigen, Mead Johnson) for 7 days reduces daily crying time by up to 5 hours and reduces crying intensity when compared with baseline in infants with colic (91264). The validity of this finding is limited by the lack of a comparator group.
• Diabetes. Consuming casein peptides with carbohydrates may be beneficial for reducing postprandial glucose and insulin levels in adults with type 2 diabetes. Casein peptides have also been evaluated for the prevention of type 1 diabetes in infants, with inconclusive results. Details: In adults with type 2 diabetes, casein protein may improve postprandial glucose levels. Most clinical research shows that consuming casein peptides in conjunction with a carbohydrate bolus increases postprandial insulin response by 26% to 300% and reduces postprandial glucose levels by 5% to 28% when compared with consuming carbohydrates alone (91276,91295,91297,91299). These effects seem to persist with casein peptide doses as low as 12 grams daily, but not 6 grams daily (91300). Preliminary clinical research also shows that adding leucine 5 grams or 0.1 grams/kg to casein peptides increases postprandial insulin levels by 52% to 200%, reduces postprandial glucose levels by 5% to 12%, and improves 24-hour glucose levels by 11% when compared with consuming carbohydrates alone (91296,91297). However, some preliminary clinical research shows that consuming casein peptides 0.4 grams/kg with each meal for one day does not improve glycemic control (91298). These differing outcomes might be related to the forms of carbohydrates used, which include carbohydrate boluses and carbohydrate-containing meals. Additionally, the evidence for the effects of intact casein protein, as opposed to casein peptides, on postprandial insulin and glucose levels is conflicting (91276,91299). Clinical research in infants 6-8 months of age who are genetically predisposed to type 1 diabetes shows that administering a specific casein peptide-based formula (Nutramigen, Mead Johnson) in place of breastmilk decreases the development of one or more diabetes-associated auto-antibodies when compared with cow's milk formula. However, there was no difference in type 1 diabetes incidence after 10 years. This study was not powered to detect a difference in this outcome (91675).
• Hypertension. The casein peptides isoleucine-proline-proline (IPP) and valine-proline-proline (VPP), sometimes referred to as lactotripeptides, can modestly reduce blood pressure in patients with hypertension. Lower doses given for shorter durations seem to produce greater effects, and the effects may be more pronounced in Japanese patients than in European patients. Details: The most comprehensive meta-analysis to-date in patients with hypertension shows that taking casein peptides reduces systolic blood pressure (SBP) by 3 mmHg and diastolic blood pressure (DBP) by 1.5 mmHg. The average dose of casein peptides was 10.5 mg daily, including IPP 5.2 mg and VPP 5.3 mg daily, for about 8 weeks. However, there may be an inverse dose-response relationship; daily doses of casein peptides of 10 mg or less, lasting for 8 weeks or less, reduced blood pressure to a greater degree when compared with higher doses given for longer durations. Furthermore, casein peptides produced by fermentation resulted in modestly greater blood pressure reduction when compared with casein peptides produced by enzymatic hydrolysis (103765). Patient ethnicity may also play a role in the magnitude of effect. Other meta-analyses show a 1-6 mmHg reduction in SBP and 0.6-1.5 mmHg reduction in DBP when compared with control (103762,103763,103765,111437). A small clinical study in healthy Japanese males and postmenopausal adults with prehypertension shows that supplementation with casein peptides IPP 2 mg and VPP 1.4 mg daily for 8 weeks reduces home-monitored 7-day mean DBP, but not SBP, by 0.9 mmHg, compared with an increase of 1.2 mmHg in those receiving placebo (106565). Although findings are positive overall, the validity of the above meta-analysis, as well as older or less comprehensive analyses, is limited by the poor reporting and methodology of the included studies (103763,103765,103770,103772). Some limited research in patients with metabolic syndrome shows conflicting blood pressure lowering effects. A small clinical study shows that taking IPP/VPP (Calpis Co., Ltd.) 10.2 mg in the morning before breakfast daily for 4 weeks lowers 24-hour ambulatory systolic blood pressure by 2 mmHg, but not diastolic blood pressure, when compared with placebo (103764). However, another study shows that taking casein peptides 5-25 mg daily with plant sterols 2 grams daily orally for 12 weeks does not reduce blood pressure when compared with placebo (103767). Notably, this study was not adequately powered to detect small changes in blood pressure.
• Neonatal jaundice. Clinical research suggests that consuming casein peptide reduces the risk of jaundice in neonates. Details: Preliminary clinical research shows that feeding newborns a specific casein peptide formula (Nutramigen, Mead Johnson) for 3 weeks reduces the risk of jaundice when compared with whey-predominant formula (91642) or human milk (91642,91651). Other preliminary clinical research in breastfed newborns shows that taking 5 mL of casein peptide formula, created by enzymatic hydrolysis, 6 times daily for 7 days decreases transcutaneous bilirubin levels when compared with breastfeeding alone (91643).

POSSIBLY INEFFECTIVE

• Asthma. Consuming casein peptide does not appear to reduce the risk of asthma in infants. Details: Most clinical research shows that feeding infants a casein peptide-based formula (Nutramigen or Progestimil, Mead Johnson), with or without breastmilk for 4 months, does not reduce the risk for asthma in the first 4 months to 6 years of life in children with a family history of atopy (91655,91659,91660). However, one preliminary clinical study shows that feeding infants Nutramigen beginning at about 3.8 months of age decreases wheezing by 61% compared to cow's milk formula; the incidence of asthma was not evaluated (91656).
• Infant development. Consuming casein peptide does not appear to affect growth or development in healthy infants, or in premature or low-birth weight infants. Details: Most clinical research shows that using casein peptide-predominant formula for 6 weeks to 6 months in premature, low-birth weight, or healthy infants does not affect growth when compared with breast milk, whey protein-based formula, rice hydrolysate formula, cow's milk formula, or amino acid-based formula (86085,91644,91672,91673). Additionally, feeding infants a specific casein peptide formula (Nutramigen, Mead Johnson) for 4 months does not affect growth at 6 or 10 years when compared with whey protein-based formula, cow's milk formula, or breast milk (86085,91644). However, clinical research suggests that a casein peptide-based formula might be beneficial in infants with cow's milk allergy. One study in this population shows that casein peptide-based formula significantly increases growth from 6-12 months of age when compared with soy-based formula (91672).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. It is unclear if oral casein peptides are beneficial in patients with acne. Details: Preliminary clinical research in adults with moderate to severe acne shows that taking a specific casein peptide (Lactium) 150 mg orally daily for 84 days does not reduce acne lesion count when compared with control. However, the study may have been inadequately powered to detect a difference between groups (111436).
• Aging skin. It is unclear if oral casein peptides are beneficial in patients with aging skin. Details: A small clinical study in healthy, normotensive older Japanese adults shows that taking casein peptides isoleucine-proline-proline (IPP) and valine-proline-proline (VPP) orally once daily for 48 weeks reduces facial pigmentation area by about 15%, compared with an increase of about 6% in patients taking placebo (106563).
• Anxiety. Although there has been interest in using oral casein peptides for anxiety, there is insufficient reliable information about the clinical effects of casein peptides for this purpose.
• Athletic performance. It is unclear if oral casein peptides are beneficial for athletic performance. Details: Preliminary clinical research in overweight male police officers shows that taking casein peptides 1.5 grams/kg orally daily in two divided doses for 12 weeks, in conjunction with resistance training, decreases body fat percentage by 3%, increases lean body mass by 2 kg, and improves chest, shoulder, and leg press strength by around 30% when compared with whey protein (85648).
• Cancer. Although there has been interest in using oral casein peptides for cancer, there is insufficient reliable information about the clinical effects of casein peptides for this purpose.
• Diarrhea. It is unclear if oral casein peptides are beneficial in patients with diarrhea. Details: Preliminary clinical research in male children with persistent diarrhea shows that consuming a casein peptide-based diet during hospitalization is less effective for reducing stool output than a yogurt-based diet (91648).
• Epilepsy. Although there has been interest in using oral casein peptides for epilepsy, there is insufficient reliable information about the clinical effects of casein peptides for this purpose.
• Exercise-induced muscle soreness. It is unclear if oral casein peptides are beneficial in patients with exercise-induced muscle soreness. Details: Preliminary clinical research in male cyclists shows that drinking 200 mL of a carbohydrate beverage containing 1.8% casein peptides every 5 km followed by 500 mL after cycling completion reduces exercise-induced muscle soreness and improves late-exercise time-trial performance when compared with drinking a carbohydrate beverage alone (91256).
• Fatigue. Although there has been interest in using oral casein peptides for fatigue, there is insufficient reliable information about the clinical effects of casein peptides for this purpose.
• Hyperlipidemia. Low quality research suggests that oral casein peptides are not beneficial in patients with hyperlipidemia. Details: A meta-analysis of randomized trials in subjects with and without hyperlipidemia shows that using casein peptide-based diets for 1-48 weeks does not improve low-density lipoprotein cholesterol, high-density cholesterol, or triglyceride levels when compared with control (111437).
• Insomnia. It is unclear if oral casein peptides are beneficial in patients with insomnia. Details: A small clinical study in Korean patients with poor sleep quality shows that taking a specific product (Lactium, Ingredia) containing bovine alpha-s1 casein peptides 300 mg one hour before bedtime for 4 weeks modestly improves sleep efficiency based on subjective reports and actigraphy measures when compared with placebo (103774). Casein peptides have also been studied as part of combination products. A small clinical study in adults with insomnia or disturbed sleep patterns shows that a specific product (RLX2; LiveLife Biosciences AG) containing a specific casein peptide, alpha-s1-casein tryptic hydrolysate, 150 mg, and L-theanine 50 mg, taken one hour before bedtime for 4 weeks, increases sleep duration by 45 minutes and improves habitual sleep efficiency and daytime dysfunction when compared with baseline. However, it does not affect blood pressure, heart rate, or cortisol levels (108556). It is unclear if these effects are due to L-theanine, alpha-s1-casein tryptic hydrolysate, or the combination.
• Physical performance. It is unclear if oral casein peptides are beneficial for physical performance. Details: Preliminary clinical research in healthy older males shows that taking casein peptides 10 grams before and after resistance training for 8 weeks does not improve strength or body composition when compared with placebo (91255).
• Stress. Although there has been interest in using oral casein peptides for stress, there is insufficient reliable information about the clinical effects of casein peptides for this purpose. More evidence is needed to rate casein peptides for these uses.

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POSSIBLY INEFFECTIVE

• Infant development. Most clinical research shows that using casein protein-predominant formula for 6 weeks to 6 months in premature, low-birth weight, or healthy infants does not affect growth when compared with breast milk, whey protein-based formula, rice hydrolysate formula, cow's milk formula, or amino acid-based formula (91645,91668,91669,91670). However, other clinical research in healthy, moderately premature, or very low birth weight infants shows that whey protein-based formula is superior to casein protein-based formula for increasing growth (91666,91667,91671).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alcohol-related liver disease. Preliminary clinical research in adults with alcohol-related liver disease shows that a specific casein protein-based supplement (Isocal HCN, Mead Johnson), dosed as 1.5 grams/kg of ideal body weight daily, administered via enteral feeding tube for 28 days, improves encephalopathy scores by over 50% when compared with baseline. Taking the casein protein-based formula also improved total caloric intake and plasma markers of liver disease when compared with control (91266). Additional clinical research in adults with alcohol-related liver disease shows that taking a specific casein-based enteral formula (ADN, Laboratorios Davis) providing 34 grams of protein daily for one year reduces hospitalization rate by approximately 50% and reduces the risk for infection when compared with control. However, there was no effect on mortality or progression of liver failure (91268).
• Athletic performance. The clinical evidence for the benefits of casein protein on athletic performance is conflicting. Some preliminary clinical research shows that taking casein protein alone or in combination with whey protein and other sports supplements for 4-12 weeks, in conjunction with resistance training, does not improve strength or body composition when compared with placebo in obese women or young men (91252,91254,91280,111440). However, other preliminary clinical research shows that taking casein protein, with or without whey protein, improves strength and athletic performance in a variety of individuals, including collegiate female basketball players, obese sedentary women, and professional male soccer players (85821,91253,91280,91641). Casein protein has also been compared with other popular athletic performance supplements. When compared with whey protein, most clinical research shows that casein protein and whey protein are equally effective for improving strength and athletic performance (91253,91280,91641,103776). Conversely, some clinical research shows that whey protein is superior to casein protein for improving strength and body composition in recreational bodybuilders (16728). Clinical research comparing casein protein to creatine daily after exercise shows that both supplement regimens have similar effects on strength in untrained men; however, creatine increases body mass by an additional 2.4 kg when compared with casein protein (91251). The reasons for these conflicting outcomes are not clear. Variable outcomes may be related to the population studied, the exercise regimen used, and the dietary advice provided to study participants. Although some have hypothesized that the timing of casein protein intake with respect to resistance training and/or sleep might alter effectiveness (111440), clinical research does not support this theory. Taking casein protein either before or after exercise does not appear to alter its effect on athletic performance (86071,91260).
• Cirrhosis. Preliminary clinical research in adults with stable cirrhosis who are unable to maintain adequate protein intake shows that taking a casein protein-based supplement (Ensure, Ross Laboratories) 20-60 grams daily for 4-6 days improves mental status when compared with taking a branched-chain amino acid supplement (91267).
• Chronic obstructive pulmonary disease (COPD). Muscle wasting is a common complication in patients with COPD. Preliminary clinical research in adults with COPD shows that taking casein protein 29.5 grams two hours prior to exercise increases protein synthesis when compared with whey protein (91263). Despite these findings, clinical research in adults with COPD shows that taking casein protein 20 grams daily for 8 weeks does not improve lung or muscle function when compared with baseline or whey protein. Furthermore, taking casein protein in conjunction with exercise training for 8 weeks is less effective than whey protein for improving endurance and fatigue in patients with COPD (86025).
• Diabetes. A clinical study in men with diabetes shows that drinking a beverage containing carbohydrates and casein protein 0.3 g/kg as a single dose increases plasma insulin levels and tends to lower levels of plasma glucose when compared with placebo. However, there was no difference between beverages containing intact casein protein or casein peptides (91276). Furthermore, a small clinical study in patients with diabetes shows that taking sodium caseinate (Saneigien) 15 grams by mouth as a single dose does not lower postprandial blood glucose, but seems to increase postprandial insulin levels by 36% and glucagon levels by about 14%, when compared with placebo (91299).
• Diarrhea. Preliminary clinical research in infants with prolonged dehydrating gastroenteritis shows that consuming formula containing casein protein, soy protein, or whey protein as 160 mL/kg daily reduces stool weight when compared with cow's milk formula (91646).
• Exercise-induced muscle soreness. Preliminary clinical research in cyclists shows that drinking 1000 mL of a supplement containing 5% casein protein and 2% carbohydrates does not improve time trial performance when compared with supplements containing either 2% carbohydrates and 5% whey protein, or 7% carbohydrates and no protein (86303). Additionally, preliminary clinical research in athletes performing intensive resistance training shows that taking a specific protein supplement (New Whey Liquid Protein, IDS Sports), containing casein protein, whey protein, collagen protein, and branched chain amino acids, 42 grams before and after exercise, does not reduce muscle soreness when compared with placebo (85945).
• Gastroesophageal reflux disease (GERD). Preliminary clinical research in neurologically impaired children with GERD shows that taking a specific casein protein formula (Osmolite, Ross Laboratories) is less effective than taking a specific whey protein formula (Peptamen, Clintec Nutrition) for reducing GERD episode frequency and duration. However, in infants with GERD, the effects of casein protein and whey protein appear to be similar (86231).
• Hepatic encephalopathy. Preliminary clinical research in adults with chronic hepatic encephalopathy shows that taking casein protein daily for 3 months is less effective than branched-chain amino acid therapy for improving symptoms of encephalopathy. Replacement of casein protein with branched-chain amino acid therapy after these 3 months led to improvements in encephalopathy symptoms (690).
• Hepatitis C. Preliminary clinical research in adults with chronic hepatitis C infection shows that taking casein protein 32 grams daily for 12 weeks improves health-related quality of life when compared with baseline. This improvement is similar to consuming soy protein 32 grams daily (91270).
• Hyperlipidemia. Clinical research assessing the effects of casein protein on blood lipids is conflicting. Casein protein is commonly used as a control treatment in clinical trials assessing other protein sources, including soy, barley, whey, and lupin. The majority of these studies show that casein protein has no effect on lipid levels in healthy and hyperlipidemic adults (842,2294,6412,8530,8963,75149,75219,75242,75276,75580)(91274,75240,75512,75540,75545,75615,86011,91273,91279,91281). However, some small preliminary clinical studies show that taking casein protein 35-40 grams daily for 6-12 weeks improves total cholesterol, low-density lipoprotein (LDL) cholesterol, and high density lipoprotein (HDL) cholesterol when compared with baseline in healthy and hyperlipidemic patients (8963,75149,91281). Also, casein protein seems to improve lipoprotein(a) levels, with some clinical studies showing lipoprotein(a) reductions of more than 50% with casein protein when compared with soy protein (75149,75219).
• Hypertension. The effects of casein protein on blood pressure are unclear. Clinical research in overweight and obese adults shows that taking casein protein 54 grams daily for 12 weeks reduces diastolic blood pressure, but not systolic blood pressure, by 3% when compared with a control diet (85981). Preliminary clinical research in obese, sedentary women shows that taking casein protein 30 grams daily, in conjunction with moderate intensity exercise for 4 weeks, reduces systolic blood pressure, but not diastolic blood pressure, by 7 mmHg compared with a control diet and moderate intensity exercise (91280).
• Obesity. Most clinical research shows that supplementation with casein protein does not reduce body weight or appetite when compared to control in overweight and obese patients (86011,86105,91286). However, some clinical research in overweight patients shows that consumption of a liquid snack containing 30 grams of casein or whey protein extends the duration of satiety compared with a carbohydrate snack (91284). Additionally, some research in obese patients shows that taking casein protein or whey protein 25 grams twice daily for 12 weeks improves weight maintenance after weight loss when compared with control (85932). Also, while some research suggests that whey protein is superior to casein protein for appetite suppression (91286), most clinical research shows that casein protein, whey protein, and soy protein have similar effects on weight loss and satiety (86011,91272,91284,91294). Preliminary clinical research in overweight children shows that drinking 1000 mL of a milk drink containing 35 grams of casein protein in place of water daily for 12 weeks increases body mass index when compared with water (86144). More evidence is needed to rate the effectiveness of casein protein for these uses.

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POSSIBLY EFFECTIVE

• Athletic performance. Oral creatine monohydrate seems to modestly improve rowing, jumping, and soccer performance. It is unclear if it is beneficial for sprinting, cycling, swimming, or tennis performance. Details: In competitive rowers, most clinical research shows that taking creatine 20 grams or 240-250 mg/kg daily for 5 days significantly improves aerobic and anaerobic performance (4605,4607,46569,46605,46833). Specifically, creatine decreases 1000-meter rowing time by 2.4 seconds and 2500-meter rowing time by 6.5 seconds and increases time to fatigue by 9.7 seconds when compared with placebo (4607,46605,46833). To improve rowing performance, creatine 20 grams (or 240-250 mg/kg) daily for 5 days has been used (4605,4607,46605,46833). Additionally, most clinical research shows that taking creatine 20-30 grams daily for 5-7 days improves jumping height by up to 6 cm when compared with placebo in active males (11331,13661,46626,46704), although some conflicting results exist (6924,46601). When compared with placebo, creatine also appears to improve spike jumping and block jumping in male volleyball players (46762), as well as peak and mean power of stationary roundhouse kicks in male trained taekwondo athletes (108333). In young male soccer players, preliminary clinical research shows that taking creatine 10 grams three times daily for 7 days can increase performance on a specific dribbling speed test by up to 2.8 seconds when compared with placebo (46626). In young female soccer players, preliminary clinical research shows that taking creatine 5 grams four times daily for 7 days followed by 5 grams daily for 5 weeks in conjunction with plyometric training modestly increases body mass index, jump and power performance, and repeated sprinting performance when compared with either plyometric training with placebo or standard soccer drills (95961). Research evaluating creatine supplementation for sprinting, cycling, high-intensity-interval training (HIIT), and swimming has been inconsistent. The reason for these mixed findings is unclear. A meta-analysis of small clinical trials shows that taking creatine decreases the peak oxygen uptake (VO2 max) during running and cycling, suggesting a worsening of aerobic fitness (108330). However, another meta-analysis of randomized controlled trials shows that taking creatine up to 20 grams orally daily for 3-7 days modestly improves mean power, but not peak power or fatigue, during repeated running or cycling sprint intervals when compared with placebo (112206). In addition, a meta-analysis of randomized clinical trials in trained athletes shows that taking creatine up to 20 grams orally daily for 5-42 days does not improve endurance running or cycling performance when compared with control (112214). A potential explanation for these conflicting results is that the studies failing to show an improvement are likely underpowered, with sample sizes of only 6-32 subjects (4582,4601). For instance, some small clinical trials show that taking creatine 20-30 grams daily for 5-7 days can improve sprint times by up to 3% and decrease time to exhaustion by up to 13% when compared with placebo in trained athletes (6924,11331,46558,46567,46626,46819); however, others show that taking creatine 20-25 grams daily for 3-7 days does not improve sprint velocity, 60-meter or 150-meter sprint times, or fatigue in these individuals (46603,46656,46797,46806,112216). In trained athletes, untrained yet healthy adults, and sedentary adults, some clinical research shows that taking creatine 10-35 grams daily for 4-7 days significantly improves power output, peak power, and fatigue indices while cycling (4591,4592,4593,4594,4602,4604,6926,10064,46522,46528) (46547,46568,46601,46614,46820); however, significant improvements in cycling performance with creatine are lacking in other studies (4582,4595,4596,4597,4598,4599,4600,4606,46520,46538) (46646). Similarly, in trained swimmers, some clinical research shows that creatine improves swimming performance (4601,4603,46600,46655,46725,46805), with a few studies reporting improvements of 1.3-2 seconds in 100-meter swim times when compared with placebo (46600,46725,46805). However, creatine does not improve 25-, 50-, or 100-meter swim performance in other trials (2106,4601,46798). To improve swimming performance, creatine 9-25 grams daily for 4-9 days has been used (4601,4603,46600,46655,46725,46805), with lower maintenance doses of 2.25-10 grams daily for 8-9 days used in some cases (4601,46600). Preliminary clinical research in trained tennis players shows that taking creatine 5 grams four times daily for 5 days or 0.3 grams/kg daily for 6 days followed by 0.03 grams/kg daily for 4 weeks does not appear to improve stroke power, stroke precision, serving speed, sprinting, or shuttle run time when compared with placebo (46536,46673). Taking creatine (Creapure, AlzChem AG) 0.3 grams/kg daily for 5 days, followed by 0.1 grams/kg daily for 23 days, while undergoing HITT 3 days each week does not improve physical performance outcomes when compared with placebo in healthy young females (95965). A preliminary clinical trial in elite female handball players shows that the beneficial effects of creatine monohydrate 0.3 grams/kg for 5 days followed by 0.03 grams/kg are not dependent on the time of day of supplementation (108332). Although this suggests that the circadian rhythm does not influence the ergogenic effect of creatine, this study was small and may have been underpowered to detect any differences. One clinical study in actively training firefighters shows that adding creatine 5 grams to daily supplemental protein and carbohydrates for 3 weeks reduces rescue and forcible entry times, but does not improve hose line advance, stair climb, or aerobic speed times, when compared with protein and carbohydrate supplementation alone (113673). One clinical study compared the efficacy of creatine monohydrate with that of creatine nitrate. At equivalent doses of 12 grams daily for 7 days, followed by 3 grams daily for 21 days, creatine nitrate and creatine monohydrate produce similar increases in fat-free mass, lean mass, and intramuscular creatine concentrations, and similar improvements in bench press lifting volume and average power output. The lower dose of creatine nitrate 6 grams daily for 7 days followed by 1.5 grams daily for 21 days does not demonstrate performance improvement benefits or result in increased intramuscular creatine (95959). In 2018, the International Society of Sports Nutrition (ISSN) recommended creatine monohydrate, but not creatine nitrate, as an ergogenic nutritional supplement for increasing athletic capacity and lean body mass (101009). Creatine has also been evaluated in combination with caffeine. A very small clinical study in healthy adult males shows that taking creatine 20 grams daily for a 5-day loading period and then adding caffeine 5 mg/kg daily for the next 3 days improves anaerobic power, but not anaerobic capacity, when compared with placebo (115980). Further research is needed to determine whether creatine is beneficial when taken with other erogenic ingredients.
• Cerebral creatine deficiency syndromes. Oral creatine seems to improve some symptoms of the cerebral creatine deficiency syndromes guanidinoacetate methyltransferase (GAMT) deficiency and arginine-glycine amidinotransferase (AGAT) deficiency. It is unclear if oral creatine is beneficial for creatine transporter defect. Details: Three inborn errors of metabolism, GAMT deficiency, AGAT deficiency, and creatine transporter defect, cause low cerebral creatine levels, resulting in mental retardation, seizures, autism, and movement disorders. In children with GAMT deficiency, taking creatine orally, 400-500 mg/kg daily for up to 8 years or 4-8 grams daily for up to 25 months, increases brain creatine levels and improves movement disorders and seizure frequency, but has little effect on intellectual ability (46722,46796,46804). Children with AGAT deficiency who take creatine 400-800 mg/kg daily for up to 8 years seem to have improved attention, language development, and academic performance (46584,46769). However, research in children up to 10 years of age with creatine transporter defect shows that taking a mixture of creatine, L-arginine, and glycine orally for 4-6 years does not increase brain creatine levels or improve motor or cognitive functioning (46757).
• Muscle strength. Oral creatine seems to modestly improve muscle strength. It is unclear if topical creatine is beneficial. Details: Pooled analyses of clinical trials assessing upper limb strength, lower limb strength, and body composition have evaluated creatine provided in typical loading doses of 20 grams daily or 0.3 grams/kg daily, although doses up to 26 grams daily have been used, in single or divided doses for 5-7 days (90323,90330,93626,93627,108316,108336,112213). Creatine maintenance doses ranged from 1.25-27 grams daily for up to 32 weeks (90323,90330,93626,93627,108316,108336,115978). In some studies, creatine doses of usually 0.1 grams/kg have been taken daily for up to 12 months in the absence of a loading dose. In others, creatine was taken only on training days (108316). Meta-analyses of research in the general adult population show that taking creatine with or without resistance training seems to improve handgrip strength, upper limb strength, and lower limb strength, with a small-to-moderate overall effect (93626,93627). In combination with resistance training, creatine also appears to be beneficial for upper and/or lower limb strength in older adults and those at risk for functional disability, although benefits on both domains have not been demonstrated in all analyses (90323,90330,108316,108336,115978). A meta-analysis limited to studies involving older females shows that while taking creatine with resistance training increases upper body strength when compared with placebo, improvements to lower body strength are limited to those studies providing supplementation for at least 24 weeks (108336). Meta-analyses of studies involving middle-aged adults, older adults, and those with chronic conditions at risk for functional disability show that creatine supplementation combined with resistance training appears to increase total body mass by 1 kg and lean body mass by 0.9-1.3 kg when compared with placebo (90323,90330,108316,115978). However, other meta-analyses of studies in older adults show no effect of creatine combined with resistance exercise on muscle mass or absolute fat mass, while effects on body fat percentage are inconsistent (90323,108335,108336,113671). While the analyses above provide a good estimate of creatine's effect on muscle strength, it is important to note that a large number of clinical trials assessing strength in patients taking creatine have been published. These studies included varying methodologies, small sample sizes, and a wide range of creatine doses, dosing times, and study durations. These differences may explain why some studies have found a benefit with creatine supplementation (2100,2101,4580,6015,6924,6928,10062,13661,46507,46510)(46523,46528,46550,46551,46561,46562,46567,46570,46581,46589)(46601,46613,46615,46618,46626,46628,46667,46709,46720,46725)(46761,46762,46801,46815,90321,90327,95958,95960,102162,103279)(104668,104670,108329,112213,112793), while others have not (4569,4570,4571,4572,4588,6183,46520,46539,46554,46569)(46579,46594,46656,46665,46673,95963,95967,95968,95969,102168,104669)(104671,108334). Topical creatine has also been evaluated. Applying 3.5 mL of a specific cream (Delivra, LivCorp Inc.) containing creatine 1% daily for 7 days moderately improves peak and average muscle power in healthy males when compared with a placebo cream. However, some study participants were also taking oral creatine monohydrate 7 grams three times daily and others were taking an oral placebo. An acute application of the cream at doses of 3.5 mL or 7 mL 30 minutes before exercise does not improve power (104669).
• Sarcopenia. When used for up to 12 weeks in combination with resistance training, oral creatine seems to modestly improve muscle strength in older adults. It is unclear if oral creatine is beneficial when used as a single dose or for more than 12 weeks. Details: Most research shows that taking creatine while taking part in a resistance training program can increase upper and/or lower body muscle strength in older adults (90323,90330,95958,102162,108316,108336). One meta-analysis of research in adults 50 years of age and older taking part in resistance training programs shows that creatine supplementation improves chest press strength with a moderate effect size, but does not improve leg press strength, when compared with placebo (90330). Also, another meta-analysis focusing on adults 45 years of age and older taking part in resistance training shows that creatine supplementation improves chest press strength by 1.74 kg and leg press strength by 3.25 kg when compared with placebo, with no effect on knee extension or biceps curl measurements (90323). A meta-analysis limited to studies involving older females shows that while taking creatine with resistance training increases upper body strength when compared with placebo, improvements to lower body strength are limited to those studies providing supplementation for at least 24 weeks (108336). However, some negative findings exist. Some clinical research in postmenopausal females with osteopenia shows that taking creatine monohydrate 1-3 grams (Creapure, AlzChem AG) daily for 1-2 years without participation in resistance training does not alter muscle function when compared with placebo (95969,102168). In addition, in healthy males aged 49-69 years, a small clinical trial shows that taking creatine monohydrate (Rivalus Inc.) 0.05 grams/kg twice daily, while undergoing supervised resistance training three days each week for one year, does not alter muscle strength when compared with placebo (104671). One clinical study shows that a single loading dose of creatine monohydrate 20 grams (Creapure, AlzCHem AG) taken 3 hours prior to exercise does not improve leg press or chest press muscle endurance in aging males (95968). Also, lower doses of creatine added to whey protein supplementation do not seem to be beneficial. One small study in adults 65 years or older shows that adding creatine monohydrate 2.5 grams twice daily along with whey protein 10 grams twice daily and resistance training for 14 weeks does not improve muscle function when compared with whey protein and resistance training alone (95966). Most research also suggests that creatine improves total muscle mass in older adults, although conflicting research exists. Some studies show that taking creatine while taking part in a resistance training program seems to increase muscle mass in older adults (90323,90330,108316,108329). Meta-analyses of studies involving middle-aged and older adults show that creatine supplementation combined with resistance training appears to increase total body mass by 1 kg and lean body mass by 0.9-1.3 kg when compared with placebo (90323,90330,108316). However, a meta-analysis of studies limited to older females shows that there was no effect of creatine on muscle mass (108336). Also, in healthy males aged 49-69 years, a small clinical trial shows that taking creatine monohydrate (Rivalus Inc.) 0.05 grams/kg twice daily, while undergoing supervised resistance training three days each week for one year, does not alter body composition when compared with placebo (104671). Despite these generally beneficial findings, significant decreases in fat mass following creatine supplementation in older adults are lacking, and effects on body fat percentage are inconsistent (90323,95958,108335).

