Raw Organic Perfect Food Green Superfood Juiced Greens Powder Original by Garden of Life

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Diabetes. Although there has been interest in using oral alfalfa for diabetes, there is insufficient reliable information about the clinical effects of alfalfa for this purpose.
• Dyspepsia. Although there has been interest in using oral alfalfa for dyspepsia, there is insufficient reliable information about the clinical effects of alfalfa for this purpose.
• Hypercholesterolemia. It is unclear if oral alfalfa seeds are beneficial in patients with hypercholesterolemia. Details: A small, uncontrolled clinical study in patients with hypercholesterolemia shows that taking heat-prepared alfalfa seeds 40 grams three times daily for 8 weeks reduces total cholesterol and low-density lipoprotein (LDL) cholesterol levels when compared to baseline (5816). The validity of these findings is limited by the lack of a control group.
• Menopausal symptoms. Although there has been interest in using oral alfalfa for menopausal symptoms, there is insufficient reliable information about the clinical effects of alfalfa for this purpose. There is insufficient reliable information available about the effectiveness of alfalfa for its other uses.

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POSSIBLY INEFFECTIVE

• Hypercholesterolemia. Preliminary clinical research shows that eating muffins made with amaranth flour or taking oral doses of amaranth oil 3-18 mL daily while following a reduced fat diet for 3-4 weeks does not reduce serum cholesterol levels more than the reduced fat diet alone (6188,31069). Similarly, two clinical trials in overweight and obese adults show that taking amaranth oil 20 mL daily for 3 weeks does not decrease low-density lipoprotein (LDL) cholesterol or triglyceride levels or increase high-density lipoprotein (HDL) cholesterol levels when compared with either rapeseed oil 20 mL daily or no intervention (104834,104837). In one of these trials, amaranth oil 20 mL increased LDL levels when compared to baseline (104834).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Iron deficiency anemia. Preliminary clinical research in children shows that consuming 150 grams of bread made with 70% amaranth grain, providing approximately 22.3 mg iron, for 6 months decreases the prevalence of anemia by 61% and increases hemoglobin levels by 8% when compared with consuming bread containing 100% maize grain. The amaranth used in this study was processed to reduce phytic acid content in order to improve iron absorption (104835).
• Peptic ulcers. Preliminary clinical research shows that taking amaranth oil from Amaranthus cruentus seeds 1 mL daily for 27 days immediately following standard treatment with lansoprazole, amoxicillin, and clarithromycin for 7 days does not improve clinical outcomes with Helicobacter pylori-associated peptic ulcers more than standard treatment alone (99235). More evidence is needed to rate amaranth for these uses.

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INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alzheimer disease. It is unclear if apple juice consumption is beneficial in patients with Alzheimer disease. Details: A small clinical study in adults with moderate to severe Alzheimer disease shows that drinking 4 ounces of apple juice twice daily for one month does not improve cognitive function when compared with baseline. However, according to caregiver assessment, it seems to improve aspects of mood and behavior, such as anxiety, depression, apathy, delusion, and agitation, when compared with baseline (94422). The validity of this finding is limited by the lack of a comparator group.
• Cancer. It is unclear if apple consumption is beneficial for preventing cancer. Details: Some population research has found that eating one or more apples daily may be associated with a decreased risk of esophageal, colorectal, larynx, or breast cancer when compared with eating less than 1 apple daily (31688). Also, a case-control study in adults with lung cancer has found that increased apple consumption may be associated with a reduced risk of lung cancer (3470).
• Dental plaque. It is unclear if apple consumption is beneficial for reducing dental plaque. Details: A small clinical study in healthy patients shows that eating an apple is less effective for reducing plaque than brushing teeth. Eating an apple actually increases plaque when compared with baseline, although it decreases the measure of bacterial vitality (99447).
• Diabetes. It is unclear if consumption of powdered, dehydrated apple is beneficial in patients with type 2 diabetes. Details: A small clinical study in patients with type 2 diabetes shows that substituting 26-52 grams of white wheat flour in bread with powdered, dehydrated apple and consuming the bread daily for up to 4 weeks does not improve fasting blood glucose or postprandial glucose levels when compared with a low-fiber white bread control (13141).
• Diarrhea. It is unclear if apple juice consumption is beneficial in infants with severe diarrhea. Details: A clinical study in infants with severe diarrhea shows that drinking apple juice 15 mL/kg twice daily during episodes of diarrhea results in more fecal loss when compared with drinking water (31687).
• Metabolic syndrome. Although there has been interest in using apple for metabolic syndrome, there is insufficient reliable information about the clinical effects of apple for this purpose.
• Muscle strength. Oral apple extract has only been evaluated in combination with other ingredients; its effects when used alone is unclear. Details: Small clinical studies in resistance trained males show that taking a specific blend of ancient peat and apple extract (elevATP, VDF FutureCeuticals Inc.) 150 mg daily as a liquid with liposomes (QuSomes, BioZone Laboratories Inc.) for 12 weeks modestly increases lower body and total strength, improves lower body power output, and increases cross-sectional area of muscle when compared with placebo (94418,94419).
• Obesity. It is unclear if apple consumption is beneficial in patients with overweight or obesity. Details: A small clinical study in females with hypercholesterolemia and overweight or obesity shows that eating apples three times daily for 12 weeks is associated with weight loss of 1.2 kg, compared with weight loss of 0.9 kg in those consuming oat cookies (17997). More evidence is needed to rate apple for these uses.

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INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Although there is interest in using oral and topical asparagus for acne, there is insufficient reliable information about the clinical effects of asparagus for this condition.
• Cancer. Although there is interest in using oral asparagus for cancer, there is insufficient reliable information about the clinical effects of asparagus for this condition.
• Constipation. Although there is interest in using oral asparagus for constipation, there is insufficient reliable information about the clinical effects of asparagus for this purpose.
• Intestinal parasite infection. Although there is interest in using oral asparagus for intestinal parasite infection, there is insufficient reliable information about the clinical effects of asparagus for this condition.
• Hypertension. Oral asparagus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with hypertension shows that taking a specific combination product (Asparagus-P, Grunwalder) containing asparagus root 6 grams and parsley leaf 6 grams daily for 6 weeks does not affect ambulatory blood pressure when compared with baseline (94940).
• Kidney stones (nephrolithiasis). Although there is interest in using oral asparagus for kidney stones, there is insufficient reliable information about the clinical effects of asparagus for this condition.
• Obesity. Oral asparagus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Observational research in overweight adults shows that taking psyllium 2-3 tablespoons each morning with 1.5 liters of elderflower juice, plus tablets providing asparagus powder 2.7 grams, elderberry powder 225 mg, and elderflower extract 600 mg daily for 2 weeks, and replacing each meal on days 5-12 with 200 mL of elderberry and elderflower juice, is associated with an average 3.2 kg weight loss and a modest reduction in blood pressure when compared with baseline (94939). It is not known if these effects are due to asparagus, other ingredients, the combination, or fasting from regular food for 8 days. Furthermore, the validity of these findings is limited by the lack of a comparator group.
• Rheumatoid arthritis (RA). Although there is interest in using oral asparagus for RA, there is insufficient reliable information about the clinical effects of asparagus for this condition.
• Urinary tract infections (UTIs). Although there is interest in using oral asparagus for UTIs, there is insufficient reliable information about the clinical effects of asparagus for this condition. More evidence is needed to rate asparagus for these uses.

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INSUFFICIENT RELIABLE EVIDENCE to RATE

• Anxiety. Although there is interest in using oral Asparagus racemosus for anxiety, there is insufficient reliable information about the clinical effects of Asparagus racemosus for this condition.
• Athletic performance. It is unclear if oral Asparagus racemosus is beneficial for improving athletic performance. Details: In recreationally trained males, taking Asparagus racemosus 500 mg daily for 8 weeks during bench press training increases the number of repetitions before exhaustion, and allows a greater increase in training loads, when compared with placebo (106413).
• Bronchitis. Although there is interest in using oral Asparagus racemosus for bronchitis, there is insufficient reliable information about the clinical effects of Asparagus racemosus for this condition.
• Cancer. Although there is interest in using oral Asparagus racemosus for cancer, there is insufficient reliable information about the clinical effects of Asparagus racemosus for this purpose.
• Dementia. Although there is interest in using oral Asparagus racemosus for dementia, there is insufficient reliable information about the clinical effects of Asparagus racemosus for this condition.
• Diabetes. Although there is interest in using oral Asparagus racemosus for diabetes, there is insufficient reliable information about the clinical effects of Asparagus racemosus for this condition.
• HIV/AIDS. Although there is interest in using oral Asparagus racemosus for HIV/AIDS, there is insufficient reliable information about the clinical effects of Asparagus racemosus for this condition.
• Lactation. Oral Asparagus racemosus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In mothers who have to supplement their breast milk or who have infants with below normal weight gain, taking an herbal mixture containing Asparagus racemosus as 2 teaspoons twice daily for 4 weeks does not increase breast milk production, infant weight gain velocity, or prolactin levels (32588). Per 100 grams, the herbal mixture contained Asparagus racemosus 15 grams, dill 1 gram, morning glory 1 gram, licorice 2.5 grams, cumin 0.5 grams, and panchatrinamol 1 gram. Another small clinical study in postpartum mothers in India shows that consuming Asparagus racemosus in the form of 1 daily granola bar that contains Asparagus racemosus and other ingredients (Shavari Bar, Act Life Sciences Ltd.) for 4 days starting the day after delivery increases breast milk volume by about 15 mL and shortens the time to breast fullness when compared with placebo (111721). However, it is unclear whether any improvement is clinically significant, especially in the longer term. Additionally, the dose of Asparagus racemosus was not specified which limits the interpretation of these results.
• Muscle strength. It is unclear if oral Asparagus racemosus is beneficial for improving muscle strength. Details: A very small clinical study in physically active postmenopausal patients shows that taking Asparagus racemosus 1000 mg daily for 6 weeks improves hand grip strength, but not knee extensor strength, when compared with placebo (110736).
• Sexual desire. Although there is interest in using oral Asparagus racemosus for sexual desire, there is insufficient reliable information about the clinical effects of Asparagus racemosus for this purpose.
• Tuberculosis. Although there is interest in using oral Asparagus racemosus for tuberculosis, there is insufficient reliable information about the clinical effects of Asparagus racemosus for this condition. More evidence is needed to rate Asparagus racemosus for these uses.

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LIKELY EFFECTIVE

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

POSSIBLY INEFFECTIVE

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

INSUFFICIENT RELIABLE EVIDENCE to RATE

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

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POSSIBLY EFFECTIVE

• Athletic performance. Oral beet may improve athletic performance associated with aerobic activities. However, it is not clear who is most likely to benefit, for which type of competition it is most useful, or what dose or duration of use is most appropriate. Details: Several small clinical trials, most of which enrolled elite athletes, recreational athletes, and sedentary males, as well as meta-analyses of some of these and other studies, show that beet improves various measures of athletic performance, including ability, muscular endurance, power output, sprinting, and strength (93844,94464,94468,94469,100143,100150,100152,105761,113422). Clinical research also shows that drinking beetroot juice improves the use of oxygen during exercise testing in recreationally-trained athletes, especially with severe exercise testing (94460,94463,94467,100147,105762). Also, in obese adolescents, taking beetroot juice daily for 6 days increases the time to exhaustion from severe exercise, but does not improve moderate exercise (100145). Not all research shows that beet supplementation benefits athletic performance. Another meta-analysis of several small clinical studies, including some of the studies above, shows that taking beetroot does not improve performance in high-intensity or sprint interval training (111159). Additionally, the majority of research in elite athletes does not support the use of beetroot juice to decrease the time needed to complete a task, aid in some sort of graded exercise test, or improve the use of oxygen during exercise testing (94455,94458,94460,94461,94464,94465,94466,94469,94473,100142,100153,105763). The supposed lack of effect of beetroot juice in elite athletes might be related to the natural production of nitrates and nitrites in the body or the increased ability to use oxygen that comes from extensive training (94458,94463). Alternatively, any changes might be very small (<1%) and not identified with statistical comparisons, although even very small changes might be beneficial in competition (94464). The most commonly used doses in all studies, regardless of effect, have included an acute dose of beetroot juice 70-500 mL up to 3 hours prior to exercise (93844,94463,94464,94466,94467,94473,97726,100142,100143,105761)(105762,111159,113422) or chronic dosing of up to 500 mL daily for 3-6 days (94459,94464,94469,100145,100147,100153,111159,113422). Less commonly, beetroot juice 70-140 mL daily, betalain-rich concentrate 100 mg daily, or a beetroot-based nutritional gel 100 grams daily, have been taken for longer dosing schedules of 7-15 days (97720,100144,100148,100152,105763,113422). Benefits in elite athletes, most often related to time trials, are usually limited to studies using chronic dosing of 7-15 days, which is longer than the duration of 6 days used in the majority of studies (94473,97720,100144,100148). Brands of juice used in clinical trials have included Beet It Sport (James White Drinks Ltd.) (94455,94458,94465,100142,100143,100144,100148,105761,105763), Beet It Stamina Shot (James White Drinks Ltd.) (93844), Beet It (James White Drinks Ltd) (94457,94459,94460,94467,94469,97726,100145,100153,105762,111159), and Love Beets Beetroot Juice (Gs Fresh Ltd.) (94461,94462). Although plasma levels have not been analyzed in all studies, the majority of studies suggest that these doses are adequate to increase levels of nitrates or nitrites, which is thought to be essential for increasing athletic potential (93844,94455,94458,94459,94460,94465,94467,94469,94466,94473,97726). The evidence also suggests benefit in both normoxic and hypoxic environments (94465,100148,105763).
• Exercise-induced muscle soreness. Drinking beetroot juice 7-8 times over 48 hours after strenuous exercise may reduce exercise-induced muscle soreness, but evidence is conflicting. Details: Some clinical research shows drinking beetroot juice (Love Beets Beetroot Juice, Gs Fresh Ltd.) 125 mL or 250 mL seven times over 48 hours after strenuous box jumps improves muscle soreness when compared with placebo and sodium nitrite (96964,97722). Other small clinical studies show that drinking beetroot juice 50-250 mL as eight separate doses over 48 hours after strenuous exerciseimproves muscle soreness and reduces tissue edema when compared with placebo (94461,113424). However, drinking beetroot juice 250 mL as seven separate doses over 48 hours after running a marathon does not appear to reduce muscle soreness when compared with placebo (94462). A meta-analysis of 4 small studies, mostly in healthy or physically active males, shows that drinking beetroot juice improves the pressure pain threshold, which is a measure of muscle soreness, at 48- and 72-hours post-exercise when compared with a fruit-flavored drink. However, beetroot juice does not improve subjective muscle soreness scores (111160). The validity of the findings from this meta-analysis is limited by the heterogeneity of the beetroot juice regimens among the included studies. Further, these results should not be generalized to elite athletes.