POSSIBLY INEFFECTIVE

• Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease). Oral creatine does not seem to reduce ALS symptoms or increase survival. Details: Taking creatine orally, 5-10 grams daily for 9-16 months, or 20 grams daily for 5-7 days followed by 3-5 grams daily for 6 months, has no effect on disease progression, respiratory function decline, or survival in patients with ALS (11332,16389,46553,46574,46707). In one case series, some patients experienced temporary improvement in muscle strength while taking 20 grams daily during the first week, but this was not maintained (46553).
• Huntington disease. Oral creatine does not seem to reduce symptoms of this condition. Details: Taking creatine orally has no effect on motor function or symptom scores in people with Huntington disease (46598,46609,95957). Clinical research shows that taking creatine 5-40 grams daily (average dose of 31.6 grams) for 24 months does not improve total motor score or total functional capacity in patients with early manifest Huntington disease (95957).
• Osteopenia. Oral creatine does not seem to be beneficial for osteopenia. Details: In postmenopausal adults with osteopenia, taking creatine monohydrate (Creapure, AlzChem GmbH ) 1-3 grams daily for 1-2 years does not improve bone mineral density (BMD) when compared with placebo (95969,102168). Another clinical trial in postmenopausal adults with osteopenia or osteoporosis shows that taking creatine monohydrate (Probiotica) 20 grams daily for 5 days and then 5 grams daily for the next 23 weeks, with or without exercise training, does not improve bone mass when compared with placebo (90321). Also, a small clinical trial in older adults, most of which had osteopenia, shows that taking creatine monohydrate (Rivalus Inc.) 0.05 grams/kg twice daily in combination with resistance training for 12 months modestly improves some measures of bone area, but not BMD, when compared with placebo (108329). Other research has evaluated creatine in patients without a definite diagnosis of osteopenia. One study shows that taking creatine (Rivalus Inc.) 0.1 gram/kg daily for 12 months or creatine (Creapure AlzChem Trostberg GmbH) 0.1 grams/kg three times weekly does not affect BMD in adults age 50 and up taking part in resistance training (104671,104674). In contrast, a small clinical trial in postmenopausal patients shows that taking creatine monohydrate (Rivalus Inc.) 0.1 gram/kg daily for 12 months while undergoing a resistance training program has a small preventive effect on bone loss at the femoral neck, but not the hip or spine (104673). However, other preliminary clinical research in postmenopausal patients shows that taking creatine (Creapure, AlzChem AG) 0.14 grams/kg orally daily for 2 years does not improve BMD when compared with placebo (112219). Also, preliminary clinical research shows that taking creatine 0.3 grams/kg for 5 days and 0.07 grams/kg for the remainder of a 12-week resistance training session increases BMD in elderly males over 70 years (46664). More information is needed to determine if creatine is beneficial when used in combination with a resistance training program in older adults.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Age-related cognitive decline. It is unclear if oral creatine is beneficial for the treatment or prevention of age-related cognitive decline. Details: Population research in the US has found a positive association between dietary creatine intake and a specific measure of cognitive function, the WAIS III Digit Symbol Substitution Test (DSS). In addition, this measure of cognitive function was highest in individuals who consumed more than 0.95 grams daily (108331). However, clinical research is conflicting. A small clinical trial in older adults shows that taking creatine monohydrate (Creapure, Deguss AG) 5 grams four times daily for one week has modest beneficial effects on some measures of cognitive function, but not others, when compared with baseline or placebo (46686). Another small clinical trial shows that taking creatine monohydrate 5 grams four times daily for five days, and then 5 grams daily for a total of 4 weeks, does not improve cognitive function when compared with placebo (108339).
• Aging skin. Topical creatine 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 creatine 0.2%, guarana 0.4%, and glycerol 8% to the face daily for 6 weeks reduces wrinkles and skin sagging when compared to baseline (46766). Other research shows that a specific cream containing creatine 0.2% and folic acid 0.03% (Nivea Visage DNAage, Beiersdorf AG) reduces wrinkles and roughness and improves firmness of photo-aged skin when compared to baseline (46696). The effect of topical creatine alone on aging skin is unclear. Also, the validity of these findings is limited by the lack of a comparator group.
• Arsenic poisoning. It is unclear if oral creatine is beneficial in patients with arsenic poisoning. Details: Preliminary clinical research in adults regularly consuming well water that contains arsenic shows that taking creatine 3 grams orally daily for 12 weeks lowers the concentration of certain serum arsenic metabolites when compared with control (112212). Creatine has not been studied for management of acute arsenic poisoning.
• Chronic fatigue syndrome (CFS). It is unclear if oral creatine is beneficial for improving post-viral CFS. Details: A very small clinical study in adults who developed CFS after COVID-19 shows that taking creatine 4 grams with breakfast daily for 6 months improves body aches and the ability to concentrate, but does not affect fatigue levels or time to exhaustion, when compared with an inulin placebo (113487). Although many other CFS-related symptoms were evaluated in this study, no statistical methods were implemented to control for multiplicity, limiting the interpretation of any additional findings.
• Chronic kidney disease (CKD). It is unclear if oral creatine is beneficial in adults with CKD. Details: A small clinical study in adults with CKD undergoing hemodialysis shows that taking creatine monohydrate 20 grams daily for a week alternating with 5 grams daily for a week, for a total of 4 weeks, attenuates loss of lean body mass and reduces the malnutrition-inflammation score when compared with taking a maltodextrin control (102166). However, another very small clinical study evaluating the same regimen over a period of 12 months shows no improvement in malnutrition-inflammation score, body composition, strength, or endurance when compared with a maltodextrin control (115981).
• Chronic obstructive pulmonary disease (COPD). It is unclear if oral creatine is beneficial in patients with COPD. Details: One clinical study shows that taking creatine 22 grams daily for 5 days, then 3.76 grams daily for 6 weeks, does not improve pulmonary function or walking distance when compared with placebo (46699). Another study shows taking creatine 5.7 grams three times daily for 2 weeks, then once daily thereafter, improves patient self-assessment of lung function, but not exercise capacity, when compared with placebo (46658). A third study shows taking creatine 0.3 grams/kg for 7 days, then 0.07 grams/kg for 7 weeks, improves walking time, but not measures of lung function, when compared with placebo (46691). A meta-analysis of the results from these and other clinical trials shows that creatine does not improve exercise capacity, muscle strength, or quality of life in COPD patients. However, the studies analyzed were of varying quality, which may limit the validity of these findings (46740).
• Cognitive function. It is unclear if oral creatine is beneficial for improving cognitive function. Details: Some preliminary clinical research in healthy adults shows that taking creatine possibly improves some measures of cognitive performance, specifically short-term memory and reasoning. However, findings related to most measures of cognitive function are inconsistent (108340). Other clinical research in healthy adults shows that taking a specific creatine product (Creapure, AlzChem) 5-20 grams orally daily for 6 weeks does not improve cognitive function, abstract reasoning, or working memory when compared with placebo (112215,113486).
• Congestive heart failure (CHF). It is unclear if oral creatine is beneficial in patients with CHF. Details: Two very small clinical studies show that taking creatine orally 20 grams daily for 5-10 days improves skeletal muscle strength and endurance, but not ejection fraction or symptoms of CHF, when compared with placebo (4562,4563). Also a small clinical study in males with class II-IV heart failure shows that taking creatine 5 grams daily for 6 months does not improve exercise capacity or ejection fraction when compared with placebo (90328). However, it is possible that these small studies were inadequately powered to detect a difference in these clinical outcomes.
• Depression. It is unclear if oral creatine is beneficial for improving symptoms of depression. Details: Preliminary clinical research shows that taking creatine 5 grams daily for 8 weeks improves response to escitalopram in females with major depressive disorder. Hamilton Depression Rating Scale (HAM-D) scores decreased by 80% when compared to baseline in those receiving creatine plus escitalopram, compared to a decrease of only 63% in those taking placebo plus escitalopram (46777). However, the World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety Treatments (CANMAT) Taskforce recommend against use of creatine for depression until more conclusive data are generated (110318).
• Diabetes. It is unclear if oral creatine is beneficial for glycemic control. Details: A meta-analysis of preliminary clinical research shows that taking creatine does not affect levels of fasting blood glucose or measures of insulin resistance when compared with placebo (108338). However, most of the studies included in this analysis were not conducted in individuals with diabetes. In people with newly-diagnosed type 2 diabetes, preliminary clinical studies show a reduction in postprandial glucose levels after taking creatine 3-6 grams orally daily for 5 days (46732,46760). The studies show that creatine 3 grams once daily has similar effects to glyburide 3.5 mg daily, and that creatine 3 grams twice daily is similar to metformin 500 mg twice daily. The effects of treatment for longer than 5 days in patients with diabetes are unknown. However, in sedentary males without diabetes, taking creatine 10 grams daily for 3 months seems to improve glucose tolerance (46682).
• Fatigue. It is unclear if oral creatine is beneficial for cognitive fatigue prevention. Details: A small clinical study in healthy young adults with mental fatigue shows that taking creatine monohydrate (Sportimaxx) 20 grams daily for 7 days improves accuracy on prolonged cognitive tasks, but not cognitive measures that require a quick response, when compared with placebo (102170).
• Fibromyalgia. It is unclear if oral creatine is beneficial for improving exercise performance in patients with fibromyalgia. Details: Preliminary clinical research shows that taking creatine 5 grams orally four times daily for 5 days, followed by 5 grams daily for a total of 16 weeks, improves leg press strength by 10% and chest press strength by 8% when compared with placebo in patients with fibromyalgia. However, creatine supplementation does not appear to improve aerobic capacity, pain, sleep, quality of life, or cognitive function (90331).
• Gyrate atrophy. Anecdotal reports suggest that oral creatine may be beneficial in some patients with gyrate atrophy. Details: Gyrate atrophy of the choroid and retina is associated with elevated plasma ornithine levels, which inhibit creatine synthesis and result in muscle fiber atrophy and eye fundus damage. Left untreated, patients with this condition progressively lose their vision (4577,4578). A small case series suggests that taking creatine 1.5 grams daily for one year might slow eye damage and visual deterioration in some patients with this condition when compared to baseline (4578). The validity of this finding is limited by the small sample size and lack of a comparator group.
• Hereditary motor and sensory neuropathy. It is unclear if oral creatine is beneficial in patients with hereditary motor sensory neuropathies. Details: Preliminary clinical studies in people with hereditary motor sensory neuropathies, such as Charcot-Marie-Tooth Disease, suggest that taking creatine orally 5 grams daily for 1-12 weeks has no effect on muscle strength, endurance, or functional capacity when compared with placebo (46548,46630,46675,46695).
• HIV/AIDS-related wasting. It is unclear if oral creatine is beneficial in patients with muscle wasting associated with HIV. Details: A small clinical study shows that taking creatine orally 20 grams daily for 5 days, then 4.8 grams daily for 14 weeks, does not increase muscle mass or strength in patients with HIV with muscle wasting when compared with placebo (46718).
• Hyperhomocysteinemia. It is unclear if oral creatine is beneficial in patients with hyperhomocysteinemia. Details: Preliminary clinical research in strict vegan adults with hyperhomocysteinemia shows that taking micronized creatine monohydrate (Bioderm) 5 grams daily for 3 weeks reduces blood levels of homocysteine by 39% when compared with baseline (102169). The validity of this finding is limited by the lack of a comparator group.
• Inflammatory myopathies. It is unclear if oral creatine is beneficial in patients with idiopathic inflammatory myopathies. Details: Preliminary clinical research in people with dermatomyositis or polymyositis shows that taking creatine orally 20 grams daily for 8 days, followed by 3 grams daily for a total of 6 months, in addition to an exercise program, decreases aggregate functional performance time by around 7% and increases shoulder abduction and hip flexion strength when compared with placebo. However, no improvements in functional index or strength as measured by elbow flexion, knee extension, or dorsi flexion are reported (15520). Taking creatine does not seem to improve muscle strength or disease activity in patients aged 7-18 years with juvenile dermatomyositis. Preliminary clinical research shows that taking creatine (AlzChem) for 4 weeks to 6 months does not improve muscle strength or disease activity when compared with placebo. The doses used in this study were 150 mg/kg daily for children weighing up to 40 kg or 4.69 grams/m2 for those weighing over 40 kg (104672).
• Juvenile idiopathic arthritis (JIA). Oral creatine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In children with JIA, taking a specific supplement (Kre-Celazine; All American Pharmaceutical) containing creatine and fatty acids 750 mg twice daily for 30 days may improve pain and inflammation when compared to baseline. Pain scores were reduced to 0 or 1 in 81% of these patients, and laboratory measures of inflammation were normalized in nearly every patient (90322). However, the effect of creatine alone in JIA patients is unclear. Also, the validity of this study is limited by a lack of control group.
• McArdle disease. It is unclear if oral creatine is beneficial for this condition. Details: There is some preliminary clinical evidence that taking creatine orally, 150 mg/kg daily for 5 days, followed by 60 mg/kg daily for 5 weeks, improves frequency and/or severity of muscle pain in some, but not all, patients with McArdle disease (70). However, continuing with the higher dose of 150 mg/kg daily throughout the 5-week period seems to INCREASE muscle pain and exercise intolerance (46564).
• Memory. It is unclear if oral creatine is beneficial for improving memory. Details: A meta-analysis of randomized controlled trials in healthy adults shows that taking creatine 2.2-20 grams orally for 5 days to 24 weeks improves performance on certain memory tests when compared with placebo (112202). However, the validity of this study is limited by high heterogeneity. In addition, the statistical methods utilized in this meta-analysis are likely to increase the risk of false positive results (112203) and re-analysis using other methods failed to reproduce the significant effects of creatine (112204).
• Mitochondrial myopathies. It is unclear if oral creatine is beneficial in patients with mitochondrial myopathies. Details: Preliminary studies using creatine orally for mitochondrial myopathies, such as chronic progressive external ophthalmoplegia and Kearns-Sayre syndrome, show mixed results. Using 150 mg/kg daily for 6 weeks or 20 grams daily for 4 weeks does not improve muscle function, exercise performance, or ease of completing activities of daily living when compared with placebo (46529,46650,104675). However, one very small clinical study shows that taking creatine 5 grams twice daily for 14 days, then 2 grams twice daily for 7 days, improves some measures of strength during high-intensity anaerobic and aerobic exercise, but not low-intensity exercise, when compared with baseline (4565).
• Multiple sclerosis (MS). It is unclear if oral creatine is beneficial in patients with MS. Details: A very small clinical study shows that taking creatine 20 grams orally daily for 5 days does not improve exercise capacity in people with relapsing-remitting multiple sclerosis when compared with placebo (46599).
• Muscle breakdown. It is unclear if oral creatine is beneficial for muscle breakdown prevention. Details: Preliminary clinical research shows that taking creatine 5 grams four times daily for 7 days seems to help maintain muscle mass and reduce loss of muscle strength associated with immobilization by a cast in young males aged 18-25 years (46713).
• Muscle cramps. It is unclear if oral creatine is beneficial in patients with muscle cramps related to hemodialysis. Details: Preliminary clinical research shows that taking creatine 12 grams orally 5 minutes before hemodialysis sessions for 4 weeks reduces the frequency of muscle cramps by around 60%, from an average of 6.4 episodes to 2.6 episodes over the course of 4 weeks of dialysis. No reduction in muscle cramp frequency is reported with placebo in these patients (46582).
• Muscular dystrophy. The evidence for the use of oral creatine in patients with various forms of muscular dystrophy is conflicting. Details: Preliminary studies have assessed oral creatine in patients with muscular dystrophy, including Duchenne dystrophy, Becker dystrophy, facioscapulohumeral dystrophy, sarcoglycan-deficient limb girdle muscular dystrophy, and myotonic dystrophies. Although a meta-analysis of available research shows that there is a small benefit of creatine on muscle strength in patients with muscular dystrophies, results of individual clinical trials have been inconsistent (104675). Some preliminary clinical research shows that measures of muscle strength or fatigue are improved after 8-16 weeks of treatment with creatine 3-5 grams or 0.1 gram/kg daily (6182,46596,46629,46739). Also, subjective improvement in muscle strength occurs in some people taking creatine 20 grams daily for one week, followed by 5 grams daily for 8 weeks (46639). The ability to perform activities of daily living improves only modestly, if at all (6182,46629,46739). Despite these positive results, some conflicting results exist. Some studies show no improvement in muscle strength or functional capacity with doses of 5 grams daily for 17-26 weeks (46616,46657), or 10.6 grams daily for 10 days followed by 5.3 grams daily for a total of 8 weeks (46587). Also, a dose of 10 grams daily for 12 weeks does not appear to improve muscle strength, although it seems to improve myalgia in some patients (10654). The inconsistent results reported in patients with muscular dystrophy may be explained by the different types of muscular dystrophies, the varied methodologies, or the small number of patients assessed. Studies failing to show an improvement with creatine may be underpowered, with sample sizes of only 20-60 (10654,46657).
• Neonatal apnea. It is unclear if oral creatine is beneficial for neonatal apnea treatment. Details: A preliminary clinical study shows that giving creatine orally 200 mg/kg daily for 2 weeks to premature infants with a gestational age of less than 32 weeks does not improve signs or symptoms of apnea of prematurity when compared with placebo (46623).
• Osteoarthritis. It is unclear if oral creatine is beneficial in patients with osteoarthritis. Details: In patients with osteoarthritis of the knee, preliminary clinical research shows that taking creatine 20 grams orally daily for one week, followed by 5 grams daily for 11 weeks, in combination with strengthening exercises, modestly improves physical functioning as measured by the number of stand-ups performed from a standard-height chair in 30 seconds when compared with exercise alone. Stiffness, pain, and quality of life were also improved with creatine supplementation; however, it is unclear if these improvements were significant when compared with exercise alone (46753).
• Parkinson disease. It is unclear if oral creatine is beneficial in patients with this condition. Details: Preliminary clinical research shows that taking creatine 5 grams twice daily for 12-18 months decreases the rate of disease progression when compared with placebo in patients who have not started conventional medications for symptom control (15353,46703). However, preliminary clinical research in patients with more advanced disease who have already started conventional medications shows that taking creatine 20 grams daily for 6 days followed by 2 grams daily for 6 months, and then 4 grams daily for 18 months does not decrease overall progression of symptoms or the need to start symptomatic treatment. However, increases in dopamine agonist doses were 3-fold lower over the course of the study in patients receiving creatine when compared with placebo (15354).
• Peripheral arterial disease (PAD). It is unclear if oral creatine is beneficial in patients with PAD. Details: A small clinical trial in patients with PAD shows that taking creatine monohydrate (Creapure, AlzChem Trostberg GmbH) 5 grams four times daily for one week, followed by 5 grams daily for the next 7 weeks, does not improve functional capacity based on walking distance, upper body strength, or lower body strength, when compared with placebo (108337). This study may have been inadequately powered to detect differences between groups.
• Physical performance. It is unclear if oral creatine is beneficial for improving physical performance in older patients and those at risk for functional disability. Details: A meta-analysis of 15 clinical studies in healthy older adults and adults of any age with chronic disease who are at risk for functional disability shows that taking oral creatine, usually at a dose of 5 grams daily, for 5 days to 32 weeks, improves lower extremity physical function, upper limb and hand strength, and lean tissue mass when compared with control. Taking creatine does not improve lower limb strength, functional mobility, walking time, or aerobic capacity. Subgroup analyses suggest that improvements are greater with an extended duration of creatine use. Additionally, combining creatine with resistance training may increase benefits for lower extremity physical function, upper body strength, and lean tissue mass (115978). The heterogeneity of the included patient populations limits the practical applicability of these findings.
• Post-stroke fatigue. It is unclear if oral creatine is beneficial in patients with post-stroke fatigue. Details: Very preliminary clinical research in patients undergoing progressive resistance training after a stroke shows that taking a specific creatine supplement (Creapure, AlzChem Trostberg GmbH) 0.3 grams/kg orally daily for 7 days, followed by 0.1 grams/kg orally daily for a total of 10 weeks modestly improves 6-minute walk test distance when compared with placebo (112207).
• Postoperative recovery. Small clinical studies suggest that oral creatine may not improve recovery of muscle strength after knee surgery. Details: Preliminary clinical research shows that taking creatine 20 grams daily for 7 days, followed by 5 grams daily for 11 weeks, does not improve recovery of muscle strength after anterior cruciate ligament (ACL) reconstruction surgery in young adults when compared with placebo (46622). Other preliminary research shows that taking creatine 10 grams daily for 10 days before total knee arthroplasty, followed by 5 grams daily for 30 days after surgery, does not improve muscle strength or functional recovery when compared with placebo (46659). These studies are limited by small size and variability in patient population and supplementation regimen.
• Rett syndrome. It is unclear if oral creatine is beneficial in patients with this condition. Details: Preliminary clinical research shows that taking creatine 200 mg/kg daily for 6 months does not improve symptom scores when compared with placebo in patients aged 3-25 years with Rett syndrome (46759).
• Rheumatoid arthritis (RA). Oral creatine does not seem to improve disease activity in patients with RA, but it might improve muscle strength. Details: Clinical research in adults with RA shows that taking creatine increases lean muscle mass, total body mass, and muscle strength, but does not alter disease activity or improve strength or physical function, when compared with placebo or a control group (6929,95964). Creatine was taken as 5 grams four times daily for 5 days, followed by 3 grams daily for 12 weeks, in one study and 5 grams four times daily for 5 days, followed by 0.5 grams four times daily for 16 days, in the other study (6929).
• Schizophrenia. It is unclear if oral creatine is beneficial in adults with schizophrenia. Details: Preliminary clinical research shows that taking creatine orally, 3 grams daily for one month followed by 5 grams daily for 2 months, does not improve symptom control or cognitive function in adults with schizophrenia when compared with placebo (16390).
• Sleep deprivation. It is unclear if oral creatine is beneficial in adults who are subjected to sleep deprivation. Details: A small crossover study in healthy adults aged 20-28 years shows that taking a single oral dose of creatine 0.35 g/kg prior to sleep deprivation attenuates fatigue and cognitive decline over the next 7 hours when compared with placebo (115979).
• Spinal cord injury. It is unclear if oral creatine is beneficial in patients with spinal cord injury. Details: Preliminary clinical research shows that taking creatine orally, 20 grams daily for 7 days, increases exercise capacity by improving respiratory function in patients with spinal cord injury (cervical level C5-7) when compared with placebo (46563). However, other preliminary clinical research shows that patients with similar injuries taking creatine 10 grams twice daily for 6 days, followed by 5 grams daily, do not have significant improvements in wrist muscle or hand function (46660).
• Spinal muscular atrophy. It is unclear if oral creatine is beneficial in patients with spinal muscular atrophy. Details: Preliminary clinical research shows that children with type II or III spinal muscular atrophy do not benefit from taking creatine orally for 6 months (46841). Doses were 2 grams daily for children aged 2-5 years, and 5 grams daily for children aged 5-18 years.
• Traumatic brain injury (TBI). It is unclear if oral creatine is beneficial in children with a TBI. Details: In children and adolescents who have suffered a TBI, preliminary clinical research shows that taking creatine orally 0.4 grams/kg daily for 6 months reduces the duration of post-traumatic amnesia by 60 days. It also reduces the risk of headache by 88%, fatigue by 87%, and dizziness by 80% when compared with control. There is also a trend towards reduced duration of intubation and total time in the intensive care unit or hospital (46694). More evidence is needed to rate creatine for these uses.

(Read more about CREATINE)

POSSIBLY EFFECTIVE

• Hypercholesterolemia. Oral Ecklonia cava seems to reduce levels of low-density lipoprotein (LDL) cholesterol. Details: Clinical research in patients with hypercholesterolemia shows that taking Ecklonia cava polyphenols (Botamedi Inc.) 200 mg twice daily for 12 weeks reduces LDL cholesterol by 11% when compared with taking placebo (106336). Also, preliminary clinical research in patients with hypercholesterolemia shows that taking a different Ecklonia cava polyphenol extract (Seapolynol, Livechem, Inc.) 400 mg once daily for 12 weeks reduces levels of LDL cholesterol by 9% when compared with baseline (106335). In overweight adults, many with hypercholesterolemia, clinical research shows that taking Ecklonia cava polyphenols 72 mg or 144 mg daily for 12 weeks reduces LDL cholesterol levels by 10% and 14%, respectively, when compared with placebo (96376). Taking Ecklonia cava does not seem to increase levels of high-density lipoprotein (HDL) cholesterol or reduce levels of triglycerides (96376,106335,106336).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Asthma. Although there is interest in using oral Ecklonia cava for asthma, there is insufficient reliable information about the clinical effects of Ecklonia cava for this condition.
• Athletic performance. It is unclear if oral Ecklonia cava is beneficial for improving athletic performance. Details: Preliminary clinical research in male college students shows that taking Ecklonia cava polyphenols 72 mg as part of 180 mL of a sport drink 30 minutes before exercise increases the time to exhaustion by approximately 2.4 minutes when compared with the sport drink alone (96377).
• Cancer. Although there is interest in using oral Ecklonia cava for cancer, there is insufficient reliable information about the clinical effects of Ecklonia cava for this condition.
• Cardiovascular disease (CVD). Although there is interest in using oral Ecklonia cava for CVD, there is insufficient reliable information about the clinical effects of Ecklonia cava for this condition.
• Diabetes. Although there is interest in using oral Ecklonia cava for diabetes, there is insufficient reliable information about the clinical effects of Ecklonia cava for this condition.
• Erectile dysfunction (ED). Although there is interest in using oral Ecklonia cava for ED, there is insufficient reliable information about the clinical effects of Ecklonia cava for this condition.
• Fatigue. Although there is interest in using oral Ecklonia cava for various causes of fatigue, there is insufficient reliable information about the clinical effects of Ecklonia cava for this use.
• Fibromyalgia. Although there is interest in using oral Ecklonia cava for fibromyalgia, there is insufficient reliable information about the clinical effects of Ecklonia cava for this use.
• Impaired glucose tolerance (prediabetes). It is unclear if oral Ecklonia cava is beneficial for prediabetes. Details: Preliminary clinical research in adults with prediabetes shows that taking a specific Ecklonia cava extract (AG-dieckol, Aqua Green Tech Co.) 500 mg three times daily for 12 weeks reduces postprandial glucose levels by 5.5%, compared with a small increase in those taking placebo. However, Ecklonia cava extract did not improve fasting blood glucose, insulin sensitivity, or glycated hemoglobin (HbA1c) when compared with placebo (96375).
• Insomnia. Although there is interest in using oral Ecklonia cava for insomnia, there is insufficient reliable information about the clinical effects of Ecklonia cava for this use.
• Male infertility. Although there is interest in using oral Ecklonia cava for male infertility, there is insufficient reliable information about the clinical effects of Ecklonia cava for this condition.
• Metabolic syndrome. Although there is interest in using oral Ecklonia cava for metabolic syndrome, there is insufficient reliable information about the clinical effects of Ecklonia cava for this condition.
• Neuropathic pain. Although there is interest in using oral Ecklonia cava for neuropathic pain, there is insufficient reliable information about the clinical effects of Ecklonia cava for this condition.
• Obesity. It is unclear if oral Ecklonia cava polyphenols improve weight loss or body composition; the available research is conflicting. Details: A small clinical trial in individuals with a body mass index (BMI) between 25 kg/m2 and 30 kg/m2 shows that taking Ecklonia cava polyphenols (Seapolynol, Botamedi Inc.) 180 mg twice daily for 12 weeks does not reduce body weight, BMI, body fat percentage, or low-density lipoprotein (LDL) cholesterol levels when compared with placebo. However, in a sub-group of patients with abdominal obesity, Ecklonia cava modestly reduced total adipose tissue levels and fat mass and increased skeletal muscle mass when compared with placebo. All patients in this study increased physical activity and consumed a diet with a mild caloric restriction (106334). Conversely, other clinical research in a similar population shows that taking Ecklonia cava polyphenols 144 mg daily for 12 weeks reduces body fat ratio by 7% and body weight, BMI, and waist circumference by 2%. These improvements were statistically significant when compared with placebo. Furthermore, taking Ecklonia cava polyphenols 72 mg or 144 mg daily reduces LDL cholesterol levels by 10% and 14%, respectively, when compared with placebo (96376). The reasons for these discrepant findings are unclear.
• Osteoarthritis. Although there is interest in using oral Ecklonia cava for osteoarthritis, there is insufficient reliable information about the clinical effects of Ecklonia cava for this condition.
• Radiation exposure. Although there is interest in using oral Ecklonia cava for radiation exposure due to its iodine content, there is insufficient reliable information about the clinical effects of Ecklonia cava for this use. More evidence is needed to rate Ecklonia cava for these uses.