POSSIBLY INEFFECTIVE

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

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Cognitive function. It is unclear if drinking beetroot juice is beneficial for cognitive function. Details: A small clinical study in adults with overweight or obesity on a calorie-restricted diet shows that drinking 70 mL of concentrated beetroot juice daily for 14 days improves the time to complete part B of the trail making test, which is a test of cognitive function, but not part A, when compared with controls (111158). However, the duration and size of this study limits its validity. Further, it is unclear whether any improvement is clinically significant. The effect of acute beet administration on cognitive function has also been studied. A very small clinical study in healthy adults shows that taking beet extract (RedNite, Enovate Biolife) chewable tablets 3 grams 90 minutes prior to neuropsychological testing improves immediate and delayed memory capacity, frontal lobe function, and lexical flexibility but does not improve working memory, information processing speed, or subjective reports of memory performance when compared with placebo (113427).
• Coronary heart disease (CHD). It is unclear if oral beetroot extract is beneficial in patients with CHD. Details: A small clinical trial in patients with CHD shows that taking red beetroot extract 500 mg, containing around 25 mg betalains, twice daily for 2 weeks reduces total cholesterol and low-density lipoprotein (LDL) cholesterol by 15 mg/dL and reduces triglycerides by 8 mg/dL when compared to baseline. Slight improvements in blood pressure and blood glucose were also reported, but these changes were not clinically significant (103883). The validity of these findings is limited by the lack of a comparator group. Also, it is unclear whether beetroot can reduce the risk of cardiovascular events in patients with CHD.
• Dyslipidemia. It is unclear if oral beetroot is beneficial in patients with dyslipidemia. Details: A meta-analysis of small clinical studies in healthy individuals or patients with dyslipidemia, cardiovascular disease, or overweight or obesity, shows that consuming beetroot juice or leaves does not improve levels of triglycerides or total, low-density lipoprotein, or high-density lipoprotein cholesterol when compared with controls (111163). However, the validity of the findings from this meta-analysis is limited by the heterogeneity of the enrolled patients and beetroot regimens.
• Exercise-induced muscle damage. It is unclear if oral beetroot juice improves recovery from muscle damage after exercise. Details: A meta-analysis of 4 small clinical studies in healthy or physically active individuals, most of which enrolled males only, shows that drinking beetroot juice improves measures of muscle recovery at 72 hours post-exercise when compared with a fruit-flavored drink. However, beetroot juice does not consistently improve recovery at earlier time points post-exercise, nor does it reduce levels of creatine kinase or markers of inflammation (i.e., interleukin-6, interleukin-8, c-reactive protein, or tumor necrosis factor-alpha) (111160). However, the validity of the findings from this meta-analysis is limited by the heterogeneity of the beetroot juice regimens among the included studies, which usually varied from 210-250 mg of nitrate in 7-11 servings over 3-7 days. Further, these results should not be generalized to elite athletes. Another very small clinical study in semi-professional female athletes shows that ingesting beetroot juice 50 mL 8 times over 48 hours after exercise-induced muscle damage enhances the recovery of some functional parameters such as muscle endurance but not others such as flexibility and vertical jump performance when compared with placebo (113424).
• Hypertension. Oral beet may slightly reduce blood pressure in healthy individuals, but it is unclear if it is beneficial in patients with hypertension. Details: Meta-analyses of small studies show the potential for a minor reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP) in healthy adults taking beetroot juice (94470,97718,97728). The average reduction in SBP and DBP with beetroot juice consumption is about 4 mmHg and 1 mmHg, respectively, which is greater than the effect seen with consuming blackcurrant juice or nitrate-depleted beetroot juice. The most benefit is seen when beetroot juice is taken for at least 2 weeks or at doses of 500 mL daily (97728). The effect of acute beet supplementation on blood pressure is conflicting. A small clinical study in healthy adults shows that drinking beet juice (Beet It, James White Company) 140 mL two hours prior to cardiovascular measurements reduces resting SBP by about 4 mmHg but does not improve resting or post-exercise DBP, central blood pressure, or arterial stiffness nor does it improve post-exercise SBP when compared with placebo. Subgroup analysis suggests that the reductions in resting SBP were only observed in males, not females (113423). Another small clinical study shows that consuming beet 100 grams baked into bread modestly decreases DBP over a 6-hour period when compared with white bread (97725). It is possible that genetics might play a role in the magnitude of effect seen with beetroot consumption. Adults with a specific gene polymorphism, eNOS Glu298Asp, experienced a greater reduction in DBP after consuming beet-containing bread (97724). Despite positive findings in studies of healthy individuals, research on the use of beetroot juice in patients with hypertension is unclear. A small clinical study in adults with hypertension who were taking antihypertensive medications shows that drinking nitrate-rich beetroot juice (Beet it; James White Drinks Ltd.) 70 mL twice daily for one week does not lower blood pressure when compared with nitrate-depleted beetroot juice (94457). Also, in patients with mild to moderate hypertension, clinical research shows that taking a combination of beetroot powder (Sensient) 300 mg, olive leaf extract 1000 mg, and green coffee bean extract 200 mg daily for 6 weeks does not lower blood pressure when compared with placebo (97723). However, some evidence suggests that at least part of the blood pressure lowering effects of beet might be independent of nitrate (97728). Furthermore, some research suggests that identifying effects on blood pressure might be dependent on the method of measurement, including clinic resting measurements, 24-hour monitoring, or morning/evening home resting measurements (97729).
• Hypertriglyceridemia. It is unclear if oral beet is beneficial in patients with hypertriglyceridemia. Details: A small clinical study in overweight or obese individuals with dyslipidemia shows that taking freeze-dried beet leaf 2.8 grams daily for 4 weeks in addition to nutritional guidance does not lower triglyceride levels when compared with nutritional guidance alone (100146). Beet has also been evaluated in combination with other ingredients. A small clinical trial in patients at risk for heart disease shows that a specific combination of beet and hawthorn berry (Neo40-Daily, Neogenis Labs), taken twice daily for 30 days, can modestly reduce blood triglyceride levels when compared to baseline (18222). It is unclear if these findings are due to beet, hawthorn berry, or the combination.
• Liver disease. Although there has been interest in using oral beet for liver disease, there is insufficient reliable information about the clinical effects of beet for this purpose.
• Muscle strength. It is unclear if oral beetroot juice is beneficial for muscle strength. Details: A meta-analysis of 18 clinical studies in healthy males shows that taking beetroot juice or beetroot gel 2-3 hours before exercise improves muscular strength when compared with placebo. Subgroup analysis suggests that beetroot-based supplements improve muscular strength in a fatigued but not resting state (113422). A small clinical study in adults with overweight or obesity on a calorie-restricted diet shows that drinking 70 mL of concentrated beetroot juice daily for 14 days improves handgrip strength by approximately 18% compared with 4% in controls (111158). However, it is unclear whether any improvement is clinically significant.
• Obesity. It is unclear if oral beet leaf or beetroot juice is beneficial for weight loss. Details: A small clinical study in patients with overweight or obesity and dyslipidemia shows that taking freeze-dried beet leaf 2.8 grams daily for 4 weeks in addition to nutritional guidance does not reduce body weight or body mass index (BMI) when compared with nutritional guidance alone (100146). Similarly, a small clinical study in adults with overweight or obesity on a calorie-restricted diet shows that drinking 70 mL of concentrated beetroot juice daily for 14 days does not improve weight loss when compared with controls (111158). However, the size and duration of this study may have been inadequate to detect differences between groups.
• Pregnancy-induced hypertension. It is unclear if oral beetroot juice is beneficial in patients with pregnancy-induced hypertension. Details: A small clinical trial in pregnant patients with hypertension who are at approximately 22-35 weeks gestation shows that taking beetroot juice (James White Drinks Ltd) 70 mL daily for 8 days does not reduce blood pressure when compared with a nitrate-depleted beetroot juice (100151). However, the study was small and designed to investigate the feasibility of using beetroot juice in this population.
• Pulmonary hypertension. It is unclear if oral beetroot juice is beneficial in patients with pulmonary hypertension. Details: A small clinical study shows that taking beetroot juice (Beet-It Sport; James White Drinks Ltd) 70 mL twice daily for 7 days does not improve right ventricular systolic function when compared with nitrate-depleted beetroot juice in patients with pulmonary hypertension (100149). However, this study was small and not adequately powered to detect differences between groups.
• Raynaud syndrome. It is unclear if oral beetroot juice is beneficial in patients with Raynaud syndrome. Details: A small clinical study in patients with Raynaud syndrome undergoing cold sensitivity tests shows that drinking beetroot juice (Beet-It, James White Drinks Ltd) 70 mL daily for 13 days, followed by 140 mL prior to testing, does not reduce pain in the hands or feet, but might improve thermal comfort in the feet, when compared to baseline (103884). The validity of this finding is limited by the lack of a comparator group. More evidence is needed to rate beet for these uses.

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There is insufficient reliable information available about the effectiveness of blackberry.

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POSSIBLY INEFFECTIVE

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

INSUFFICIENT RELIABLE EVIDENCE to RATE

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

(Read more about BLUEBERRY)

POSSIBLY EFFECTIVE

• Colorectal cancer. Consumption of cruciferous vegetables, including broccoli, seems to reduce the risk of developing colorectal cancer. Details: Epidemiological research suggests that the highest intakes of cruciferous vegetables, including broccoli, are associated with an 18% to 20% reduced risk of developing colorectal neoplasms when compared with the lowest intakes (14148,96187,96189).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Bladder cancer. It is unclear if consumption of broccoli reduces the risk of developing bladder cancer. Details: Epidemiological research suggests that eating about 1.75 cups daily of cruciferous vegetables, such as broccoli or cabbage, is associated with a 30% reduced risk of developing bladder cancer (14864).
• Breast cancer. It is unclear if consumption of broccoli reduces the risk of developing breast cancer. Details: Epidemiological research suggests that consumption of broccoli is associated with a modestly reduced risk of developing breast cancer in premenopausal adults. However, broccoli consumption does not seem to be associated with breast cancer risk in postmenopausal adults (14146).
• Fibromyalgia. Broccoli has only been evaluated in combination with ascorbigen; its effect when used alone is unclear. Details: A small clinical study in females with fibromyalgia shows that taking one capsule containing ascorbigen 100 mg and broccoli powder 400 mg once daily for one month improves pain by 18% and reduces physical impairment by 20% when compared to baseline (19605). It is unclear if this effect is due to broccoli, ascorbigen, or the combination. The validity of these findings is limited by the lack of a comparator group.
• Gastric cancer. It is unclear if consumption of broccoli reduces the risk of developing gastric cancer. Details: A small epidemiological study suggests that higher consumption of broccoli is associated with a reduced risk of developing gastric cancer when compared with lower consumption (14148).
• Helicobacter pylori. It is unclear if consumption of broccoli is beneficial for treating Helicobacter pylori infection. Details: A moderate-sized clinical study in adults with Helicobacter pylori infection shows that taking broccoli seed extract 200 mg, containing 16% glucosinolates, daily before bedtime for 2 months does not improve Helicobacter pylori eradication rate when compared with placebo (112445,112446).
• Hypercholesterolemia. Broccoli has only been evaluated in combination with cabbage; its effect when used alone is unclear. Details: A small clinical study in patients with mild to moderate hypercholesterolemia shows that consuming 160 grams of a beverage containing broccoli, cabbage, and fruit twice daily for 12 weeks reduces levels of low-density lipoprotein (LDL) cholesterol by 8.5% when compared to baseline. It is unclear if the improvement from baseline differed when compared with those consuming a similar beverage without broccoli and cabbage (19607). It is unclear if this effect is due to broccoli, other ingredients, or the combination.
• Hypertension. It is unclear if consumption of broccoli can prevent hypertension in healthy adults. Details: A meta-analysis of 3 prospective cohort studies in healthy adults suggests that eating 100 grams of broccoli daily is associated with a 12% reduced risk of hypertension. However, 2 other studies in the meta-analysis suggest that broccoli, consumed as part of a larger group of cruciferous vegetables, is associated with an 11% increased risk of hypertension per 100 grams eaten daily (112087).
• Prostate cancer. It is unclear if consumption of broccoli reduces the risk of developing prostate cancer; the available research is conflicting. In patients with prostate cancer, broccoli has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Some epidemiological research suggests that consumption of Brassica vegetables, such as broccoli, Brussels sprouts, cauliflower, and cabbage, is associated with a reduced risk of developing prostate cancer (14145). However, other epidemiological research has found no association (14147,15172). Clinical research in adults with prostate cancer shows that taking a whole food formulation containing broccoli powder 100 mg, turmeric powder 100 mg, pomegranate whole fruit powder 100 mg, and green tea extract 20 mg three times daily for 6 months prevents an increase in prostate specific antigen (PSA) levels. Mean PSA levels increased by 15% in the whole food formulation group, compared with 79% in the placebo group. Also, 46% of those taking the whole food formulation showed final PSA levels that were the same or lower than initial PSA levels, compared with 14% of those in the placebo group (89730). However, it is not yet known whether the whole food formulation reduces the risk of prostate cancer progression or recurrence. It is unclear if these effects are due to broccoli, other ingredients, or the combination. More evidence is needed to rate broccoli for these uses.

(Read more about BROCCOLI)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Benign prostatic hyperplasia (BPH). Population research has found that higher intake of Brussels sprout is not associated with significantly reduced risk of BPH (26190).
• Bladder cancer. Epidemiologic research has found that eating about 1 cup daily of cruciferous vegetables, such as cabbage, Brussels sprout, cauliflower, broccoli, kale, or collards, is associated with a 30% lower risk of developing bladder cancer in adults (14864). Other population research has found that higher intake of cruciferous vegetables, such as cauliflower, Brussels sprout, cabbage, broccoli, and kale, is associated with a 51% reduction in the risk of developing bladder cancer in males. However, higher intake of Brussels sprout alone does not seem to be associated with a reduced risk of bladder cancer (26184).
• Breast cancer. Some population research has found that higher intake of cruciferous vegetables, including broccoli, Brussels sprout, cabbage, cauliflower, collards, and kale, is associated with a slight increase in the risk of breast cancer in premenopausal adults, while higher intake appears to be associated with a slight but statistically insignificant decrease in the risk in postmenopausal adults (26188). However, other population research has found that higher intake of Brussels sprout alone is not associated with a reduced risk of breast cancer (26189). Cruciferous vegetables might increase urinary levels of 2-hydroxyestrone, and its ratio to 16-alpha-hydroxyestrone, which could reduce the risk of breast cancer. However, research in pre-menopausal adults shows that taking a dried Brussels sprout and kale supplement, 3.3 grams daily for 8 weeks, or increasing dietary intake of Brussels sprout or broccoli by one 40-gram serving daily, does not increase urinary levels of 2-hydroxyestrone, or its ratio to 16-alpha-hydroxyestrone, when compared with placebo (112086).
• Diabetes. Population research has found that higher intake of cruciferous vegetables, including broccoli, cabbage, cauliflower, and Brussels sprout, is not associated with a reduced risk of developing type 2 diabetes (26187). A meta-analysis of 23 studies shows that the highest levels of combined vegetable and fruit intake are associated with a 7% reduction in the risk of developing type 2 diabetes, when compared with the lowest intakes, but higher intake of Brussels sprout alone is associated with a 7% increase in the risk (112088).
• Hypertension. A meta-analysis of 18 studies in healthy adults shows that the highest levels of combined vegetable and fruit intake are associated with a 9% to 11% reduction in the risk of developing hypertension, when compared with the lowest intakes, but higher intake of Brussels sprout alone is associated with a 25% increase in the risk (112087).
• Lung cancer. Population research has found that people who consume Brussels sprout and broccoli at least once weekly have a 22% lower risk of developing lung cancer when compared with those who consume these vegetables less than once monthly (26192).
• Non-Hodgkin lymphoma. Population research has found that females who consume at least half a serving of Brussels sprout or other cruciferous vegetables daily have a lower risk of developing non-Hodgkin lymphoma, particularly the follicular lymphoma subtype, when compared to those who eat these vegetables less often. However, eating Brussels sprout and other cruciferous vegetables does not appear to be associated with a reduced risk of non-Hodgkin lymphoma in males (26186).
• Pancreatic cancer. Population research has found that consuming higher amounts of Brussels sprout is not associated with a reduced risk of pancreatic cancer (26181).
• Prostate cancer. Population research has found that people who consume higher amounts of Brussels sprout and other cruciferous vegetables have a lower risk of developing prostate cancer (25420,25421).
• Stroke. Population research has found that higher intake of Brussels sprout and other cruciferous vegetables is associated with a 32% reduction in the risk of ischemic stroke (7394). More evidence is needed to rate Brussels sprout for these uses.

(Read more about BRUSSELS SPROUT)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Cardiovascular disease (CVD). A meta-analysis of clinical research shows that taking buckwheat seems to improve some, but not all, markers of CVD risk. Buckwheat was found to decrease total cholesterol by 19 mg/dL, triglycerides by 22 mg/dL, and blood glucose by 15 mg/dL, but had no effect on blood pressure, body weight, insulin, or low-density lipoprotein (LDL) cholesterol when compared with a control group (100947). The patient populations included in this analysis ranged from healthy adults to those with diabetes or hyperlipidemia; it's unclear whether the results are consistent across patient groups or if the benefits are more pronounced in certain types of patients. The effects of buckwheat on cardiovascular events, such as myocardial infarction, stroke, or cardiovascular death, in patients with CVD, are unknown.
• Chronic venous insufficiency (CVI). Preliminary clinical research shows that drinking common buckwheat tea for 3 months attenuates leg swelling compared with placebo in patients with chronic venous insufficiency (37351).
• Diabetes. Preliminary clinical research shows that patients with type 2 diabetes who replace a portion of white rice or white flour with tartary buckwheat 50 grams three times daily for 4 weeks show a 3% reduction in fasting insulin and a 7% reduction in low-density lipoprotein (LDL) cholesterol compared to baseline. Patients who consume the standardized recipe containing white rice and/or white flour three times daily for 4 weeks show no significant changes in these measurements. Neither groups show improvement in fasting blood glucose or hemoglobin A1c levels (96063).
• Diabetic retinopathy. Preliminary clinical research shows that taking common buckwheat 1 gram three times daily for 3 months does not significantly improve visual acuity compared with baseline in patients with diabetic retinopathy (37358). More evidence is needed to rate the effectiveness of buckwheat for these uses.

(Read more about BUCKWHEAT)

POSSIBLY EFFECTIVE

• Breast engorgement. Most research shows that applying cabbage leaves to engorged breasts reduces pain and hardness to the same degree as cold compresses in lactating females with breast engorgement. Details: Several small clinical studies suggest that applying whole cabbage leaves to the engorged breasts of lactating females produces subjective relief similar to the use of chilled gel-packs (6781,6784,93677). Both chilled and room temperature cabbage leaves seem to provide the same relief (6782). Another small clinical study shows that whole cabbage leaves also seem to improve breast pain and hardness when compared with general nursing care (93673). When compared with hot and cold compresses, one small clinical study found that using chilled cabbage leaves reduces postnatal breast engorgement to a similar degree, but is not as effective for reducing pain (101966). The preparation of cabbage leaves for this purpose sometimes includes stripping out the large vein of the cabbage leaf and cutting a hole for the nipple. Cabbage leaves are rinsed and chilled. The chilled cabbage leaf is worn inside the bra or as a compress under a cool towel. This procedure is typically repeated 1-4 times daily for 1-3 days (6781,6784,93673,93677,101966). A cabbage leaf extract applied as a cream has also been tried. The cabbage leaf extract cream seems to provide subjective relief when compared to baseline, but it does not provide superior relief when compared with a placebo cream (6783).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Bladder cancer. It is unclear if consuming cabbage is effective for the prevention of bladder cancer. Details: Observational research has found that eating about 1.75 cups of cruciferous vegetables such as cabbage or broccoli is associated with a 30% reduced risk of bladder cancer in men and women (14864).
• Colorectal cancer. It is unclear if consuming cabbage is effective for the prevention of colorectal cancer. Details: Observational research has found that consuming large amounts of cabbage and other Brassica vegetables such as kale, broccoli, and cauliflower is associated with a lower risk of developing colorectal cancer (6792).
• Gastric cancer. It is unclear if consuming cabbage is effective for the prevention of gastric cancer. Details: Observational research has found that consuming large amounts of cabbage and other Brassica vegetables such as kale, broccoli, and cauliflower is associated with a lower risk of developing stomach cancer (6792).
• Gastritis. Although there has been interest in using oral cabbage for gastritis, there is insufficient reliable information about the clinical effects of cabbage for this purpose.
• Hyperlipidemia. It is unclear if oral cabbage is beneficial in patients with hyperlipidemia. Details: A small clinical study in Japanese adults with hyperlipidemia shows that adding broccoli and cabbage to a beverage consisting of fruits and vegetables for 3-9 weeks reduces low-density lipoprotein (LDL) cholesterol levels by 8.5% when compared to baseline. The reduction in LDL cholesterol was significant when compared with the same beverage without broccoli and cabbage added (25423).
• Knee pain. It is unclear if topical cabbage is beneficial in patients with knee pain. Details: A small clinical study in males with an acute mild to moderate traumatic knee ligament injury shows that use of crushed fresh cabbage leaf and cooling dressing wraps improves recovery over the first 24 hours of use by a moderate amount when compared with the cooling dressing alone. Normal fluid release occurred in 67% to 80% of patients using crushed cabbage leaf compared with 47% to 50% of those given the cooling dressing alone (101969).
• Lung cancer. It is unclear if consuming cabbage is effective for the prevention of lung cancer. Details: Observational research has found that consuming large amounts of cabbage and other Brassica vegetables such as kale, broccoli, and cauliflower is associated with a lower risk of developing lung cancer (6792).
• Osteoarthritis. Small clinical studies suggest that topical cabbage leaf modestly improves pain and other symptoms in patients with osteoarthritis of the knee. Details: A small clinical study in patients with osteoarthritis of the knee shows that applying cabbage leaf wraps to the knees for at least 2 hours daily for 4 weeks decreases pain by around 12 points on a 100 mm visual analog scale when compared with usual care. The analgesic effect of cabbage leaf wraps in these patients appears to be similar to treatment with topical gel containing the nonsteroidal anti-inflammatory drug diclofenac 10 mg/gram (93671). Another small, open-label clinical study in patients with moderate to severe osteoarthritis of the knee shows that applying cabbage leaf wraps to the knees for 1 hour daily for 4 weeks reduces knee pain and improves symptom severity when compared with diclofenac gel applied four times daily. Improvements in pain and overall symptoms were similar between cabbage leaf and the use of cooling gel pads (110558). The validity of these findings is limited by a lack of blinding.
• Pancreatic cancer. It is unclear if consuming cabbage is effective for the prevention of pancreatic cancer. Details: Observational research in elderly and middle-aged individuals has found that consuming one or more servings of cabbage per week is associated with a 38% lower risk of developing pancreatic cancer when compared with those who do not eat cabbage (25422).
• Peptic ulcers. Although there has been interest in using oral cabbage for peptic ulcers, there is insufficient reliable information about the clinical effects of cabbage for this purpose.
• Prostate cancer. It is unclear if consuming cabbage is effective for the prevention of prostate cancer. Details: Some observational research has found that consuming higher amounts of cabbage and other Brassica vegetables such as kale, broccoli, and cauliflower is not associated with a lower risk of prostate cancer (25417,25419). However, other observational studies have found that consuming higher amounts of cabbage and other Brassica vegetables is associated with a lower risk of developing prostate cancer (25418,25420,25421). More evidence is needed to rate cabbage for these uses.

(Read more about CABBAGE)

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.

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LIKELY EFFECTIVE

• Diabetic neuropathy. Applying a specific prescription patch containing capsaicin 8% or a specific cream containing capsaicin 0.075% can reduce pain in diabetic neuropathy. Details: Clinical research has evaluated the use of a specific patch (Qutenza, NeurogesX Inc.) containing capsaicin 8%, which is approved as a prescription medication by the US Food and Drug Administration (FDA) for the treatment of diabetic peripheral neuropathy. The research in this population shows that a single application of the patch on the painful parts of the feet for 30-90 minutes following pretreatment with topical anesthetics reduces pain for up to 12 weeks when compared with placebo (40719,96453). Patients using the patch experience reduced sleep interference and an average 28% reduction in pain, compared with a 21% reduction with placebo. Additionally, 50% of patients receiving the patch experience pain relief within 19 days, compared to 72 days for those receiving placebo (96453). A meta-analysis of the available clinical research for diabetic peripheral neuropathy found that one-time application of this patch is equally effective to duloxetine 20-120 mg daily, pregabalin 75-600 mg daily, and gabapentin 300-3600 mg daily in producing a 30% or 50% pain reduction. The dose of oral medication used in the evaluated studies did not impact the comparative efficacy of the capsaicin patch (96450). Other clinical research shows that applying cream containing capsaicin 0.075% four times daily for 8 weeks reduces pain intensity when compared with placebo in patients with diabetic peripheral neuropathy (40547,40592,40607). A meta-analysis of clinical research shows that applying cream containing capsaicin 0.075% reduces pain similarly to 5% lidocaine-medicated plaster (40674). Topical cream containing capsaicin 0.075% (Zostrix-HP, Link Medical Products Pty Ltd.) is FDA-approved as an over-the-counter (OTC) medication for this indication (272). However, applying a capsaicin lotion less frequently or with a lower concentration of capsaicin does not seem to be beneficial. A small clinical study in patients with diabetic neuropathy shows that applying a specific lotion (Capsika-75 lotion, Bangkok Drug Company) containing capsaicin 0.075% three times daily for 8 weeks improves pain to a similar degree as a placebo lotion (102277). This study was limited by a high dropout rate, high placebo effect, and poor adherence to therapy. Furthermore, cream or gel (such as Capsika-25 gel, Bangkok Drug Company) containing lower amounts of capsaicin do not appear to be effective for reducing diabetic peripheral neuropathy pain (92984).
• Pain (chronic). Topical cream containing capsaicin can reduce chronic pain associated with various conditions. Topical capsaicin is FDA-approved for this use. Details: Several clinical studies show that topically applying cream containing capsaicin, the active capsicum constituent, 0.05% to 0.075% temporarily relieves chronic pain from rheumatoid arthritis, osteoarthritis, back pain, jaw pain, psoriasis, and neuropathic conditions (12401,17701). Capsaicin, used in topical preparations, is FDA-approved for these uses (272). It can take up to 14 days for the full analgesic effect. For neuropathic pain, the number needed to treat using capsaicin 0.075% for eight weeks is 5.7 (12401). For musculoskeletal pain, for every 8.1 patients treated with capsaicin 0.025%, 1 patient would achieve at least a 50% reduction in pain (12401). Also, applying capsaicin 0.05% (Finalgon CPD Warmecreme) three times daily for 21 days seems to cause a 49% reduction in chronic soft tissue pain when compared with placebo (17701).
• Postherpetic neuralgia. Applying a specific prescription patch containing capsaicin can reduce postherpetic neuralgia pain, especially in patients with the lowest pain scores. Details: Clinical research has evaluated the use of a specific patch (Qutenza, NeurogesX Inc.) containing capsaicin 8%, which is approved as a prescription medication by the US Food and Drug Administration (FDA) for the treatment of postherpetic neuralgia. Research in this population shows that applying a single patch for 60-90 minutes reduces average pain over 24 hours by 27% to 37% for up to 12 weeks, compared to only 4.4% to 26% in patients in the control group (40659,40679,40686,40691,40719,40728,40800,92985,96451,96452). The number needed to treat to achieve at least a 30% or 50% reduction in pain intensity is 10 and 12, respectively; the number needed to treat to achieve an additional beneficial outcome over placebo at 8 weeks and 12 weeks is 9 and 7, respectively (40800,96451). The pain reduction with this patch has an onset of a few days after treatment and the effect lasts for about 5 months (92986). However, some evidence shows that the reduction in pain is only significant for patients who have had postherpetic neuralgia for at least 6 months (40686). Additionally, the reduction in pain and duration of response appears to be greatest for patients with lower pain scores and low sensitivity to light touch at baseline, as well as patients not using concomitant systemic neuropathic pain medications, whereas patients with high pain scores, high sensitivity to touch, or those using systemic neuropathic pain medications experience the smallest and least sustained reduction in pain (40728,96458). Also, other evidence suggests that this patch may be less effective at relieving postherpetic neuralgia when compared with 5% lidocaine-medicated plaster (40688).