(Read more about ECKLONIA CAVA)

POSSIBLY EFFECTIVE

• Diabetes. Oral fenugreek seed seems to improve glycemic control in type 2 diabetes. Details: Meta-analyses of 10-14 clinical trials in patients with type 2 diabetes or other metabolic conditions show that taking fenugreek lowers fasting glucose by approximately 14-23 mg/dL, 2-hour postprandial glucose by 21-23 mg/dL, and glycated hemoglobin (HbA1c) by 0.6-1.2% when compared with placebo. The most effective doses and formulations seem to include powdered seed or debitterized seed powder 5-100 grams daily, taken as capsules or added to meals, for up to 3 years or seed hydroalcoholic extract about 1 gram daily for up to 2 months (90112,96065,105016,111503,113499,112120). The validity of these effects is limited by high heterogeneity and low quality in the included studies. Most research also shows that fenugreek seed lowers total cholesterol levels and triglycerides in patients with diabetes, but has inconsistent effects on low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol (96065,102252). Some research shows that taking fenugreek in combination with other ingredients also seems to improve glycemic indices in people with diabetes. These combination products have combined fenugreek with guar gum and gymnema (10284) or millets and legumes (9784). Limited research has also evaluated fenugreek in type 1 diabetes. In one small clinical study, taking 50 grams of defatted fenugreek seed powder twice daily with meals for 10 days reduced 24-hour urine glucose levels by 54% when compared to baseline (622). The validity of this finding is limited by the lack of a comparator group.
• Dysmenorrhea. Oral fenugreek seed might help to reduce menstrual pain. Details: Clinical research in adults with moderate to severe dysmenorrhea shows that taking fenugreek seed powder 1800-2700 mg three times daily for the first 3 days of menstruation followed by 900 mg three times daily for the remainder of two menstrual cycles reduces pain severity when compared with placebo. Patients taking fenugreek seed powder showed a reduction in pain severity of 3.22, compared with a reduction of only 0.18 in the placebo group (90116).
• Sexual arousal. Oral fenugreek seed might help to improve sexual arousal. Details: Clinical research shows that taking a specific fenugreek seed extract (Testofen, Gencor Pacific Ltd) 600 mg daily for 12 weeks increases sexual function by 15% over baseline, compared with no change in the placebo group; the main benefits were in sexual arousal and drive. Morning erection and sexual frequency also improve by 2- to 3-fold (93419). Another clinical study in healthy males shows that taking the same fenugreek seed extract 600 mg daily in combination with magnesium 34 mg, zinc 30 mg, and vitamin B6 10 mg for 6 weeks, improves a composite of symptoms such as sexual cognition, sexual arousal, sexual behavior, and orgasm. The overall improvement in the composite score was 23%, compared with a worsening in the placebo group (93421).
• Sexual dysfunction. Oral fenugreek seed extract might help to improve sexual dysfunction. Details: Clinical research shows that taking a specific fenugreek seed extract (Libifem, Gencor Pacific Ltd.) 300 mg twice daily for two menstrual cycles improves sexual function in healthy pre-menopausal adults with low sex drive. In one clinical trial, overall improvement based on a composite of symptoms was 26% in the fenugreek group, compared with only 2% in the placebo group. Individual scores for sexual cognition, arousal, behavior, drive, and orgasm were all improved. Patients taking fenugreek also had an increased frequency of sexual activity from 1-2 times per month to once per week, compared to no change in the placebo group (93420). Other clinical research in males aged 35-60 years with symptomatic hypogonadism shows that taking a specific fenugreek seed extract (Furosap; Chemical Resources) 500 mg daily after breakfast for 12 weeks improves sexual arousal, mental alertness, and mood when compared with baseline. This fenugreek seed extract was fortified with 20% protodioscin; the other constituents were not specified (108700). The validity of this finding is limited by the lack of comparator group.

POSSIBLY INEFFECTIVE

• Benign prostatic hyperplasia (BPH). Oral fenugreek extract does not seem to improve BPH symptoms. Details: A clinical study in healthy adults with BPH shows that taking a specific fenugreek extract (Testofen, Bluegum Pharmaceuticals) 300 mg twice daily for 12 weeks does not improve BPH symptoms when compared with placebo (102253).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alopecia areata. Although there is interest in using oral fenugreek for alopecia areata, there is insufficient reliable information about the clinical effects of fenugreek for this condition.
• Alzheimer disease. It is unclear if oral fenugreek seed extract is beneficial for Alzheimer disease. Details: A moderate-sized study in adults with mild to moderate Alzheimer disease shows that taking fenugreek seed extract 5 mL daily for 4 months modestly improves memory but does not improve depression or quality of life measures when compared with placebo (113498).
• Athletic performance. It is unclear if oral fenugreek seed is beneficial for improving athletic performance. Details: Two small clinical studies in resistance-trained young males shows that taking a fenugreek supplement (AI or Torabolic, Indus Biotech) 500 mg daily for 8 weeks in addition to training 4 days every week, decreases body fat by about 2% and sometimes increases leg and bench press performance, but does not improve power, when compared with placebo (18352,18353). Another small study in healthy males undergoing strength training also shows that taking a specific fenugreek extract enriched in furostanol glycosides (Fenu-FG, Indus Biotech Private Limited) 300 mg twice daily for 8 weeks might help to modestly increase the number of bench press repetitions, but not overall strength, when compared with placebo (93423).
• Atopic dermatitis (eczema). Although there is interest in using topical fenugreek for eczema, there is insufficient reliable information about the clinical effects of fenugreek for this condition.
• Cough. Although there is interest in using oral fenugreek for cough, there is insufficient reliable information about the clinical effects of fenugreek for this purpose.
• Gastroesophageal reflux disease (GERD). It is unclear if oral fenugreek fiber is beneficial for improving heartburn symptoms. Details: A small clinical study in patients with frequent heartburn shows that taking a specific fenugreek fiber product (FenuLife, Frutarom Belgium), 2 grams twice daily 30 minutes before the two biggest meals of the day, improves heartburn after one week of treatment and continuing through the 2-week study period. Fenugreek seemed to be similarly effective to ranitidine 75 mg twice daily (17372).
• Gout. Although there is interest in using topical fenugreek for gout, there is insufficient reliable information about the clinical effects of fenugreek for this condition.
• Hyperlipidemia. Small clinical studies suggest that oral fenugreek supplements might be beneficial for improving lipid levels. Details: Overall, fenugreek powdered seed seems to modestly reduce lipid levels in people with or without hyperlipidemia; however, most studies have been low-quality, small, and exploratory. Meta-analyses of these studies show that fenugreek reduces total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides, and increases high-density lipoprotein (HDL) cholesterol (103283,103284). Powdered fenugreek seed has been studied in doses of 0.5-100 grams daily for 10 days to 3 years. While some studies show modest improvement, others show no benefit (622,7389,9783,18359,18361,18362,102252,103283,103284,113497).
• Hypertension. Analysis of small clinical studies suggests that oral fenugreek might slightly improve systolic blood pressure (SBP). Details: A meta-analysis of 6 small clinical studies in healthy adults or those with diabetes, prediabetes, or metabolic syndrome shows that taking fenugreek seed 0.5-50 grams daily for 6-144 weeks reduces SBP by 3.5 mmHg but does not improve diastolic blood pressure (DBP) when compared with placebo. However, subgroup analysis suggests that taking fenugreek at a dose of 15 grams or more daily or for a duration of 12 weeks or less modestly reduces DBP (112110).
• Impaired glucose tolerance (prediabetes). It is unclear if oral fenugreek is beneficial in patients with prediabetes. Details: A small clinical study in adults with prediabetes shows that taking a specific fenugreek seed extract (Trigogen, Gencor Pacific Ltd.) 250 mg twice daily for 12 weeks reduces fasting blood glucose and postprandial blood glucose but not glycated hemoglobin (HbA1c), fasting insulin, or postprandial insulin when compared with placebo (113497). Another small clinical trial in patients with prediabetes shows that taking fenugreek seed extract 200 mg, bergamot extract 500 mg, and olive leaf extract 100 mg daily for 6 months does not improve glycated hemoglobin or fasting blood glucose when compared with placebo (102251).
• Joint pain. Although there is interest in using oral fenugreek for joint pain, there is insufficient reliable information about the clinical effects of fenugreek for this condition.
• Lactation. Small clinical studies suggest that oral fenugreek, either as a supplement or tea, might increase lactation. Details: A network meta-analysis of 4 small clinical trials shows that taking fenugreek shortly after delivery may modestly increase breast milk production when compared with placebo. Patients in the included studies took fenugreek 1-2 grams as capsules or tea up to 3 times daily for 21-244 days. In most cases, fenugreek treatment was initiated one or two days after delivery. However, fenugreek might be less beneficial for breast milk production when compared with the natural ingredients Indian borage or palm date (96067). Fenugreek has also been used in combination with other ingredients. A small clinical study suggests that drinking a specific herbal tea containing fenugreek. hibiscus, fennel, rooibos, vervain, raspberry, goat's rue, and fennel oil (Humana Still-Tee, Humana, Germany) 200 mL three times daily modestly increases milk production when compared with placebo (22569). Another study in exclusively breastfeeding parents of 2-month-old infants shows that eating lactation cookies containing fenugreek, oatmeal, brewer's yeast, and flaxseed meal daily for 30 days do not improve milk production, perceived insufficiency, or breastfeeding self-efficacy when compared with control (112116).
• Male infertility. It is unclear if oral fenugreek seed is beneficial for improving sperm quality in males with infertility. Details: A small clinical study in healthy male patients ages 20-30 years with oligospermia shows that taking fenugreek seed oil 12 macro drops orally three times daily for 4 months improves sperm count from 6.2 million to 20.1 million, increases sperm motility from 43% to 61%, and reduces sperm abnormality from 68% to 53% when compared with baseline. However, taking the remaining fenugreek seed components 10 grams three times daily for 4 months does not seem to have this effect (90119). The validity of this finding is limited by the lack of a comparator group.
• Menopausal symptoms. It is unclear if oral fenugreek seed is beneficial for improving menopausal symptoms. Details: A small clinical study in perimenopausal patients shows that taking a specific fenugreek seed extract (FenuSMART) 250 mg, standardized to protodioscin 10.3%, trigonelline 3.1%, and total saponin 42.6%, twice daily with meals for 42 days does not improve menopausal symptoms when compared with placebo. However, there was a non-significant trend to reduced hot flashes, night sweats, depression, and insomnia in the treatment group (105000). This study was funded by the supplement manufacturer.
• Metabolic syndrome. It is unclear if oral fenugreek seed is beneficial for metabolic syndrome. Details: A meta-analysis of 29 small clinical studies in healthy adults or those with type 2 diabetes or other metabolic conditions shows that taking fenugreek at doses ranging from 25 mg to 60 grams daily for up to 144 weeks reduces fasting blood glucose by 17 mg/dL, triglycerides by 20 mg/dL, waist circumference by 2.5 cm, and systolic blood pressure by 3.5 mmHg and increases high-density lipoprotein cholesterol by 3.5 mg/dL when compared with control. However, no effect was found on diastolic blood pressure or body mass index (113500).
• Muscle strength. It is unclear if oral fenugreek seed is beneficial for increasing muscle strength. Details: A small study in healthy, active males shows that taking fenugreek seed extract 400 mg or 500 mg daily for 60 days increases grip strength when compared with placebo (103285).
• Myalgia. Although there is interest in using topical fenugreek for myalgia, there is insufficient reliable information about the clinical effects of fenugreek for this condition.
• Obesity. Small clinical studies suggest that oral fenugreek seed or fiber may increase satiety and decrease caloric intake. Details: Two small clinical studies in overweight and normal weight males shows that taking fenugreek seed extract modestly reduces daily fat intake. At a dose of 392 mg three times daily for 2-6 weeks, fat intake is reduced by 13% to 17%. However, a lower dose of 196 mg three times daily appears to be ineffective. Neither of the doses affect weight, appetite, or satiety (18348,18349). Another small clinical study in obese adults shows that adding 8 grams of fenugreek fiber powder (FenuLife, Frutarom Inc) to a low-calorie beverage increases feelings of satiety and decreases hunger and lunchtime food intake. A lower dose of 4 grams appears to be less effective for reducing hunger but was considered to be more palatable (18350).
• Parkinson disease. It is unclear if oral fenugreek seed is beneficial for Parkinson disease symptoms. Details: One small clinical study in patients with Parkinson disease who are also using levodopa shows that taking fenugreek seed extract (Indus Biotech Private Limited, Pune) 300 mg twice daily for 6 months does not seem to improve behavioral or motor symptoms when compared with placebo (90113).
• Peptic ulcers. Although there is interest in using oral fenugreek for peptic ulcers, there is insufficient reliable information about the clinical effects of fenugreek for this condition.
• Polycystic ovary syndrome (PCOS). It is unclear if oral fenugreek seed is beneficial for PCOS. Details: A small clinical study in adults with symptomatic PCOS shows that adding a specific fenugreek seed extract (Goldarou Pharmaceutical Co.) 500 mg twice daily to metformin for 8 weeks does not improve insulin resistance, insulin sensitivity, or other symptoms when compared with placebo and metformin (90117). However, other small clinical studies in adults with PCOS show that taking another specific fenugreek seed extract (Furocyst, Cepham Inc.) 1000 mg, enriched with 40% furostanolic saponins, daily for 90 days is associated with a reduction in ovarian cyst size in 46% of patients, complete dissolution in 36% of patients, normalization of menstrual cycles in 71% to 80% of patients, and subsequent pregnancy in 12% of patients. Further, this extract appears to reduce mean cyst size by 42% to 45%, the number of cysts by 38%, ovary volume by 24% to 40%, and hirsutism by 27% while reducing luteinizing hormone, follicle-stimulating hormone, free testosterone, and prolactin and improving liver function and the severity of PCOS-associated ailments including insulin resistance and dyslipidemia (93422,112112,113502). The validity of some of these findings is limited by the lack of a comparator group. Furthermore, this study was funded by the supplement manufacturer.
• Vaginitis. There is limited evidence on the topical use of fenugreek cream in patients with atrophic vaginitis. Details: One small clinical study in postmenopausal patients with atrophic vaginitis shows that administration of 0.5 grams of fenugreek 5% cream intravaginally twice weekly for 12 weeks reduces symptoms of atrophic vaginitis and reduces vaginal pH when compared to baseline. However, fenugreek was not as effective as vaginal cream containing conjugated estrogens (103286). Another small clinical study in postmenopausal patients with vaginal atrophy shows that applying a fenugreek cream 5% intravaginally daily for 8 weeks seems to reduce dyspareunia and vaginal dryness and increase vaginal maturation when compared with a placebo cream (105023).
• Wound healing. Although there is interest in using topical fenugreek for wound healing, there is insufficient reliable information about the clinical effects of fenugreek for this purpose. More evidence is needed to rate fenugreek for these uses.

(Read more about FENUGREEK)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aging skin. Although there has been interest in using topical Fucus vesiculosus for aging skin, there is insufficient reliable information about the clinical effects of Fucus vesiculosus for this purpose.
• Cardiovascular disease (CVD). Although there has been interest in using oral Fucus vesiculosus for CVD, including atherosclerosis and hypertension, there is insufficient reliable information about the clinical effects of Fucus vesiculosus for this purpose.
• Constipation. Although there has been interest in using oral Fucus vesiculosus for constipation, there is insufficient reliable information about the clinical effects of Fucus vesiculosus for this purpose.
• Diarrhea. Although there has been interest in using oral Fucus vesiculosus for diarrhea, there is insufficient reliable information about the clinical effects of Fucus vesiculosus for this purpose.
• Dyspepsia. Although there has been interest in using oral Fucus vesiculosus for dyspepsia, there is insufficient reliable information about the clinical effects of Fucus vesiculosus for this purpose.
• Hypercholesterolemia. It is unclear if oral Fucus vesiculosus is beneficial in hypercholesterolemia. Details: A small clinical study in patients with obesity or overweight and low-density lipoprotein (LDL) cholesterol levels exceeding 77 mg/dL shows that taking a polyphenol-rich extract of Fucus vesiculosus (Maritech Synergy, Marinova) 2000 mg, providing 560 mg of polyphenols, daily for 12 weeks increases levels of high-density lipoprotein (HDL) cholesterol by 10%, compared with 2% in those receiving placebo. No differences were observed for total cholesterol, LDL cholesterol, or triglycerides (106723).
• Hypothyroidism. Although there has been interest in using oral Fucus vesiculosus for hypothyroidism, there is insufficient reliable information about the clinical effects of Fucus vesiculosus for this purpose.
• Impaired glucose tolerance (prediabetes). Oral Fucus vesiculosus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with prediabetes and dysglycemia shows that taking a specific product (Gdue, Aesculapius), containing extracts of Fucus vesiculosus and Ascophyllum nodosum in a 5:95 ratio along with chromium picolinate three times daily for 6 months reduces fasting and postprandial blood glucose, glycated hemoglobin (HbA1c), insulin, and insulin resistance when compared with placebo (100847). It is unclear if these effects are due to Fucus vesiculosus, other ingredients, or the combination. Another small clinical study in adults with prediabetes and also overweight or obese shows that taking a specific product (InSea2, InnoVactiv Inc.) containing 500 mg of Fucus vesiculosus and Ascophyllum nodosum extracts daily for 12 weeks reduces postprandial blood glucose but does not improve fasting blood glucose, HbA1c, body weight, lipids, or blood pressure when compared with placebo (110560).
• Iodine deficiency. Although there has been interest in using oral Fucus vesiculosus for iodine deficiency and goiter, there is insufficient reliable information about the clinical effects of Fucus vesiculosus for this purpose.
• Metabolic syndrome. Oral Fucus vesiculosus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Observational research in adults with one or more components of metabolic syndrome has found that taking a specific combination product (Gdue, Aesculapius) containing extracts of Fucus vesiculosus and Ascophyllum nodosum in a 5:95 ratio along with chromium picolinate two to three times daily with meals for around 6 months is associated with reductions in body weight by 7.3 kg, waist circumference by 7.5 cm, fasting blood glucose by 16 mg/dL, glycated hemoglobin (HbA1c) by 0.55%, systolic blood pressure by 7 mmHg, diastolic blood pressure by 4 mmHg, low-density lipoprotein (LDL) cholesterol by 18 mg/dL, and 10-year cardiovascular risk scores by 1.8% when compared to baseline (110559). It is unclear if these effects are due to Fucus vesiculosus, other ingredients, or the combination. Further, the validity of these findings is limited by a lack of control group.
• Obesity. Oral Fucus vesiculosus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in moderately overweight females shows that seaweeds such as Fucus vesiculosus, taken in combination with lecithin and vitamins for up to 2 years, do not result in sustained weight loss when compared to baseline (13663). Another small clinical study in adults with prediabetes and also overweight or obese shows that taking a specific product (InSea2, InnoVactiv Inc.) containing 500 mg of Fucus vesiculosus and Ascophyllum nodosum extracts daily for 12 weeks does not reduce body weight, body mass index (BMI), body fat, lipids, blood pressure, or measures of glycemic control when compared with placebo (110560).
• Wound healing. Although there has been interest in using topical Fucus vesiculosus for wound healing, there is insufficient reliable information about the clinical effects of Fucus vesiculosus for this purpose. More evidence is needed to rate Fucus vesiculosus for these uses.

(Read more about FUCUS VESICULOSUS)

POSSIBLY EFFECTIVE

• Schizophrenia. Oral glycine may improve negative, but not positive, symptoms of schizophrenia when used as adjunct to therapy with typical antipsychotics in patients resistant to monotherapy. However, glycine does not seem to provide additional benefit when used with clozapine. Details: Some small clinical trials show that taking glycine 0.4-0.8 grams/kg daily in divided doses along with conventional treatment seems to reduce negative symptoms of schizophrenia in patients that are resistant to monotherapy with typical antipsychotics such as thioridazine, haloperidol, and perphenazine (10250,10251,10252,98591). However, when used with the atypical antipsychotic clozapine, glycine appears to have a negligible effect on or worsen symptoms of schizophrenia (10253,11321). Additionally, glycine does not seem to improve positive symptoms of schizophrenia (10250,10251,10252,98591).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• 3-phosphoglycerate dehydrogenase (3-PGDH) deficiency. It is unclear if oral glycine is beneficial in patients with 3-PGDH deficiency. Details: A case series describing two patients with 3-PGDH deficiency who did not respond to serine supplementation suggests that taking oral glycine 0.2 grams/kg daily along with serine might reduce seizure frequency. 3-PGDH deficiency is a rare condition in which serine is not synthesized properly (10254).
• Aging. Oral glycine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in adults aged 61-80 years with overweight or obesity shows that taking a specific combination product (GlyNAC), providing glycine 100 mg/kg and N-acetyl cysteine 100 mg/kg, daily for 16 weeks improves some markers associated with aging, including glutathione levels, oxidative stress, mitochondrial impairment, genomic damage, inflammation, and endothelial dysfunction, when compared to baseline. Improvements in these measures were lacking in the placebo group (110624). The validity of these findings is limited by a lack of statistical comparison between groups. Also, it is unclear if these effects are due to glycine, N-acetyl cysteine, or the combination.
• Attention deficit-hyperactivity disorder (ADHD). Although there has been interest in using oral glycine for ADHD, there is insufficient reliable information about the clinical effects of glycine for this purpose.
• Benign prostatic hyperplasia (BPH). Although there has been interest in using oral glycine for BPH, there is insufficient reliable information about the clinical effects of glycine for this purpose.
• Cognitive function. Small clinical studies suggest that oral glycine may modestly improve memory and cognitive function in some patients. Details: Two small clinical studies in healthy young adults and adults with psychosis risk syndrome show that taking glycine 0.2-0.4 grams/kg once or twice daily for up to 24 weeks may improve some measures of memory and cognitive performance when compared with baseline or placebo (11322,92321).
• Cystic fibrosis. It is unclear if oral glycine is beneficial in patients with cystic fibrosis. Details: A small clinical trial in patients 6-23 years of age with cystic fibrosis shows that taking glycine 0.5 grams/kg daily for 8 weeks modestly improves some measures of lung function and reduces sputum and dyspnea by 15% and 23%, respectively, when compared with placebo. However, taking glycine does not improve appetite or energy (98583).
• Gout. Oral glycine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study in patients with mild hyperuricemia shows that taking a powder containing glycine 3 grams and L-tryptophan 0.2 grams nightly at bedtime for 6 weeks reduces serum uric acid levels by 0.3 mg/dL when compared with placebo. Improvements also occurred in the subgroup of patients with uric acid levels greater than 7 mg/dL, the point at which symptoms of gout can occur (99883). However, it is unclear if this combination improves gout-related pain. Also, it is not clear if these findings are due to glycine, L-tryptophan, or the combination.
• Insomnia. Small clinical studies suggest that oral glycine may modestly improve sleep quality and daytime feelings of fatigue in patients with poor sleep quality or a restricted sleep duration. Details: Two very small studies in patients who have reported a subjective reduction in sleep quality show that taking glycine 3 grams one hour before bedtime for 2-4 days improves overall sleep quality and sleep efficacy when compared with placebo (92318,92320). Another very small clinical study in healthy males shows that taking glycine 3 grams 30 minutes before bedtime for 3 nights, during which time sleep duration is restricted by 25%, modestly reduces feelings of fatigue after the first night, but not after the third night, when compared with placebo (92316). The effects of glycine on sleep measures have also been evaluated in combination with other ingredients. A very small crossover study in healthy adults without documented sleep disorders shows that taking a combination product containing glycine 3000 mg, tryptophan 1000 mg, magnesium 300 mg, tart cherry powder 220 mg, and L-theanine 200 mg before bed for 3 nights reduces sleep onset latency, increases total sleep time, increases sleep efficiency, and reduces morning sleepiness when compared with placebo (111184). It is unclear if these effects are due to glycine, other ingredients, or the combination.
• Isovaleric acidemia. Although there has been interest in using oral glycine for isovaleric acidemia, there is insufficient reliable information about the clinical effects of glycine for this purpose.
• Metabolic syndrome. Although there has been interest in using oral glycine for metabolic syndrome, there is insufficient reliable information about the clinical effects of glycine for this purpose.
• Obesity. Oral glycine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in adults aged 61-80 years with overweight or obesity shows that taking a specific combination product (GlyNAC), providing glycine 100 mg/kg and N-acetyl cysteine 100 mg/kg, daily for 16 weeks reduces waist circumference but does not improve body weight or body mass index (BMI) when compared to baseline. None of these outcomes were improved in individuals taking placebo (110624). The validity of these findings is limited by a lack of statistical comparison between groups. Also, it is unclear if these effects are due to glycine, N-acetyl cysteine, or the combination.
• Overactive bladder. It is unclear if oral glycine is beneficial in patients with overactive bladder. Details: One very small, non-randomized, crossover trial in patients with overactive bladder shows that taking glycine 3 grams twice daily for 4 weeks reduces urinary urgency, urinary incontinence, and nighttime urinary frequency and improves quality of life scores when compared with placebo (106497). The validity of these findings is limited by a lack of randomization.
• Physical performance. Oral glycine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in adults aged 61-80 years with overweight or obesity shows that taking a specific combination product (GlyNAC), providing glycine 100 mg/kg and N-acetyl cysteine 100 mg/kg, daily for 16 weeks improves upper and lower extremity strength and gait speed, but not walking distance, when compared to baseline. None of these outcomes were improved in individuals taking placebo (110624). The validity of these findings is limited by a lack of statistical comparison between groups. Also, it is unclear if these effects are due to glycine, N-acetyl cysteine, or the combination.
• Stroke. It is unclear if sublingual glycine is beneficial in patients with acute ischemic stroke. Details: One small clinical study in patients with acute ischemic stroke in the carotid artery territory shows that taking glycine 1-2 grams sublingually daily for 5 days, starting within 6 hours after the onset of stroke, modestly improves clinical outcomes on the Orgogozo Stroke Scale, the Scandinavian Stroke Scale, and the Barthel index when compared with placebo (11320).
• Venous leg ulcers. Topical glycine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study shows that applying a cream containing glycine, L-cysteine, and DL-threonine to leg ulcers reduces pain and modestly improves healing when compared with a placebo cream (10255). It is unclear if these effects are due to glycine, other ingredients, or the combination.
• Wound healing. Although there has been interest in using topical glycine for wound healing, there is insufficient reliable information about the clinical effects of glycine for this purpose. More evidence is needed to rate glycine for these uses.