POSSIBLY EFFECTIVE

• Back pain. Topical capsicum or capsaicin seems to be beneficial for reducing back pain. Details: A meta-analysis of generally low-quality clinical research, as well as individual studies, show that applying a capsicum-containing plaster providing 11 mg of capsaicin per plaster or 22 mcg of capsaicin per square centimeter of plaster to the back once daily in the morning for 4-8 hours reduces low back pain when compared with placebo (15259,15260,15261). Applying capsaicin 0.05% (Finalgon CPD Warmecreme) three times daily for 21 days seems to cause a 58% reduction in low back pain when compared with placebo (17701). Also, in a mixed group of patients with acute back or neck pain, a large clinical trial shows that four topical applications with a gel containing capsaicin 0.075% with diclofenac 2% every 12 hours modestly reduces pain on motion when compared with diclofenac alone or placebo. The number of patients with at least a 50% reduction in pain from baseline was modestly higher. Capsaicin 0.075% was similarly effective alone and when combined with diclofenac 2% (105202). However, only about half of the patients in this study had back pain.
• Cluster headache. Intranasal capsaicin seems to be beneficial for preventing cluster headaches. Its effect in the treatment of cluster headache is unclear. Details: Some clinical research shows that using the capsicum constituent capsaicin intranasally reduces the frequency of episodic or chronic cluster headache attacks (14323,14351,14352,14358). Capsaicin suspensions of 0.1 mL of a 10 mM suspension, providing 300 mcg/day of capsaicin, has been applied to the ipsilateral nostril. Applications are continued once daily until a burning sensation is no longer experienced (14351,14358). Intranasal application of capsaicin 0.025% (Zostrix, Rodlen Laboratories) might also decrease symptom severity during an acute cluster headache attack. Clinical research shows that daily treatment for 7 days decreases symptom severity over the following week (14353). Ipsilateral, or same side, nostril application of capsaicin appears to be more effective than contralateral application (14351). Due to severe pain associated with intranasal capsaicin administration, pretreatment with intranasal local anesthetic is usually used.
• Nonallergic rhinitis. Intranasal capsaicin in a dose of at least 0.1 mM seems to improve symptoms of nonallergic rhinitis. It is unclear if lower doses of capsaicin are beneficial. Details: Clinical research shows that repeated intranasal in-clinic treatments with capsaicin, the active capsicum constituent, or with capsicum oleoresin, over a period of one to three days, can significantly decrease symptoms of non-allergic, non-infectious perennial rhinitis symptoms (14328,14357,15016,40595,105204,105205). A decrease of symptoms has been observed for up to 6-9 months following these treatments (14328,14357). The following doses have been used: capsaicin 0.15 mg per dose for up to 7 doses over a 14-day period (14328), capsaicin 0.0033 mol once weekly for 5 weeks (14357), capsaicin 15 mcg/0.1 mL applied three times daily for 3 days (15016), and capsaicin 1-4 mcg per puff, applied 3 times in each nostril daily for 3 days (40595). Due to severe pain associated with intranasal capsaicin administration, pretreatment with intranasal local anesthetic is usually used. Personal use of an intranasal spray with a lower dose of capsaicin might also be effective. Clinical research shows that two 0.4 mL puffs with an intranasal spray in each nostril daily for 4 weeks providing capsaicin 0.01 mM, but not 0.001 mM, is more effective than placebo for reducing symptoms of idiopathic rhinitis. This benefit is maintained for an additional 8 weeks. This protocol was at least as effective as receiving five repeated hourly intranasal spray treatments in hospital with capsaicin 0.1 mM (105204).
• Osteoarthritis. The American College of Rheumatology (ACR) conditionally recommends topical capsaicin for knee osteoarthritis, but not for hip or hand osteoarthritis. Details: A meta-analysis of 4 preliminary clinical trials shows that using topical capsaicin 0.025% four times daily has modest benefit for osteoarthritis when compared with placebo. Using capsaicin 0.0125% doesn't seem to be effective (102408). The American College of Rheumatology (ACR) conditionally recommends topical capsaicin for knee osteoarthritis. However, it does not recommend its use for hip osteoarthritis due to the depth of the joint beneath the skin surface, nor for hand osteoarthritis, due to the risk for contamination of the eye (102114).
• Pain (acute). Topical capsicum seems to be beneficial for reducing acute pain due to trauma. Details: Clinical research in patients with trauma-related acute pain shows that topical application with a gel (Sanli Gel) containing capsaicin 0.05% three times daily for 3 days reduces pain by at least 50% in 87% of patients, compared with 63% of those using a piroxicam gel 0.5% (Felden). There was also a significantly greater number of patients with a final pain score of 4 or less. In the capsaicin group, only 12% of patients did not achieve either of these endpoints, compared with 31% in the group receiving piroxicam (105197).
• Postoperative nausea and vomiting (PONV). Applying topical capsicum to acupoints seems to be beneficial for preventing PONV. Details: Clinical research shows that applying a capsicum-containing plaster to acupoints on the hand and forearm 30 minutes prior to anesthesia and leaving in place for 6-8 hours daily for up to 3 days after surgery reduces the incidence of PONV by about 29% to 36% when compared to control (40405,40483,40610). Plasters used in these studies included Sinsin PAS (Sinsin Pharm Co.), which is standardized to contain capsicum 345.8 mg and capsicum tincture 34.58 mg per sheet (40405,40610); and Johnson's Perforated Capsicum Plaster (Johnson & Johnson Ltd.), which is standardized to contain capsicum oleoresin 1% w/w (40483).
• Postoperative pain. Applying topical capsicum-containing plaster to acupoints seems to be beneficial for reducing postoperative pain. It is unclear if a capsicum patch or capsaicin instillation prior to wound closure is beneficial for reducing postoperative pain. Details: Some clinical research shows that applying a capsicum-containing plaster to acupoints on the hands or near the knees of adults or children 30 minutes prior to anesthesia, and leaving in place for 6-8 hours daily for up to 3 days after surgery, reduces the amount of rescue analgesics needed by 29% to 39% within the first 24 hours and by 16% to 19% within the first 48 hours when compared to control (40405,40483,40520,40524,40610). The capsicum-containing plaster used in these studies (Sinsin PAS, Sinsin Pharm Co.) is standardized to contain capsicum 345.8 mg and capsicum tincture 34.58 mg per sheet (40520,40610). Other preliminary clinical research shows that applying a single patch containing the capsicum constituent capsaicin 8% (Qutenza, NeurogesX Inc.) for 30-60 minutes leads to an improvement in overall health status and an average 22% reduction in pain that lasts up to 12 weeks in patients with postoperative and posttraumatic neuropathic pain. Patches were applied to various parts of the body, including the legs, torso, feet, hands, arms, head, and neck, and the reduction in pain continued with the use of a second and third patch application. The validity of these findings is limited by the lack of a control group (96452). Other clinical evidence suggests that instilling capsaicin 15 mg during surgery immediately prior to wound closure reduces the need for pain medication for up to 2 weeks postoperatively when compared with placebo (40741).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Allergic rhinitis (hay fever). It is unclear if intranasal capsaicin is beneficial for preventing allergic rhinitis symptoms. Details: Preliminary clinical research shows that intranasal treatment with cotton wads soaked in the active capsicum constituent capsaicin 30 mcM, applied for 15 minutes and repeated over two days, reduces the severity of experimentally-induced allergic rhinitis. The severity of symptoms seems to be reduced for up to 2 months after treatment (14324). However, contradictory research shows that patients with allergic rhinitis caused by house dust mites do not have significantly improved symptoms after using a capsaicin solution providing 0.15 mg/dose for up to 7 doses over a 14-day period when compared with placebo (14360).
• Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease). Although there is interest in using oral capsicum for ALS, there is insufficient reliable information about the clinical effects of capsicum for this condition.
• Athletic performance. It is unclear if oral capsaicin is beneficial for improving athletic performance; the available research is limited to small, conflicting studies. Details: Several small clinical studies in physically active young adults show that taking capsaicin might improve some measures of athletic performance, but results are mixed overall (99409,99410,102276,105191,105198,105200). A meta-analysis of these and several other small clinical studies shows that taking the capsicum constituents capsaicin or capsiate 45 minutes before exercise improves measures of muscular endurance but does not improve aerobic endurance when compared with placebo. Doses of the capsicum constituents ranged from 1.2-24 mg, with most studies assessing a single 12 mg dose (111515). The included studies have a number of methodological problems that limit the validity of the findings, such as a small sample size, short study duration, and insufficient blinding. Also, most of the study participants were male. Other small clinical studies not included in the meta-analysis also show conflicting results. One small clinical study in untrained young adults undergoing resistance training shows that taking capsiate, a capsaicin analog, 6 mg orally twice daily for 6 weeks improves upper body, but not lower body, weightlifting performance when compared with placebo (109024). However, another small clinical trial in experienced male athletes shows that taking cayenne (GNC Nature's Fingerprint Cayenne Herbal Supplement) 3 grams, providing capsaicin 25.8 mg, daily for 7 days does not improve sprint time, rate of perceived exertion, or muscle soreness over three days when compared with placebo (105206). Capsicum has also been evaluated in combination with other ingredients. One small clinical study in untrained males shows that taking a supplement containing capsicum extract 66.7 mg, caffeine 400 mg, black pepper extract 10 mg, and niacin 40 mg prior to exercising does not improve strength, time to exhaustion, or maximal oxygen consumption when compared with placebo (37873).
• Burning mouth syndrome. It is unclear if applying topical capsaicin in the mouth is beneficial for burning mouth syndrome. Details: Preliminary clinical studies show that using 15 mL of a mouth rinse containing the active capsicum constituent capsaicin 0.02% for 30 seconds daily for 7-21 days modestly decreases burning discomfort when compared to baseline in patients with burning mouth syndrome (92991,105195). Other preliminary clinical research shows that applying 0.5 mL of a gel containing capsaicin 0.01% or 0.025% to the tongue three times daily for 14 days modestly reduces pain when compared to baseline in patients with burning mouth syndrome. The gel is spread with a cotton swab, and no food or drink is consumed for 30 minutes after application (96456). The validity of these findings is limited by the lack of a control group, the small number of patients, and occasionally unclear statistical comparisons.
• Cancer. It is unclear if eating more chili is beneficial for preventing mortality due to cancer. Details: Population research has found that consuming chili more than four times weekly is not associated with a reduced odds of cancer mortality (105208). Also, other population research has found that any consumption of hot red chili peppers is not associated with a reduced odds of mortality related to cancer (105210).
• Cannabinoid hyperemesis syndrome (CHS). Preliminary clinical research suggests that topical capsaicin might be beneficial for reducing symptoms of CHS. Details: One small clinical study in adults presenting to an emergency department (ED) with CHS shows that applying 5 grams of a cream containing capsaicin 0.1% to the abdomen modestly reduces nausea severity at 60 minutes, but not 30 minutes, when compared with a placebo cream. Nausea was completely resolved in 29% of patients, compared with 0% of those using the placebo cream. However, there was no difference in vomiting at 30 or 120 minutes (105193). This study may not have been adequately powered to detect a difference in some of these outcomes. A meta-analysis of two small, low-quality studies involving the topical use of capsaicin on the abdomen, chest, and possibly back, shows that the mean time to resolution of symptoms was 326 minutes and the mean length of stay in the emergency department was 379 minutes. However, it is unclear how these times compare to the use of placebo or standard antiemetics. This study also conducted a systematic review of the available literature, which indicates that the creams most commonly used in research provide 0.025% to 0.1% capsaicin (105201). Two low-quality, retrospective reviews also suggest that capsaicin cream may be beneficial for CHS. A retrospective review of patients in the ED with CHS has found that applying capsaicin cream 0.025% is associated with a 39% shorter time to discharge when compared with control. Patients treated with capsaicin also required fewer additional rescue treatments when compared with control (109021). Another retrospective review of patients in the ED with CHS also suggests that capsaicin cream 0.025% modestly reduces abdominal pain when compared with baseline. However, 47% and 28% of patients, respectively, received additional antiemetics or an opioid after the use of the cream (105345).
• Cardiovascular disease (CVD). It is unclear if eating more chili is beneficial for preventing mortality due to CVD. Details: Population research has found that consuming chili more than four times weekly is associated with a 34% reduced odds of CVD mortality when compared with never or rarely consuming chili, as well as 44% and 61% reduced odds of ischemic heart disease and cerebrovascular death, respectively (105208). Other population research has found that consumption of hot red chili peppers is not associated with a reduced odds of mortality related to CVD when compared with not eating hot red chili peppers (105210).
• Diabetes. It is unclear if oral capsaicin is beneficial for gestational diabetes. Details: Preliminary clinical research shows that taking chili powder containing capsaicin 5 mg daily for 4 weeks modestly reduces total cholesterol levels and reduces postprandial blood glucose levels by an average of 36 mg/dL and postprandial insulin levels by an average of 14 IU/L in patients with gestational diabetes. Compared to a placebo group, these changes are significant. However, capsaicin intake does not alter fasting plasma glucose or insulin levels (96457).
• Dry skin. It is unclear if oral capsicum is beneficial for dry skin. Details: Preliminary clinical research in adult females with low skin moisture shows that taking paprika oil extract 400 mg, standardized to include 9 mg of xanthophyll, orally daily for 4 weeks improves skin moisture and viscoelasticity scores, but not the number of wrinkles, when compared with control (109026).
• Dyslipidemia. It is unclear if oral capsicum is beneficial for reducing lipid levels. Details: A meta-analysis of three or four mainly small clinical trials in healthy adults shows that taking capsicum does not improve levels of triglycerides, total cholesterol, or high-density lipoprotein (HDL) cholesterol when compared with no treatment or placebo. However, there was a small to moderate effect on levels of low-density lipoprotein (LDL) cholesterol. Freshly chopped chili or fermented red pepper were studied for 4 and 12 weeks, respectively (105194). It is unclear if capsicum can lower lipid levels in patients with dyslipidemia or hyperlipidemia.
• Dyspepsia. It is unclear if oral capsicum is beneficial for dyspepsia. Details: Preliminary clinical research shows that taking red pepper powder 2.5 grams daily in three divided doses for 5 weeks reduces symptoms of functional dyspepsia when compared with placebo. However, in some patients, there seems to be a worsening of symptoms prior to any improvement (12410).
• Fibromyalgia. It is unclear if oral capsicum is beneficial for fibromyalgia. Details: Preliminary clinical research shows that applying cream containing the active capsicum constituent capsaicin 0.025% four times daily to tender points for 4 weeks reduces localized tenderness in patients with fibromyalgia (7038). Other preliminary clinical research shows that applying capsaicin 0.075% cream (Sensedol) three times daily to tender points for 6 weeks in addition to standard therapy increases the pain threshold when compared with standard therapy in patients with severe fibromyalgia (92979). However, capsaicin does not appear to reduce overall pain or improve physical function in patients with fibromyalgia (7038,92979). Also, the long-term effects of capsaicin on fibromyalgia-related pain are unclear.
• Gastroesophageal reflux disease (GERD). Although there is interest in using oral capsicum for GERD, there is insufficient reliable information about the clinical effects of capsicum for this condition.
• HIV/AIDS-related peripheral neuropathy. It is unclear if topical capsaicin is beneficial for this condition. Details: There is conflicting evidence regarding the effects of Qutenza (NeurogesX Inc.), which contains the active constituent of capsicum, capsaicin 8%. Although some research shows it reduces pain in patients with HIV and peripheral neuropathy (22395), other research shows no significant benefit (40746). A meta-analysis of results from both of these studies shows that applying a single capsaicin 8% patch for 30-90 minutes reduces pain intensity by at least 30% in about 30% more patients when compared to control (40800). Additional meta-analyses of the results from these two studies suggests that pain reduction with capsaicin begins a few days after treatment and lasts for about 5 months, with a number needed to treat of 11 to achieve at least a 30% reduction in pain intensity (92986,96451). Reduction in pain and duration of response appears to be greatest for females with lower pain scores at baseline, whereas males with high pain scores at baseline experience the smallest and least sustained reduction in pain (96458). Some research has also evaluated topical capsaicin 0.075%. One small clinical study shows that applying this cream does not relieve symptoms of HIV-associated peripheral neuropathy when compared with placebo (3891).
• Hypertension. It is unclear if oral capsicum is beneficial for lowering blood pressure. Details: Two meta-analyses of small clinical trials show that taking capsicum as freshly chopped chili, fermented red pepper, red pepper capsules, or capsinoid capsules orally daily for 4-12 weeks does not reduce systolic or diastolic blood pressure when compared with control. However, most subjects included in these clinical trials did not have hypertension (105194,109025).
• Intermetatarsal neuroma. It is unclear if injecting capsaicin into the third intermetatarsal space is beneficial for intermetatarsal neuroma. Details: Clinical research in adults with intermetatarsal neuroma shows that a single injection of capsaicin 0.1 mg into the third intermetatarsal space 5 minutes after administration of 2 mL of lidocaine 2% with epinephrine leads to a modest reduction in pain at weeks 1 and 4, but not weeks 2 and 3, when compared with placebo. Capsaicin also reduces the extent to which pain interferes with walking and mood, but not with work, sleep, relationships, or general activity (96454).
• Irritable bowel syndrome (IBS). It is unclear if oral capsicum is beneficial for IBS. Details: Preliminary clinical research shows that taking ground guajillo chili 1 gram, containing capsaicin 0.112%, with each meal for 7 days does not reduce symptoms of IBS (12403). A small clinical study shows that taking chili (Nguan Soon Co., Ltd.) 2.1 grams, providing 2.5 mg capsaicin, daily before meals for 6 weeks does not improve abdominal burning, fecal urgency, or abdominal pain or bloating after a spicy meal. However, there was a modest reduction in abdominal burning after a spicy meal (105207). This study may not have been adequately powered to detect a difference in some of these outcomes.
• Laryngitis. Although there is interest in gargling with capsicum for laryngitis, there is insufficient reliable information about the clinical effects of capsicum for this condition.
• Motion sickness. Although there is interest in oral capsicum for motion sickness, there is insufficient reliable information about the clinical effects of capsicum for this condition.
• Myofascial pain syndrome. It is unclear if topical capsaicin is beneficial for myofascial pain syndrome. Details: Preliminary clinical research shows that applying a specific capsaicin cream (Dipental Cream, Dalim BioTech) containing capsaicin 0.25 mg/gram along with a ketoprofen 30 mg patch (KetotopVRPlaster, Pacific Pharma) to the trapezius does not reduce pain when compared with a ketoprofen patch alone in patients with myofascial pain (92983).
• Neck pain. It is unclear if topical capsaicin is beneficial for neck pain. Details: In a group of patients with acute back or neck pain, a large clinical trial shows that four topical applications with a gel containing capsaicin 0.075% with diclofenac 2% every 12 hours modestly reduces pain on motion when compared with diclofenac alone or placebo. The number of patients with at least a 50% reduction in pain from baseline was modestly higher. Capsaicin 0.075% was similarly effective alone or when combined with diclofenac 2% (105202). However, only about half of the patients in this study had neck pain.
• Neuropathic pain. It is unclear if topical capsicum is beneficial for neuropathic pain. Details: A very small study in adults with neuropathic pain secondary to spinal cord injury shows that applying a patch containing the capsicum constituent capsaicin 8% for 60 minutes daily to the affected area for 12 weeks reduces pain at weeks 2 and 4 and improves mobility, but not quality of life, for up to 12 weeks when compared with placebo (111517). The validity of these findings is limited by insufficient blinding and the small sample size.
• Obesity. It is unclear if oral capsicum is beneficial for obesity. Details: A meta-analysis of 3-5 small clinical trials shows that taking capsicum does not reduce body weight, body fat, or body mass index (BMI) in individuals with a BMI of at least 25 kg/m2 when compared with placebo or no treatment. Freshly chopped chili, fermented red pepper, or capsicum constituents were studied for 4-12 weeks (105194). In one clinical trial included in the analysis, taking capsinoids 3 mg twice daily 30 minutes prior to eating for 12 weeks reduced abdominal fat by about 1%, but did not significantly reduce body weight, when compared with placebo (40599). In overweight individuals, one small clinical trial shows that taking a specific chili extract 200 mg, formulated with fenugreek dietary fiber for sustained release (Capsifen, Akay Natural Ingredients), providing capsaicinoids 4 mg daily for 28 days reduces body weight and BMI by about 2% when compared with placebo. There was no effect on blood pressure (105196). Capsicum has also been evaluated in combination with other ingredients, with some evidence of benefit. One study evaluated a combination product (Prograde Metabolism) containing capsicum extract (Capsimax, OmniActive Health Technologies), raspberry ketone (Razberi K, Integrity Nutraceuticals), caffeine, garlic root extract, ginger root extract, bitter orange fruit (Advantra Z, Nutratech Inc), L-theanine, and black pepper fruit extract (Biperine, Sabinsa Corporation) twice daily for 8 weeks (40802).
• Overall mortality. Eating chili may be beneficial for preventing mortality. It is unclear if taking capsicum supplements is beneficial for preventing overall mortality. Details: Population research has found that consuming chili is associated with a reduced risk of overall mortality. In one study, eating chili more than four times weekly was associated with a 23% reduced odds of overall mortality when compared with never or rarely consuming chili (105208). Other population research has found that any consumption of hot red chili peppers is associated with a 13% reduced odds of mortality when compared with not eating these peppers (105210). Also, eating spicy foods at least once each week, consisting mainly of fresh chili pepper, dried chili pepper, chili sauce, or chili oil, was associated with at least a 10% reduced risk of death when compared with eating these foods less than once a week (105211).
• Peptic ulcers. It is unclear if oral capsicum is beneficial for peptic ulcers. Details: Population research has found that eating capsicum fruit (chili) an average of 24 times per month is associated with a reduced likelihood of having an ulcer when compared with eating chili an average of 8 times per month. This applies to chili in the form of chili powder, chili sauce, curry powder, and other chili-containing foods (12053). However, clinical research shows that consuming chili peppers 1 gram three times daily for 4 weeks does not improve duodenal ulcer healing when compared to control (40828).
• Peripheral neuropathy. Preliminary clinical research suggests that topical capsaicin might be beneficial for reducing peripheral neuropathy pain. Details: Preliminary clinical research shows that applying patches containing the capsicum constituent capsaicin 8% (Qutenza, NeurogesX Inc.) reduces pain in people with non-diabetic peripheral neuropathy (96452,111516). Up to four patches, applied to different painful areas, are used at one time and are left in place for 30 minutes on the feet, or 60 minutes on other parts of the body such as the legs, torso, hands, arms, head, or neck (96452). After an interval of at least 90 days, treatment can be repeated, with new patches applied for 30-60 minutes (99407). There is an average 27% reduction in pain when compared to baseline, lasting up to 12 weeks (96452). Another similar study reported a decrease of 1 point, on a 10-point pain scale, in the typical daily pain intensity (99407). The validity of these findings is limited by methodological problems, including the lack of control groups. Further research shows that using a single application of up to four capsaicin 8% patches for 30-60 minutes, or taking pregabalin orally, 150-600 mg in 2-3 divided doses daily for 8 weeks, reduces the intensity and area of dynamic mechanical allodynia (DMA, pain evoked by light brushing of the skin) in people with non-diabetic peripheral neuropathy. Complete resolution of DMA occurred in 24% of people using the patches, and 12% of those taking pregabalin (99408). The validity of these findings is limited by methodological problems, including a lack of blinding.
• Prurigo nodularis. It is unclear if topical capsaicin is beneficial for prurigo nodularis. Details: Preliminary clinical research shows that applying a cream containing the active capsicum constituent, capsaicin 0.025% to 0.3%, 4-6 times daily improves burning sensations, erythema, pruritus, and healing of skin lesions over a period of 2 weeks to 33 months when compared to baseline. Symptoms may return after discontinuation of therapy (10650).
• Sinonasal polyposis. It is unclear if intranasal capsaicin is beneficial for sinonasal polyposis. Details: Preliminary clinical research in patients with severe sinonasal polyposis shows that intranasal application of 0.5 mL of a 30 mmol/L capsaicin solution to each nostril for 3 days, followed by 0.5 mL of a 100 mmol/L capsaicin solution for 2 days, can cause significant subjective improvement in symptoms as well as objective improvement in nose/sinus air volume and endoscopy scores; however, capsaicin does not seem to significantly affect eosinophil cationic protein levels (14359).
• Swallowing dysfunction. Preliminary research shows that oral capsaicin might be beneficial for improving swallowing ability. Details: Preliminary clinical research shows that elderly patients at risk for aspiration pneumonia due to swallowing dysfunction have improved swallowing reflexes after dissolving a lozenge containing capsaicin 1.5 mcg in the mouth before each meal when compared with using a placebo lozenge (13100). Preliminary clinical research also shows that capsaicin may be beneficial in patients with swallowing dysfunction due to stroke (102278,105192). One study shows that taking 1 mL of nectar containing capsaicin 150 mcM/L with each meal daily for 3 weeks, in addition to thermal tactile stimulation, improves eating and swallowing when compared with using thermal tactile stimulation and placebo nectar (102278). Another study shows that 20 minutes of stimulation with an ice swab containing capsaicin 0.15 mM before lunch and dinner daily for three weeks modestly improves the ability to swallow water when compared with ice stimulation alone. After treatment, approximately 70% of those using the capsaicin ice were able to drink the water without choking, compared with only 33% in those using ice alone (105192). Capsaicin solution has also been administered by nebulizer. A clinical study in patients with swallowing dysfunction secondary to hemorrhagic stroke shows that inhaling capsaicin solution twice daily for one week reduces the incidence of post-swallow residue and pulmonary infection and increases number of coughs in response to capsaicin compared with placebo. However, treatment with nebulized capsaicin does not reduce the number of patients with swallow or cough reflexes compared with control (111518). More evidence is needed to rate capsicum for these uses.

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POSSIBLY EFFECTIVE

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

INSUFFICIENT RELIABLE EVIDENCE to RATE

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

(Read more about CARROT)

INSUFFICIENT RELIABLE EVIDENCE to RATE

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

(Read more about CAULIFLOWER)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Anxiety. It is unclear if oral celery seed extract is beneficial in patients with anxiety. Details: A small clinical study in Iranian adults with hypertension on standard antihypertensive therapy shows that taking celery seed extract 1.34 grams daily for 4 weeks reduces symptoms of anxiety and depression when compared with placebo (112409). However, it is unclear if these benefits can be extrapolated to patients in geographic locations other than Iran.
• Depression. It is unclear if oral celery seed extract is beneficial in patients with depression. Details: A small clinical study in Iranian adults with hypertension on standard antihypertensive therapy shows that taking celery seed extract 1.34 grams daily for 4 weeks reduces symptoms of anxiety and depression when compared with placebo (112409). However, it is unclear if these benefits can be extrapolated to patients in geographic locations other than Iran.
• Diabetes. It is unclear if oral celery seed extract is beneficial in patients with diabetes. Details: A small clinical study in adults with type 2 diabetes shows that taking celery seed powder 250 mg three times daily for 12 weeks does not improve fasting blood glucose, fasting insulin, insulin resistance, total cholesterol, low-density lipoprotein or high-density lipoprotein cholesterol, triglycerides, or blood pressure when compared with placebo (112411). However, the study may have been inadequately powered to detect a difference between groups.
• Dysmenorrhea. Oral celery seed has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One clinical trial in female college students shows that taking a specific combination product containing celery seed, saffron, and anise extracts (SCA, Gol Daro Herbal Medicine Laboratory) 500 mg three times daily for 3 days, starting at the beginning of bleeding or pain, reduces severity and duration of pain symptoms associated with menstruation when compared with placebo (17214). It is not clear if these effects are due to celery, other ingredients, or the combination.
• Dyspepsia. Oral celery seed has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A moderate-sized clinical trial in adults with functional dyspepsia conducted in Iran shows that taking celery seed powder 500 mg daily with bishop's weed 500 mg daily spread over three doses after meals for 4 weeks reduces patient-reported dyspepsia symptom severity when compared with domperidone. Taking celery and bishop's weed also reduces patient-reported symptom frequency when compared to baseline (112410). However, it is unclear if these effects are due to celery, bishop's weed, or the combination, or if results can be extrapolated to patients in geographic locations other than Iran. The interpretation of these results is also limited by the lack of a placebo group.
• Gout. Oral celery has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small, open-label clinical study in patients with gout shows that taking a specific combination product (GoutFigher, Max Biocare) containing celery seed extract 600 mg, devil's claw root extract 300 mg, sour cherry extract 200 mg, and other ingredients twice daily for 45 days reduces pain, joint inflammation, and uric acid levels when compared to baseline (106488). The validity of these findings is limited by the lack of a control group. Additionally, it is unclear if these findings are due to celery, other ingredients, or the combination.
• Headache. Although there has been interest in using oral celery for headache, there is insufficient reliable information about the clinical effects of celery for this purpose.
• Hypertension. It is unclear if oral celery seed extract is beneficial in patients with hypertension. Details: A small clinical study in Iranian adults with hypertension on standard antihypertensive therapy shows that taking celery seed extract 1.34 grams daily for 4 weeks reduces daytime systolic blood pressure by about 12 mmHg compared to less than 1 mmHg with placebo. Celery seed extract also reduces night-time blood pressure, diastolic blood pressure, and mean arterial pressure, but does not impact the heart rate (110755). However, it is unclear if these benefits can be extrapolated to patients in geographic locations other than Iran.
• Impaired glucose tolerance (prediabetes). It is unclear if oral celery leaf extract is beneficial in patients with prediabetes. Details: A small clinical study in elderly patients with prediabetes shows that taking celery leaf extract 250 mg three times daily for 12 days reduces postprandial plasma glucose levels, but not insulin levels, when compared to baseline (99572). Although a control group was included in the study, statistical comparisons between treatment and control groups were not reported.
• Mosquito repellent. It is unclear if topical celery seed extract is beneficial for use as a mosquito repellant. Details: One small clinical study shows that applying gel formulations containing celery seed extract 5% to 25% can repel mosquitos in a dose-dependent manner for up to 4.5 hours. These formulations show similar repellant action when compared with DEET-containing formulations and appear to be superior to commercial repellants without DEET (40988). Celery extract has also been evaluated in combination with other ingredients. Two clinical studies show that application of a specific formulation (G10, E.A.R. Samunpri) containing celery seed extract 5%, along with vanillin, eucalyptus oil, orange oil, and citronella oil, seems to repel mosquitos for up to 4.5 hours comparably to other commercial products, including DEET 25% and Insect Block 28 (41049,41052). It is unclear if these findings are due to celery, other ingredients, or the combination.
• Osteoarthritis. Oral celery seed has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small, open-label clinical study in patients with mild knee osteoarthritis shows that taking a specific combination product (Tregocel, Max Biocare) providing celery seed 1000 mg, Boswellia serrata resin extract 1000 mg, devil's claw 1000 mg, ginger rhizome 330 mg, and curcumin 180 mg daily for 36 weeks reduces pain, improves functional capacity, and increases walking distance when compared to baseline (106078). The validity of these findings is limited by the lack of a control group. Additionally, it is unclear if these findings are due to celery, other ingredients, or the combination.
• Rheumatoid arthritis (RA). Although there has been interest in using oral celery juice for RA, there is insufficient reliable information about the clinical effects of celery for this purpose.
• Sexual dysfunction. It is unclear if oral celery seed powder is beneficial in females with sexual dysfunction. Details: One small clinical study in females with sexual dysfunction shows that taking celery seed powder 500 mg three times daily for 6 weeks improves sexual dysfunction symptom scores, primarily due to patient-rated improvements in sexual desire, arousal, lubrication, and pain, when compared with placebo (106486).
• Urinary tract infections (UTIs). Although there has been interest in using oral celery juice for UTIs, there is insufficient reliable information about the clinical effects of celery for this purpose. More evidence is needed to rate celery for these uses.

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POSSIBLY INEFFECTIVE

• Hyperlipidemia. A meta-analysis of small clinical studies suggests that consuming chia seeds, flour, powder, or oil for 7-24 weeks does not improve lipid levels in patients with conditions associated with hyperlipidemia. Details: A meta-analysis of 10 small clinical trials in patients with various metabolic conditions, including diabetes, metabolic syndrome, nonalcoholic fatty liver disease, and obesity, shows that consuming chia seeds, flour, or powder 15-60 grams daily for 7-24 weeks, or taking chia oil 6 grams daily for 8 weeks, does not reduce total cholesterol, low-density lipoprotein (LDL) cholesterol, or triglyceride levels or increase high-density lipoprotein (HDL) cholesterol levels when compared with control groups consuming wheat bran, oat bran, dietary fiber, poppy seeds, or soybean oil (106657). While the patient populations in the studies analyzed are more likely to develop hyperlipidemia, it is unclear if these findings can be generalized to patients diagnosed with hyperlipidemia.
• Obesity. Small clinical studies suggest that consuming chia seeds for up to 12 weeks does not reduce body weight in overweight or obese adults. Details: One small clinical study in overweight or obese individuals shows that ingesting chia seeds 25 grams mixed in 0.25 liters of water twice daily before meals for 12 weeks does not improve body composition or reduce blood pressure when compared with placebo (25533). Another small clinical study in overweight, postmenopausal females shows that ingesting milled or whole chia seeds 25 grams daily for 10 weeks does not improve body composition or blood pressure when compared to baseline (25532).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Athletic performance. It is unclear if oral chia is beneficial for improving athletic performance. Details: A small clinical study in trained athletes shows that drinking a beverage containing 50% of calories from chia seeds (Greens Plus Omega 3 Chia seeds) and 50% of calories from a carbohydrate-containing beverage (Gatorade) for 2 days prior to participating in an endurance exercise lasting more than 90 minutes leads to similar performance when compared with Gatorade alone (25531).
• Cardiovascular disease (CVD). Although there has been interest in using oral chia for CVD, there is insufficient reliable information about the clinical effects of chia for this purpose.
• Diabetes. Small clinical studies suggest that consuming chia for 4-6 months might reduce systolic blood pressure (SBP) in patients with type 2 diabetes, although it does not appear to improve glycemic control or lipid levels and has shown mixed effects on body weight and inflammatory markers. Details: One small clinical trial in patients with type 2 diabetes shows that consuming bread containing a specific, selectively bred type of chia (Salba, Salba Smart Natural Products LLC), providing 37 grams of chia daily for 12 weeks reduces SBP, C-reactive protein, and vonWillebrand factor, but not lipid levels, when compared with consuming bread containing wheat bran. This form of chia also significantly reduced glycated hemoglobin (HbA1c) when compared to baseline, but not when compared with a wheat bran control (16124). Another small clinical study in adults with type 2 diabetes and obesity shows that consuming Salba chia 40 grams daily, either baked into bread or as a powder, in conjunction with a restricted calorie diet for 6 months reduces weight by 1.6 kg and waist circumference by 2.8 cm when compared with an oat bran control. However, consuming chia had no effect on body fat percentage, HbA1c, or fasting glucose levels (97940). Also, a small clinical study in adults with type 2 diabetes shows that consuming chia seeds 40 grams daily for 12 weeks reduces SBP, but does not improve body weight, HbA1c, or levels of fasting glucose, lipids, or C-reactive protein, when compared with those not consuming chia (106658).
• Hypertension. It is unclear if oral chia is beneficial in patients with hypertension. Details: A very small clinical study in patients with mild hypertension shows that consuming chia flour 35 grams daily for 12 weeks reduces systolic blood pressure (SBP) by around 10 mm Hg and diastolic blood pressure (DBP) by almost 9 mm Hg when compared to baseline. In patients already taking antihypertensive drugs, chia seems to have an even greater impact on SBP and DBP. However, in patients not being treated with antihypertensive drugs, chia flour modestly reduces SBP by 6.5%, but does not significantly reduce DBP. No improvements in blood pressure were reported in patients consuming a wheat bran control (91516).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral chia is beneficial in patients with NAFLD. Details: Small, uncontrolled clinical studies in patients with NAFLD show that consuming milled chia seeds 25 grams daily for 8 weeks may reduce hepatic steatosis, as measured by the liver: spleen attenuation ratio, in up to 43% of subjects with prediabetes and 100% of subjects with diabetes when compared to baseline. Chia seed supplementation may also modestly reduce visceral fat, body mass index, and waist circumference in patients with prediabetes when compared to baseline, but does not seem to improve lipid levels (104530,110438). The validity of these findings is limited by the lack of a comparator group in both studies.
• Metabolic syndrome. Oral chia has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with metabolic syndrome shows that reducing daily caloric intake by 500 kcal and drinking a beverage containing chia seed 4 grams, soy protein 32 grams, dehydrated nopal 7 grams, and oat 22 grams daily for 2 months reduces body weight, body mass index, and waist circumference when compared to baseline, but not when compared with following a reduced calorie diet alone. However, following the reduced calorie diet and drinking this beverage appears to lower serum triglycerides and C-reactive protein and improve glucose tolerance when compared with a reduced calorie diet alone (25534). It is unclear if these findings are due to chia, other ingredients, or the combination.
• Muscle strength. It is unclear if oral chia is beneficial for increasing muscle strength and muscle mass during resistance training. Details: A very small clinical trial in healthy, non-resistance trained males shows that drinking a supplemental beverage containing chia flour 50 grams, providing 20 grams of protein and 3 grams of omega-3 fatty acids, is no more effective than whey protein 20 grams or placebo for augmenting the increases in muscle strength and fat-free mass that occur with an 8-week whole body resistance training program (112385). The habitual baseline diet of the study participants already contained dietary protein intakes recommended for strength training, and the beverage was only consumed three times per week immediately after training sessions.
• Pruritus. It is unclear if topical chia seed oil is beneficial in patients with pruritus. Details: One very small, uncontrolled clinical study in patients with xerotic pruritus or pruritus caused by kidney failure or diabetes shows that applying lotion containing chia seed oil 4% for 8 weeks improves skin hydration and reduces the severity of lichen simplex chronicus and prurigo nodularis when compared to baseline (25537). The validity of these findings is limited by the small study size and lack of a comparator group. More evidence is needed to rate chia for these uses.

(Read more about CHIA)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Burns. Although there has been interest in using topical cucumber fruit for burns, there is insufficient reliable information about the clinical effects of cucumber for this purpose.
• Diabetes. Although there has been interest in using oral cucumber seed for diabetes, there is insufficient reliable information about the clinical effects of cucumber for this purpose.
• Hyperlipidemia. It is unclear if oral cucumber seed is beneficial in patients with hyperlipidemia. Details: A small clinical trial in patients with mild hyperlipidemia shows that taking cucumber seed extract 500 mg orally daily for 6 weeks reduces levels of low-density lipoprotein (LDL) cholesterol by 27% and levels of triglycerides by 32%, compared with improvements of only 3% and 11%, respectively, in those taking placebo. High-density lipoprotein (HDL) cholesterol levels were also improved (103386).
• Hypertension. Although there has been interest in using oral cucumber stems for hypertension, there is insufficient reliable information about the clinical effects of cucumber for this purpose.
• Osteoarthritis. It is unclear if oral cucumber is beneficial in patients with osteoarthritis. Details: Two moderate-sized clinical trials in patients with moderate knee osteoarthritis shows that taking a specific cucumber extract (Q-Actin) 20 mg or 100 mg daily for 6 months improves the subjective measuresof pain, stiffness, and function at each time point beginning on day 30 when compared with placebo or glucosamine chondroitin. Improvements from baseline range from about 30% to 70% (103385,115615). The generalizability of these findings is limited by the fact that these studies included mostly patients from India or Cameroon (103385).
• Wound healing. Although there has been interest in using topical cucumber fruit for wound healing, there is insufficient reliable information about the clinical effects of cucumber for this purpose. More evidence is needed to rate cucumber for these uses.

(Read more about CUCUMBER)

EFFECTIVE

• Folate deficiency. Oral or intravenous folic acid is effective for the prevention or treatment of folate deficiency. Details: Administering folic acid orally or parenterally improves and prevents folate deficiency (505,8739). Clinical research shows that supplementation with folic acid 100 mcg to 5 mg daily during pregnancy decreases the risk of developing megaloblastic anemia by up to 79% (91307).

LIKELY EFFECTIVE

• Kidney failure. Taking folic acid orally reduces homocysteine levels in people with kidney failure who are on hemodialysis. Details: Over 85% of people with kidney failure have hyperhomocysteinemia. Treatment of hyperhomocysteinemia in kidney failure is often more difficult than with normal kidney function (1489,3324,7289,9413,9414,9416). The reasons for this are not fully understood; renal uptake and metabolism of homocysteine may be reduced in severe kidney failure, and hemodialysis may contribute to vitamin deficiencies (6884,9414,9417). Folic acid 0.8-15 mg daily or 3 times weekly is generally used, but the degree of homocysteine reduction varies between 12% to 50%, and normal homocysteine levels (less than 12 µmol/L) cannot always be achieved. Adding vitamin B12 400-1000 mcg daily and vitamin B6 20-50 mg daily produces an additional reduction in homocysteine (1489,6884,7289,7881,9322,9413,9414,9415,9416,9417). Folic acid doses greater than 15 mg daily do not seem to provide additional benefit. Also, doses of 30-60 mg might cause a rebound in homocysteine levels when treatment is stopped (9219). Despite the homocysteine-lowering effect of folic acid in kidney failure, the most robust meta-analysis of 11 clinical trials suggests that folic acid supplementation does not seem to reduce the risk of cardiovascular events (50527). A smaller meta-analysis of 7 clinical trials that used a different primary composite outcome suggests that folic acid might reduce the risk of cardiovascular events by 15% when compared with control (91311). There has also been interest in using a reduced form of folic acid, L-5-methyltetrahydrofolate (L-5-MTHF). One study in patients on hemodialysis suggests that taking L-5-MTHF 17 mg daily for 12 weeks might lower homocysteine levels to a greater extent than an equimolar 15 mg of folic acid (104908). Another clinical trial in patients on hemodialysis suggests that giving intravenous L-5-MTHF 50 mg three times weekly is associated with an increased survival of about 36 months, compared with about 26 months with folic acid 5 mg daily. There was no difference in homocysteine reduction between groups (104909). These results should be interpreted with caution because they have not been replicated, and there was no placebo control. Furthermore, survival may have been affected by the availability of kidney transplants.
• Hyperhomocysteinemia. Oral folic acid, taken alone or in combination with other B vitamins, lowers homocysteine levels in most patients. However, it is unclear if this has cardiovascular benefits. Details: Taking folic acid orally 0.4-5 mg daily lowers fasting homocysteine levels by 20% to 30% in people with normal to moderately elevated homocysteine levels at baseline. Folic acid 0.8-1 mg daily seems to provide maximal reduction (9307,9400,9401,9405,9408,11337,11338,50145). Doses above 1 mg daily do not seem to add benefit (9307), except in some people with certain gene mutations that cause homocysteine levels of 20 µmol/L or higher (9408). The higher the initial homocysteine levels, the lower the folic acid dose needed to attain maximum homocysteine reduction (9307). The effects of folic acid supplementation on homocysteine concentrations appear to be greater in females than males (50145). Adding vitamin B6 25-250 mg or vitamin B12 500 mcg seems to further reduce homocysteine levels (1489,9400,9405,9406,9408,107136). Some experts recommend routine use of vitamin B12 in homocysteine-lowering regimens to avoid the risk of neuropathy in people with undetected vitamin B12 deficiency (9405). Increasing folic acid intake with supplements or folate-fortified cereal products is more effective for reducing homocysteine levels than increasing intake of folate-rich foods (6367). Fortification of cereals and flour with 140 mcg folic acid per 100 grams reduces the mean homocysteine level in the general population by about 7% (7881,9404,9407). Elevated homocysteine levels are considered by some to be an independent risk factor for atherosclerosis progression, recurrent thromboembolism, deep vein thrombosis, myocardial infarction, ischemic stroke, and other vascular complications (3886,3887,6236,7725,9314,9318,50509). However, elevated homocysteine levels may be a marker, as opposed to a cause, of vascular disease (11387,11388). Although folic acid lowers homocysteine levels, it is not yet known whether this reduces the risk of vascular disease. One meta-analysis shows that taking folic acid can reduce the risk of stroke by about 10% in patients with cardiovascular disease (CVD); the reduction is greatest in patients for whom homocysteine levels are lowered by at least 25% (96157). A meta-analysis of 10 clinical trials, including over 44,000 patients at risk for or with a history of CVD, shows that B vitamin supplementation reduces the relative risk of stroke by 10% when compared with placebo (97619). Also, a meta-analysis in patients with a history of stroke shows that B vitamin supplementation, including folic acid, reduces the relative risk of stroke recurrence by 13% and the risk of vascular death by 11% when compared with placebo (107136). However other research does not agree. Meta-analyses of clinical research show that folic acid does not prevent CVD or coronary heart disease, in spite of lowering homocysteine by up to 55%, when individuals with normal or high levels of homocysteine are considered (50539,96147,97619). Furthermore, most research shows that folic acid supplementation, alone or in combination with vitamin B6 and vitamin B12, does not improve endothelial function or improve secondary prevention of cardiovascular events such as myocardial infarction in people with existing CVD despite a homocysteine-lowering effect (9313,11337,11387,13482,50437,97619). Some research even suggests an increase in CVD risk concurrent with homocysteine lowering (13482). Large randomized controlled trials are needed to confirm or refute these findings. Some researchers hypothesize that different genetic profiles might explain some of these conflicting results. For instance, individuals with a homozygous 677TT MTHFR genotype typically have increased homocysteine levels. However, a meta-analysis suggests that treatment with folic acid does not reduce the risk of ischemic heart disease despite reducing homocysteine levels in individuals with 677TT MTHFR (50456). It has also been theorized that a reduced form of folic acid, 5-methyltetrahydrofolate (5-MTHF) might work better in these individuals. Although [6RS]-5-MTHF has been shown to lower homocysteine levels (104915), studies assessing its cardiovascular benefits are lacking.
• Methotrexate toxicity. Oral folic acid reduces the severity of methotrexate toxicity. Details: Oral folic acid reduces methotrexate toxicity symptoms, such as nausea and vomiting, in the treatment of rheumatoid arthritis (RA) and psoriasis (768,2162,2163,2164,4492,4493,4494,9369,9419). Folic acid also seems to reduce methotrexate-induced hepatic side effects by approximately 36% (50320). Some research shows that a low, 0.8 mg weekly dose of folic acid is equally effective to a higher dose of 5 mg weekly for the prevention of methotrexate toxicity (102388).
• Neural tube birth defects. Oral folic acid helps to prevent neural tube birth defects in newborns. Details: Clinical practice guidelines recommend that anyone capable of becoming pregnant take folic acid 400 mcg daily from fortified foods or supplements to prevent neural tube birth defects in infants. Folic acid 600 mcg daily is advised during pregnancy (94811,96146). This recommendation is based on research showing that a higher intake of folic acid from food and supplements during pregnancy reduces the primary incidence of neural tube birth defects by 41% to 69% (3325,9309,50344,50403,50468,95156). Individuals with a history of children with neural tube birth defects usually take a higher dose of folic acid 4000 mcg daily starting one month before and continuing for up to 3 months after conception (96146). Evidence shows that, when used for secondary prevention, folic acid supplementation reduces the incidence of neural tube defects by 66% to 87% (21235,50263,50344,50403,95156). In the US, foods containing at least 60 mcg of folic acid can be labeled with a health claim stating that healthful diets with adequate folic acid intake may reduce the risk of having a child with a brain or spinal cord defect (102369).