(Read more about GLYCINE)

POSSIBLY EFFECTIVE

• Angina. Oral L-arginine seems to improve symptoms and exercise tolerance in patients with angina. Details: Clinical research shows that taking L-arginine orally seems to decrease symptoms and improve exercise tolerance and quality of life in patients with mild to severe angina (3593,7815,7816,31866,31923). Some patients with severe angina who have frequent attacks at rest despite treatment with standard antianginal agents might also benefit from L-arginine (3593). However, L-arginine does not seem to improve objective measures of blood vessel dilation or increase circulating concentrations of nitric oxide (7817,99262). Also, when used in combination with ten 200 mcg injections of vascular endothelial growth factor (VEGF)-165 plasmid DNA, L-arginine 6 grams daily orally for 3 months does not improve angina severity in patients with coronary artery disease who underwent surgical angiogenesis compared to patients who did not receive this combination (32001). In addition, intravenous infusion of arginine 10% solution does not improve exercise capacity in patients with stable angina when compared with placebo (31843,32293).
• Erectile dysfunction (ED). Oral L-arginine might improve symptoms of ED. When taken with phosphodiesterase type 5 (PDE5) inhibitors, L-arginine seems to provide a small additional benefit. Details: Taking L-arginine orally in high doses, 5 grams daily, improves subjective assessment of sexual function in males with organic ED when compared with placebo (222,102586). Additionally, a meta-analysis of 4 small clinical studies in patients with ED, including those with diabetes and/or cardiovascular disease risk factors, shows that although PDE5 inhibitors improve sexual function better than L-arginine, the combination of PDE5 inhibitors and L-arginine may be more effective than either treatment alone (105065). In most clinical trials, doses of L-arginine 2.5-5 mg daily for 6-12 weeks were used alone or in addition to PDE5 inhibitors such as sildenafil 50 mg or tadalafil 5-10 mg daily (102586,102587,102592,104222). Higher doses have also been investigated. One clinical trial shows that taking L-arginine (Bioarginina, Farmaceutici Damor S.p.A., Napoli, Italy), 2 grams three times daily for 3 months improves sexual function compared with placebo (110387). However, taking lower doses, 1.5 grams daily, might not be effective in patients with mixed-type ED (2038). L-arginine has also been examined in combination with other ingredients. A meta-analysis of 2 small clinical studies in males with mild-to-moderate ED shows that taking L- arginine, up to 3 grams daily, in combination with maritime pine for 1-6 months improves a subjective assessment of sexual function when compared with control (112715). Some preliminary clinical evidence suggests that taking L-arginine orally in low doses, 1.7 grams daily in combination with maritime pine bark extract (Pycnogenol) or taking 0.69 grams daily along with maritime pine bark extract and aspartic acid (Edicare, Kobayashi Pharmaceutical Co. Ltd.) modestly improves symptoms of ED (10416,50924). Another preliminary clinical trial has investigated the effects of a combination of L-arginine 2.5 grams daily for 6 months and tadalafil 5 mg daily for 3 months, both starting with the initiation of weekly extracorporeal shock wave (ESW) therapy. When compared with ESW alone, this combination modestly improves sexual function for up to 12 months (110388). The effect of L-arginine alone is not clear from these studies.
• Hypertension. Oral L-arginine can modestly reduce systolic and diastolic blood pressure. Details: Oral L-arginine seems to have additive vasodilating effects when used with angiotensin converting enzyme (ACE) inhibitors or nitrate vasodilators such as isosorbide mononitrate (7822,20192,31916). A meta-analysis of clinical research in a variety of populations shows that taking L-arginine reduces systolic and diastolic blood pressure (SBP; DPB) by an average of 6.40 mmHg and 2.64 mmHg, respectively. Sub-analyses show that these reductions occur in both normotensive and hypertensive individuals. Beneficial effects were limited to adults with a body mass index (BMI) of 18.5 to 19.9 kg/m² (110384). The effect of L-arginine on blood pressure levels in adults exposed to traffic-related air pollution (TRAP) has also been investigated. Clinical research in adults with hypertension shows that taking L-arginine 3 grams three times daily for 2 weeks modestly reduces SBP and DBP elevations following a 2-hour exposure to TRAP during an outdoor walk compared with taking placebo (110383). Doses have included 4-24 grams daily, with the best evidence of benefit for doses of less than 9 grams daily, for 2-24 weeks (7818,10636,31871,31923,32167,32201,110383,110384).
• Necrotizing enterocolitis (NEC). Oral L-arginine may help prevent NEC in premature infants. Details: In a meta-analysis of 3 clinical trials, L-arginine 260 mg/kg orally in a single dose or two divided doses daily reduces the absolute risk of NEC in premature infants by about 62% when compared with placebo. To prevent one case of NEC, 6 infants would need to be treated with L-arginine (8474,91194,96803).
• Peripheral arterial disease (PAD). Short-term use of intravenous or oral L-arginine may improve symptoms of PAD, but long-term use does not seem to be beneficial. Details: Clinical research shows that using L-arginine intravenously or orally for up to 8 weeks increases flow-mediated dilation and improves symptoms of intermittent claudication associated with PAD (3465,31857,31905). However, long-term administration of L-arginine orally for up to 6 months does not improve walking speed, walking distance, or absolute claudication distance in patients with PAD and intermittent claudication (31957,31985).
• Pre-eclampsia. Intravenous L-arginine may have beneficial effects in pre-eclampsia. However, it is unclear if oral L-arginine is effective. Details: One small clinical study shows that intravenous L-arginine 30 grams as a one-time dose decreases systolic blood pressure (SBP) by 5 mmHg and diastolic blood pressure by 11 mmHg when compared to baseline in pregnant patients with hypertension or pre-eclampsia (31847), while intravenous L-arginine 20 grams daily for 5 days decreases SBP and DBP by about 2% when compared with placebo (31978). Another small clinical study shows that oral use of L-arginine 3 grams daily for 3 weeks reduces SBP and DBP by around 7 and 5 mmHg, respectively, when compared with placebo (31938); however, taking L-arginine 12 grams daily by mouth for 5 days does not seem to improve blood pressure in these patients (11828). Another preliminary clinical trial allowing for both oral and intravenous dosing shows that taking L-arginine 3.5 grams by mouth every 6 hours or 10 grams via intravenous infusion every 8 hours shortly before or immediately after delivery and continuing until postpartum day 3 does not improve blood pressure when compared with placebo (31959). The reasons for the disparate findings are unclear, but the small study sizes, as well as variations in the dose, duration, and timing of therapy before and/or after delivery, may explain some of the differences. Oral L-arginine has also been evaluated for the prevention of pre-eclampsia. One clinical study in patients at high risk for pre-eclampsia shows that taking L-arginine 3 grams daily starting the 20th week of gestation reduces the risk of pre-eclampsia by about 74% when compared with placebo (96811). Based on these results, one case of pre-eclampsia is prevented for every 6 high-risk pregnant patients treated with L-arginine 3 grams daily. Another clinical study also shows that taking two bars of a specific medical food (Heart Bars, Nellson Nutraceutical) containing L-arginine 6.6 grams and antioxidant vitamins daily starting at 14-32 weeks gestation and continuing until delivery reduces the risk of pre-eclampsia by 44% when compared with a bar containing antioxidant vitamins alone in patients at high risk of pre-eclampsia (91197). Based on these results, one case of pre-eclampsia is prevented for every 11 high risk patients treated with this L-arginine-containing medical food.
• Pregnancy-induced hypertension. Intravenous L-arginine may have beneficial effects in pregnancy-induced hypertension. Details: Some clinical research in patients with pregnancy-induced hypertension shows that intravenous infusion of L-arginine 20 grams daily for up to 5 days decreases systolic blood pressure by 2% to 3% and diastolic blood pressure by about 3% when compared with placebo (31933,31961,31978). Clinical research in patients with pre-existing hypertension has also been conducted. One clinical trial shows that taking L-arginine 4 grams by mouth daily for 10-12 weeks does not seem to reduce blood pressure in those with pre-existing hypertension or mild gestational hypertension. However, these results are confounded by the fact that more patients taking placebo needed to be placed on antihypertensive therapy during the study. L-arginine reduced the risk of being placed on antihypertensive drug therapy during the pregnancy by 47% when compared with placebo (32191). Based on this study, for every 5 patients with pregnancy-induced hypertension treated with L-arginine over placebo, antihypertensive drug therapy is avoided in one additional patient. L-arginine has also been investigated in combination with other ingredients in patients with pre-existing hypertension. Preliminary clinical research in patients with pre-existing hypertension and a previous history of pre-eclampsia, stillbirth, intrauterine growth restriction (IUGR), or other placenta vascular disorder shows that taking L-arginine and other ingredients starting at 14 weeks gestation prevents an increase in blood pressure and reduces the percentage of patients requiring new antihypertensive medication by about 73% compared with 24.5% of those not taking this combination. In this study, L-arginine 3 grams daily was taken with magnesium 350 mg and salicylate 100 mg. Therefore, the effect of L-arginine alone is unclear. All patients in the study were taking low dose aspirin 100 mg daily (110382).

POSSIBLY INEFFECTIVE

• Chronic kidney disease (CKD). Oral or intravenous L-arginine does not seem to improve CKD. Details: Most preliminary clinical research shows that taking L-arginine, either orally for up to 6 months or intravenously short-term, does not improve kidney function, glomerular filtration rate, or renal plasma flow in patients with CKD, although proteinuria may be reduced in some patients (31844,31904,32235,32303).
• Hypercholesterolemia. Oral L-arginine does not seem to reduce cholesterol levels. Details: Preliminary clinical research in patients with hypercholesterolemia shows that taking L-arginine 21 grams daily for 4 weeks does not reduce plasma lipids (1363). Furthermore, meta-analyses of clinical research show that taking L-arginine for up to about 6 months does not reduce total or low-density lipoprotein (LDL) cholesterol levels in populations of healthy individuals or those with cardiovascular disease risk factors. However, there was a very small effect on fasting triglyceride levels (102590,102591).
• Myocardial infarction (MI). Oral L-arginine does not seem to improve outcomes after MI. Details: Patients who have had an ST-segment MI who take L-arginine within 24 hours to 21 days, titrated up to a dose of 3 grams three times a day for up to 6 months, do not seem to have reduced vascular stiffness or increased ejection fraction (13221,32137). Also, there is some concern that long-term use of L-arginine might actually worsen outcomes and increase mortality in these patients (13221). Population studies also suggest that intake of L-arginine does not reduce the risk of experiencing an acute coronary event such as MI or coronary heart disease-related mortality (3332,6896,7821,10637).
• Tuberculosis. Oral L-arginine does not seem to improve symptoms or the clearance of tuberculosis infection. Details: Clinical research shows that taking L-arginine (ArgimaxH) 6 grams daily orally for 8 weeks, with or without vitamin D, does not improve symptoms of tuberculosis or the clearance of tuberculosis infection when used with standard treatment (91196).
• Wound healing. Oral L-arginine does not seem to improve wound healing. Details: Clinical research shows that taking L-arginine (as arginine aspartate) 17 grams orally in three divided doses daily for 2 weeks does not improve epithelialization in healthy, elderly patients with catheter wounds, although it may improve collagen deposition (32247). Also, taking L-arginine (as L-arginine hydrochloride) 26 grams daily for 5 days perioperatively does not improve angiogenesis, re-epithelialization, or neutrophil count in patients undergoing skin graft donation when compared with placebo (20692). In addition, taking a wound-specific oral nutrition supplement containing L-arginine 4.5 grams, zinc, and vitamin C twice daily for 4 weeks, along with standard wound care for 8 weeks, is no more effective for wound healing than a standard oral nutrition supplement along with standard wound care (90198). L-arginine has also been studied in combination with other ingredients. Taking L-arginine enterally or orally, before or after surgery, in combination with ribonucleic acid (RNA) and either eicosapentaenoic acid (EPA) or fish oil, seems to improve wound healing when compared with a control group (5531,32174). Another observational study conducted in Italy in newborns shows that applying a specific topical powder containing L-arginine, arnica extract, zinc oxide, and other ingredients (Cicaben, Orsana Italia S.r.l.) to the newborn's umbilical cord stump 3 to 4 times daily until stump detachment reduces the rates of mild complications 48 hours after discharge such as a wet cord stump but does not change the time to cord stump detachment or the rates of purulent secretions or umbilical granulomas when compared with standard dry care. However, no differences were noted between the groups one week after discharge (113662). The validity of these results is limited by the observational nature of the study and the ability of the parents to select a treatment group. It is unclear if the effects in these studies are due to L-arginine, other ingredients, or the combination.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acute respiratory distress syndrome (ARDS). Small clinical studies suggest that oral L-arginine may prevent ARDS. Details: A meta-analysis of three small studies shows that taking L-arginine 3 grams daily, starting in the second or third trimester usually until delivery, reduces the risk of ARDS in the infant by about 54% when compared to control, including placebo or no treatment (110379).
• Altitude sickness. It is unclear if oral L-arginine is beneficial in patients with altitude sickness. Details: Preliminary clinical research shows that taking L-arginine 4 grams orally three times daily for 2 days while ascending to a high altitude and for 24 hours while at high altitude does not reduce altitude sickness when compared with placebo (31955).
• Anthracycline cardiotoxicity. Although there is interest in using oral L-arginine for anthracycline cardiotoxicity, there is insufficient reliable information about the clinical effects of L-arginine for this purpose.
• Anemia of chronic disease. It is unclear if oral L-arginine is beneficial for anemia in patients with chronic kidney disease. Details: One very small clinical study in elderly adults with chronic kidney disease and anemia shows that taking L-arginine orally 1.3 grams daily might increase hemoglobin and erythropoietin levels in some patients when compared to baseline (31988). The validity of these findings is limited by the small study size and the lack of a comparator group.
• Asthma. It is unclear if oral L-arginine is beneficial in patients with asthma. Details: Preliminary clinical research in adults with severe asthma shows that taking L-arginine 0.05 gram/kg ideal body weight twice daily does not reduce asthma exacerbations when compared with placebo (104223). This study may have been inadequately powered to detect a difference in exacerbation rates between groups. While other studies have shown adverse airway effects in patients with asthma (121,31849), this study demonstrated no change in exacerbations and reported no adverse airway effects.
• Athletic performance. Small clinical studies suggest that oral L-arginine may improve measures of athletic performance. Details: A meta-analysis of 5 small clinical trials shows that taking L-arginine seems to modestly improve measures of cardiorespiratory fitness, as measured by a 0.07 L/minute increase in maximal oxygen uptake, when compared with control (105064). L-arginine has also been examined for its effects on athletic performance. Most research suggests that taking L-arginine does not improve athletic performance. However, clinical trials are small and may not be adequately powered to detect a difference in these outcomes Taking L-arginine as a single dose of 5 or 6 grams or as 5-10 grams daily for 2-4 weeks does not improve grip strength, strength during resistance exercise, power output during cycling, or muscle function during recovery from intense resistance exercise in healthy adults (91190,97393,99265,110381,110389). Also, taking L-arginine 5 grams daily for 4 weeks (Bioarginina Farmaceutici Damor) or 8 grams daily for 8 days does not increase swim speed (110381,110386). In contrast, some research suggests that drinking a single beverage containing the same dose of L-arginine 6 grams increases the time to exhaustion during high-intensity exercise when compared with placebo (32180). Also, a meta-analysis of small clinical trials shows that supplementation with L-arginine has a large beneficial effect on aerobic performance and a small beneficial effect on anaerobic performance. However, publication bias was evident in the aerobic performance data, limiting these conclusions. Doses found to be beneficial in this analysis included an acute dose of L-arginine 0.15 gram/kg 60-90 minutes before performance or chronic dosing of 1.5 grams to 2 grams daily for 4-7 weeks for aerobic performance. The chronic dose of L-arginine most likely to be beneficial for anaerobic performance is unclear from this analysis due to inclusion of studies using arginine alpha-ketoglutarate (110395). With the exception of a few studies which include a very small number of healthy females (99265,110395,110386), research on the use of L-arginine for athletic performance has focused almost exclusively on healthy males. Also, studies are heterogeneous with respect to sport and endpoints. Therefore, whether results can be applied to females or specific athletes is unclear. L-arginine has also been evaluated in overweight males. One small clinical study shows that taking a single dose of L-arginine 6 grams 90 minutes prior to high-intensity interval training seems to improve exercise tolerance by improving ventilation, heart rate, and oxygen uptake when compared with placebo (105060). L-arginine has also been evaluated in combination with other ingredients. Research in male soccer players shows that taking L-arginine 1.2 grams and L-citrulline 1.2 grams daily for 7 days increases total power output over a 10-minute cycling test and improves subjective perceptions of exertion when compared with placebo (100956). Another study shows that taking L-arginine 1.5 or 3 grams daily, in combination with grape seed extract, increases physical working capacity at fatigue threshold when compared with pretreatment in untrained, college-aged males (32164).
• Beta-thalassemia. It is unclear if oral L-arginine is beneficial in children with beta-thalassemia. Details:Preliminary clinical research in children aged 6-18 years treated conventionally for pulmonary hypertension related to beta-thalassemia shows that taking L-arginine 0.1 mg/kg daily for 60 days reduces Doppler echocardiography pulmonary arterial pressure by 35% compared with baseline. This measurement was increased by up to 15% in children given conventional treatments only; however, a statistical comparison between these treatment groups was lacking (110391).
• Breast cancer. It is unclear if oral L-arginine is beneficial in patients with breast cancer. Details: Preliminary clinical research shows that taking L-arginine 30 grams daily for 3 days prior to chemotherapy does not improve the clinical response rate in breast cancer patients when compared with placebo (32282).
• Cognitive impairment. It is unclear if oral L-arginine is beneficial in patients with cognitive impairment. Details: A small clinical trial in frail adults aged 65 years of age and up with hypertension shows that taking L-arginine (Bioarginina) 1.66 grams twice daily for 4 weeks modestly improves cognitive function when compared to placebo (110385).
• Congestive heart failure (CHF). It is unclear if oral L-arginine is beneficial in patients with CHF. Details: One small clinical study in patients with CHF stage 2-3 shows that taking L-arginine 15 grams daily for 5 days, in combination with conventional treatment, seems to improve glomerular filtration rate (GFR), creatinine clearance, and sodium and water elimination after saline loading, indicating an improvement in kidney function (3596).
• Coronavirus disease 2019 (COVID-19). It is unclear if oral L-arginine is beneficial in patients with severe COVID-19 infection. Details: A small clinical trial in patients with severe COVID-19 shows that receiving oral L-arginine (Argin, Nutrigrow, India) 3 grams daily for a maximum of 10 days while on oxygen support does not affect the percentage of patients weaned off oxygen support after 10 days, the length of time requiring oxygen support, the duration of hospitalization, or the incidence of adverse thrombotic events, compared with placebo (110392). This study may not have been adequately powered to detect differences between groups. An interim analysis of a small clinical trial in patients hospitalized with severe COVID-19 shows that adding oral L-arginine (Bioarginina, Farmaceutici Damor) 1.66 grams twice daily to standard therapy throughout hospitalization increases the rate of respiratory support reduction by 60% after 10 days of therapy, but not after 20 days of therapy, when compared with placebo. L-arginine also significantly reduced the length of hospital stay. The median hospital stay was 25 days and 46 days, respectively, for L-arginine and placebo (106500). L-arginine has also been investigated in combination with other ingredients for post-acute COVID symptoms. Preliminary clinical research in adults with persistent fatigue following a COVID infection shows that taking L-arginine 1.66 grams plus vitamin C 500 mg (Bioarginina C, Farmaceutici Damor) twice daily for 28 days increases the distance walked in 6 minutes by 30 meters and reduces the percentage of patients with fatigue by about 89%, when compared with placebo. Grip strength was also increased (110390).
• Coronary artery bypass graft (CABG) surgery. It is unclear if oral L-arginine is beneficial for preventing complications after CABG surgery. Details: Preliminary clinical research shows that venous infusion of L-arginine hydrochloride 30 grams as a 10% solution over 15 minutes helps maintain mean arterial pressure, coronary vascular resistance, and graft blood flow when compared with a placebo infusion in patients that have undergone CABG (31840). Administering L-arginine 7.5 grams in 500 mL of cardioplegic solution also seems to reduce wedge pressure and intensive care unit stay in patients undergoing CABG; however, it does not reduce hospital stay duration or postoperative complications when compared with cardioplegic solution alone (31958,31886).
• Critical illness (trauma). Oral L-arginine has only been evaluated in combination with other ingredients; its effects when used alone are unclear. Details: A meta-analysis of clinical research shows that taking L-arginine orally with glutamine, nucleotides, and omega-3 fatty acids reduces the recovery time, the need for ventilation, and infection rates in critically ill patients, but does not reduce the risk of mortality (31853).
• Cyclosporine-induced nephrotoxicity. Although there is interest in using oral L-arginine for cyclosporine-induced nephrotoxicity, there is insufficient reliable information about the clinical effects of L-arginine for this purpose.
• Cystic fibrosis. It is unclear if oral L-arginine is beneficial in patients with cystic fibrosis. Details: Preliminary clinical research in teens and adults with cystic fibrosis shows that twice daily inhalation with L-arginine 500 mg for 2 weeks does not improve lung function when compared with inhaling 2.6% hypertonic saline twice daily (96807).
• Dental caries. Small clinical studies suggest that using a dentifrice containing L-arginine might prevent dental caries. Details: A meta-analysis of small studies shows that use of a dentifrice containing L-arginine 1.5% w/w in combination with calcium base (Dical or calcium carbonate) and fluoride 1450 ppm 2-3 times daily for up to 2 years reduces the risk of developing dental caries by a small to moderate amount when compared with a dentifrice containing only fluoride in children and adults (96806). Also, preliminary clinical research shows that using a confection containing an L-arginine complex (CaviStat) for one year reduces the number of dental caries in molars of children when compared with a sugarless mint control (32011). L-arginine has also been investigated as a prebiotic in combination with probiotics. In 5- to 9-year-old children with low caries risk, clinical research shows that taking one lozenge daily for 10-12 months containing arginine 20 mg along with Lacticaseibacillus paracasei and Lacticaseibacillus rhamnosus, modestly reduces caries severity, but does not reduce caries progression, active caries lesions, plaque, or gingivitis, when compared with placebo (113241,113242).
• Dental hypersensitivity. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that using a toothpaste containing L-arginine, calcium, and fluoride twice daily reduces dentin hypersensitivity when compared with pretreatment or control (32130,32131,32132,32177). Another moderate-sized clinical study in adults shows that applying a topical combination of L-arginine 10% and ibuprofen to tooth enamel surfaces for 10 minutes prior to in-office tooth bleaching reduces the risk and intensity of tooth sensitivity when compared with placebo (115354). It is unclear whether the effects are due to L-arginine, other ingredients, or the combination.
• Diabetes. Small, low-quality studies suggest that oral L-arginine does not improve glycemic control in people with type 2 diabetes. Details: A meta-analysis of small, low-quality studies shows that taking L-arginine 2-20 grams daily for up to 77 weeks decreases fasting blood glucose and serum insulin levels in adults without diabetes. However, no improvements occurred in adults WITH type 2 diabetes. This may be explained by previous studies which suggest L-arginine affects glucose control only in the early steps of beta-cell dysfunction. L-arginine did not improve insulin resistance or glycated hemoglobin (HbA1c) in patients with or without diabetes (104225). Also, a prospective observational study in patients with type 1 or type 2 diabetes has found that taking a specific product (Flebotrofine, AMNOL Chimica Biologica) containing L-arginine for 3 months is not associated with improvements in HbA1c, cholesterol, or triglyceride levels when compared with baseline. Other ingredients in this product included diosmin, troxerutin, hesperidin, black currant extract, and gotu kola extract (108151). The validity of these findings is limited by the lack of a comparator group.
• Diabetic foot ulcers. It is unclear if oral or subcutaneous L-arginine is beneficial in patients with diabetic foot ulcers. Details: A very small clinical study shows that administering L-arginine subcutaneously at the site of diabetic foot ulcers does not decrease healing time or rate of amputation when combined with conventional therapies (14914). Also, taking a specific drink containing L-arginine 7 grams, L-glutamine 7 grams, and calcium hydroxymethylbutyrate (HMB) 1.5 grams (Juven/Abound, Abbott Nutrition) orally twice daily for 16 weeks does not improve diabetic foot ulcer healing when compared with a control drink in non-ischemic patients or those with normal albumin levels. However, in specific populations with low albumin and/or poor limb perfusion, up to 74% more patients had total wound healing when compared with the control drink (96637).
• Diabetic neuropathy. It is unclear if oral L-arginine is beneficial in patients with diabetic neuropathy. Details: Preliminary clinical research shows that taking L-arginine 3 grams daily for 3 months does not improve circulation, disability, or nerve function in patients with diabetic neuropathy when compared with placebo (32145).
• Head and neck cancer. It is unclear if oral L-arginine is beneficial in patients with head and neck cancer. Details: Small clinical studies suggest that enteral nutrition supplemented with L-arginine does not seem to have any beneficial effects on markers of immune function such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), length of postoperative hospital stay, or fistula rates; however, it seems to reduce wounds and general infections after surgery in patients with head and neck cancer when compared with control (10160,32008).
• Heart failure. It is unclear if oral L-arginine is beneficial in patients with heart failure. Details: Preliminary clinical research in adults with heart failure shows that taking L-arginine 3.0-12.6 grams orally daily for 6-12 weeks does not consistently improve exercise tolerance or peripheral vascular resistance (3595,6028,32138). However, some research shows that taking L-arginine 1000 mg three times daily for 10 weeks modestly improves measures of cardiac function compared with placebo (110380). Although some research disagrees (32138), most research shows that taking L-arginine modestly improves quality of life (3595,110380).
• Heart transplant complications. It is unclear if oral L-arginine is beneficial in patients that have received a heart transplant. Details: Preliminary clinical research shows that taking L-arginine 6 grams orally twice daily for 6 weeks increases walking distance and oxygen uptake and delays the ventilatory threshold in heart transplant patients when compared with baseline (32150).
• HIV/AIDS-related wasting. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One clinical study in patients with HIV/AIDS shows that taking L-arginine orally, in combination with hydroxymethylbutyrate (HMB) and glutamine for 8 weeks, increases body weight, particularly lean body mass, and positively affects immune status when compared with placebo (1909). However, other clinical research in HIV-positive patients shows that taking L-arginine 7.4 grams daily orally, in combination with omega-3 fatty acids and a balanced oral nutritional supplement for 6 months, does not improve body weight or fat mass, total energy intake, or immune status when compared to taking the nutritional supplement alone (113).
• Impaired glucose tolerance (prediabetes). It is unclear if oral L-arginine can prevent the development of type 2 diabetes in adults with prediabetes. Details: Clinical research shows that taking L-arginine (Bioarginine, Farmaceutici Damor) 3.2 grams orally twice daily for 18 months does not reduce the incidence of diabetes in patients with impaired glucose tolerance (prediabetes). However, when assessed one year after treatment discontinuation, patients who took L-arginine had a 58% lower risk of developing diabetes when compared with placebo (91195).
• Infertility. It is unclear if oral L-arginine improves outcomes in people undergoing an assisted reproductive technology (ART) program. Details: Some preliminary clinical research shows that taking L-arginine 16 grams daily decreases the cancellation rate of in vitro fertilization (IVF) and increases the number of oocytes collected in females undergoing an ART program when compared with control. However, taking L-arginine does not seem to improve the number of viable pregnancies (31842). A small clinical study of females undergoing an ART program shows that taking a combination product containing L-arginine 1 gram with folate 200 mcg or L-arginine 2 grams, folate 400 mcg, and vitamin E 10 mg daily for 12 weeks does not affect the hCG-positive rate or clinical pregnancy rate when compared with placebo. A subgroup analysis suggests that taking these combination products might improve HCG-positive and clinical pregnancy rates in females who are undergoing ART due to male infertility (104224). However, this small study was not adequately powered to detect a difference in these outcomes, limiting the validity of these findings.
• Interstitial cystitis. Small clinical studies suggest that oral L-arginine may improve pain in interstitial cystitis. Details: Taking L-arginine orally seems to reduce some symptoms, especially pain, that are associated with interstitial cystitis (107,114,3460,31855,32267). Research shows that patients with interstitial cystitis having a bladder capacity greater than 800 mL and/or a history of recurrent genitourinary infections might respond more favorably to L-arginine than patients with bladder capacity less than 800 mL and/or no history of recurrent genitourinary infections. Three months of treatment may be necessary before significant symptom improvement occurs (3460). However, L-arginine does not seem to reduce the need to urinate at night or improve urgency or frequency of urination (3460,31855).
• Intrauterine growth restriction (IUGR). Small clinical studies suggest that oral or intravenous L-arginine may increase birthweight in IUGR. Details: A meta-analysis of mainly small studies shows that L-arginine given orally or intravenously in the third trimester for a time period of 7 days or until delivery increases the birthweight by up to 650 grams in patients with an IUGR pregnancy. Furthermore, there is evidence from a small number of these studies that L-arginine supplementation decreases the risk of neonatal respiratory distress syndrome and fetal intracranial hemorrhage (96804). A more recent meta-analysis of small studies also shows that taking L-arginine 3 grams daily, starting in the second or third trimester usually until delivery, reduces the risk of an IUGR infant by about 32% when compared to control, including placebo or no treatment (110379). Doses used in clinical research have usually been 3 grams daily orally, although some studies have used up to 20 grams intravenously (31930,31937,96804,110379). However, supplementation with L-arginine does not seem to increase birthweight or reduce neonatal mortality or morbidity when compared with placebo in patients with severe IUGR (32083).
• Kidney transplant. Small clinical studies suggest that oral L-arginine may not improve kidney function in patients after kidney transplantation. Details: Although preliminary clinical research showed some benefit, evidence from other clinical research shows that infusion with L-arginine does not increase renal plasma flow or glomerular filtration rate in kidney transplant patients treated with cyclosporine, including those experiencing transplant dysfunction (112,31876,32229). Other evidence suggests that intravenous L-arginine improves kidney function only in transplant patients receiving organs with a short cold ischemia time or those receiving kidneys from young donors (31887).
• Male infertility. It is unclear if oral L-arginine is beneficial in males with infertility. Details: Preliminary clinical research shows that taking L-arginine 4 grams daily for 12 weeks does not improve semen quality in males with oligospermia when compared with placebo (32209). However, one small clinical study shows that a specific formulation of L-arginine aspartate and maritime pine bark extract (Prelox), taken for 6 months, improves sperm quality in males with idiopathic male infertility when compared to baseline (32061). The validity of this finding is limited by the lack of a comparator group. Additionally, it is unclear if this effect is due to L-arginine, maritime pine bark, or the combination.
• Mitochondrial myopathies. Small clinical studies suggest that intravenous L-arginine may modestly improve symptoms in patients with MELAS (mitochondrial encephalopathy with lactic acidosis and stroke-like episodes syndrome). Details: Preliminary clinical research shows that infusions of L-arginine, 0.5 grams/kg administered within one hour of stroke-like symptoms, improves headaches, nausea, vomiting, transient blindness, and the appearance of bright spots when compared to pretreatment in patients with MELAS (31943,99263). Also, taking oral L-arginine 4-24 grams daily for 18 months seems to reduce the frequency and severity of stroke-like symptoms associated with MELAS when compared to baseline (31943). However, other preliminary clinical research shows that taking oral L-arginine 0.3-0.5 grams/kg daily in three divided doses for 2 years does not reduce the severity of MELAS symptoms, including migraine and stroke-like episodes. If a stroke-like episode did occur, administration of intravenous L-arginine 0.5 grams/kg improved headache, nausea, vomiting, and visual disturbance (99263). The validity of this research is limited by the small study sizes and the absence of comparator groups.
• Migraine headache. Although there is interest in using oral L-arginine for migraine, there is insufficient reliable information about the clinical effects of L-arginine for this condition.
• Muscular dystrophy. There is limited evidence on the oral use of L-arginine in patients with Duchenne muscular dystrophy. Details: A very small study in five children with Duchenne muscular dystrophy, shows that drinking a beverage containing L-arginine hydrochloride (L-Arginine Hydrochloride, Selectchemie) 2.5 grams three times daily, in addition to metformin 250 mg twice daily, for 16 weeks improves motor function by 4% and increases distance walked in two minutes by 9.6 meters when compared to baseline (96805). The validity of these findings is limited by the very small study size and lack of a comparator group.
• Nitrate tolerance. It is unclear if oral L-arginine is beneficial for nitrate tolerance. Details: A very small crossover study in adults with stable angina shows that taking L-arginine orally 700 mg four times daily for up to 10 days seems to prevent tolerance to transdermal nitrate when compared with placebo (8475).
• Obesity. Small clinical studies suggest that oral L-arginine may be beneficial for weight loss. Details: A meta-analysis of mainly small clinical trials shows that taking L-arginine daily for at least 8 weeks modestly reduces body weight, body mass index (BMI), and waist circumference when compared with placebo. However, when taking L-arginine for less than 8 weeks, BMI and body weight were not affected. The optimal dose of L-arginine was 2-6 grams (110398). An additional small clinical study suggests that taking a specific arginine supplement (NOW Foods) 3 grams by mouth three times daily for 12 weeks, in addition to receiving dietary counseling, reduces waist circumference by 4-6 cm and reduces body weight by 1.8-2.9 kg when compared to baseline in obese females 18-40 years of age (91193). The validity of these findings is limited by the lack of a comparator group.
• Oral mucositis. Oral L-arginine 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 combination of L-arginine 7 grams, L-glutamine 7 grams, and hydroxymethylbutyrate (HMB) 1.2 grams (Abound; Abbott) in water twice daily during chemoradiotherapy treatment for head and neck cancer does not reduce the incidence of severe oral mucositis when compared with a historical control (99243). The validity of this finding is limited by the lack of a placebo control. Additionally, a small open-label study in patients undergoing chemoradiation for head and neck cancer shows that taking a specific combination product (Abound, Abbot) containing L-arginine, glutamine, and HMB twice daily throughout chemoradiation treatments decreases the incidence of grade 3 or higher oral mucositis and ameliorates body weight loss when compared with no intervention (113726). However, the incidence of grade 2 or higher oral mucositis was not reduced. It is unclear if this effect is due to L-arginine, other ingredients, or the combination. Additionally, the validity of the study is limited by the lack of blinding.
• Periodontitis. It is unclear if oral L-arginine is beneficial in patients with periodontitis. Details: Preliminary clinical research in patients with chronic periodontitis shows that using L-arginine aspartate (Yuria-Pharm, Ukraine) 1 gram three times daily orally for 10 days after scaling and root planing, modestly reduces bleeding on probing but not periodontal pocket depth, when compared with untreated controls (108926).
• Physical performance. It is unclear if oral L-arginine is beneficial for improving physical performance in older adults. Details: A small study in physically active females 65 years of age and older shows that taking L-arginine 8 grams as a single dose does not improve lower body strength, measured by knee flexion and extension tests, or functional performance, measured by sit-stand, tandem gait, and timed up-and-go tests, when compared with placebo (96812).
• Polycystic ovary syndrome (PCOS). Oral L-arginine 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 N-acetylcysteine 1200 mg daily plus L-arginine 1600 mg daily for 6 months modestly improves menstrual function and decreases insulin resistance in patients with PCOS when compared to baseline (32094). The validity of these findings is limited by the lack of a comparator group.
• Postoperative infection. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Small clinical studies show that taking L-arginine, enterally or orally, either before or after surgery, in combination with fish oil, or with ribonucleic acid (RNA) and eicosapentaenoic acid (EPA), seems to reduce the rate of perioperative infection when compared with a control group. The risk of infection was 41% lower when compared to taking no arginine-based formulations. However, there is no good evidence to support the use of L-arginine alone for this purpose, and it is possible that this effect is due to the other ingredients or the combination of ingredients (5531,32174,32196).
• Postoperative recovery. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Small clinical studies show that taking L-arginine, enterally or orally, either before or after surgery, in combination with fish oil, or with ribonucleic acid (RNA) and eicosapentaenoic acid (EPA), seems to reduce the recovery time after surgery or serious illness when compared with a control group. This seems to be related to a reduced number of perioperative infections and improved wound healing. However, there is no good evidence to support the use of L-arginine alone for this purpose, and it is possible that this effect is due to the other ingredients or the combination of ingredients (5531,32174,32196). The effect of another combination product containing L-arginine is unclear. In one clinical study, taking a combination product (Abound, Abbott) containing L-arginine 7 grams, glutamine 7 grams, and hydroxymethylbutyrate 1.2 grams orally daily for 3 days before and 7 days after abdominal surgery did not reduce the incidence of wound infection or other complications when compared with placebo (99413). However, when a similar combination of L-arginine 14 grams, glutamine 14 grams, and hydroxymethylbutyrate 3 grams (Heallagen) was taken orally daily for one month before heart surgery, the length of hospital and ICU stay were reduced by about one day. Recovery, based on some but not all biochemical or other measurements, was also improved. However, there was no difference in risk of overall postoperative complications (110394). The discrepancies between these two studies may be related to differences in the dose or duration of the combination product and/or the type of surgery.
• Pressure ulcers. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Oral L-arginine has been evaluated in combination with other ingredients for the treatment of grade II-IV pressure ulcers. Two small clinical studies in hospitalized patients show that administering an oral nutritional supplement enriched with L-arginine, zinc, and vitamin C improves ulcer healing when compared with a standard diet (31953,87173). A small preliminary clinical study in sedentary older adults in care facilities shows that giving an oral or enteral combination of L-arginine 7.4 grams, L-glutamine 7.4 grams, and hydroxymethylbutyrate (HMB) 1.3 grams (Abound, Abbott) daily for 20 weeks reduces median time to healing by 48 days when compared with standard care only (110396). Also, preliminary clinical research in patients living in long-term care facilities with grade II-IV pressure ulcers shows that taking an oral nutritional supplement enriched in protein, energy, L-arginine, vitamin C, 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.
• Preterm labor. Small clinical studies suggest that oral L-arginine may prevent preterm labor. Details: A meta-analysis of three small studies shows that taking L-arginine 3-6.6 grams daily, starting in the second or third trimester usually until delivery, reduces the risk of preterm labor by about 50% when compared to control, usually placebo (110379).
• Pulmonary hypertension. It is unclear if oral L-arginine is beneficial in children with pulmonary hypertension related to beta-thalassemia. Details: Preliminary clinical research in children aged 6-18 years treated conventionally for pulmonary hypertension related to beta-thalassemia shows that taking L-arginine 0.1 mg/kg daily for 60 days reduces Doppler echocardiography pulmonary arterial pressure by 35% compared with baseline. This measurement was increased by up to 15% in children given conventional treatments only; however, a statistical comparison between these treatment groups was lacking (110391).
• Radiation dermatitis. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with head and neck cancer shows that taking a combination of L-arginine 7 grams, L-glutamine 7 grams, and hydroxymethylbutyrate (HMB) 1.2 grams (Abound, Abbott) in water twice daily from the first day of radiation to approximately 1 week after completion does not reduce the number of patients with severe dermatitis when compared with taking no supplement. However, there was a 34% reduction in the incidence of moderate dermatitis and the overall duration of dermatitis was reduced (96639).
• Restenosis. It is unclear if intravenous L-arginine helps to prevent restenosis after stent implantation. Details: Some clinical research suggests that intravenous and intracoronary infusion of L-arginine during stent implantation followed by oral L-arginine for 2 weeks does not reduce the risk of restenosis when compared with placebo (31925). However, local delivery of 6 mL of L-arginine 100 mg/mL for 15 minutes after stent deployment seems to reduce neointimal formation at 6 months after stent placement when compared with placebo (31883).
• Respiratory tract infections. Although there is interest in using oral L-arginine for respiratory tract infections, there is insufficient reliable information about the clinical effects of L-arginine for these conditions.
• Schizophrenia. It is unclear if oral L-arginine is beneficial in patients with schizophrenia. Details: A small clinical study shows that taking L-arginine 3 grams twice daily for 3 weeks, in conjunction with an individualized medication regimen, does not improve positive, negative, or depressive symptoms associated with schizophrenia when compared with taking the medication regimen alone (99264).
• Sexual dysfunction. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in females with sexual dysfunction who are taking oral contraceptives shows that taking a specific combination product (Lady Prelox, Horphag Research) containing L-arginine, maritime pine bark extract, L-citrulline, and rose hip extract daily for 8 weeks improves symptoms of sexual dysfunction by 18% when compared with a control group (91963). Taking the same product in a dose of 2 tablets twice daily for 8 weeks, in addition to the lifestyle management program, improves vaginal dryness in pre- and post-menopausal patients when compared with lifestyle management alone (103611). It is unclear if this effect is due to L-arginine, the other ingredients, or the combination.
• Sickle cell disease. Small clinical studies suggest that oral or intravenous L-arginine may modestly improve complications in patients with sickle cell disease. Details: Two small clinical studies in hospitalized children aged 3-19 years with sickle cell disease-related veno-occlusive crisis shows that administering L-arginine intravenously or orally 100 mg/kg three times daily for 5 days or until discharge reduces total opioid use by 26% to 54%, pain scores at discharge by 23%, and median length of hospital stay by about 36 hours when compared with placebo (97392,105063). Another very small clinical study in patients aged 13-63 years with sickle cell disease shows that taking L-arginine 0.1 grams/kg orally three times daily for 5 days reduces pulmonary hypertension when compared to baseline (11428).
• Stress. Oral L-arginine 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 a single dose of L-arginine 50 mg plus L-theanine 200 mg modestly reduces stress associated with a stress-loading test when compared with placebo, but was no more effective than taking L-theanine alone (110393).
• Valproic acid-induced toxicities. Although there is interest in using intravenous L-arginine for valproic acid toxicity, there is insufficient reliable information about the clinical effects of L-arginine for this purpose. More evidence is needed to rate L-arginine for these uses.