POSSIBLY EFFECTIVE

• Cognitive impairment. Taking folic acid alone, with other B vitamins or with docosahexaenoic acid (DHA), might improve thinking and memory skills in older patients with cognitive impairment. Details: One clinical trial in patients aged 65 years and older with mild cognitive impairment (MCI) shows that taking folic acid 400 mcg daily for 2 years increases IQ scores when compared with placebo (100952). Two small, low-quality clinical studies in patients aged 70-90 years with cognitive impairment and low folate levels or folate deficiency shows that taking folic acid 5 or 15 mg daily for up to 63 days improves cognitive function, including measures such as memory and attention, when compared with placebo or baseline (50301,104911). Folic acid also appears to be beneficial when used in combination with other B vitamins or with DHA. A clinical trial in patients aged 70 years and older with MCI shows that taking folic acid 800 mcg, vitamin B6 20 mg, and vitamin B12 500 mcg daily for 2 years mitigates decline in executive function and, in patients with high baseline homocysteine levels, improves cognition and memory when compared with placebo (50480). Taking folic acid 800 mcg with or without DHA 800 mg daily for 6 months modestly improves cognition, as measured on the full-scale intelligence quotient, when compared with placebo (103978,109196). However, this benefit is no longer present at 6 months after treatment discontinuation (109196).
• Depression. Oral folic acid seems to modestly reduce depression severity when added to conventional antidepressant therapy. It is unclear if folic acid can reduce the prevalence of depression or the risk for suicide. Details: Observational studies suggest that depression is correlated with low folate status, particularly in females (50105,50127,50243). Taking folic acid 0.2-15 mg daily for up to 6 months with conventional antidepressants seems to improve treatment response in patients with major depressive disorder (3657,10884,10887,50566,109190). One meta-analysis shows that taking L-methylfolate or folic acid as an adjunct to treatment with conventional antidepressants modestly reduces depression severity when compared with placebo and conventional antidepressants. The response and remission rates were improved by 36% and 39%, respectively (109190). However, limited clinical research suggests that folic acid is not effective as a replacement for conventional antidepressant therapy (10886). Also, a small clinical study in adolescents at high familial risk for mood disorders suggests that taking folic acid 2.5 mg daily for up to 36 months does not prevent mood disorders when compared with placebo. However, in the patients that were eventually diagnosed with depression, the time of onset was delayed from 5 months to 15.5 months in the group using folic acid when compared with placebo (91313). Guidelines from The World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety Treatments (CANMAT) Taskforce state that folic acid is not currently recommended as monotherapy treatment for unipolar depression (110318). Observational research has also evaluated the association between folic acid supplementation and suicidal events in patients with or without depression. One within-person cohort study, in which only 12% of patients were diagnosed with depression, has found that filling a folic acid prescription of 0.4-5 mg daily, either alone or as part of a multivitamin, is associated with a reduced risk for suicidal events during the following months when compared with months without a prescription (109201). It is unclear what percentage of these patients, if any, had folate deficiency at baseline.
• Hypertension. Oral folic acid seems to modestly reduce hypertension. Details: A meta-analysis of clinical research shows that taking folic acid 5-10 mg daily for at least 6 weeks reduces systolic blood pressure by 2mmHg and improves flow-mediated dilation by 1.6% in hypertensive individuals (50364). Some research has evaluated folic acid in hypertensive patients when used with antihypertensive drugs. Results show that taking folic acid 400-800 mcg in combination with enalapril 10 mg daily for about 4.5 years does not improve blood pressure when compared with enalapril alone (50302,96158). However, in hypertensive patients with heavy proteinuria, this combination seems to reduce the risk of all-cause mortality by about 41% when compared with enalapril alone (96158).
• Phenytoin-induced gingival hyperplasia. Topical folic acid seems to reduce gingival hyperplasia due to phenytoin. The effect of oral folic acid is unclear. Details: Applying folic acid topically seems to inhibit gingival hyperplasia secondary to phenytoin therapy (2151). However, taking folic acid orally does not seem to improve gingival hyperplasia secondary to phenytoin therapy in adults (2150,2151,2152), although some evidence suggests that taking folic acid 500 mcg daily reduces the risk of phenytoin-induced gingival hyperplasia by 33% in children when compared with placebo (50463).
• Stroke. Although some clinical research has shown that oral folate reduces stroke risk by a small amount, more research is needed to determine who is most likely to benefit. Most individual clinical trials show that folic acid seems to reduce stroke risk only in regions without food-fortification policies. Details: Multiple clinical studies have shown that folic acid supplementation reduces the risk of stroke by 10% to 25% in regions WITHOUT established policies mandating folic acid fortification of grain products (50240,50485,50525,50539,91325,96154,96157,96159,97308). The effect appears to be greatest when folic acid is taken in low doses (usually 0.8 mg daily or lower) (50525,96157,96159), in regions with a low prevalence of statin use (50525,96159), in patients with high cholesterol levels at baseline (96152), in patients who achieve homocysteine reduction of at least 20% (50407,96157), and in patients with the lowest folate levels at baseline (96154,96157). There is also some evidence that the effect of folic acid on stroke risk is greatest in patients with low baseline levels of vitamin B12 (96159). In 2001, the US Food and Drug Administration (FDA) allowed a qualified health claim stating that, as part of a well-balanced diet that is low in saturated fat and cholesterol, folic acid, vitamin B6, and vitamin B12 may reduce the risk of vascular disease (102368). Most research shows that folic acid supplementation does not reduce the risk of stroke in regions WITH established policies mandating folic acid fortification (50240,50485,50525,50539,96157,96159,97308). However, there is some evidence that folic acid may reduce the risk of stroke in patients from regions with folic acid fortification who have recently had a stroke or transient ischemic attack and are not using antiplatelet drugs (90379). Meta-analyses of clinical research have been conducted. However, possible confounding due to the presence or absence of folic acid fortification is unclear. A meta-analysis of the available research in adults with existing CVD shows that folic acid supplementation at a daily dose of less than 2 mg reduces the risk for stroke by about 10% (102386). Also, a meta-analysis of 10 clinical trials, including over 44,000 patients at risk for or with a history of CVD, shows that B vitamin supplementation, including folic acid, reduces the relative risk of stroke by 10% when compared with placebo (97619). In patients with a history of stroke, a meta-analysis shows that B vitamin supplementation reduces the relative risk of stroke recurrence by 13% and the risk of vascular death by 11% when compared with placebo (107136). It is unclear if folic acid reduces the stroke risk in patients with impaired kidney function. Some research shows that taking folic acid in combination with high doses of vitamin B12 (cyanocobalamin) does not reduce the risk of stroke in these patients (11387,96150). However, there is concern that the lack of benefit may have been due to the decline in kidney function from high doses of cyanocobalamin (96150). Additional research is needed to determine if folic acid supplementation is beneficial in patients with impaired kidney function when used with other forms of vitamin B12 such as methylcobalamin or hydroxycobalamin.
• Vitiligo. Oral folic acid seems to improve vitiligo symptoms. Details: Taking folic acid orally seems to improve symptoms of vitiligo (2153,2154). This finding is supported by a meta-analysis of observational research which shows that patients with vitiligo have higher serum homocysteine levels when compared with patients without vitiligo (100951).

POSSIBLY INEFFECTIVE

• Anemia. Adding oral folic acid to oral iron therapy does not seem to improve hematologic parameters in patients with anemia. Details: In postpartum patients with anemia, clinical research shows that taking iron as ferrous fumarate 600 mg and folic acid 1 mg daily is no more effective than iron alone for improving hemoglobin status (91319). Also, clinical research in non-pregnant menstruating females shows that taking folic acid 0.4 mg daily or 2.8 mg once weekly for 16 weeks with iron 60 mg daily does not reduce anemia or improve iron status when compared with iron alone (109193). During pregnancy, clinical research shows that folic acid supplementation does not decrease the risk of pre-delivery anemia or low hemoglobin levels (91307).
• Age-related cognitive decline. Oral folic acid does not seem to prevent cognitive decline in healthy elderly adults. Details: Most clinical research shows that taking folic acid, alone or in combination with other B vitamins, does not improve cognitive function, including memory, language, or executive function, in elderly adults with age-related cognitive decline (50318,50412,50510). In fact, a large-scale observational study in the US has found that people over 65 years of age who consume large amounts of folic acid (median of 742 mcg daily) have cognitive decline at a rate twice as fast as those consuming smaller amounts (median of 186 mcg daily) (13068). While most research on folic acid for age-related cognitive decline lacks positive findings, many of the studies are small, short-term (<1 year), underpowered to detect significant differences, and not specific to patients with high homocysteine levels. Population research has found that high homocysteine levels are associated with decreased cognition in older adults, suggesting that using folic acid to lower homocysteine levels might mitigate cognitive decline in these patients (50094). Two long-term clinical trials examining the effects of folic acid in elderly adults with high homocysteine levels show mixed results. A large-scale clinical trial of patients aged 50-70 years from the Netherlands who have high homocysteine levels shows that taking folic acid 800 mcg daily for 3 years increases memory, information processing, and other measures of cognitive function when compared with placebo (15271). However, another large-scale clinical trial of patients aged 65 years and older from the Netherlands who have high homocysteine levels shows that taking folic acid 400 mcg and vitamin B12 500 mcg daily for 2 years lowers homocysteine levels, but does not appear to improve overall measures of cognitive function, when compared with placebo (90392). The reasons for the discrepant findings in these two studies are not clear but might relate to differences in the dose of folic acid, duration of treatment, and age of patients included.
• Cataracts. Oral folic acid does not seem to reduce cataract development. Details: Clinical research in females with existing cardiovascular disease (CVD) or with risk factors for CVD shows that taking folic acid 2.5 mg, vitamin B6 50 mg, and vitamin B12 1 mg daily for an average of 7.3 years does not reduce the risk of developing cataracts. Furthermore, the risk of cataract extraction was increased by 28% in these patients (96149).
• Diarrhea. Oral folic acid does not seem to reduce the risk of diarrhea, and might even increase the incidence of diarrhea in children. Details: In children aged 6-30 months at risk of malnourishment, clinical research shows that taking a nutritional supplement (Nutriset Ltd) enriched in folic acid 75-150 mcg, with or without vitamin B12 0.9-1.8 mcg, daily for 6 months does not reduce the incidence of diarrhea when compared with placebo. Enrichment with folic acid, with or without vitamin B12, actually seems to increase the likelihood of having more episodes of both persistent diarrhea and diarrhea lasting over 3 days (90391).
• Fall prevention. Oral folic acid does not seem to reduce the risk of falls. Details: Clinical research shows that taking a combination of B vitamins, including folic acid 400 mcg and vitamin B12 500 mcg daily, for 2 years, does not prevent falls when compared with placebo in elderly individuals also taking vitamin D (96148).
• Fetal and premature infant mortality. Oral vitamin B12 does not seem prevent mortality in premature infants. Details: Clinical research shows that supplementation with folic acid during pregnancy does not decrease the risk of miscarriage, stillbirth, or neonatal death (91307,96156).
• Leukemia. Oral vitamin B12 does not seem to reduce the risk for pediatric acute lymphoblastic leukemia. Details: A meta-analysis of results from two case-control studies has found that increased folate intake during pregnancy is not associated with a reduced risk of childhood acute lymphoblastic leukemia (50247).
• Male infertility. Oral folic acid does not seem to improve sperm parameters or pregnancy rates in males with infertility. Details: Some small clinical studies show that taking folic acid, alone or with zinc, increases sperm count in males with idiopathic infertility or in males with a grade III varicocele (9334,90194). However, another small study in males with asthenozoospermia shows that taking folic acid 5 mg, selenium 200 mcg, and vitamin E 400 IU daily for 3 months does not improve sperm parameters when compared with placebo (104907). Furthermore, there seems to be no improvement in clinical outcomes. One large, high-quality clinical study in males with idiopathic infertility shows that taking folic acid 5 mg with zinc 30 mg daily for 6 months does not improve sperm morphology, pregnancy rate, or live birth rate when compared with placebo (102085). Folic acid has also been evaluated in combination with other ingredients. A retrospective study in males with or without varicocele-related infertility suggests that taking a specific combination product containing folic acid 0.2 mg, vitamin C, zinc, L-carnitine fumarate, acetyl-L-carnitine, coenzyme Q10, selenium, and vitamin B12 (Proxeed Plus, Sigma-Tau) twice daily for 6 months is associated with improvements in sperm count, sperm concentration, and sperm motility when compared to baseline. Improvement in semen parameters were greatest in subjects with more severe varicoceles (111296). The validity of this study is limited by the lack of a comparator group.
• Osteoporosis. Oral folic acid does not seem to reduce the risk of osteoporotic fractures. Details: Clinical research in elderly adults or adults with a history of cerebrovascular disease shows that taking vitamin B12 500 mcg and folic acid 0.4-2 mg, with or without vitamin B6 25 mg, daily for 2-3 years does not seem to reduce the risk for osteoporotic fractures when compared with placebo (90377,90393). A 5-7 year follow-up of this research has also found no benefit (103981).
• Physical performance. Oral folic acid does not seem to improve physical performance in older adults. Details: Clinical research shows that taking a combination of B vitamins, including folic acid 400 mcg and vitamin B12 500 mcg daily for 2 years, does not improve hand strength or improve performance such as walking when compared with placebo in elderly individuals also taking vitamin D (96148).
• Pre-eclampsia. Oral folic acid does not seem to prevent pre-eclampsia in pregnant patients. Details: While the effect of low-dose prenatal folic acid is unclear, high-dose folic acid does not seem to reduce the risk of pre-eclampsia. Some population research has found that low-dose folic acid is associated with a 22% reduced odds of pre-eclampsia, while other research has found no association (91308,99370,99372,110447). A large clinical trial evaluating high-dose folic acid in pregnancies at risk for pre-eclampsia shows that taking 4 mg daily, starting at 8-16 weeks of gestation and continuing until delivery, does not reduce the risk of pre-eclampsia when compared with placebo (103929). A secondary analysis of this study in twin pregnancies has also found no benefit with high-dose folic acid supplementation (103977).
• Respiratory tract infections. Oral folic acid does not seem to prevent respiratory tract infections. Details: Clinical research in children aged 6-30 months at risk of malnourishment shows that taking a nutritional supplement (Nutriset Ltd) enriched in folic acid 75-150 mcg, with or without vitamin B12 0.9-1.8 mcg, daily for 6 months does not reduce the incidence of lower respiratory infections when compared with a supplement not enriched with folic acid and vitamin B12 (90391).