(Read more about L-ARGININE)

POSSIBLY EFFECTIVE

• Neural tube birth defects. High dietary intake of methionine during pregnancy seems to reduce the risk of neural tube birth defects. Details: Population research has found that higher dietary intake of methionine during pregnancy is associated with a reduced risk of neural tube defects when compared with lower dietary intake (63117,63135).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acetaminophen poisoning. It is unclear if oral methionine is beneficial in patients with acute acetaminophen poisoning. Details: Observational research has found that taking methionine 2.5 grams every 4 hours for a total of four doses, starting within 10 hours of acetaminophen overdose, may have similar efficacy to acetylcysteine for preventing liver damage and death (2413).
• Allergic rhinitis (hay fever). Although there has been interest in using oral methionine for seasonal allergies, there is insufficient reliable information about the clinical effects of methionine for this purpose.
• Asthma. Although there has been interest in using oral methionine for asthma, there is insufficient reliable information about the clinical effects of methionine for this purpose.
• Breast cancer. It is unclear if high dietary intake of methionine reduces the risk of breast cancer. Details: A meta-analysis of observational studies suggests that higher dietary intake of methionine is associated with a 6% lower risk of breast cancer, especially for postmenopausal adults, when compared with lower intake. Increasing dietary intake of methionine by 1 gram daily may be associated with a 4% reduction in the risk of breast cancer. These results appear to be more prominent in postmenopausal adults when compared with premenopausal adults; however, this could have been by chance due to the small number of studies that assessed premenopausal adults (94093). A more recent meta-analysis, including 4 additional observational studies, suggests that there is no significant association between methionine intake and breast cancer risk. This finding is largely influenced by inclusion of the European Prospective Investigation into Cancer and nutrition (EPIC) cohort study, which analyzed data from over 300,000 subjects and found no relationship between methionine intake and breast cancer risk (111416).
• Cisplatin-associated ototoxicity. It is unclear if oral D-methionine prevents cisplatin-associated ototoxicity. Details: A small clinical study in adults with cancer receiving cisplatin shows that taking D-methionine 100 mg/kg one hour prior to chemotherapy for up to 5 cycles prevents shifts in the hearing threshold at all four tested frequencies, compared with shifts occurring at three of the four tested frequencies in those receiving placebo (108039). The validity of these findings is limited by the lack of statistical comparison between groups.
• Colorectal cancer. It is unclear if high dietary intake of methionine reduces the risk of colorectal cancer. Details: A meta-analysis of observational research has found that higher dietary intake of methionine is associated with an 11% lower risk of colorectal cancer, a 23% lower risk of colon cancer, and a 12% lower risk of rectal cancer, when compared with lower intake of methionine. Increasing dietary intake of methionine by 1 gram daily is associated with a 11% reduction in the risk of colorectal cancer. Subgroup analyses have shown a significant inverse relationship between risk of colorectal cancer and dietary methionine intake in patients followed for at least 13.3 years, in Western populations, and in males (94094). There is some evidence that high dietary intake of methionine and folate might have a synergistic effect in decreasing the risk of colon cancer, especially in those with a family history of colon cancer and in those who consume large amounts of alcohol (9325,9326).
• Genital herpes. Oral L-methionine has only been evaluated in combination with other ingredients; its effects when used alone is unclear. Details: A small clinical study in patients with genital warts caused by herpes simplex virus (HSV) shows that taking acyclovir 200 mg five times daily for 5 days followed by 4 capsules of a combination product providing a total daily dose of L-methionine 200 mg, coenzyme Q10 50 mg, vitamin E 50 mg, and selenium 50 mcg for 90 days increases the rate of skin reepithelization by approximately 2 days and decreases the incidence of relapse when compared with acyclovir alone. Patients receiving combination therapy had a relapse rate of 13%, compared with a rate of 43% with acyclovir alone (94091).
• Herpes zoster (shingles). Oral L-methionine has only been evaluated in combination with other ingredients; its effects when used alone is unclear. Details: A small clinical study in patients with herpes zoster shows that taking acyclovir 800 mg five times daily for 10 days followed by 4 capsules of a combination product providing a total daily dose of L-methionine 200 mg, coenzyme Q10 50 mg, vitamin E 50 mg, and selenium 50 mcg for 90 days increases the rate of skin reepithelization by approximately 2 days, decreases the incidence of relapse, and decreases postherpetic neuralgia pain when compared with acyclovir alone. Patients receiving combination therapy had a relapse rate of 7%, compared with a rate of 44% with acyclovir alone (94091).
• Human papillomavirus (HPV). It is unclear if oral methionine is beneficial for the treatment of HPV lesions or for reducing the incidence of relapse. Details: A clinical study in patients aged 14 years or older with cutaneous warts caused by HPV shows that receiving conventional therapy in combination with one capsule of a product containing methionine, echinacea, inulin, taurine, vitamin A, vitamin C, coenzyme Q10, vitamin B3, zinc gluconate, and probiotics (Immuno Skin Plus tablets, Morgan Pharma S.r.l) daily for 20 days each month for 4 months reduces the number of warts at 6 months by about 5, with complete remission achieved in 86% of patients. The group receiving conventional therapy alone had a reduction in the number of warts by about 3, with complete remission achieved in 55% of patients. Conventional therapy consisted of either liquid nitrogen cryotherapy or topical therapy with salicylic acid 15% and lactic acid 15%. These findings are limited by the fact that patients in the combination therapy group had more warts at baseline when compared with those receiving conventional therapy alone (94092). Another small clinical study in patients with skin warts caused by HPV shows that cryotherapy followed by taking 4 capsules of a product containing a total dose of L-methionine 200 mg, coenzyme Q10 50 mg, vitamin E 50 mg, and selenium 50 mcg daily for 180 days increases the rate of complete recovery and decreases the incidence of relapse when compared with cryotherapy followed by placebo. At 180 days, 56% of patients in the active group experienced complete recovery, compared with 44% in the placebo group, and 30% of patients in the active group experienced a relapse, compared with 41% in the placebo group (94091). It is unclear if these effects are due to methionine, other ingredients, or the combination.
• Menopausal symptoms. It is unclear if oral L-methionine is beneficial for reducing hot flashes. Details: Preliminary clinical research in postmenopausal adults experiencing at least 5 hot flashes daily for the prior two months shows that taking L-methionine 1 gram twice daily for 12 weeks, then 2 grams twice daily for 8 weeks, does not improve hot flashes when compared with placebo (94090).
• Pancreatitis. Oral methionine has only been evaluated in combination with other ingredients; its effects when used alone is unclear. Details: A meta-analysis of eight randomized and nonrandomized clinical studies in patients with chronic or recurrent acute pancreatitis shows that taking a combination of methionine, selenium, vitamin E, vitamin C, and beta-carotene reduces pain when compared with placebo. However, when the two nonrandomized studies were excluded, the significant reduction in pain was lost. Daily doses of individual components studied included methionine 1.6-2.88 grams, selenium 300-600 mcg, vitamin E 188-280 mg, vitamin C 540-720 mg, and beta-carotene 12-54 mg. The study durations ranged from 10 weeks to 12 months (94095). The validity of these findings is limited by the heterogeneity of the included studies.
• Parkinson disease. Although there has been interest in using oral methionine for Parkinson disease, there is insufficient reliable information about the clinical effects of methionine for this purpose.
• Urinary tract infections (UTI). Oral methionine has only been evaluated in combination with other ingredients; its effects when used alone is unclear. Details: A low-quality observational study in patients with symptomatic UTI and culture-confirmed bacteriuria during pregnancy has found that taking a specific combination of methionine 800 mg, Hibiscus sabdariffa extract 200 mg, and Boswellia serrata 200 mg (Acidif Plus, Biohealth S.r.l) daily for one week increases the rate of negative urine cultures to 70% and symptom resolution to 63%, compared with 43% and 46%, respectively, in patients who increased fluid intake but did not take the combination product (97263). The validity of these findings is limited by the fact that the study groups were not comparable at baseline.
• Wound healing. Although there has been interest in using oral methionine for wound healing, there is insufficient reliable information about the clinical effects of methionine for this purpose. More evidence is needed to rate methionine for these uses.

(Read more about METHIONINE)

EFFECTIVE

• Hypokalemia. Oral or intravenous potassium can treat and prevent hypokalemia. Details: Administering potassium orally or intravenously is effective for treating and preventing hypokalemia (15,107970). Oral potassium 20 mEq (780 mg of elemental potassium) is typically taken once daily to prevent hypokalemia (15,95010). Oral potassium 40-100 mEq (1560-3900 mg of elemental potassium) is typically taken in 2-5 divided doses daily to treat hypokalemia (95010). Doses should be limited to 40 mEq (1560 mg of elemental potassium), and the total dose should not exceed 200 mEq (7800 mg of elemental potassium) in 24 hours (95010). Potassium supplementation and route of administration should be individualized based on serum potassium level and patient status (15,107970).

LIKELY EFFECTIVE

• Hypertension. Oral potassium, via dietary intake or supplementation, reduces blood pressure. Details: Population research has found that higher dietary potassium consumption is associated with a lower risk of developing hypertension (1310,8817,69512). Additionally, most clinical research shows that potassium, taken orally as part of the diet or as a supplement, reduces systolic blood pressure by about 3-9.5 mmHg and diastolic blood pressure by about 2-6.4 mmHg in patients with or without hypertension (3385,92104,92106,95624,107974). In most of these studies, daily intake of potassium typically ranged from about 1500-7800 mg, with the most common intake being about 2340-2540 mg daily (92104,95624). However, some research shows that taking potassium does not lower systolic or diastolic blood pressure (69541,69550,107966). Differences in the patient populations, potassium intake, and salt intake could have contributed to the conflicting results. Potassium seems to be more effective for people with hypertension, low potassium levels, high daily sodium intake, and for Black adults (3384,3385,3386,92104,92106). Some research also shows that the greatest blood pressure-lowering effects of potassium occur at doses of about 3900-7800 mg daily (95624). A meta-analysis of clinical trials using a novel computational technique to assess both potassium intake and excretion suggests that the optimal blood pressure reduction occurs when taking about 1500 mg supplemental potassium daily or an overall intake of 4500-6500 mg potassium daily (105448). This analysis is limited by the heterogeneity and short duration of the included trials. There is also interest in utilizing low-sodium, high-potassium food substitutes to treat hypertension. Research shows that using salt substitutes containing 25% to 30% potassium chloride reduces systolic and diastolic blood pressure by 3-4.6 mmHg and 1 mmHg, respectively, when compared with regular table salt (107971,107976). In 2017, the American College of Cardiology and the American Heart Association (ACC/AHA) published guidelines recommending that patients with hypertension consume 3500-5000 mg of potassium daily (95680). This intake of potassium is expected to lower systolic blood pressure by about 4-5 mmHg in patients with hypertension and by about 2 mmHg in normotensive patients (3385). Although potassium supplements and dietary potassium both seem to be beneficial, the guidelines recommend getting potassium from dietary sources, since potassium-rich diets are usually heart-healthy (95680). Additionally, the US Food and Drug Administration (FDA) has determined that foods containing at least 350 mg potassium and that are low in sodium, saturated fat, and cholesterol can state that "diets containing foods that are good sources of potassium and low in sodium may reduce the risk of high blood pressure and stroke" (1310,8817).
• Kidney stones (nephrolithiasis). Oral prescription potassium citrate reduces the risk of kidney stone recurrence. It is unclear if non-prescription potassium citrate would be beneficial. Details: The American Urological Association (AUA) recommends potassium citrate therapy for patients with recurrent calcium stones and low urinary citrate, those with recurrent calcium or calcium oxalate stones without current metabolic abnormalities, and those with uric acid or cystine stones. The citrate component reduces urine calcium excretion and increases urine citrate and urine pH, which in turn alleviates crystal growth, formation, and aggregation. Sodium citrate may also be used to prevent stone recurrence; however, due to sodium's propensity to increase urine calcium excretion, potassium citrate remains the preferred salt formulation (107972). It is important to note that potassium citrate supplements are not equivalent to prescription potassium citrate products. Dose and duration of treatment is determined by a healthcare professional and individualized based on a patient's urinary citrate levels (107975,107989). Serum potassium levels should be monitored prior to starting potassium citrate, within 2 weeks of treatment initiation, and every 12 months (107975).

POSSIBLY EFFECTIVE

• Cardiovascular disease (CVD). Eating foods high in potassium and low in sodium might reduce the risk of cardiovascular disease. It is unclear if taking potassium supplements has the same benefit. Details: Large population studies in adults without prior CVD have found that higher dietary potassium intake is associated with a lower risk of cardiovascular events (109395,109399). One study found that daily potassium intake of about 3300 mg is associated with a 13% reduction in CVD risk when compared with intake of about 1920 mg (109399). The other study found that each additional 1000 mg of daily urinary potassium excretion, which is a marker of dietary intake, is associated with an 18% reduction in CVD risk (109395). Another observational study in over 15,000 adults with history of stroke or hypertension shows that replacing regular table salt with a substitute product containing 75% sodium chloride and 25% potassium chloride for an average of 5 years decreases the rate of stroke, major cardiovascular events, or death (107976). High quality clinical trials are needed to confirm this association. The US Food and Drug Administration (FDA) has determined that foods containing at least 350 mg potassium and that are low in sodium, saturated fat, and cholesterol can state that "diets containing foods that are good sources of potassium and low in sodium may reduce the risk of high blood pressure and stroke" (1310,8817).
• Stroke. Eating foods high in potassium and low in sodium might reduce the risk of stroke. It is unclear if taking potassium supplements has the same benefit. Details: Higher dietary intake of potassium seems to be associated with a lower risk of stroke. Population research has found that increasing dietary potassium intake by 1-1.5 grams daily is associated with up to a 20% reduced risk of stroke (92105,92107). Some population research has found that higher supplemental intake of potassium is associated with a 29% reduced risk of ischemic stroke. However, supplemental potassium intake is not found to be associated with a lower risk of hemorrhagic or total stroke (92107). An observational study in over 15,000 adults with history of stroke or hypertension shows that replacing regular table salt with a substitute product containing 75% sodium chloride and 25% potassium chloride for an average of 5 years decreases the rate of stroke, major cardiovascular events, or death (107976). High quality clinical trials are needed to confirm this association. The US Food and Drug Administration (FDA) has determined that foods containing at least 350 mg potassium and that are low in sodium, saturated fat, and cholesterol can state that "diets containing foods that are good sources of potassium and low in sodium may reduce the risk of high blood pressure and stroke" (1310,8817).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Dental hypersensitivity. It is unclear if topical potassium improves dental hypersensitivity. Details: One meta-analysis of clinical research shows that using a dentifrice containing 5% potassium nitrite reduces dentin sensitivity when compared with a dentifrice that does not contain potassium nitrite (69549). Other clinical research published in a systematic review shows that potassium-containing toothpastes might reduce dentin sensitivity more than controls that do not contain potassium. However, these toothpastes might be less effective than other active toothpastes, such as those containing sodium monofluorophosphate, and the effect may result from a placebo effect, since the mechanism of action of potassium is unclear (69456).
• Diabetes. It is unclear if increasing dietary potassium reduces the risk of diabetes. Details: A meta-analysis of 7 large population studies has found that consuming dietary potassium 3300-3500 mg daily is associated with a 20% reduction in the risk of diabetes when compared with consumption below 1000 mg daily. Results were similar when studies that measured potassium intake with a dietary questionnaire were analyzed separately from those that measured intake based on urinary potassium excretion (110776). However, the validity of this finding is limited by the heterogeneity of the included studies. Furthermore, despite use of data from various databases, most studies included in the analysis were conducted by the same author.
• Impaired glucose tolerance (prediabetes). It is unclear if oral potassium improves glycemic control in prediabetes. Details: A small clinical study in Black patients with prediabetes shows that taking extended-release potassium (Klor-Con M10, Cardinal Health) 40 mEq daily as potassium chloride for 3 months does not improve glucose tolerance when compared with placebo. Although fasting glucose levels were slightly reduced in the potassium group when compared with placebo, both groups experienced a worsening of glucose intolerance, with no change in insulin levels or glycated hemoglobin (98533).
• Osteoporosis. Although there is interest in using oral potassium for osteoporosis, there is insufficient reliable information about the clinical effects of potassium for this condition.
• Physical performance. It is unclear if oral potassium improves physical performance in older adults. Details: Observational research in older adults has found that decreased dietary potassium intake and increased dietary sodium intake over 5 years is associated with worsened physical performance (105450).
• Systemic lupus erythematosus (SLE). It is unclear if oral potassium is beneficial in patients with SLE. Details: Observational research in patients with SLE has found that increased dietary potassium intake is not associated with improvements in disease activity scores or markers of cardiovascular disease, including lipid levels and blood pressure, when compared with low dietary potassium intake. However, higher potassium intake does seem to reduce the odds of having elevated levels of C-reactive protein, a marker of inflammation, in these patients (109397). More evidence is needed to rate potassium for these uses.

(Read more about POTASSIUM)

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 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). Quercetin has also been evaluated in combination with another ingredient. A small clinical study in trained athletes shows that taking a single dose of quercetin (Quercetin Powder from Sophora Japonica Flower, Aki Organics) 140 mg and mangiferin 84 mg, a mango constituent, one hour prior to an intermittent high-intensity exercise test improves performance as measured by circuit time and reduces perceived exertion, but does not improve heart rate, sprint time, or subjective muscle soreness when compared with placebo (113077). It is unclear whether these effects are due to quercetin, mangiferin, or the combination.

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.