LIKELY INEFFECTIVE

• Colorectal adenoma. Oral folic acid does not prevent colorectal adenomas. Details: Although some population research and one clinical study has found that high folate intake is associated with reduced colorectal adenoma risk (2142,2143,91303), most clinical research does not support this finding. Clinical research shows that taking a combination of B vitamins, including folic acid 2.5 mg, vitamin B6 50 mg, and vitamin B12 1 mg daily for up to 9.2 years, does not reduce the risk of colorectal adenoma in females at high risk of cardiovascular disease when compared with placebo (90389). Other clinical research suggests that taking folic acid does not reduce the occurrence or recurrence of adenomas or incidence of advanced adenomas (34596,50241,50265,50369,50394,50449,50522). Furthermore, treatment with folic acid for more than 3 years seems to be associated with an increased risk of advanced adenomatous lesions (50378).
• Fragile X syndrome. Oral folic acid does not improve symptoms in children with fragile X syndrome. Details: Clinical research shows that taking folic acid orally does not improve symptoms of fragile X syndrome (2155,2156,2157,2158,2159,2160,50575).
• Preterm labor. Oral folic acid does not seem to reduce the risk of preterm birth. Details: Meta-analyses of clinical research show that supplementation with folic acid 200 mcg to 5 mg during pregnancy does not decrease the risk of preterm birth (91307,96155). An observational study in patients with and without epilepsy found that folic acid supplementation during pregnancy was associated with a lower odds of preterm birth in patients receiving antiseizure medications; however, no link between folic acid and preterm labor was reported in patients without epilepsy or in those with epilepsy not receiving antiseizure medications (110447).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Abdominal wall defects. It is unclear if oral folic acid helps to prevent abdominal wall defects in newborns. Details: Observational research in a population in northern China has found that taking folic acid supplements until the end of the first trimester modestly reduces the risk of abdominal wall defects and the risk of omphalocele, specifically, in the newborn when compared with not taking folic acid. However, this association was not found in a population in southern China (109191). These differing outcomes may be related to the lower dietary folate intakes in northern China.
• Acne. Oral folic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults and children with inflammatory acne shows that taking 1-4 tablets of a specific product (NicAzel, Elorac Inc.) containing folic acid, vitamin B6, nicotinamide, azelaic acid, zinc, and copper for 8 weeks reduces inflammatory lesions and improves appearance in 88% and 81% of patients, respectively, when compared with baseline (90800).
• Age-related macular degeneration (AMD). Oral folic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A large-scale clinical study shows that taking folic acid 2.5 mg, vitamin B6 50 mg, and vitamin B12 1 mg daily reduces the risk of developing AMD in females over 40 years of age with a history of cardiovascular disease (CVD) or with risk factors for CVD. Those who took this combination for an average of 7.3 years had a 34% reduced risk of developing AMD and a 41% reduced risk of visually significant AMD when compared with placebo (14620). It is unclear if this effect is due to folic acid, other ingredients, or the combination.
• Age-related testosterone deficiency. Folic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in males with overweight or obesity, mild erectile dysfunction, and normal to low androgen levels shows that taking a combination product containing folic acid 400 mcg, alpha-lipoic acid, myo-inositol, and apple (Sinopol Forte) increases testosterone, luteinizing hormone, and measures of erectile dysfunction but not follicle-stimulating hormone or sperm parameters when compared to baseline (111674). The validity of these effects is limited by the small sample size and the lack of a comparator group, and it is unclear if these effects are due to folic acid, other ingredients, or the combination.
• Alzheimer disease. It is unclear if oral folic acid reduces the risk of developing this condition. Details: Low levels of folate and high levels of homocysteine have been linked to a greater risk of Alzheimer disease (50094). Also, some observational studies have found that higher intake of folate from the diet and supplements in elderly adults is associated with a reduced risk of developing Alzheimer disease when compared with lower intake (13165,15270). One small clinical trial in patients with Alzheimer disease who are taking cholinesterase inhibitors shows that taking folic acid 1 mg daily for 6 months increases the likelihood of treatment response, classified as global improvement in behavioral and/or functional status with no decline in mental status scores, by 78% to 87% when compared with placebo (50246). Also, preliminary clinical research in patients with probable Alzheimer disease who are not consuming a folate-fortified diet shows that taking vitamin B12 50 mcg daily plus folic acid 1.2 mg daily for 6 months modestly improves some measures of cognitive performance and decreases levels of homocysteine when compared with placebo (107150). However, not all research agrees. Clinical research in patients with probable Alzheimer disease using routine medications shows that taking folic acid 5 mg, vitamin B12 1 mg, and vitamin B6 25 mg daily for 18 months does not have a beneficial effect on cognitive function or the severity of disease when compared with placebo (50319). However, all patients in this study were also consuming a folate-fortified diet.
• Angioplasty. Oral folic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Some evidence suggests that folic acid 1 mg, vitamin B12 400 mcg, and pyridoxine 10 mg daily can decrease the rate of restenosis in patients treated with balloon angioplasty (8009,9412). However, this combination does not seem to be as effective for reducing restenosis in patients after coronary stenting (8009). An intravenous loading dose of folic acid, vitamin B6, and vitamin B12 followed by oral administration of folic acid 1.2 mg, vitamin B6 48 mg, and vitamin B12 60 mcg daily after bare metal coronary stenting also does not seem to reduce restenosis and might actually increase restenosis (12150,12151). Due to the lack of evidence of benefit and potential for harm, this combination of vitamins should not be recommended for patients receiving coronary stents (12151).
• Atopic dermatitis (eczema). It is unclear if oral folic acid during pregnancy reduces the risk of eczema in the child. Details: Observational research has found that consuming both iron and folic acid supplements during pregnancy is associated with a four-fold reduced risk for developing atopic dermatitis in the child. However, use of either iron or folic acid supplementation alone is not associated with an effect on the child's risk for atopic dermatitis (102387).
• Autism spectrum disorder. It is unclear if oral folic acid intake during pregnancy reduces the risk of autism spectrum disorder in the child. Details: A meta-analysis of population research has found that consumption of folic acid of at least 400 mcg daily from both diet and supplements during pregnancy is associated with a 45% reduced risk of autism in the child at 2-15 years of age. Also, supplementation with folic acid during the prenatal to early period of pregnancy is associated with an approximate 43% reduced risk of autism in the child. This association did not differ between countries with or without a folate fortification program (109198). An individual population study has also found that prenatal folic acid supplementation initiated the first day of the last menstrual period before conception is associated with a 39% reduced odds of autism in the child at age 3.3-10.2 years when compared to pregnancies without folic acid supplementation (91324).
• Beta-thalassemia. There is limited evidence on the oral use of folic acid for beta-thalassemia minor. Details: Patients with beta-thalassemia minor may experience decreased muscle strength and increased bone or muscle pain. A small clinical study in children with this condition shows that taking folic acid 1 mg, with or without L-carnitine 50 mg/kg, daily for 3 months reduces bone pain by 64% to 84% and increases the number of stairs climbed by 2- to 5-fold when compared with baseline (90631). The validity of this finding is limited by the lack of a control group.
• Bipolar disorder. It is unclear if adding oral folic acid to conventional bipolar therapy further improves symptoms. Details: Some clinical evidence suggests that folic acid does not improve the antidepressant effects of lithium in patients with bipolar disorder (50566). However, other clinical evidence suggests that taking folic acid in combination with valproate during the acute phase of mania improves the effects of valproate (50357).
• Breast cancer. It is unclear if oral folic acid reduces breast cancer risk. Details: Some older population research suggests that increased intake or levels of folic acid alone does not affect the risk of breast cancer or breast cancer-related mortality (50218,50224). However, in a specific group of women who also consume high amounts of dietary methionine, cyanocobalamin (vitamin B12), or pyridoxine (vitamin B6), dietary intake of folate is associated with a reduced risk of breast cancer (9328,50224). Also, more recent population research has found that folic acid plus folate dietary intakes between 153-400 mcg are associated with a reduced risk of breast cancer. This risk is further reduced in those who drink relatively large amounts of alcohol (90794). Folate intakes greater than 400 mcg daily do not appear to be protective against breast cancer (90794).
• Cancer. It is unclear if oral folic acid prevents cancer. Details: A large cohort study of children born to mothers with epilepsy on antiseizure medications suggests that prenatal folic acid exposure of 1 mg daily or more, at an average of 4.3 mg daily, is associated with a 2.7-fold greater risk of pediatric cancer when compared with children born to mothers with epilepsy but without prenatal exposure to high-dose folic acid. Additionally, this risk is not present in children of mothers without epilepsy taking high-dose folate (112103). It is unclear how maternal epilepsy, antiseizure medications, and folate interact to increase the risk of pediatric cancers. However, in the absence of clear guidelines, mothers with epilepsy should take no more than 4 mg of folic acid daily (112101,112102).
• Cardiovascular disease (CVD). Although oral folic acid does not seem to prevent most CVD events, some research suggests that increased dietary folic acid might lower the risk of stroke and CVD-related mortality in patients at high risk for CVD. Details: In 2001, prior to the publication of the highest quality research on this topic, the US Food and Drug Administration (FDA) approved a qualified health claim stating that, as part of a well-balanced diet that is low in saturated fat and cholesterol, folic acid, vitamin B6, and vitamin B12 may reduce the risk of vascular disease (102368). Meta-analyses of available research show that folic acid might lower the risk of stroke in patients with CVD (97619,102386,107136). Some clinical research shows that taking folic acid reduces the risk of CVD by 15% in patients with kidney failure or chronic kidney disease (50444,91311). However, most research shows that folic acid supplementation, alone or in combination with vitamin B6 and vitamin B12, does not improve endothelial function or reduce the risk of death or CVD events in patients with existing hyperhomocysteinemia, coronary heart disease, CVD, kidney disease, or prior stroke, despite having a homocysteine-lowering effect (9313,9322,11337,11387,13482,50437) (50512,50527,96154,96147,97619,102386). Some population research has evaluated adults at high risk for CVD. This research has found that dietary folate intake of at least 382 mcg daily is associated with a modest reduction in CVD-related mortality and possibly all-cause mortality. Consuming folic acid as a component of fortified food in doses of more than 251 mcg daily is associated with a modest reduction in CVD-related mortality. Conversely, folic acid supplementation is associated with a higher risk of CVD and overall mortality, and there is a J-shaped association between folate intake, serum folate levels, and red blood cell folate levels, with both CVD-related and all-cause mortality (109199).
• Cervical cancer. It is unclear if oral folic acid prevents cervical cancer. Details: Epidemiological evidence has found that increasing folate intake from dietary and supplement sources, along with thiamine, riboflavin, and vitamin B12, might decrease the risk of precancerous cervical lesions (11074).
• Child development. It is unclear if oral folic acid supplementation during pregnancy improves child development. Details: Clinical research in Northern Ireland shows that taking folic acid 400 mcg daily starting in the 14th week of gestation and continuing until the end of pregnancy improves word reasoning in the child at 7 years of age when compared with placebo. When compared with a historical cohort from Britain, folic acid supplementation was associated with an increase in full scale IQ, verbal IQ, performance IQ, and general language at 7 years of age (102385). At age 11, benefits in word reasoning were no longer significant. However, there were modest benefits in some measures of processing speed when compared with placebo. Verbal comprehension was modestly improved in females, but not males (109192). Observational research in pregnant individuals and their children in Spain has found that taking less than 400 mcg of folic acid daily during pregnancy is associated with lower mental alertness scores in children at ages 7-9 years when compared with folic acid 400-999 mcg daily, while taking folic acid 1000 mcg or more daily during pregnancy was associated with improvements in some measures of working memory in the children. However, no relationship between folic acid dosing and most other measures of cognitive function was identified (110449).
• Chronic fatigue syndrome (CFS). Although there is interest in using oral or injectable folic acid for CFS, there is insufficient reliable information about the clinical effects of folic acid for this condition.
• Chronic kidney disease (CKD). While adding oral folic acid to enalapril might slow CKD progression, adding folic acid to high-dose vitamin B12 does not seem to be beneficial. Details: Clinical research in adults with hypertension and CKD shows that taking enalapril with folic acid 800 mcg for a median of 4.4 years reduces the risk of worsening kidney function by 21% and slows the rate of kidney function decline by 44% when compared with enalapril alone (96153). However, clinical research does not support the use of folic acid in patients with CKD when used in combination with high-dose vitamin B12 (cyanocobalamin). Vitamin B12 might increase the risk of negative outcomes (50253,50409,96150). More research is needed to determine the benefits of folic acid when used alone.
• Colorectal cancer. It is unclear if oral folic acid prevents colorectal cancer. Details: Although the majority of population research suggests that taking folic acid orally from dietary and supplemental sources reduces the risk of colorectal cancer (505,2140,2144,2145,2250,6271,9325,9326,50109,50427,50450)(91306,91323,96160,109188,110450), clinical evidence in general is not supportive. Most clinical research and meta-analyses of clinical trials suggest that taking folic acid from dietary or supplemental sources does not reduce the risk of colorectal cancer (2141,34596,50394). The reason for this discrepancy is unclear. Some observational research suggests that an inverse association between folate intake and risk of colorectal cancer was not apparent until at least 12 years after baseline folate intake was determined (109188). A meta-analysis of observational studies suggests that the benefits of folic acid supplementation on colorectal cancer risk might be limited to patients with moderate to high alcohol consumption (110450). Other clinical evidence suggests that the beneficial effect of folic acid may be limited to colon, but not rectal, cancer (21501). Furthermore, the beneficial effect for colon cancer may be limited to only certain subtypes. For instance, females with folate intake of at least 400 mcg daily seem to have a 46% reduction in the risk of p53-overexpressing colon cancer, but not p53-negative tumors, when compared with those who consume less than 200 mcg daily (21300). Also, the source of folic acid may influence its effects. Some observational research suggests that dietary folate, but not folic acid supplementation, reduces the risk of colon cancer (21501).
• Congenital heart disease. It is unclear if oral folic acid prevents congenital heart disease. Details: The exact cause of congenital heart disease is unknown but is thought to be a combination of genetic and environmental factors. Population research has found that supplementation with folic acid or folic acid-containing prenatal vitamins during pregnancy is associated with up to a 40% lower risk of congenital heart defects in newborns (99373).
• Dementia. It is unclear if oral folic acid is beneficial for the prevention or treatment of dementia. Details: While some preliminary research shows that folic acid might aid in the prevention and treatment of Alzheimer disease (13165,15270,50246,90374), two small clinical trials show that taking folic acid 15-20 mg daily for 10-12 weeks does not seem to improve cognitive function or the severity of dementia in patients with various forms of dementia, including vascular dementia, Lewy body dementia, probable Alzheimer disease, or dementia due to other causes (50062,50597).
• Diabetes. Small clinical studies suggest that oral folic acid does not improve glycemic control. Details: Meta-analyses of small clinical trials in patients with type 2 diabetes show that folic acid does not reduce glycated hemoglobin (HbA1C) when compared with placebo (50528,109197). Another small clinical study in patients with diabetes who are stabilized on metformin and/or a sulfonylurea shows that taking folic acid 5 mg daily for 8 weeks does not affect HbA1C when compared with placebo (104917). The validity of this study is limited by its small size and lack of blinding. Conversely, a meta-analysis of clinical research shows that taking folate modestly reduces fasting blood glucose and insulin levels, as well as measures of insulin resistance, when compared with placebo or no intervention (109197). There was no clear relationship between these changes and the dose or duration of folate. However, the studies included in this analysis evaluated multiple patient populations; the effect of folate in patients with diabetes, specifically, is unclear. Beyond glycemic control, some research has assessed the impact of dietary folate intake on cardiovascular risk in patients with diabetes. An observational study in Chinese adults with type 2 diabetes has found that dietary intake of folate in the highest quartile is associated with 68% lower odds of developing cardiovascular disease, defined as a non-fatal myocardial infarction, non-fatal stroke, or hospitalization for unstable angina, when compared with folate intake in the lowest quartile (110452). Folic acid has also been evaluated in gestational diabetes. A meta-analysis of 20 studies shows that serum and red blood cell (RBC) folate levels are higher in patients with gestational diabetes than without gestational diabetes. Subgroup analysis suggests that patients with gestational diabetes have higher serum and RBC folate levels in the second trimester than in those without gestational diabetes, while RBC folate levels in patients with gestational diabetes were higher in the first trimester than those without gestational diabetes. Overall, higher serum folate levels are associated with a slight increase in the odds of gestational diabetes when compared with lower serum folate levels (112107).
• Diabetic neuropathy. Oral folic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with diabetic neuropathy shows that taking a combination of B vitamins, including folic acid (L-methylfolate), vitamin B12 (methylcobalamin), and vitamin B6 (pyridoxal-5'-phosphate), for 24 weeks does not improve neural dysfunction based on vibration perception, but does seem to improve total neuropathy symptoms, when compared with placebo. These symptoms, which include both sensation and pain, decreased by 25% with the B vitamin combination, compared with only 15% in those taking placebo (90375).
• Epilepsy. It is unclear if oral folic acid reduces seizure frequency. Details: A meta-analysis of preliminary clinical research shows that taking folic acid does not reduce seizure frequency in patients with epilepsy (50124). However, there is some speculation that folate deficiency might be linked to increased seizure frequency. A preliminary clinical study in folate-deficient children with epilepsy shows that taking folic acid 5 mg daily for 3 months reduces seizure frequency when compared to baseline, but not when compared with a control group that is not deficient in folate (99371).
• Erectile dysfunction (ED). Oral folic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in males with mild erectile dysfunction, overweight or obesity, and normal to low androgen levels shows that taking a combination product containing folic acid 400 mcg, alpha-lipoic acid, myo-inositol, and apple (Sinopol Forte, Laborest) improves measures of erectile dysfunction when compared to baseline (111674). The validity of these effects is limited by the small sample size and the lack of a comparator group, and it is unclear if these effects are due to folic acid, other ingredients, or the combination.
• Esophageal cancer. Higher dietary folate intake is associated with a lower risk of esophageal cancer. Details: One meta-analysis of observational research has found that higher levels of dietary folate are associated with a 34% lower risk of esophageal squamous cell carcinoma and a 50% lower risk of esophageal adenocarcinoma when compared with low levels of dietary folate (50208). Another meta-analysis of observational research has found that consuming high amounts of folate is associated with a 36% decrease in the odds of esophageal cancer when compared with lower dietary folate intake (100950).
• Fenofibrate (Tricor)-induced hyperhomocysteinemia. Folic acid seems to attenuate increases in homocysteine in people taking fenofibrate. Details: A small open-label clinical trial in patients taking fenofibrate shows that adding folic acid 10 mg every other day might reduce elevated plasma homocysteine levels by up to 59% when compared with taking fenofibrate alone (9321).
• Gastric cancer. It is unclear if oral folic acid reduces gastric cancer risk. Details: Observational research has found that taking folic acid reduces the risk of gastric cardia adenocarcinoma by 17% and the risk of noncardia gastric cancer by 33%, but does not reduce the risk of gastric cancer overall (50208). Also, a meta-analysis of 13 small clinical studies in patients with gastric precancerous conditions shows that taking folic acid 20-30 mg daily for 3-6 months improves gastric mucosal atrophy and intestinal metaplasia but does not seem to improve symptoms when compared with a control (110448). Whether these findings are associated with a lower risk of gastric cancer is unclear.
• Gout. It is unclear if oral folic acid reduces the risk for gout. Details: An observational study has found that increased dietary folate intake is associated with a lower incidence of gout (50454).
• Head and neck cancer. It is unclear if oral folic acid is beneficial for head and neck cancer prevention. Details: Population research has found that the highest intake of dietary folate is associated with a 50% reduced risk of head and neck cancer when compared with the lowest intake of folate. Each 100 mcg increase per day seems to reduce the risk by about 4% (96151).
• Hearing loss. It is unclear if oral folic acid prevents hearing loss. Details: Low levels of serum folate seem to be a risk factor for sudden sensorineural hearing loss in adults (21283). Observational research in females has found that serum folate levels in the lowest quintile are associated with a 19% increased risk for hearing loss when compared with levels in the second quintile. Also, folate levels in the highest quintile are associated with a 12% lower risk of hearing loss when compared with the second quintile (109807). A clinical study in older adults from the Netherlands shows that taking folic acid 800 mcg daily for 3 years slows the decline of age-related low-threshold hearing loss when compared with placebo (15163). However, at the time of this study, folate enrichment of foods was not allowed in the Netherlands. As a result, baseline folate levels in this study population were about 50% lower than in the US population. The effect of folic acid supplementation in people with higher baseline folate levels is unclear.
• Infertility. It is unclear if oral 5-methyltetrahydrofolate (5-MTHF) in combination with vitamin B6 and vitamin B12 is more beneficial than folic acid alone for increasing pregnancy rate in females undergoing assisted reproductive technology (ART). Details: Retrospective research from Italy suggests that taking 5-MTHF 400 mcg, vitamin B12 5 mcg, and vitamin B6 3 mg daily results in clinical pregnancy and live birth rates of approximately 60% and 49%, respectively, compared with 45% and 35% of those taking folic acid 400 mcg daily. A sub-analysis suggests that beneficial effects on pregnancy rates are limited to individuals aged less than 40 years (109189). The findings from this study are limited by its retrospective design. Also, it is unclear if these findings are generalizable to countries with folate fortification.
• Kidney failure. It is unclear if oral folic acid is beneficial in patients with kidney failure. Details: Because hemodialysis removes folate from the body, there is concern that folate deficiency may cause complications in patients with kidney failure receiving hemodialysis. Observational research in Taiwanese patients with kidney failure undergoing hemodialysis has found that taking folic acid 5 mg daily for an average of 5.8 years is associated with a 31% lower risk of arteriovenous access thrombosis when compared with folic acid 5 mg weekly. However, daily folic acid supplementation was not linked to a lower risk of cardiovascular events, cancer, or mortality when compared with weekly folic acid (110120). Oral folic acid has also been evaluated in combination with other ingredients. A small, low-quality clinical study in adults with kidney failure undergoing regular hemodialysis shows that taking oral folic acid 30 mg daily with thiamine 90 mg daily for 96 weeks reduces overall mortality by 67% and improves cognitive scores by 31% when compared with no intervention (107724). It is unclear if these findings are due to folic acid, thiamine, or the combination.
• Lometrexol toxicity. While oral folic acid might reduce lometrexol toxicity, intravenous folic acid does not seem to help. Details: In a phase I trial, intravenous folic acid 5-25 mg administered 1 hour or 3 hours prior to lometrexol 15-30 mg/m2 every 3 weeks does not seem to reduce cumulative lometrexol toxicity (2161). However, in a phase II study, taking oral folic acid 3 mg/m2 daily in addition to lometrexol 10 mg/m2 weekly seems to attenuate cumulative toxicity and improve its tolerability in cancer patients (104948).
• Low birth weight. It is unclear if oral folic acid supplementation during pregnancy reduces the risk of a low birth weight. Details: Clinical research shows that supplementation with folic acid 200 mcg to 5 mg daily during pregnancy increases mean birth weight when compared with placebo (91307). Furthermore, some population research has found that pre- or peri-conception folic acid supplementation, usually 400 mcg daily, is associated with a reduced risk of a child born small-for-gestational age. However post-conception folic acid supplementation is not associated with reduced risk (91304,103983). An observational study in pregnant Chinese patients found that supplementation with folic acid is associated with a 20% lower odds of low birth weight when compared with no supplementation. This association was observed when folic acid was used both before conception and during pregnancy for at least 24 weeks or during pregnancy only for at least 12 weeks. Increased dietary folate intake was not linked to a lower risk of low-birth-weight infants (110446). However, other observational research has found no association between folic acid supplementation during pregnancy and the risk for small-for-gestational age births (110447).
• Lung cancer. It is unclear if oral folic acid reduces lung cancer risk. Details: There does not appear to be a relationship between deficiency of folate and lung cancer (9454). However, consuming at least 130.4 mcg of folate per 1000 kcal daily seems to reduce the risk of lung cancer by 40% in former smokers when compared to those with lower dietary folate intake (50065).
• Melanoma. It is unclear if oral folic acid reduces melanoma risk. Details: Population research has found that folic acid supplementation of 2-2.5 mg daily in combination with vitamin B6 and vitamin B12 is linked with a 53% reduced risk of melanoma (91312).
• Metabolic syndrome. Although there is interest in using oral folic acid for metabolic syndrome, there is insufficient reliable information about the clinical effects of folic acid for this condition.
• Nitrate tolerance. It is unclear if oral folic acid helps to prevent the development of tolerance to treatment with nitroglycerin. Details: Some clinical evidence suggests that taking folic acid 1 mg daily for 1 week does not prevent the development of nitroglycerin-induced endothelial dysfunction or tolerance in healthy individuals (50442). However, other research suggests that taking folic acid 10 mg daily for 1 week prevents nitric oxide synthase dysfunction caused by continuous nitroglycerin (9316).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral folic acid is beneficial for NAFLD. Details: A cross-sectional analysis suggests that adults with NAFLD have lower levels of serum folate and its major component 5-MTHF when compared with healthy controls. Additionally, adults with NAFLD seem to consume less supplementary and dietary folate when compared with healthy controls. Overall, serum folate levels are negatively associated with the risk of NAFLD, and inadequate folate intake is associated with an increased risk of NAFLD (112104).
• Oral clefts. It is unclear if oral folic acid reduces the risk of oral clefts in infants. Details: Observational research has found that maternal folic acid supplementation is associated with an up to 49% reduced risk of cleft lip with or without cleft palate (50220,104921). Furthermore, a large clinical trial in pregnancies at-risk for oral cleft suggests that taking a higher dose of folic acid 4 mg from pre-conception until the end of the first trimester results in a similar oral cleft recurrence rate of 2.5%, compared with a 2.9% recurrence with a lower dose of folic acid (400 mcg). Both doses demonstrate a lower incidence of oral clefts when compared with historical rates of 6.3% (91322). Although there is speculation that genetic markers of folate status impact the effect of folic acid on orofacial cleft incidence, the current data do not show a relationship (104921).
• Overall mortality. It is unclear if oral folic acid reduces the risk of overall mortality. Details: Observational research in US adults has found that dietary intake of folic acid in the highest quintile is associated with a 14% to 23% lower risk of all-cause mortality and a 41% to 47% lower risk of cardiovascular mortality when compared with the lowest quintile of dietary folic acid intake (110451).
• Pancreatic cancer. It is unclear if oral folic acid reduces pancreatic cancer risk. Details: Consuming greater than 280 mcg daily of dietary folate is associated with a decreased risk of exocrine pancreatic cancer (9327). A meta-analysis of case-control and cohort studies suggests that consuming higher amounts of dietary folate reduces the risk of pancreatic cancer by 51% compared to low levels of dietary folate (50208). However, another meta-analysis of prospective cohort studies suggests that folate/folic acid intake does not significantly affect the overall risk of pancreatic cancer (50499). The contradictory results may be associated with the form of intake or may be related to the gender of the participants. A meta-analysis of clinical research shows that dietary folate, but not folic acid, significantly reduces the risk of pancreatic cancer (50387). Also, one meta-analysis of observational studies has found that high dietary folate decreases the risk of pancreatic cancer in females, but not males (50387).
• Peripheral neuropathy. Oral folic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows taking a combination of folic acid 400 mcg, vitamin B12 3 mcg, and uridine monophosphate 50 mg daily (Keltican) for 60 days reduces pain associated with peripheral neuropathy. Use of this product reduces pain intensity by approximately 44%, with loss of burning pain in approximately 50% of patients, strong tingling or pricking in approximately 57% of patients, strong pain attacks in 92% of patients, and numbness in 90% of patients when compared with baseline. Radiating pain and the use of concomitant medications are also reduced (90384). The validity of this finding is limited by the lack of a comparator group. Furthermore, it is unclear if the benefits are due to folic acid, other ingredients, or the combination.
• Pharyngeal cancer. It is unclear if oral folic acid reduces pharyngeal cancer risk. Details: Population research has found that intake of folic acid and folate from natural, fortified, and supplemented sources, may protect against oropharyngeal cancer. Intake of at least 258-816 mcg total folate/folic acid reduces the odds by 35% when compared with intakes of less than 344 mcg. Furthermore, folate/folic acid may be more beneficial for oral cancer versus pharyngeal cancer and in heavy alcohol users versus non users or light users (91302).
• Polycystic ovary syndrome (PCOS). It is unclear if oral folic acid is beneficial for PCOS. Details: One clinical study in overweight or obese patients with PCOS shows that taking folate 1 mg or 5 mg daily for 8 weeks modestly reduces levels of homocysteine, as well as insulin resistance, when compared with placebo. However, only the 5 mg dose modestly reduces insulin, total cholesterol, and low-density lipoprotein (LDL) cholesterol levels. Neither dose appears to affect fasting plasma glucose, high-density lipoprotein (HDL) cholesterol, or triglyceride levels when compared with placebo (109200). Other clinical research in patients with PCOS taking metformin shows that taking folate 400 mcg daily for 6 months does not affect glycemic parameters, plasma lipid levels, or hormone levels when compared with placebo (109194). The reasons for discrepancies between studies are unclear but may relate to patient characteristics. One study included only overweight or obese individuals with at least two of the three PCOS criteria, whereas the other study limited enrollment to patients in any weight category but with all three PCOS criteria (109194,109200).
• Pregnancy-induced hypertension. It is unclear if oral folic acid reduces the risk of hypertension during pregnancy. Details: Population research has found that taking folic acid during pregnancy is not associated with a reduced risk of gestational hypertension (91308,99370,99372).
• Restless legs syndrome (RLS). Although there is interest in using oral folic acid for RLS, there is insufficient reliable information about the clinical effects of folic acid for this condition.
• Schizophrenia. Oral folic acid 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 folic acid 2 mg and vitamin B12 400 mcg daily for 16 weeks improves negative symptoms when compared with placebo in patients with schizophrenia who have persistent symptoms and a specific genetic variant of the folate transporter gene FOLHI. This variant normally results in reduced folate absorption. However, in patients without this genetic variant, folate is not beneficial with respect to negative symptom improvement (90387).
• Sickle cell disease. Oral folic acid has only been evaluated in combination with other B vitamins; its effect when used alone is unclear. Details: Preliminary clinical research in adults with sickle cell disease shows that taking vitamin B12 4.2-6 mcg, folic acid 700 mcg, and vitamin B6 4.2-6 mg daily might lower homocysteine levels. However, it is unknown if this will reduce the risk of endothelial damage in these patients (9324).
• Suicidal ideation. It is unclear if oral folic acid reduces the risk of suicidal ideation or suicide attempts. Details: One observational study has evaluated the association between folic acid supplementation and suicidal events in patients with various underlying conditions, including 12% with depression, 15% with anxiety, and 46% with pain. This within-person cohort study found that filling a prescription for folic acid 0.4-5 mg daily, either alone or as part of a multivitamin, is associated with a 44% reduced rate of suicidal events during the months after the prescription when compared with the months without the prescription. For the 48% of patients who received folic acid 1 mg daily, each additional month of taking the prescription was associated with a 5% decrease in suicidal events (109201). Prospective clinical research is needed to confirm any benefits of folic acid and to determine whether baseline folate deficiency plays a role in these outcomes. More evidence is needed to rate folic acid for these uses.