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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 EFFECTIVE

• Breast cancer. High dietary intake of soy might be beneficial for the prevention of breast cancer and breast cancer recurrence in some patients. However, soy supplements do not seem to be beneficial. Details: For prevention, most population research has found that higher dietary intake of soy is associated with up to a 26% reduced odds of developing breast cancer when compared with a lower intake (7335,7336,11038,11807,75377,75587,90955,108251). One meta-analysis of population research found that patients who consumed more than 15 mg soy isoflavones daily made up about 25% of all cases of breast cancer, compared with 75% of cases in the group of patients consuming less than 15 mg daily (108251). The effects appear to vary depending on the ethnicity of the patient. Population research has consistently found that a high-soy diet in Asian and Asian-American females is associated with a significantly reduced risk of breast cancer (7335,7336,11038,11807,75377,75587,90955). However, the amount of soy consumed in a Western diet, even among those who consume the highest amounts of soy, was not found to have a preventative effect (11391,17109,90955,90967). The reason for the disparate findings are unknown but may be related to genetic differences or differences in quantification of soy intake (7663,94153). Also, the prophylactic benefit seems to apply regardless of whether high amounts of soy are consumed during adolescence or later in life (7335,7336,9674). Limited population research has also found that consuming a diet high in soy is associated with up to a 25% reduced risk of breast cancer recurrence; however, it is unclear whether there is an association with reduced mortality in breast cancer patients (90956,90969,94154). The effect appears to be greater for certain subgroups of breast cancer patients. Increased dietary soy intake is associated with a 28% to 36% risk reduction in patients with estrogen receptor (ER)-negative tumors, a 30% risk reduction in patients with ER-positive/progesterone receptor (PR)-positive tumors, and a 25% to 36% risk reduction in postmenopausal patients (90956). Some small clinical studies have also evaluated the use of soy isoflavone extract . One small clinical study in patients with breast cancer shows that taking a soy isoflavone extract 200 mg daily for 2 weeks prior to surgery does not seem to affect cancer cell growth when compared with a historical control (11042). Another small clinical study in patients at high risk for breast cancer or with a history of breast cancer shows that taking a soy tablet containing 50 mg soy isoflavones (Novasoy, Archer Daniels Midland Co.) daily for 12 months does not alter mammographic or breast tissue density when compared with placebo (95999).
• Chronic kidney disease (CKD). Oral soy protein seems to improve some measures of disease severity in patients with CKD. Details: Clinical research shows that consuming soy protein seems to reduce proteinuria in people with kidney disease (2286,2287,2288,75249,75634). Also, a meta-analysis of clinical research in patients with CKD who are not on dialysis shows that soy protein intake reduces serum levels of creatinine by 0.07 mg/dL, phosphorus by 2.5 mg/dL, and triglyceride by 18 mg/dL when compared with placebo or control (90989).
• Diabetes. Diets high in soy seem to reduce the risk of type 2 diabetes. Also, oral soy protein, but not soy isoflavones, seems to modestly improve glycemic indices. It is unclear if soy is beneficial for lowering blood lipid levels or reducing cardiovascular (CVD) mortality risk in adults with type 2 diabetes. Details: A meta-analysis of observational studies has found that higher dietary intake of tofu, soy protein, or soy isoflavones is associated with an 8% to 16% lower risk of developing diabetes when compared with a lower dietary intake (105608). In menopausal patients without diabetes, a meta-analysis of clinical research shows that intake of soy isoflavones 40-161 mg daily seems to improve glycemic indices when compared with control (96423). Some research shows that soy can modestly improve glycemic indices in patients with diabetes. A meta-analysis of small low-quality clinical studies in patients with diabetes or metabolic syndrome shows that taking various formulations of soy protein modestly reduces fasting plasma glucose and insulin levels, as well as insulin resistance, when compared with control (96001). An older meta-analysis assessing both healthy patients and patients with diabetes shows that a whole soy diet reduces fasting blood glucose by about 4 mg/dL when compared with control (75493). Small clinical studies also suggest that an extract of the fermented soybean product, Touchi, acts as an alpha-glucosidase inhibitor. It seems to modestly lower blood glucose, glycated hemoglobin (HbA1c), and triglycerides in patients with type 2 diabetes (11762,75205). However, some conflicting evidence exists. A meta-analysis of small, low-quality clinical studies in patients with type 2 diabetes shows that taking soy isoflavones does not improve glycemic indices when compared with control (105610). Also, another meta-analysis of clinical research in patients with type 2 diabetes shows that taking soy protein and/or soy isoflavones for 6-12 weeks does not improve glycemic indices when compared with either soy protein without isoflavones, other protein, or placebo (105610). Reasons for these conflicting results are unclear but may relate to differences in baseline blood glucose levels, the formulation of soy, or the duration of treatment. Some research shows that soy may modestly improve the lipid profile in patients with diabetes. A meta-analysis of clinical research in patients with diabetes shows that taking soy protein and/or soy isoflavones for 6-12 weeks modestly reduces levels of total and low-density lipoprotein (LDL) cholesterol, but not high-density lipoprotein (HDL) cholesterol or triglycerides, when compared with control (105610). Consuming soy foods might reduce the risk of mortality related to CVD in patients with diabetes. Population research suggests that consuming soy foods at least four days each week is associated with a 23% reduced risk of CVD mortality when compared with never consuming soy foods. Consuming soy foods less than four times weekly is not associated with CVD mortality risk (108242). Soy is also of interest in the prevention or treatment of gestational diabetes. Population research has found that consumption of less than 40 grams of soy daily in the second trimester is associated with a 2.1-fold increased risk of gestational diabetes when compared with daily soy intake of 40 grams or more (108241). Also, a small clinical trial in patients with gestational diabetes shows that consuming a diet containing about 0.3 grams/kg soy protein for 6 weeks, beginning at 24-28 weeks' gestation, reduces blood glucose levels, insulin resistance, and triglyceride levels when compared with consuming a non-soy control diet (95993).
• Diarrhea. Oral soy fiber seems to reduce acute diarrhea in infants, although it may not be beneficial in adults. Details: Giving soy fiber-supplemented formula orally, either alone or in combination with oral rehydration solution, seems to reduce the duration of acute diarrhea in infants when compared with cow's milk formula or oral rehydration solution alone (2291,2292,75474,75517,75523,75531,75572). However, in some studies, a reduction in the duration of acute diarrhea was not observed when compared with cow's milk formula (75522,75542). In adult patients receiving nutrition via intubation, preliminary clinical research suggests that treatment with soy-polysaccharide fiber does not improve the incidence of diarrhea when compared to control (75508).
• Galactosemia. Oral soy protein can be used in infant formula to prevent symptoms of galactosemia. Details: Soy does not contain the sugar galactose. Some research suggests that giving oral isolated soy protein-based formula in place of milk-based formula to infants seems to be helpful for preventing symptoms of galactosemia (3400).
• Hyperlipidemia. Oral soy protein seems to modestly reduce lipid levels. However, purified soy isoflavone may not have the same benefit. Details: Consuming soy protein orally, in place of other dietary protein, seems to modestly reduce total cholesterol and low-density lipoprotein (LDL) cholesterol by about 3% to 4% when compared with control (842,2293,2294,2296,2585,3402,4755,6412,7346,7803)(8530,10459,42059,75356,105598,105604). Additionally, some research shows that soy protein might be more effective in patients with more severe hyperlipidemia (75497). The FDA has approved labeling for specific soy products that states that they may be used for cholesterol reduction in combination with a diet low in saturated fat and cholesterol. To be eligible for this labeling, soy products must provide at least 6.25 grams of soy protein per serving, which is 25% of the effective daily intake (3977). However, not all evidence is positive. Some studies have shown no benefit of soy protein or isoflavones on LDL cholesterol levels when compared to control (8521,9679,12034,17105,53771,75236)(75242,75274,75276). Furthermore, although a few clinical trials have shown significant decreases in triglycerides following supplementation with soy or soy protein isolate (75258,75365), most studies suggest that soy protein does not decrease triglycerides when compared to control (2293,6412,8530,12034,17105). The effect of soy protein on high-density lipoprotein (HDL) cholesterol is inconsistent. Most studies suggest that it does not increase HDL levels (2293,6412,8530,12034,75286)(75524), although some analyses of clinical research suggest that soy might increase HDL cholesterol levels by up to 4% when compared to control (75480,75497). Doses of soy protein have ranged from 25-135 grams daily, providing 40-318 mg daily of isoflavones; however, higher doses do not seem to be more effective (17106,105598). Some evidence suggests that soy protein providing more isoflavones, or supplemented with isoflavones, might be more effective (3402,6413,10459), but this has not been consistently found in studies (3402). Most studies evaluating soy protein products containing little to no isoflavones suggest that these products are not effective (3402,7346,9679); however, purified soy isoflavone supplements alone do not seem to decrease LDL cholesterol (851,4738,7345,8502,10459,14066). In addition to soy protein, limited evidence suggests that soy fiber alone might reduce total cholesterol, LDL cholesterol, and triglyceride levels when compared with placebo (75686,75689). There is also some evidence that ultra-high temperature (UHT) treatment of soy milk destroys any cholesterol-lowering activity (17106).
• Hypertension. Oral soy seems to modestly reduce blood pressure in some patients. Details: A meta-analysis of the available clinical research shows that consuming soy products modestly lowers systolic and diastolic blood pressure by an average of 1.6 mmHg and 1.2 mmHg, respectively, when compared with control (105605). This analysis is limited by high risk of bias and the lack of a dose-response relationship. An older meta-analysis, as well as individual clinical studies, in patients with prehypertension or mild hypertension show that consuming soy protein 18-40 grams, providing 118-143 mg of isoflavones, daily or black soy peptide 4.5 grams daily for 8 weeks reduces systolic blood pressure by about 4-8 mmHg and diastolic blood pressure by about 3-5 mmHg when compared with control (1313990962,90965). In normotensive patients, soy protein does not seem to reduce systolic or diastolic blood pressure (90965).
• Lactose intolerance. Oral soy protein can be used in infant formula to prevent symptoms of lactose intolerance. Details: Providing isolated soy protein-based formula orally to infants is an acceptable alternative to milk-based formulas, especially for infants with symptoms of lactose intolerance (3400).
• Menopausal symptoms. Oral soy seems to reduce hot flashes in patients with menopausal symptoms. Details: Consuming soy protein 15-60 grams, providing 34-100 mg of isoflavones, daily seems to modestly decrease the frequency and severity of hot flashes in some menopausal adults. Improvement seems to be greater in those with a higher frequency of hot flashes at baseline (2296,2297,3978,3986,3987,7653,9917,11805,15220,17110,75478)(75486,75649,92661,95997). Taking concentrated soy isoflavone extracts, providing 35-200 mg of isoflavones, daily seems to have similar effects (4751,6455,7802,9916,10460,11805,11993,11994,13209,15220)(15850,75478,90950,90979,92661). Higher doses of 100-200 mg of isoflavones daily and higher frequency of dosing intervals seem to have greater benefit (90950). Furthermore, the amount of the specific isoflavone genistein contained in a soy product may influence outcomes. According to one analysis, studies using products that provide at least 15 mg of genistein daily consistently show positive outcomes. Studies using products containing a lower concentration of genistein have produced inconsistent findings (15133). Not all research has found that soy extracts reduce hot flashes (7801,11806,14062,15038,15851,16762); some experts speculate that this is due to a high placebo response (9916). Some clinical research has compared soy isoflavone extracts to conventional estrogen replacement. In one study, a concentrated soy isoflavone extract of genistein 54 mg daily reduced hot flashes by 22% to 29%, compared to 54% in those taking 17beta-estradiol as 1 mg daily plus norethisterone acetate 0.5 mg daily (11994). Additional preliminary research suggests that taking a soy isoflavone extract providing 60 mg isoflavones twice daily is comparable in efficacy to conjugated estrogens 0.625 daily for reducing menopausal symptoms. Conjugated estrogens seem to work more quickly; it seems to take up to 2 months to achieve the full effect of soy isoflavones (13209). One clinical trial compared soy isoflavones 10-40 mg daily to S-equol, a soy isoflavone metabolite. Soy isoflavones were less effective for reducing hot flash frequency when compared with S-equol (90960). This has led to some speculation that the effectiveness of soy in relieving hot flashes is influenced by a patient's ability to convert daidzen, a soy isoflavone, to S-equol (90950). It is theorized that patients who are S-equol producers are more likely to achieve symptom relief from soy. However, observational and clinical research does not support this theory (90990,94162). Soy has also been evaluated for the management of other symptoms of menopause. Some clinical research in menopausal patients with depression suggests that taking soy 100 mg, providing 50 mg of soy isoflavones, in combination with sertraline 50 mg daily for three months improves depression severity when compared with sertraline or soy alone (90958). An analysis of two small clinical trials shows that supplemental soy providing 50-118 mg of isoflavones can reduce vaginal dryness scores by 0.26 when compared with control (92661). Also, an open-label study suggests that drinking a specific beverage (ViveSoy) containing soy protein 15 grams and soy isoflavones 50 mg orally daily for 12 weeks reduces overall urogenital symptoms when compared with a control group (95997). However, one small clinical study in perimenopausal patients shows that a soy-rich diet does not relieve urogenital symptoms, including vaginal dryness, itching, and urinary incontinence, when compared with a soy-free diet (75285).
• Metabolic syndrome. Oral soy protein seems to improve glycemic control and other markers of metabolic syndrome. Details: A meta-analysis of clinical research in patients with diabetes or metabolic syndrome shows that following a diet high in soy protein can decrease fasting plasma glucose and insulin levels, as well as insulin resistance, when compared with a control diet. Furthermore, dietary intake of soy protein modestly decreases diastolic blood pressure and low-density lipoprotein (LDL) cholesterol by a small amount in this population, although there is no effect on systolic blood pressure, high-density lipoprotein (HDL) cholesterol, or triglycerides (96001). Other clinical research shows that consuming a soy nut diet or a soy protein diet reduces fasting plasma glucose and LDL cholesterol levels when compared to baseline in postmenopausal adults with metabolic syndrome; however, the soy nut diet seems to more beneficial than either the soy protein diet or a Dietary Approaches to Stop Hypertension (DASH) diet (75378).
• Muscle strength. Oral soy protein seems to increase muscle strength. Details: Overall, soy protein combined with resistance training seems to increase muscle strength when compared with placebo (16748,75246,96942,98871). A meta-analysis of three clinical studies shows that consuming soy protein in addition to resistance training improves strength and lean body mass in untrained athletes (98871). Other clinical research shows that soy also improves muscle strength in trained athletes and postmenopausal adults (75246,96942). One study in Olympic endurance athletes shows that consuming isolated soy protein (Supro) 1.5 grams/kg daily for 8 weeks increases body mass and strength indices and reduces fatigue when compared with no protein supplementation (75246). Clinical research in postmenopausal adults undergoing resistance training 3 days weekly shows that taking soy protein 25 grams daily in skim milk for 16 weeks increases the maximum amount of weight lifted in one repetition by over 80% for both bench press and knee extension when compared to a maltodextrin placebo (96942). Soy protein has also been compared with other protein supplements. A meta-analysis of preliminary clinical studies and other clinical research show that soy protein seems to work as well as whey, beef, and dairy (casein and whey) protein for improving muscle strength (75404,85941,98871,105591). However, the validity of these findings is limited by the small size and high heterogeneity of the studies.
• Osteoporosis. Oral soy isoflavones seem to improve bone density and reduce the risk of osteoporosis in post-menopausal adults. Details: Most clinical research suggests that soy protein or soy extract containing 75-90 mg of isoflavones can increase bone mineral density (BMD), or slow BMD loss, and improve biochemical markers of bone turnover in peri- and postmenopausal adults when compared with control (842,4951,6449,9775,11082,90972,90980). Lower doses of isoflavones do not seem to be as beneficial. However, some observational research in postmenopausal Japanese adults and Chinese females aged 30-40 years has found that consuming about 50 mg dietary soy isoflavones daily is associated with a higher BMD when compared with lower soy isoflavone intake (7342,11081). An observational study in postmenopausal Asian patients has found that consuming higher dietary soy protein is associated with a lower risk of developing fractures when compared with lower amounts (13181). However, not all research has been positive. Some conflicting evidence suggests that soy protein does not improve BMD in some postmenopausal adults. The discrepancy in findings may be due to differences in soy formulations, concomitant treatments, or variable patient populations (4952,12034,14064,90978). For example, most evidence shows that soy does not affect BMD in premenopausal patients or bone turnover in adolescents (7660,8532,9684,11086). It is theorized that only people who can convert daidzein, a soy isoflavone, to S-equol might obtain benefits from soy (4952). However, clinical research suggests that there is no difference in bone calcium retention between equol producers and nonproducers (95995).

POSSIBLY INEFFECTIVE

• Benign prostatic hyperplasia (BPH). Oral soy does not seem to reduce BPH symptoms. Details: Clinical research in patients with BPH shows that taking soy isoflavones 40 mg (Soylife 40, Acatris) daily for 12 months does not improve peak urine flow rate, residual urine volume, symptoms of BPH, or general quality of life when compared with placebo (90983).
• Breast cancer-related hot flashes. Oral soy does not seem to reduce the risk for breast cancer-related hot flashes. Details: Clinical research shows that consuming a soy beverage providing soy isoflavones 90 mg daily or taking a soy extract providing soy isoflavones 50 mg three times daily does not reduce hot flashes in breast cancer survivors (3991,7658,8499). Observational research in breast cancer survivors has also found no association between hot flash incidence and soy isoflavone consumption (105602).
• Colorectal cancer. Oral soy does not seem to reduce the risk for colorectal cancer. Details: Some observational research from China and Japan has found that intake of soy protein or soy isoflavone is not associated with the risk of developing colorectal cancer (105601). Furthermore, some clinical research shows that soy protein powder 58 grams containing isoflavones 83 mg, taken daily for 12 months, does not reduce the proliferation of colorectal epithelial cells in patients with adenomatous polyps when compared to control (75282).
• Exercise-induced muscle soreness. Oral soy does not seem to reduce muscle soreness after exercise. Details: Some clinical research shows that taking soy isoflavone extract 120 mg orally for 30 days prior to exercise doesn't ameliorate muscle soreness caused by exercise when compared with placebo (8524).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alzheimer disease. It is unclear if oral soy improves cognition in patients with Alzheimer disease. Details: Preliminary clinical research in patients with Alzheimer disease shows that taking soy isoflavones (Novasoy, Archer Daniels Midland Co.) 100 mg daily for 6 months does not improve cognition when compared with placebo (96424).
• Androgen deprivation therapy (ADT)-associated hot flashes. One small clinical study in patients with prostate cancer receiving ADT shows that taking soy protein powder 20 grams, providing 160 mg of isoflavones, alone or along with venlafaxine 75 mg, once daily for 12 weeks does not improve the severity of hot flash symptoms when compared with milk protein, with or without venlafaxine (90981).
• Asthma. It is unclear if oral soy reduces asthma symptoms. Details: One population study has found that people with asthma who consume soy foods providing more than 250 mcg of genistein for every 1000 kcal consumed (e.g., 500 mcg/day for 2000 kcal diet) daily have increased lung function, as measured by FEV1 scores, when compared to those who consume less (11084). However, clinical research in adult and pediatric patients with poorly controlled asthma shows that taking soy isoflavones 50 mg twice daily for 24 weeks does not improve FEV1 scores, reduce the number of asthma episodes, or improve asthma symptoms when compared with placebo (90977).
• Cardiovascular disease (CVD). It is unclear if soy consumption reduces the risk for CVD or CVD-related mortality. More research is needed to determine whether certain populations may benefit from increased soy intake. Details: Due to mixed findings, it is unclear if consuming soy is associated with a reduced risk of CVD events. One population study has found that consuming at least 60 grams of soy daily over a 12-month period is associated with a 14% reduced risk of having a CVD event over the next 5 years, as well as a reduced risk of stroke, when compared with consuming less than 15 grams daily (108253). A study in Japan has found that consuming soy five or more times per week over a 10-year period is associated with fewer adverse cardiovascular outcomes in only a certain subset of patients when compared with consuming soy twice a week or less. Postmenopausal adults with the highest consumption had a 36% lower risk of stroke, a 45% lower risk of myocardial infarction, and a 65% lower risk of CVD mortality. However, risk was not significantly reduced in males or premenopausal adults (17108). In contrast, a study in Korea has found that consuming a median of 16.5 servings of soy per week is associated with a 64% reduced risk of CVD incidence in premenopausal, but not postmenopausal, adults when compared with a median of 4.7 servings per week. A subgroup analysis has found that the highest intake of tofu, but not soybeans, fermented soy paste, or soy milk, is associated with a reduced incidence of CVD (108243). Additionally, higher dietary intake of soy does not seem to be associated with a reduced risk of cardiovascular events in Western females (13040). The amount of phytoestrogens typically consumed in Western diets is significantly lower than the amount typically consumed in Asian diets. The form of soy food and isoflavone content might play a role in these discrepancies. Any association between consumption of soy-containing foods and CVD mortality is also unclear. A meta-analysis of observational studies conducted in China or Japan has found that the highest intake of soy-containing foods is not associated with a lower risk of CVD-related mortality when compared with the lowest intake (96941). A population study in patients with or without a prior history of CVD has also found that soy-containing food consumption is not associated with a lower risk of CVD-related mortality when compared with the lowest intake (108244). However, some research has found a positive effect of soy consumption on CVD mortality risk. A subgroup analysis of a meta-analysis has found that the highest intake of fermented soy products is associated with a 16% reduced risk of CVD mortality; higher intake of non-fermented soy is not associated with CVD mortality (96941). Population research in patients without a prior history of CVD has found that soy-containing food consumption is associated with a lower risk of myocardial infarction-related mortality when compared with the lowest intake (108244). Also, one population study in adults with type 2 diabetes has found that consuming soy-containing foods at least four days each week is associated with a 23% reduced risk of CVD mortality when compared with never consuming soy foods. Consuming soy foods less than four times weekly is not associated with CVD-related mortality (108242).
• Cervical cancer. It is unclear if oral soy reduces the risk for cervical cancer. Details: Population research has found that the highest dietary intake of soy over approximately 17 years is associated with a 57% decreased risk of cervical cancer when compared to the lowest intake of soy in females who also drank green tea. However, neither soy intake nor green tea intake alone was associated with a decreased risk of cervical cancer. Additionally, other population research has not confirmed an association between soy intake and cervical cancer (101800).
• Child growth. It is unclear if oral soy protein enhances child growth. Details: Preliminary clinical research in Colombian children 2-7 years of age shows that consuming a soy protein supplement dissolved in fruit juice on 6 days of every week for 1 year does not improve body mass index, body composition, weight, or height when compared with consuming fruit juice and whole milk. A sub-analysis shows that children consuming the soy protein supplement had an increase in weight-for-age when compared with the control group, indicating that the supplement may be beneficial for ensuring adequate weight and nutritional status during prepubertal growth (100320). However, the children in this study had normal or below average weight-for-age at baseline, limiting the applicability of these findings to other patient populations.
• Cognitive function. It is unclear if oral soy improves cognitive function; research is conflicting. Details: Some research shows that college students who increase consumption of soy foods providing isoflavones 100 mg daily have improved short- and long-term memory (9671). Postmenopausal patients aged 50-65 years who take a soy extract supplement providing isoflavones 60 mg daily also seem to have some improvement in some measures of cognitive function (12048). There is also evidence in postmenopausal patients aged 55-75 years that taking a soy extract supplement providing isoflavones 110 mg daily might improve verbal memory scores (12040). However, another study in this population shows that consuming 25.6 grams daily of soy protein providing 99 mg of isoflavones does not improve cognitive function (12034). Similarly, population research in females aged 42-52 years has found that increasing dietary intake of the isoflavones genistein and daidzein is not associated with improved measures of cognitive function (15042). These differing findings might be explained by variations in study design and soy formulations.
• Cognitive impairment. Oral soy has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults 55 years of age and older with mild cognitive impairment shows that taking a specific combination product (DW2009) containing fermented soybean powder and Lactobacillus plantarum daily for 12 weeks modestly improves composite cognitive function when compared with placebo (100319). It is not clear if this effect is due to soy, lactobacillus, or the combination.
• Colic. It is unclear if oral soy is beneficial in infants with colic. Details: Preliminary clinical research shows that consuming soy-based formula might reduce the duration of colic symptoms in infants with cows' milk intolerance (75509,75543). However, other clinical research shows that consuming soy-based formula does not improve crying in infants with colic when compared with dicyclomine hydrochloride 3 mg/kg daily (75573). Also, a meta-analysis of only high quality clinical research shows that soy milk formula does not improve the persistence of colic or the duration of crying in infants with colic when compared with control (75611).
• Crohn disease. It is unclear if oral soy improves symptoms of Crohn disease. Details: A small observational study in patients with inactive Crohn disease has found that taking oral soy-derived protein in combination with enteral treatment for 4 weeks is associated with increased bowel movements, improved symptoms such as fatigue and mental strain, and increased body weight when compared with standard enteral treatment alone (75175).
• Diabetic nephropathy. It is unclear if oral soy improves kidney function in patients with diabetic nephropathy. Details: A meta-analysis of small clinical trials in patients with diabetic nephropathy shows that consuming soy products, such as soy protein and soy milk, modestly reduces proteinuria and blood urea nitrogen (BUN), as well as levels of total and low-density lipoprotein (LDL) cholesterol, triglycerides, and fasting blood glucose, when compared with animal protein or cow's milk. However, there was no effect on any measures of kidney function (108247). Some individual small clinical trials show that replacing dietary animal protein with soy protein reduces urinary albumin excretion in patients with diabetic nephropathy (7348,12555,12556). However, one small clinical study shows that consuming soy milk 240 mL daily for 4 weeks does not affect urinary creatinine, blood urea nitrogen, proteinuria, or glomerular filtration rate in patients with diabetic nephropathy (90966).
• Dyspepsia. Oral soy protein has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults with mild or moderate dyspepsia shows that consuming 1 gram of toasted soy flour fermented with Lactobacillus delbrueckii up to three times daily for 3 weeks does not improve heartburn severity or frequency when compared with placebo (105599).
• Endometrial cancer. It is unclear if oral soy protein reduces the risk for endometrial cancer. Details: Most epidemiological research has found that increased soy intake is associated with a lower risk of endometrial cancer. Endometrial cancer incidence is lower in Japan, China, and other Asian countries where the typical diet is low in calories and high in soy, whole grain foods, vegetables, and fruits (7338,11036,90954). Also, a large meta-analysis of population research has found that the highest total and fermented soy intake is associated with a 17% to 19% reduced risk of developing endometrial cancer when compared to the lowest intakes in postmenopausal adults (96002). However, one clinical study shows that taking soy protein 25 grams daily providing 91 mg of aglycon equivalents of isoflavones and glycosides for three years does not reduce the risk of endometrial hyperplasia or cancer when compared with placebo in postmenopausal adults. However, this study may not have been adequately powered to detect small differences in the low rates of endometrial hyperplasia (90971).
• Fibromyalgia. It is unclear if oral soy reduces fibromyalgia symptoms. Details: Clinical research shows that consuming a shake containing soy protein 20 grams and soy isoflavone 160 mg once daily for 6 weeks does not improve physical functioning or symptoms of depression in patients with fibromyalgia when compared with placebo (75451).
• Gastric cancer. It is unclear if oral soy reduces the risk for gastric cancer. Details: Meta-analyses of population research have found that the highest intake of soy-containing foods and nonfermented soy products is associated with a 21% to 37% decreased risk of gastric cancer when compared with the lowest intake (95998,108246). Intake of at least 100 grams daily of nonfermented soy foods was found to be the most protective (95998). However, a high intake of fermented soy products is associated with an increased risk of gastric cancer, and intake of 1-5 cups daily of the fermented soy product miso soup is associated with an increased risk of gastric cancer in males (95998,108246).
• Hepatitis C. It is unclear if oral soy is beneficial for hepatitis C. Details: Preliminary clinical research in patients with hepatitis C shows that taking soy protein 32 grams daily for 12 weeks reduces the number of cases of steatosis by 47% and reduces alanine aminotransferase (ALT) levels by 13% when compared to baseline. However, it is no different than taking casein protein (90970).
• Irritable bowel syndrome (IBS). A small study suggests that oral soy isoflavones might reduce IBS symptoms. Details: A small clinical study in females with IBS shows that taking soy isoflavones 40 mg daily for 6 weeks improves symptoms of IBS, such as abdominal distention and abdominal pain severity and duration, by approximately 27% when compared with placebo. Quality of life is also improved. Some symptoms are also improved when soy isoflavones are taken in combination with vitamin D; however, the combination of soy isoflavones and vitamin D does not seem to improve symptoms better than soy isoflavones alone (96425).
• Lung cancer. It is unclear if dietary soy reduces the risk for lung cancer. Details: A meta-analysis of epidemiological research has found that although increased soy intake is not associated with a reduced risk of lung cancer overall, it is associated with a slightly reduced risk in nonsmoking adults (90985).
• Mastalgia. It is unclear if oral soy is beneficial for mastalgia. Details: A small clinical study suggests that soy milk providing 34 grams soy protein daily might reduce cyclical breast pain when compared with no intervention (2428).
• Migraine headache. Oral soy has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking a combination of soy isoflavones 60 mg, dong quai 100 mg, and black cohosh 50 mg daily for 24 weeks reduces the frequency of menstrual-associated migraine attacks when compared with placebo (35797). It is not clear if this effect is due to soy, the other ingredients, or the combination.
• Neonatal jaundice. It is unclear if oral soy reduces the risk of neonatal jaundice. Details: Clinical research shows that patients with gestational diabetes who consume a diet containing soy protein along with other plant and animal proteins for 6 weeks beginning at 24-28 weeks' gestation have a 73% reduced risk for newborn hyperbilirubinemia when compared with those consuming a control diet containing only non-soy plant and animal proteins (95993).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral soy is beneficial for the treatment or prevention of NAFLD. Details: Observational research in a Chinese population has found that increased frequency of dietary soy consumption is associated with a lower incidence of NAFLD when compared with lower consumption (105612). A meta-analysis of three small clinical trials in patients living in Iran with NAFLD shows that consuming soy milk, soy foods, or a genistein supplement for 8 weeks might reduce some liver transaminase levels when compared with control (105611). Another meta-analysis of small clinical trials in patients with NAFLD shows that consuming soy milk, soy foods, or a genistein supplement for 8 or 24 weeks modestly improves insulin resistance but does not improve body mass index, cholesterol levels, or liver transaminase levels (108239). These analyses are limited by their generally small population size and the heterogeneity of interventions.
• Obesity. It is unclear if consuming oral soy protein as part of a calorie-restricted diet improves weight loss; research is conflicting. Details: Some clinical research shows that consuming soy protein in conjunction with calorie restriction for 2-6 months helps reduce weight in those who are obese and overweight when compared with calorie restriction alone (11085,75397). Other clinical research shows that consuming soy protein for 16 weeks improves weight loss in overweight females when compared with consuming protein from meat (75620). Also, consuming black soy peptide 4.5 grams daily for 12 weeks reduces body weight and body fat mass more than placebo in overweight and obese adults (90961). In addition, some clinical evidence shows that eating biscuits supplemented with soy fiber 100 grams daily for 12 weeks reduces body weight, body mass index (BMI), and low-density lipoprotein (LDL) cholesterol when compared to control in overweight and obese patients (90960). However, contradictory evidence exists. Some clinical research shows that following a calorie-restricted diet and consuming soy-based meal replacements 3-5 times daily for 12-16 weeks, or eating soy protein-rich foods in place of animal protein for 2-12 weeks, does not improve weight loss in overweight or obese individuals when compared to a calorie-restricted diet alone (75277,75372,75376,90968). Also, in overweight and obese females following a free-choice diet, soy protein 56 grams daily for 23 weeks does not appear to improve weight loss when compared to eating an isoenergetic amount of carbohydrates (86077). Finally, a subgroup analysis of six preliminary clinical trials shows that soy products do not improve weight loss in postmenopausal adults (98870). The reason for these disparate findings is unclear but may be due to differences in the soy products used or differences in patient population. For example, a meta-analysis of clinical research shows that phytoestrogen consumption reduces weight in healthy postmenopausal adults but not in those with comorbid conditions (98870). However, the clinical validity of this analysis is limited because it did not evaluate the effect of soy-only phytoestrogens. Soy protein has also been compared with whey protein. One small clinical study in overweight and obese adults shows that patients taking soy protein isolate 52 grams for 23 weeks had similar overall weight and fat loss as those taking whey protein concentrate 52 grams daily (86077). In contrast, another small clinical study in overweight males shows that taking soy isolate 60 grams before lunch daily for 12 weeks is less effective for weight loss when compared with taking whey protein concentrate 65 grams (91801).
• Osteoarthritis. It is unclear if oral soy protein reduces osteoarthritis pain. Details: Preliminary clinical research shows that taking soy protein 40 grams daily for three months improves range of motion, pain, and quality of life in osteoarthritis patients, particularly males, when compared to baseline. However, these beneficial effects seem to also be observed following supplementation with milk-based protein, indicating that the benefits may have resulted from a placebo effect (75266).
• Overall mortality. It is unclear if dietary soy reduces overall mortality; the available research is conflicting. Details: A meta-analysis of observational studies has found that the highest intake of soy products is not associated with a lower risk of overall mortality, mortality from cardiovascular disease, or mortality from cancer when compared with the lowest intake (96941). However, a more recent population study has found that consuming at least 60 grams of soy daily over a 12-month period is associated with a 17% reduced risk of overall mortality over the next 5 years when compared with consuming less than 15 grams daily (108253). Also, an observational study in Japanese patients followed over 14.8 years has found that although overall soy intake is not associated with any benefit, increased intake of fermented soy products, such as natto and miso, was found to be associated with a slightly reduced risk of mortality (105600).
• Polycystic ovary syndrome (PCOS). It is unclear if oral soy reduces PCOS symptoms. Details: Clinical research shows that taking soy isoflavones 50 mg daily for 12 weeks improves insulin levels and insulin resistance by a small amount when compared with placebo in patients with PCOS. Furthermore, taking soy isoflavones improves the free androgen index by approximately 25% and triglyceride levels by 14% when compared to baseline. However, taking soy isoflavones does not improve low- or high-density lipoprotein (LDL or HDL) cholesterol levels or markers of inflammation (95994).
• Postmenopausal conditions. It is unclear if oral soy is beneficial for postmenopausal conditions. Details: A meta-analysis of generally small clinical trials in postmenopausal adults shows that taking soy protein with isoflavones or soy isoflavones, usually for 3-24 months, has modest beneficial effects on total cholesterol, and possibly high-density lipoprotein (HDL) cholesterol, when compared with milk protein, soy protein without isoflavones, or placebo. However, there was no effect on low-density lipoprotein (LDL) cholesterol or triglyceride levels. Subgroup analyses show that reductions in LDL cholesterol levels occur when soy is used for less than 6 months, in individuals older than 55 years, and when the soy protein contains isoflavones (108249).
• Preterm labor. It is unclear if oral soy reduces the risk for preterm labor. Details: Clinical research in patients with gestational diabetes shows that consuming a diet containing soy protein along with other plant and animal proteins for 6 weeks, beginning at 24-28 weeks' gestation, does not reduce the likelihood for caesarean section, preterm delivery, or maternal hospitalization when compared with a control diet containing only non-soy plant and animal proteins (95993).
• Premenstrual syndrome (PMS). It is unclear if oral soy reduces PMS symptoms. Details: Preliminary clinical research in patients with PMS shows that taking isolated soy protein containing soy isoflavones 68 mg daily for two menstrual cycles reduces cramps and swelling when compared with placebo (75279).
• Prostate cancer. It is unclear if oral soy is beneficial for the treatment or prevention of prostate cancer; research is conflicting. Details: Observational and clinical research has evaluated the effects of soy intake on prostate cancer risk. Observational research has found that consuming an Asian diet, which contains 10 times more soy than the average American diet, is associated with a lower risk of prostate cancer; however, it is unclear whether it is the soy content of the diet or if genetic differences or environmental factors such as fat ingestion are responsible for this correlation (2298,12884,12886,12887). A meta-analysis of observational trials from North America, Europe, and Asia has found that highest intake of total soy foods, unfermented soy foods, or soy isoflavones is associated with a reduced risk of prostate cancer when compared with the lowest intakes. However, higher intake of fermented soy foods is not associated with a reduced risk (96939). Furthermore, some observational research in Japanese males has found a weak association between increased prostate cancer mortality and a higher dietary intake of soy isoflavones when compared with a lower intake (105607). Research evaluating the use of soy supplements is also conflicting. One clinical study shows that taking soy protein 40 grams daily for 6 months reduces the development of prostate cancer six-fold in those at risk of prostate cancer when compared with milk protein (75432). However, another clinical study in healthy adults aged 50-80 years shows that taking soy protein, providing 83 mg isoflavones, daily for a year does not affect PSA levels when compared with a soy protein drink without isoflavones (12888). Soy products have also been evaluated in patients with prostate cancer. One clinical study shows that consuming a specific bread containing 50 grams of soy, providing 117 mg isoflavones, reduces PSA levels after about 3 weeks of treatment when compared with control (13140). Other preliminary clinical research in patients with rising PSA levels following prior therapy for prostate cancer shows that consuming 8 ounces of soy milk, standardized to contain 47 mg isoflavones, three times daily for 12 months slows the increase in PSA levels from 56% to 20% when compared with baseline (75435). However, one clinical study shows that taking soy protein 40 grams daily for 6 months does not reduce prostate size or improve PSA levels in those diagnosed with prostate cancer when compared with milk protein (75432). Also, in those with early stage prostate cancer, consuming a soy beverage daily providing genistein 60 mg does not seem to affect risk factors for progression of prostate cancer, including testosterone, estradiol, PSA, and sex hormone binding globulin (SHBG) levels (11033). Furthermore, consuming soy protein isolate 20 grams standardized to contain approximately 70 mg isoflavones daily for two years does not prevent prostate cancer recurrence following radical prostatectomy when compared with placebo (90953). Reasons for the discrepancies are not entirely clear, but may include the relatively short trial durations (up to 12 months) and heterogeneity of soy preparations and dosing regimens.
• Rheumatoid arthritis (RA). It is unclear if oral soy reduces RA symptoms. Details: Preliminary clinical research in patients with RA shows that consuming a liquid diet containing hydrolyzed soy protein (Top Up) daily for 4 weeks does not improve pain intensity, morning stiffness, or joint swelling and tenderness when compared to consuming a normal daily diet (75619).
• Sarcopenia. It is unclear if oral soy reduces age-related muscle loss; evidence is conflicting. Details: Some clinical research in postmenopausal adults shows that consuming soy protein containing isoflavones 99 mg daily for 12 months does not improve hand grip strength or physical performance when compared with a milk protein placebo (75283). However, another small clinical study in older adults with low muscle mass living in China shows that taking soy, or a whey-soy blended protein, 16 grams daily for 6 months, slightly attenuates muscle loss when compared with no intervention (105603).
• Stroke. It is unclear if oral soy improves outcomes and overall function in people who have had a stroke. Details: One small clinical study shows that older adults with a history of stroke who consumed soy milk 500 mL daily while participating in a rehabilitation program had greater improvements in hand grip strength, 8-feet walking speed, walking performance, and 6-minute walk test after 8 weeks when compared with placebo. However, consuming soy milk did not lead to greater improvements in lean mass or overall short physical performance battery (SPPB) scores when compared with placebo (100321).
• Thyroid cancer. It is unclear if dietary soy reduces the risk for thyroid cancer. Details: Epidemiological research has found that high dietary intake of soy is associated with a reduced risk of thyroid cancer when compared with lower intake (7662,12041).
• Vaginal atrophy. It is unclear if topical soy improves vaginal atrophy. Details: A small clinical study in postmenopausal adults with vaginal atrophy shows that applying one gram of soy extract 4% vaginal gel daily for 12 weeks reduces vaginal dryness and pain during sexual intercourse and improves vaginal endometrial thickness when compared with placebo (90964).
• Wrinkled skin. Small studies suggest that oral and topical soy might reduce wrinkles. Details: A small clinical study in middle-aged females shows that consuming soy isoflavone 40 mg daily for 12 weeks improves skin elasticity and the appearance of fine wrinkles when compared with placebo (75388). Another small clinical study in females with photodamaged skin shows that applying a soy moisturizer containing soybean trypsin inhibitor and Bowman-Birk protease inhibitor (Aveeno Positively Radiant Daily Moisturizer, Johnson & Johnson CCI) twice daily for 12 weeks improves skin pigmentation, fine lines, texture, tone, and appearance when compared with a placebo moisturizer (75410). More evidence is needed to rate soy for these uses.

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POSSIBLY EFFECTIVE

• Athletic performance. Regular consumption of whey protein in conjunction with exercise may improve muscle strength and performance. However, inconsistent consumption of whey protein, as well as intake of whey protein without concomitant exercise, may not be beneficial. Details: Most clinical research shows that taking whey protein 1.2-1.5 grams/kg or 30-33 grams daily in combination with strength training for 6-21 weeks can increase lean body mass, strength, and muscle hypertrophy in healthy young adults (16728,16729,16748,46552,85765,85910,91806,96025,102173). Higher doses of whey protein, such as 46-77 grams daily, have also been shown to increase strength when combined with athletic training (98886,98888). Some clinical research shows that whey protein hydrolysate (Lacprodan HYDRO.365, Arla Food Ingridiens Group P/S) twice daily for 1 week may slightly improve running speed (91793). However, less frequent intake or lower doses of whey protein do not seem to be beneficial for muscle strength. Some clinical research in middle-aged males shows that taking whey protein 35 grams three times weekly with resistance training for 14 weeks does not improve strength or muscle mass when compared with placebo (46736,85893). A small clinical study in trained males shows that taking whey protein 25 grams daily has no effect on body mass or strength after 2 weeks of detraining and 4 weeks of retraining when compared with maltodextrin (96021). Also, consuming whey protein without concomitant exercise does not seem to improve body composition or strength. Some clinical research shows that whey protein does not improve muscle mass or strength in obese postmenopausal patients who are losing weight through diet without exercise (98889). Some research has compared whey protein to other types of protein. A meta-analysis of preliminary clinical research, as well as individual clinical studies, show that whey protein is similarly beneficial to soy, beef, chicken, and dairy (casein with whey) protein for improving muscle strength (85941,98871,98888,105591). However, the validity of these findings is limited by the small size and high heterogeneity of the studies.

POSSIBLY INEFFECTIVE

• Chronic obstructive pulmonary disease (COPD). Oral whey protein does not seem to improve COPD symptoms. Details: Clinical research in adults with COPD shows that taking a specific whey protein supplement (ImuPower) 12 grams twice daily for 6 weeks can improve shortness of breath, but not lung function, exercise tolerance, or quality of life, when compared with placebo (86302). Other clinical research shows that taking a pressurized whey protein supplement 20 grams daily for 16 weeks, in combination with strength training for weeks 8-16, does not improve exercise tolerance, lung function, or muscle function when compared with placebo (86025).
• Osteoporosis. Oral whey protein does not seem to improve bone mineral density in older adults. Details: Clinical research shows that taking whey protein 30-45 grams daily for up to 2 years does not improve bone density when compared with a low-protein placebo in postmenopausal patients and males over 70 years of age (86074,91796). Taking whey protein 20-60 grams daily for 36 weeks also does not improve bone density when compared with an isoenergetic placebo in overweight or obese adults undergoing an exercise program (96027). The effect of whey protein in patients with osteoporosis has not been evaluated.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Age-related cognitive decline. It is unclear if oral whey protein is beneficial for age-related cognitive impairment. Details: Preliminary clinical research in older adults with subjective cognitive decline shows that taking whey peptide 1 gram for 12 weeks does not improve memory, executive functioning, or attention when compared with placebo. However, in a subgroup of patients with high levels of fatigue, whey peptide modestly improved memory (98885).
• Asthma. It is unclear if oral whey protein is beneficial in children with asthma. Details: A very small clinical study in children with asthma shows that taking a specific type of whey protein (HMS 90, Immunotec Inc.) 20 grams daily for 30 days does not improve lung function when compared to baseline (85833). The validity of this finding is limited by the lack of a comparator group.
• Atopic dermatitis (eczema). It is unclear if consuming infant formula containing whey protein reduces the risk of developing eczema. Details: A high-quality meta-analysis of small clinical studies shows that use of infant formula containing hydrolyzed whey protein for 4-6 months is no better than standard milk formula for reducing the risk of eczema (105585). This is in contrast to older meta-analyses that found benefit after consumption of fully or partially hydrolyzed whey protein (85987,86007,86048). However, these older publications had notable conflicts of interest and did not include small negative studies (105585). In 2011, the US Food and Drug Administration (FDA) allowed a qualified health claim in healthy infants with a family history of allergy who are not solely breastfed. It stated that feeding a formula of 100% partially hydrolyzed whey protein instead of formula containing intact cow's milk proteins from birth up to 4 months of age may reduce the risk of atopic dermatitis throughout 1-3 years of age. However, the FDA has concluded that there is very little scientific evidence to support this claim (102311).
• Atopic disease. It is unclear if consuming infant formula containing whey protein reduces the risk of developing atopic disease. Details: A high-quality meta-analysis of small clinical studies shows that use of infant formula containing hydrolyzed whey protein for 4-6 months is no different than standard milk formula for reducing the risk of atopic disease. However, there was a non-significant trend to reduced risk in the hydrolyzed whey protein group (105585). This finding conflicts with older meta-analyses which found benefit with hydrolyzed whey protein formula (85987,86007). However, these older publications had notable conflicts of interest and did not include small negative studies (105585).
• Cystic fibrosis. It is unclear if oral whey protein is beneficial for children or adults with cystic fibrosis. Details: A small clinical study in patients with cystic fibrosis shows that taking pressurized whey protein, 20 grams in children and 40 grams in adults, daily for 28 days, improves lung function in children, but not adults, when compared with baseline (85995). The validity of this finding is limited by the lack of a comparator group.
• Diabetes. It is unclear if oral whey protein is beneficial for improving glycemic control in people with type 2 diabetes. Details: A small clinical study in patients with well-controlled diabetes shows that consuming a 220 kcal drink containing whey protein concentrate 50 grams (Beit Haemek Advanced Technologies, Beit Haemek) before a meal lowers blood glucose levels by 28% and increases insulin levels in the first 3 hours after a meal when compared with drinking water (91795). However, whey protein does not seem to have long-term benefit on glycemic control when added to an exercise regimen. Another small clinical study in middle-aged males with type 2 diabetes shows that adding 20 grams of whey protein daily for 10 weeks to high-intensity mixed-mode interval training (MMIT) does not further improve glycemic control or body composition when compared to MMIT with placebo (98883).
• Exercise-induced asthma. It is unclear if oral whey protein is beneficial for exercise-induced asthma. Details: A small clinical study in patients with exercise-induced asthma shows that taking whey protein 30 grams daily for 10 days improves lung function when compared to baseline (85791). The validity of this finding is limited by the lack of a comparator group.
• Exercise-induced muscle damage. It is unclear if oral whey protein is beneficial for attenuating exercise-induced muscle damage; evidence is conflicting. Details: A meta-analysis of small heterogeneous clinical studies in trained and untrained adults shows that supplementation with a median dose of whey protein 25 grams (range 20-120 grams) given after and/or before exercise modestly improves muscle recovery measured over 3 days when compared with control (98881). Individual studies included in the analysis used whey protein 1.5 grams/kg daily for up to 2 weeks (86044), and whey protein isolate or whey protein hydrolysate (NatraPro or NatraBoost XR, MG Nutritionals) 25 grams three times in 24 hours (85915). Other small studies have not found benefit, but it is unclear if they were adequately powered. One small clinical study in healthy untrained males shows that taking whey protein 36.6 grams daily, starting 7 days before and continuing until 4 days after arm exercise, does not prevent muscle soreness over 5 days or attenuate reductions in strength (96024). Another small study in untrained healthy males shows that taking whey protein isolate (biPro, Eden Prairie) 0.3 grams/kg three times daily for 5 days does not reduce self-reported delayed onset muscle soreness, but may reduce creatine kinase, a biomarker of muscle damage, when compared with water (104758). Whey protein may not be beneficial for recovery from exercise in trained athletes. Small clinical studies show that consuming a whey protein beverage before or after exercise does not improve muscle recovery for trained adult and adolescent athletes when compared with a carbohydrate or non-caloric control (86303,91799,105592).
• Hepatitis. It is unclear if oral whey protein is beneficial for hepatitis. Details: A small clinical study in patients with chronic hepatitis B shows that taking a specific type of whey protein (Immunocal) 12 grams twice daily for 12 weeks can reduce liver transaminase levels and can increase glutathione (GSH) levels when compared with baseline. However, whey protein supplementation does not seem to improve liver function in patients with chronic hepatitis C (85687). The validity of these findings is limited by the lack of a comparator group.
• HIV/AIDS. It is unclear if oral whey protein is beneficial for improving immune function in children with HIV/AIDS. Details: One small clinical study in children with rapidly progressive HIV infection shows that taking whey protein at levels corresponding to 20% to 50% of total required protein for 4 months does not affect CD4 or CD8 cell count or the ratio of CD4+/CD8+ when compared with baseline. However, the occurrence of acute co-infections might be reduced with whey protein supplementation when compared with control (85781).
• HIV/AIDS-related wasting. Although oral whey is an adequate source of protein, it is unclear if it is better than other protein sources for reducing HIV/AIDs-related wasting. Details: A small open-label clinical study in malnourished patients with HIV shows that taking whey protein (dose unspecified) daily for 14 weeks increases muscle and fat mass when compared with baseline (85693). The validity of these findings is limited by the lack of a comparator group. Another small study in patients with HIV, stable weight, and a history of unintentional weight loss shows that taking whey protein 40 grams daily for 12 weeks does not affect weight or muscle mass when compared with taking an isocaloric control (85921). These study findings are limited because they cannot be generalized to patients with active weight loss or wasting. Another limitation is the higher dropout rate in the whey protein group due to gastrointestinal adverse events.
• Hyperlipidemia. It is unclear if oral whey protein is beneficial for lowering cholesterol levels. Details: A very small clinical study in overweight males with hyperlipidemia shows that taking whey protein 26.6 grams daily while participating in a resistance training program for 12 weeks reduces total cholesterol levels when compared with baseline but not when compared with placebo (85941). A meta-analysis of small heterogeneous clinical studies in healthy adults, as well as those with obesity and/or mild hypertension, shows that consuming whey protein alone or with other interventions seems to reduce lipid levels when compared with control (105586). However, most included studies were in patients without hyperlipidemia; it is unclear if whey protein is beneficial in patients with hyperlipidemia. Furthermore, these findings are limited by the variability in whey protein dosing, study duration, and patient population.
• Hypertension. It is unclear if oral whey protein reduces blood pressure. Details: Preliminary clinical research shows that drinking a beverage containing whey protein 2.6 grams daily for 12 weeks does not lower blood pressure in patients with mild hypertension when compared with placebo (85835). Also, taking whey protein 28 grams twice daily in water for 8 weeks reduces 24-hour systolic and diastolic blood pressure by 2.9 mm Hg and 2 mmHg, respectively, when compared with maltodextrin or casein in adults with mild hypertension and prehypertension. There were also improvements in endothelial function (96019).
• Mitochondrial myopathies. It is unclear if oral whey protein improves symptoms in patients with mitochondrial myopathies. Details: A small clinical study in individuals with mitochondrial diseases shows that taking a whey protein supplement 10 grams daily for one month does not improve muscle strength or quality of life when compared with placebo (85984).
• Nonalcoholic steatohepatitis (NASH). It is unclear if oral whey protein improves NASH. Details: A small clinical study in patients with untreated NASH shows that taking whey protein 20 grams daily for 12 weeks can reduce liver function tests, including alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and reduce hepatic macrovesicular steatosis when compared with baseline (85961). The validity of these findings is limited by the lack of a comparator group.
• Obesity. It is unclear if oral whey protein is beneficial for weight loss when used without dietary modifications. Adding whey protein to a calorie-restricted diet or an exercise regimen does not seem to improve weight loss. Details: Most research in overweight and obese individuals shows that taking whey protein along with a low-calorie diet and/or in addition to an exercise program does not further increase weight loss when compared with the low-calorie diet or exercise alone (85897,86069,86130,91794,91798,91802,96027,102172). However, a small clinical study in patients who have regained weight after bariatric surgery shows that following a low-calorie diet and taking whey protein 0.5 grams/kg daily for 16 weeks reduces body weight by about 2 kg and fat mass by about 3 kg when compared with following a low-calorie diet alone (96022). When whey protein is taken without diet modifications, studies have yielded conflicting results. One small clinical study in overweight and obese adults shows that taking whey protein isolate 27 grams twice daily for 12 weeks does not reduce body weight when compared with a glucose control (86011). However, another small clinical study in overweight and obese adults shows that taking whey protein concentrate 52 grams daily for 23 weeks reduces weight by 1.8 kg and fat by 2.4 kg when compared with a carbohydrate control, but is no better than taking soy protein isolate 52 grams (86077). In contrast, a small clinical study in overweight males shows that taking whey protein concentrate 65 grams before lunch daily for 12 weeks decreases calorie intake and reduces weight by about 1 kg when compared with taking soy protein isolate 60 grams (91801). In contrast to adults, supplementation with whey protein might increase weight in adolescents. A clinical study in overweight adolescents shows that consuming 1 liter of a milk-based whey protein drink daily for 12 weeks increases weight and body mass index when compared with a water control (86144).
• Parkinson disease. It is unclear if oral whey protein improves symptoms of Parkinson disease. Details: Clinical research in a small group of patients shows that taking a specific type of whey protein isolate (HMS 90/Immunocal) 10 grams twice daily for 6 months does not improve symptoms of Parkinson disease when compared with placebo (96026). However, this study may have been inadequately powered to detect a difference between groups.
• Polycystic ovary syndrome (PCOS). It is unclear if oral whey protein improves symptoms and metabolic effects of PCOS. Details: One small clinical study in patients with PCOS shows that taking 240 kcal as a nutritional supplement containing pure whey protein 96% daily, in addition to a calorie-restricted diet for 2 months, reduces body weight, fat mass, and cholesterol and apolipoprotein B levels when compared with a simple sugar control supplement. However, the whey protein supplement does not improve glucose or insulin levels, and seems to decrease high-density lipoprotein (HDL) cholesterol levels (85912). The validity of this study is limited by its small size and a significant dropout rate.
• Polymyalgia rheumatica. It is unclear if oral whey protein improves muscle function in patients with polymyalgia rheumatica. Details: A small clinical study in patients with polymyalgia rheumatica shows that taking a whey protein-enriched dairy product twice daily for 8 weeks does not improve lower limb muscle function, walking speed, chair stand test performance, peak jump power, or peak jump force when compared with a regular dairy product (Play, Valio Ltd.) (86075).
• Psoriasis. It is unclear if oral whey protein improves psoriasis. Details: A small clinical study in patients with stable psoriasis shows that taking a specific whey protein extract product (Dermylex, Advitech, Inc.) 5 grams daily for 8 weeks modestly decreases symptom severity when compared with placebo (85885).
• Sarcopenia. Research on the use of oral whey protein in older adults with sarcopenia is conflicting. Details: Small clinical studies in trained older females show that consuming whey protein 35 grams three times weekly for 12 weeks, either before or after resistance training, modestly increases skeletal muscle mass, strength, and functional capacity when compared with resistance training and insufficient protein intake (98887,98890). Research on the use of whey supplementation without exercise is conflicting. A small clinical study in older adults with low muscle mass living in China shows that taking whey, or a whey-soy protein blend, 16 grams daily for 6 months slightly attenuates muscle loss when compared with no intervention (105603). However, a clinical study in healthy, active older adults living in Denmark shows that taking whey protein hydrolysate 20 grams twice daily does not increase muscle size or strength when compared with a carbohydrate control (105593). This finding may not be generalizable to frail adults or those with existing sarcopenia. Whey protein with or without exercise has shown benefit when used in combination with other nutrients. Specifically, whey protein 60 grams has been used with creatine 5 grams, calcium 800 mg, vitamin D 1000 IU, and omega-3 fatty acids 3 grams (Infinit Nutrition) for 6 weeks (96016). A beverage with leucine-enriched whey protein 20 grams has been used in combination with vitamin D 800 IU (Nutricia Advanced Medical Nutrition) daily for 6 weeks (96017). Another beverage containing whey protein 20 grams and vitamin D 800 IU has been used daily for 6 months (98882).
• Sepsis. It is unclear if oral whey protein is beneficial in children with sepsis. Details: A very small clinical study in long-term intensive care pediatric patients shows that taking a specific whey protein supplement (Beneprotein) 0.3 grams/kg daily for up to 28 days has a similar effect on the time to onset and the rate of hospital-acquired infection or sepsis when compared with taking a combination of zinc, selenium, glutamine, and metoclopramide. It is not clear how these results compare to patients receiving no supplementation (86095). More evidence is needed to rate whey protein for these uses.

(Read more about WHEY PROTEIN)

POSSIBLY SAFE ...when used orally and appropriately for up to 3 years (5311,18113,30784,30785,30778). When used topically for up to 8 weeks (111125). ...when used intravenously and appropriately (5308,5309,5310,5311,5312,5313).

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

(Read more about ALPHA-KETOGLUTARATE (AKG))

LIKELY SAFE ...when used orally and appropriately in doses of up to 6 grams daily (698,10631). However, some patients have used up to 20 grams daily with apparent safety (698). Betaine anhydrous is available as an FDA-approved prescription product (Cystadane) (698), and also as a supplement. The European Food Safety Authority states that betaine anhydrous is safe to use in doses up to 6 mg/kg daily, in addition to usual dietary intake (105548). There is insufficient reliable information available about the safety of topical betaine anhydrous.

CHILDREN: LIKELY SAFE
when used orally and appropriately in doses up to 150 mg/kg daily (698). However, some patients have used up to 20 grams daily with apparent safety (698). Prescription betaine anhydrous (Cystadane) is approved by the US FDA for use in infants and children (698).

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

(Read more about BETAINE ANHYDROUS)

LIKELY SAFE ...when used orally and appropriately. BCAAs 12 grams daily have not been associated with significant adverse effects in studies lasting for up to 2 years (68,72,73,74,10117,10146,10147,37120,92643,97531,103351,103352). ...when used intravenously and appropriately. BCAAs are an FDA-approved injectable product (13309).

CHILDREN: LIKELY SAFE
when used orally in dietary amounts of 71-134 mg/kg daily (11120,13308).

CHILDREN: POSSIBLY SAFE
when larger, supplemental doses are used orally and appropriately for up to 6 months (13307,13308,37127).

PREGNANCY:
Insufficient reliable information available; avoid using amounts greater than those found in food. Although adverse effects have not been reported in humans, some animal research suggests that consumption of supplemental isoleucine, a BCAA, during the first half of pregnancy may have variable effects on birth weight, possibly due to abnormal placental development (103350).

LACTATION:
Insufficient reliable information available; avoid using amounts greater than those found in food. Although the safety of increased BCAA consumption during lactation is unclear, some clinical research suggests that a higher concentration of isoleucine and leucine in breastmilk during the first 6 months postpartum is not associated with infant growth or body composition at 2 weeks, 2 months, or 6 months (108466).

(Read more about BRANCHED-CHAIN AMINO ACIDS (BCAA))

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). Other clinical studies suggest that, when combined with vitamin D supplementation, calcium supplementation is not associated with an increased risk of CVD, CHD, or MI (93533,107231). 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, to consider total calcium intake from both dietary and supplemental sources (17484), and to combine calcium supplementation with vitamin D supplementation (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). Other clinical studies suggest that, when combined with vitamin D supplementation, calcium supplementation is not associated with an increased risk of CVD, CHD, or MI (93533,107231). 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, to consider total calcium intake from both dietary and supplemental sources (17484), and to combine calcium supplementation with vitamin D supplementation (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).

(Read more about CALCIUM)

LIKELY SAFE ...when used orally and appropriately. Casein peptides have been safely used in clinical trials lasting up to 5 months (85648,103763,103764,103765,103770,103772).

CHILDREN: LIKELY SAFE
when used orally and appropriately. Casein peptide formulas have been safely used in healthy, premature, and very low birth weight infants (91262,91264,91643,91673,91675).

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

(Read more about CASEIN PEPTIDES)

LIKELY SAFE ...when used orally and appropriately. Casein protein has been safely used in clinical trials lasting up to 12 months (16728,85932,91251,91253,91255,91266,91267,91268,91286,91294)(91641).

CHILDREN: POSSIBLY SAFE
when used orally and appropriately. Casein protein formulas have been safely used in healthy, premature, and very low birth weight infants (91646,91667).

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

(Read more about CASEIN PROTEIN)

LIKELY SAFE ...when used orally and appropriately, short-term. Creatine supplementation appears to be safe when used at loading doses of up to 25 grams daily or 0.3 grams/kg daily for up to 14 days in healthy adults (1367,2100,2101,3996,4569,10064,15354,15520,46570,46587)(46673,46688,46719,46753,46801,103278,103279,108336). Creatine supplementation also appears to be safe when used at maintenance doses of 4-5 grams daily for up to 18 months (2101,4578,15353,15354,15520,46587,46673,46690,46753,46838,102164,103278,108336).

POSSIBLY SAFE ...when used orally and appropriately, long-term. Creatine supplementation has been safely used at doses of up to 10 grams daily for up to 5 years in some preliminary clinical research (1367,3996). There is insufficient reliable information available about the safety of creatine when used topically.

CHILDREN: POSSIBLY SAFE
when used orally and appropriately. Creatine supplementation appears to be safe when used in appropriate doses in infants and children. Creatine 3-5 grams daily for 2-6 months has been safely used in children 5-18 years of age (6182,46596,46739,46841). Creatine 2 grams daily for 6 months has been safely used in children 2-5 years of age (46841). Additionally, weight-based dosing of creatine 0.1-0.4 grams/kg daily in infants and children or 4.69 grams/m2 in children weighing over 40 kg has been used safely for up to 6 months (46623,46629,46694,46759,104672).

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

(Read more about CREATINE)

POSSIBLY SAFE ...when a specific Ecklonia cava phlorotannin extract (SeaPolynol) is used orally and appropriately. Doses of up to 400 mg daily have been used with apparent safety for 12 weeks (106334,106336). According to the European Food Safety Authority (EFSA), doses of up to 263 mg daily are considered safe based on extrapolation from animal toxicity research (106333). ...when other sources of Ecklonia cava polyphenols are used orally, short-term. Doses up to 144 mg daily have been used with apparent safety for up to 12 weeks (96376). ...when a specific Ecklonia cava polyphenol-rich extract (AG-dieckol, Aqua Green Tech Co.) is used orally and appropriately. Doses of up to 1500 mg daily have been used with apparent safety for up to 12 weeks (96375).

CHILDREN: POSSIBLY SAFE
when a specific Ecklonia cava phlorotannin extract (SeaPolynol) is used orally and appropriately in children 12 years and older. According to the EFSA, doses of up to 163 mg daily are considered safe in children aged 12-14 years, and 230 mg daily is considered safe in children aged 14 years and above, based on extrapolation from animal toxicity research (106333). There is insufficient reliable information available about the safety of Ecklonia cava in children under 12 years of age.

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

(Read more about ECKLONIA CAVA)

LIKELY SAFE ...when used orally in amounts commonly found in foods. Fenugreek has Generally Recognized as Safe (GRAS) status in the US (4912).

POSSIBLY SAFE ...when the seed is used orally in medicinal amounts. Fenugreek seed powder 5-10 grams daily has been used with apparent safety for up to 3 years. Fenugreek seed extract 1 gram daily has been used with apparent safety for up to 3 months (7389,9783,18359,18362,49868,90112,90113,90117,93419,93420)(93421,93422,93423,96065,103285,108704).

CHILDREN: LIKELY SAFE
when used orally in amounts commonly found in foods (4912). There is insufficient reliable information available about the safety of fenugreek when used in larger amounts. Unusual body and urine odor has been reported after consumption of fenugreek tea. Although the odor appears to be harmless, it may be misdiagnosed as maple syrup urine disease (9782,96068).

PREGNANCY: LIKELY UNSAFE
when used orally in amounts greater than those found in food. Fenugreek has potential oxytoxic and uterine stimulant activity (12531). There are case reports of congenital malformations, including hydrocephalus, anencephaly, cleft palate, and spina bifida, after consumption of fenugreek seeds during pregnancy (96068). Consumption of fenugreek immediately prior to delivery may cause the neonate to have unusual body odor. Although this does not appear to cause long-term sequelae, it may be misdiagnosed as maple syrup urine disease (9781,96068).

LACTATION: POSSIBLY SAFE
when used orally to stimulate lactation, short-term. Although most available clinical studies lack safety testing in the lactating parent or infant (12535,22569,22570), some evidence suggests that taking fenugreek 1725 mg three times daily orally for 21 days does not cause negative side effects in the infant (90115).

(Read more about FENUGREEK)

POSSIBLY SAFE ...when applied topically to the skin. A gel containing 1% Fucus vesiculosus extract, applied to the skin twice daily, has been used in clinical research with apparent safety for up to 5 weeks (12799).

POSSIBLY UNSAFE ...when used orally due to its iodine content and possible heavy metal content. Fucus vesiculosus contains up to 0.05% iodine or 226 mcg/gram dry weight (12789,74217). Ingesting more than 150 mcg of iodine daily can cause hyperthyroidism or exacerbate existing hyperthyroidism (12788). Fucus vesiculosus can also contain heavy metals, including cadmium, arsenic, and lead, and can cause heavy metal nephropathy (12789,12800,74213).

PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used orally because it may contain iodine and heavy metals (12789,74213,74217); avoid using.

(Read more about FUCUS VESICULOSUS)

POSSIBLY SAFE ...when used orally and appropriately. Glycine has been used safely at doses up to 6 grams daily for 4 weeks (106497) and doses up to 9 grams daily for 3 days (10250,10251,10252,92319). There is insufficient reliable information available about the safety of glycine when used topically.

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

(Read more about GLYCINE)

POSSIBLY SAFE ...when used orally and appropriately. L-arginine has been used safely in clinical studies at doses of up to 24 grams daily for up to 18 months (3331,3460,3595,3596,5531,5532,5533,6028,7815,7816)(8014,8473,13709,31943,91195,91196,91963,99264,99267,110380)(110387). A tolerable upper intake level (UL) for arginine has not been established, but the observed safe level (OSL) of arginine intake established in clinical research is 20 grams (31996). ...when used intravenously and appropriately. Parenteral L-arginine is an FDA-approved prescription product (15). ...when used topically and appropriately. L-arginine appears to be safe when 5 grams is applied as a topical cream twice daily for 2 weeks or when a dentifrice is used at a dose of 1.5% w/w for up to 2 years (14913,96806). ...when inhaled, short-term. L-arginine appears to be safe when inhaled twice daily at a dose of 500 mg for up to 2 weeks (96807).

CHILDREN: POSSIBLY SAFE
when used orally in premature infants and children (8474,32286,96803,97392,110391). ...when used intravenously and appropriately (97392). Parenteral L-arginine is an FDA-approved prescription product (15). ...when used topically, short-term. A dentifrice containing L-arginine appears to be safe when used at a dose of 1.5% w/w for up to 2 years in children at least 3.7 years of age (96806). ...when inhaled, short-term. L-arginine appears to be safe when inhaled twice daily at a dose of 500 mg for up to 2 weeks in children at least 13 years of age (96807).

CHILDREN: POSSIBLY UNSAFE
when used intravenously in high doses. Parenteral L-arginine is an FDA-approved prescription product (15). However, when higher than recommended doses are used, injection site reactions, hypersensitivity reactions, hematuria, and death have occurred in children (16817).

PREGNANCY: POSSIBLY SAFE
when used orally and appropriately, short-term. L-arginine 12 grams daily for 2 days has been used with apparent safety in pregnancy during the third trimester (11828). L-arginine 3 grams daily has been taken safely during the second and/or third trimesters (31938,110379,110382). ...when used intravenously and appropriately, short-term. Intravenous L-arginine 20-30 grams daily has been used safely in pregnancy for up to 5 days (31847,31933,31961,31978).

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about L-ARGININE)

LIKELY SAFE ...when used orally in amounts commonly found in food (94500).

POSSIBLY SAFE ...when used orally or intravenously and appropriately in medicinal amounts under the supervision of a healthcare professional (2410,2411,2413).

POSSIBLY UNSAFE ...when used orally or intravenously in excessive doses. Doses larger than 100 mg/kg should be avoided to prevent severe and potentially lethal cerebral effects (9339).

CHILDREN: LIKELY SAFE
when used orally in amounts commonly found in foods (94500).

CHILDREN: POSSIBLY SAFE
when used intravenously and appropriately (9338).

CHILDREN: POSSIBLY UNSAFE
when used intravenously in infants receiving parenteral nutrition. In infants, blood methionine concentration can increase due to lower enzyme activity and inability to metabolize methionine. High levels of methionine can cause liver toxicity (9338).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts commonly found in food (94500). There is insufficient reliable information available about the safety of methionine in medical doses during pregnancy and lactation; avoid using.

(Read more about METHIONINE)

LIKELY SAFE ...when used orally in doses up to 100 mEq total potassium daily, not to exceed 200 mEq in a 24-hour period (95010,107989). Oral potassium chloride and potassium citrate are FDA-approved prescription products (95010,107989). Larger doses increase the risk of hyperkalemia (15). ...when administered intravenously (IV) at appropriate infusion rates (95011). Parenteral potassium is an FDA-approved prescription product (15,95011). A tolerable upper intake level (UL) for potassium has not been established; however, potassium levels should be monitored in individuals at increased risk for hyperkalemia, such as those with kidney disease, heart failure, and adrenal insufficiency (100310,107966).

CHILDREN: LIKELY SAFE
when used orally and appropriately in dietary amounts. A tolerable upper intake level (UL) has not been established for healthy individuals (6243,100310).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in dietary amounts of 40-80 mEq daily (15). A tolerable upper intake level (UL) has not been established for healthy individuals (100310).

(Read more about POTASSIUM)

POSSIBLY SAFE ...when used orally and appropriately. Various proteolytic enzymes have been safely used orally in clinical research (716,964,965,968,969,6252,6253,10622,11457,18281,18284) (91104,91105,91106,91111,96449). Side effects are typically mild to moderate and most often include gastrointestinal effects. See specific monographs for more detailed information related to the safety of individual proteolytic enzymes. ...when used topically and appropriately. Various proteolytic enzymes have been safely used topically in clinical research (67835,67843,67845,91113). Some proteolytic enzymes might cause allergic reactions when used topically. See specific monographs for more detailed information related to the safety of individual proteolytic enzymes.

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

(Read more about PROTEOLYTIC ENZYMES (PROTEASES))

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)

LIKELY SAFE ...when soy protein is used orally and appropriately. Soy protein products in doses up to 60 grams, providing up to 185 mg isoflavones, daily have been safely used in studies lasting up to 16 weeks (842,2293,2294,2296,3025,3402,3977,4755,6412,8530)(10372,11805).

POSSIBLY SAFE ...when soy extracts are used orally and appropriately, short-term. Soy extracts containing concentrated isoflavones in doses of 35-120 mg daily have been used with apparent safety for up to 6 months (4751,6455,7802,12040,12048,13209,95994,95999).

CHILDREN: LIKELY SAFE
when consumed in amounts commonly found in foods or as a component of infant formula (3400,4912,7331). Soy milk that's not designed for infants should not be used as a substitute for infant formula. Regular soy milk can lead to nutrient deficiencies (12045). Most evidence shows that exposure to soy formula or other soy products in infancy does not cause early onset of puberty or health or reproductive problems later in life (7331,11080,108245). However, some small cohort studies have suggested that higher soy intake during childhood may be associated with an increased risk of precocious puberty (108240) and may be weakly correlated with the development of breasts in children less than 2 years of age (75520). This is in contrast to an observational study in Chinese children ages 7-9 years which suggests that higher soy intake is associated with delayed puberty (108252). One small cohort study has also found that use of soy infant formula may be associated with an increased risk of endometriosis in adulthood, although endometriosis was also correlated with prematurity, which may have confounded the findings (101803).

CHILDREN: POSSIBLY UNSAFE
when used orally as an alternative to cow's milk in children with severe milk allergy (75359). Although soy protein-based infant formulas are often promoted for children with milk allergy, children with a severe allergy to cow's milk are also frequently sensitive to soy protein (9883). There is insufficient reliable information available about the safety of soy products when used in amounts higher than typical food quantities for children.

PREGNANCY: LIKELY SAFE
when used orally in amounts commonly found in foods (4912).

PREGNANCY: POSSIBLY UNSAFE
when used orally in medicinal amounts. Soy contains mildly estrogenic constituents (3373,3988,3989,3990,3994,6029,75303). Theoretically, therapeutic use of soy might adversely affect fetal development; avoid using.

LACTATION: LIKELY SAFE
when used orally in amounts commonly found in foods (4912). A single 20-gram dose of roasted soybeans, containing 37 mg isoflavones, produces four to six times less isoflavones in breast milk than provided in a soy-based infant formula (2290). There is insufficient reliable information available about the safety of long-term use of therapeutic amounts of soy during lactation.

(Read more about SOY)

LIKELY SAFE ...when used orally and appropriately. Whey protein up to 30 grams has been safely used in clinical trials for up to 6 months (4930,16728,16729,105587).

CHILDREN: LIKELY SAFE
when used orally and appropriately as a dietary protein in food or infant formula. Hydrolyzed whey protein-based formula has been safely used in infants for up to 6 months in clinical trials (4927,105585,105594).

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

(Read more about WHEY PROTEIN)

(Read more about ALPHA-KETOGLUTARATE (AKG))

(Read more about BETAINE ANHYDROUS)

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Theoretically, BCAAs might alter the effects of antidiabetes medications.  Details Some evidence suggests that BCAAs might stimulate insulin release (10105,10110,10113,10114,10118). However, a small clinical study in adults with liver cirrhosis and high nocturnal levels of blood glucose suggests that BCAAs might increase blood glucose levels (103348).

LEVODOPA Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B BCAAs in large doses can reduce the effects of levodopa.  Details BCAAs may compete with levodopa for transport systems in the intestine and brain and decrease the effectiveness of levodopa (66,2719). Small clinical studies how that concomitant ingestion of protein or high doses of leucine or isoleucine (100 mg/kg) and levodopa can exacerbate tremor, rigidity, and the "on-off" syndrome in patients with Parkinson disease (3291,3292,3293,3294).

(Read more about BRANCHED-CHAIN AMINO ACIDS (BCAA))

ALUMINUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Calcium citrate might increase aluminum absorption and toxicity. Other types of calcium do not increase aluminum absorption.  Details Calcium citrate can increase the absorption of aluminum when taken with aluminum hydroxide. The increase in aluminum levels may become toxic, particularly in individuals with kidney disease (21631). However, the effect of calcium citrate on aluminum absorption is due to the citrate anion rather than calcium cation. Calcium acetate does not appear to increase aluminum absorption (93006).

BISPHOSPHONATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = C Calcium reduces the absorption of bisphosphonates.  Details Advise patients to take bisphosphonates at least 30 minutes before calcium, but preferably at a different time of day. Calcium supplements decrease absorption of bisphosphonates (12937).

CALCIPOTRIENE (Dovonex) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Taking calcipotriene with calcium might increase the risk for hypercalcemia.  Details Calcipotriene is a vitamin D analog used topically for psoriasis. It can be absorbed in sufficient amounts to cause systemic effects, including hypercalcemia (12938). Theoretically, combining calcipotriene with calcium supplements might increase the risk of hypercalcemia.

CALCIUM CHANNEL BLOCKERS Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = D Intravenous calcium may decrease the effects of calcium channel blockers; oral calcium is unlikely to have this effect.  Details Intravenous calcium is used to decrease the effects of calcium channel blockers in the management of overdose. Intravenous calcium gluconate has been used before intravenous verapamil (Isoptin) to prevent or reduce the hypotensive effects without affecting the antiarrhythmic effects (6124). But there is no evidence that dietary or supplemental calcium when taken orally interacts with calcium channel blockers (12939,12947).

CEFTRIAXONE (Rocephin) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = D Co-administration of intravenous calcium and ceftriaxone can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys.  Details Avoid administering intravenous calcium in any form, such as parenteral nutrition or Lactated Ringers, within 48 hours of intravenous ceftriaxone. Case reports in neonates show that administering intravenous ceftriaxone and calcium can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys. In several cases, neonates have died as a result of this interaction (15794,21632). So far there are no reports in adults; however, there is still concern that this interaction might occur in adults.

DIGOXIN (Lanoxin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Using intravenous calcium with digoxin might increase the risk of fatal cardiac arrhythmias.  Details Hypercalcemia increases the risk of fatal cardiac arrhythmias with digoxin (12940). However, one retrospective analysis of clinical data suggests that intravenous calcium does not increase the risk of dysrhythmias or mortality in patients receiving digoxin (38960).

DILTIAZEM (Cardizem, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, calcium may reduce the therapeutic effects of diltiazem.  Details Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation (10574). Theoretically, calcium might increase this risk of hypercalcemia and reduce the effectiveness of diltiazem.

DOLUTEGRAVIR (Tivicay) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B Calcium seems to reduce levels of dolutegravir.  Details Advise patients to take dolutegravir either 2 hours before or 6 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium carbonate 1200 mg concomitantly with dolutegravir 50 mg reduces plasma levels of dolutegravir by almost 40%. Calcium appears to decrease levels of dolutegravir through chelation (93578).

ELVITEGRAVIR (Vitekta) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B Calcium seems to reduce levels of elvitegravir.  Details Advise patients to take elvitegravir either 2 hours before or 2 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium along with elvitegravir can reduce blood levels of elvitegravir through chelation (94166).

LEVOTHYROXINE (Synthroid, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Calcium seems to reduce the absorption and effectiveness of levothyroxine.  Details Advise patients to take levothyroxine and calcium supplements at least 4 hours apart. Calcium reduces levothyroxine absorption, probably by forming insoluble complexes (5082). Calcium carbonate supplements reduce effectiveness of levothyroxine in patients with hypothyroidism (5081,5082,6137).

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, concomitant use of calcium and lithium may increase this risk of hypercalcemia.  Details Clinical research suggests that long-term use of lithium may cause hypercalcemia in 10% to 60% of patients (38953). Theoretically, concomitant use of lithium and calcium supplements may further increase this risk.

QUINOLONE ANTIBIOTICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Calcium seems to reduce the absorption of quinolone antibiotics.  Details Advise patients to take oral quinolones at least 2 hours before or 4-6 hours after calcium supplements or calcium-fortified foods. Taking calcium at the same time as oral quinolones can reduce quinolone absorption. Calcium binds to quinolones in the gut (4412,10339,21638,38570).

RALTEGRAVIR (Isentress) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Calcium may reduce levels of raltegravir.  Details Pharmacokinetic research shows that taking a single dose of calcium carbonate 3000 mg along with raltegravir 400 mg twice daily modestly decreases the mean area under the curve of raltegravir, but the decrease does not necessitate a dose adjustment of raltegravir (94164). However, a case of elevated HIV-1 RNA levels and documented resistance to raltegravir has been reported for a patient taking calcium carbonate 1 gram three times daily plus vitamin D3 (cholecalciferol) 400 IU three times daily in combination with raltegravir 400 mg twice daily for 11 months. It is thought that calcium reduced raltegravir levels by chelation, leading to treatment failure (94165).

SOTALOL (Betapace) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Calcium seems to reduce the absorption of sotalol.  Details Advise patients to separate doses by at least 2 hours before or 4-6 hours after calcium. Calcium appears to reduce the absorption of sotalol, probably by forming insoluble complexes (10018).

TETRACYCLINE ANTIBIOTICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = C Calcium seems to reduce the absorption of tetracycline antibiotics.  Details Advise patients to take oral tetracyclines at least 2 hours before, or 4-6 hours after calcium supplements. Taking calcium at the same time as oral tetracyclines can reduce tetracycline absorption. Calcium binds to tetracyclines in the gut (1843).

THIAZIDE DIURETICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = C Taking calcium along with thiazides might increase the risk of hypercalcemia and renal failure.  Details Thiazides reduce calcium excretion by the kidneys (1902). Using thiazides along with moderately large amounts of calcium carbonate increases the risk of milk-alkali syndrome (hypercalcemia, metabolic alkalosis, renal failure). Patients may need to have their serum calcium levels and/or parathyroid function monitored regularly.

VERAPAMIL (Calan, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, calcium may reduce the therapeutic effects of verapamil.  Details Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation (10574). Theoretically, use of calcium supplements may increase this risk of hypercalcemia and reduce the effectiveness of verapamil.

(Read more about CALCIUM)

ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Theoretically, combining these casein peptides with antihypertensive drugs might increase the risk of hypotension.  Details Clinical research shows that some casein peptides, including the lactotripeptides isoleucine-proline-proline (IPP) and valine-proline-proline (VPP), can modestly reduce blood pressure in patients with hypertension (103763,103765,103770,103772).

(Read more about CASEIN PEPTIDES)

(Read more about CASEIN PROTEIN)

(Read more about CREATINE)

(Read more about ECKLONIA CAVA)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, fenugreek might have additive effects when used with anticoagulant or antiplatelet drugs.  Details Some of the constituents in fenugreek have antiplatelet effects in animal and in vitro research. However, common fenugreek products might not contain sufficient concentrations of these constituents for clinical effects. A clinical study in patients with coronary artery disease or diabetes shows that taking fenugreek seed powder 2.5 grams twice daily for 3 months does not affect platelet aggregation, fibrinolytic activity, or fibrinogen levels (5191,7389,49643).

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Theoretically, fenugreek seed might have additive hypoglycemic effects when used with antidiabetes drugs.  Details Clinical research shows that fenugreek seed can reduce fasting blood glucose and 2-hour postprandial glucose levels in adults with type 2 diabetes (10284,90112,96065,105016).

CLOPIDOGREL (Plavix) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, fenugreek seed might alter the clinical effects of clopidogrel by inhibiting its conversion to the active form.  Details Animal research shows that fenugreek seed 200 mg/kg daily for 14 days increases the maximum serum concentration of clopidogrel by 21%. It is unclear how this affects the pharmacokinetics of the active metabolite of clopidogrel; however, this study found that concomitant use of fenugreek seed and clopidogrel prolonged bleeding time by an additional 11% (108701).

METOPROLOL (Toprol) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Theoretically, fenugreek seed might have additive hypotensive effects when used with metoprolol.  Details Animal research shows that fenugreek seed 300 mg/kg daily for 2 weeks decreases systolic and diastolic blood pressure by 9% and 11%, respectively, when administered alone, and by 15% and 22%, respectively, when given with metoprolol 10 mg/kg (108703).

PHENYTOIN (Dilantin) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, fenugreek might decrease plasma levels of phenytoin.  Details Animal research shows that taking fenugreek seeds for 1 week decreases maximum concentrations and the area under the curve of a single dose of phenytoin by 44% and 72%, respectively. This seems to be related to increased clearance (110905). So far, this interaction has not been reported in humans.

SILDENAFIL (Viagra) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concurrent use of sildenafil and fenugreek might reduce levels and therapeutic effects of sildenafil.  Details Animal research shows that taking fenugreek seeds for 1 week reduces maximum concentrations and the area under the curve of a single dose of sildenafil by 27% and 48%, respectively (110898). So far, this interaction has not been reported in humans.

THEOPHYLLINE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, fenugreek may reduce the levels and clinical effects of theophylline.  Details Animal research shows that fenugreek 50 grams daily for 7 days reduces the maximum serum concentration (Cmax) of theophylline by 28% and the area under the plasma drug concentration-time curve (AUC) by 22% (90118).

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, fenugreek might have additive effects with warfarin and increase the international normalized ratio (INR).  Details Some fenugreek constituents have antiplatelet effects, although these might not be present in concentrations that are clinically significant (7389). In one case report, a patient taking warfarin experienced an increased INR when starting to take fenugreek in combination with boldo (5191).

(Read more about FENUGREEK)

AMIODARONE (Cordarone) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, combining Fucus vesiculosus with amiodarone might cause excessively high iodine levels.  Details Fucus vesiculosus contains high concentrations of iodine (7135). Amiodarone contains 37.3% iodine and can increase iodine levels. Concomitant use might increase the risk of having excessive iodine levels and adversely affecting thyroid function (7135,17574). Monitor thyroid function.

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = D Theoretically, taking Fucus vesiculosus with antiplatelet or anticoagulant drugs might increase the risk of bruising and bleeding.  Details In vitro evidence suggests that a constituent of Fucus vesiculosus, known as fucoidan, has anticoagulant effects (12797,74149,74183,74240). However, in clinical research, fucoidan does not seem to have significant anticoagulant activity when taken orally, possibly due to poor absorption (74183).

ANTITHYROID DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Due to its iodine content, Fucus vesiculosus might alter the effects of antithyroid drugs.  Details Fucus vesiculosus contains high concentrations of iodine (7135). Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking Fucus vesiculosus while using antithyroid drugs could alter the effects of the antithyroid drugs (2138,17574).

CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of Fucus vesiculosus with CYP2C8 substrates might increase the risk for adverse effects.  Details In vitro research shows that fucoidan, a constituent of Fucus vesiculosus, inhibits CYP2C8 (97791). This interaction has not been reported in humans.

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of Fucus vesiculosus with CYP2C9 substrates might increase the risk for adverse effects.  Details In vitro research shows that fucoidan, a constituent of Fucus vesiculosus, inhibits CYP2C9 (97791). This interaction has not been reported in humans.

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.  Details In vitro research shows that fucoidan, a constituent of Fucus vesiculosus, both inhibits and induces CYP2D6 (97791). This interaction has not been reported in humans.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.  Details In vitro research shows that fucoidan, a constituent of Fucus vesiculosus, inhibits CYP3A4 (97791). This interaction has not been reported in humans.

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Concomitant use of Fucus vesiculosus and lithium has resulted in hyperthyroidism.  Details There is a case of hyperthyroidism occurring in a patient taking Fucus vesiculosus and lithium (74217). Monitor thyroid hormones closely in patients taking lithium and Fucus vesiculosus concomitantly.

THYROID HORMONE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.  Details Fucus vesiculosus contains high concentrations of iodine (7135). Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking Fucus vesiculosus while using thyroid hormone could alter the effects of thyroid hormone.

(Read more about FUCUS VESICULOSUS)

CLOZAPINE (Clozaril) Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Theoretically, glycine might decrease the effectiveness of clozapine.  Details One small clinical study in patients with schizophrenia shows that adding glycine to clozapine therapy worsens symptoms of schizophrenia when compared with clozapine alone (10253). The mechanism of this interaction is unclear.

(Read more about GLYCINE)

ACE INHIBITORS (ACEIs) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, concomitant use of L-arginine and ACE inhibitors may increase the risk for hypotension and hyperkalemia.  Details Combining L-arginine with some antihypertensive drugs, especially ACE inhibitors, seems to have additive vasodilating and blood pressure-lowering effects (7822,20192,31854,31916). Furthermore, ACE inhibitors can increase potassium levels. Use of L-arginine has been associated with hyperkalemia in some patients (32213,32218). Theoretically, concomitant use of ACE inhibitors with L-arginine may increases the risk of hyperkalemia.

ANGIOTENSIN RECEPTOR BLOCKERS (ARBs) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, concomitant use of L-arginine and ARBs may increase the risk of hypotension and hyperkalemia.  Details L-arginine increases nitric oxide, which causes vasodilation (7822). Combining L-arginine with ARBs seems to increase L-arginine-induced vasodilation (31854). Furthermore, ARBs can increase potassium levels. Use of L-arginine has been associated with hyperkalemia in some patients (32213,32218). Theoretically, concomitant use of ARBs with L-arginine may increases the risk of hyperkalemia.

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of L-arginine with anticoagulant and antiplatelet drugs might have additive effects and increase the risk of bleeding.  Details Preliminary research suggests that L-arginine infusions reduce platelet aggregation in humans (32260,31864,32239,32220,32257,32263,32276,32188). The clinical significance of this effect is unclear.

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of L-arginine might have additive effects with antidiabetes drugs.  Details Preliminary clinical research shows that L-arginine decreases blood glucose levels in patients with type 2 diabetes (31964,32085,31964,104225).

ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, concomitant use of L-arginine and antihypertensive drugs may increase the risk of hypotension.  Details L-arginine increases nitric oxide, which causes vasodilation (7822). Clinical evidence shows that L-arginine can reduce blood pressure in some individuals with hypertension (7818,10636,31871,32201,32167,32225,31923,32232,110383,110384). Furthermore, combining L-arginine with some antihypertensive drugs seems to have additive vasodilating and blood pressure-lowering effects (7822,20192,31854,31916).

ISOPROTERENOL (Isuprel) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, concurrent use of isoproterenol and L-arginine might result in additive effects and hypotension.  Details Preliminary clinical evidence suggests that L-arginine enhances isoproterenol-induced vasodilation in patients with essential hypertension or a family history of essential hypertension (31932).

POTASSIUM-SPARING DIURETICS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically concomitant use of potassium-sparing diuretics with L-arginine may increases the risk of hyperkalemia.  Details Potassium-sparing diuretics can increase potassium levels. Use of L-arginine has been associated with hyperkalemia in some patients (32213,32218).

SILDENAFIL (Viagra) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concurrent use of sildenafil and L-arginine might increase the risk for hypotension.  Details In vivo, concurrent use of L-arginine and sildenafil has resulted in increased vasodilation (7822,8015,10636). Theoretically, concurrent use might have additive vasodilatory and hypotensive effects. However, in studies evaluating the combined use of L-arginine and sildenafil for erectile dysfunction, hypotension was not reported (105065).

TESTOSTERONE Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of L-arginine and testosterone might have additive effects.  Details In clinical research, L-arginine increases the level of testosterone in male patients with erectile dysfunction (102586,104222). The clinical significance of this finding is unclear.

(Read more about L-ARGININE)

(Read more about METHIONINE)

ACE INHIBITORS (ACEIs) Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Likely •  Level of Evidence = C Using ACEIs with high doses of potassium increases the risk of hyperkalemia.  Details ACEIs block the actions of the renin-angiotensin-aldosterone system and reduce potassium excretion (95628). Concomitant use of these drugs with potassium supplements increases the risk of hyperkalemia (15,23207). However, concomitant use of these drugs with moderate dietary potassium intake (about 3775-5200 mg daily) does not increase serum potassium levels (95628).

ANGIOTENSIN RECEPTOR BLOCKERS (ARBs) Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Likely •  Level of Evidence = C Using ARBs with high doses of potassium increases the risk of hyperkalemia.  Details ARBs block the actions of the renin-angiotensin-aldosterone system and reduce potassium excretion (95628). Concomitant use of these drugs with potassium supplements increases the risk of hyperkalemia (15,23207). However, concomitant use of these drugs with moderate dietary potassium intake (about 3775-5200 mg daily) does not increase serum potassium levels (95628).

POTASSIUM-SPARING DIURETICS Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Likely •  Level of Evidence = C Concomitant use increases the risk of hyperkalemia.  Details Using potassium-sparing diuretics with potassium supplements increases the risk of hyperkalemia (15).

(Read more about POTASSIUM)

(Read more about PROTEOLYTIC ENZYMES (PROTEASES))