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POSSIBLY EFFECTIVE

• Atherosclerosis. When used alone or in combination with other ingredients, oral garlic seems to slow the progression of atherosclerosis. Details: Taking low doses of garlic powder (Kwai, Lichtwer Pharma) 300 mg, administered as a single dose or three times daily for up to 4 years, seems to lessen age-related decreases in aortic elasticity (4797,51595). Additionally, taking a specific time-released garlic powder supplement (Allicor, INAT-Farma) 150 mg twice daily for 24 months seems to reduce the rate of atherosclerosis progression, as measured by carotid intima-media thickness, when compared with placebo in males with early evidence of carotid atherosclerosis (88394). Higher doses of 900 mg daily seem to slow development of atherosclerosis in both aortic and femoral arteries when used over a four-year period in females, but not in males (3315,4798). In patients with evidence of coronary artery calcium and a Framingham risk score of greater than 10%, taking aged garlic extract (Kyolic Reserve, Wakunaga) 1200 mg twice daily for 12 months reduces coronary artery calcium progression by 29% when compared with placebo (102670). A meta-analysis also found that garlic powder tablets and aged garlic extract may reduce coronary artery calcium scores when compared with placebo (110721). Some clinical research has investigated the use of garlic in combination with other ingredients. Taking a specific supplement (Kyolic, Total Heart Health, Formula 108, Wakunaga) containing aged garlic extract 250 mg plus vitamin B12 100 mcg, folic acid 300 mcg, vitamin B6 12.5 mg, and L-arginine 100 mg daily for 12 months significantly reduces coronary artery calcium progression and improves vascular function in patients with a Framingham risk score of 10% to 20% without coronary artery disease (88385). In addition, taking a combination product containing aged garlic extract 1200 mg and coenzyme Q10 120 mg daily for one year significantly improves vascular elasticity endothelial function in firefighters facing high degrees of occupational stress (44225).
• Diabetes. Most clinical research suggests that oral garlic, taken alone or in combination with metformin for at least 12 weeks, modestly reduces fasting blood glucose levels in patients with diabetes. It is unclear if garlic improves postprandial glucose levels or glycated hemoglobin (HbA1c). Details: A meta-analysis of results from seven clinical studies in adults with type 2 diabetes shows that taking garlic powder 600-1500 mg daily, garlic oil 8.2 mg daily, or aged garlic extract 1000 mg daily reduces fasting blood glucose levels by about 2 mg/dL when compared with control. The greatest benefit is seen for patients with hyperglycemia at baseline, for interventions lasting at least 12 weeks, and for formulations consisting of garlic powder (96004). Specific garlic formulations used in the reviewed studies have included garlic powder 300 mg 2-3 times daily as tablets (Kwai, Lichtwer Pharmaceuticals) or time-released tablets (Allicor, INAT-Farma) for 4-24 weeks, sometimes in combination with metformin or a sulfonylurea (51396,51463,96004). In one study, when used in combination with metformin, garlic reduced fasting blood glucose levels 70% more than when metformin was used alone (51463). The findings from these studies are in contrast with the results from older meta-analyses, which showed that garlic does not improve glycemic indices or lipid levels in patients with diabetes. Reasons for these discrepancies may relate to the fact that the older analyses included lower quality research (6465,6897). There is insufficient reliable information available to determine if garlic significantly improves postprandial glucose levels or HbA1c (96004). A small clinical trial shows that taking aged garlic extract (Kyolic, Wakunaga) 2400 mg daily for 12 months does not reduce left ventricular myocardial mass, a marker of poor cardiac outcomes, in patients with diabetes. However, this study may have been inadequately powered to detect a difference between groups (102671).
• Endometriosis. Oral garlic seems to improve pain in people with endometriosis. Details: A clinical study in patients with endometriosis shows that taking a tablet containing garlic powder 400 mg, providing allicin 1.1 mg, daily for 3 months along with standard care reduces overall pain scores from baseline by 72%, compared with an increase of 4% from baseline in patients receiving placebo along with standard care (106615).
• Hyperlipidemia. Most research shows that taking oral garlic for at least 8 weeks seems to modestly reduce total and low-density lipoprotein (LDL) cholesterol and slightly increase high-density lipoprotein (HDL) cholesterol in patients with hyperlipidemia. However, evidence is conflicting on whether garlic reduces triglyceride levels. Details: Meta-analyses of clinical studies in patients with hyperlipidemia show that taking garlic daily for 2-12 months reduces total cholesterol by about 15-25 mg/dL, low-density lipoprotein (LDL) cholesterol by about 6-17 mg/dL, and increases high-density lipoprotein (HDL) cholesterol by about 1.5 mg/dL when compared with control (88399,114891). Results regarding triglyceride levels are mixed, with one of these analyses showing a reduction of triglyceride levels of about 15 mg/dL and the other showing no reduction (88399,114891). The impact on lipid levels appears to be more pronounced when garlic is taken for more than 8 weeks and in patients with total and LDL cholesterol levels that are at least borderline high before treatment (88399). Another meta-analysis supports prior findings that taking garlic improves HDL, LDL, and apolipoprotein-A levels while having no impact on triglycerides level. The meta-analysis found that while garlic does not appear to reduce cholesterol in the general population, it may reduce total cholesterol when taken by patients with cardiovascular risk factors (110721). Similarly, a meta-analysis of 17-19 clinical studies in healthy adults and patients with a variety of cardio-metabolic conditions, including hyperlipidemia, shows that taking garlic daily for 1-12 months reduces total cholesterol by about 14 mg/dL, LDL cholesterol by about 8 mg/dL, increases HDL by about 2 mg/dL, but does not reduce triglyceride levels when compared with placebo (114890). Another partially conflicting meta-analysis found that garlic powder reduces total cholesterol, LDL, and triglyceride levels, but has no impact on HDL levels (110720). The majority of available research supports these findings, but conflicting results exist (279,731,732,1873,1875,4782,4783,4784,4785,4786)(4787,4788,4789,4792,4793,4794,4795,4807,6457,6897)(51343,15295,15296,51422,51429,51469,51590,88399,107238)(107352,110721). Whether garlic is beneficial for treating hyperlipidemia may also depend on the specific formulation or product taken. Mixed results have been reported for a variety of specific garlic products, including garlic powder tablets (Kwai, Lichtwer Pharma) 600-900 mg daily in two or more divided doses for 6-16 weeks (279,731,4782,4783,4784,4785,4787,4789,4792,4793)(4795,4807), aged garlic extract (Kyolic, Wakunaga) 1000-7200 mg daily in divided doses for 4-6 months (1873,1875,15295), a garlic powder product (Garlex, Bosch Pharmaceuticals) 300 mg twice daily for 12 weeks (51343), aged black garlic extract (ABG+; PharmActive Biotech Products) 250 mg daily for 6 weeks (108607), and others (732,15295). Subgroup analyses from one meta-analysis suggest that products containing aged garlic extract may be more effective for lowering total cholesterol than garlic powder preparations. If garlic powder preparations are used, total cholesterol levels seem to be lowered to a greater degree in patients taking enteric-coated garlic powder tablets. The opposite trend may be true for reducing LDL cholesterol. Garlic powder tablets seem to reduce LDL cholesterol levels while aged garlic extract does not. However, the few studies that did evaluate the effect of aged garlic extract on LDL cholesterol did so in patients with low baseline LDL cholesterol levels. There is limited evidence on the use of raw garlic or garlic oil products for treating hyperlipidemia (88399). A subgroup analysis from another meta-analysis of clinical studies suggests that garlic oil reduces total and LDL cholesterol more effectively than garlic powder (114891). Taking garlic 1200 mg with fish oil 3 grams daily for 4 weeks or garlic oil 500 mg with fish oil 700 mg daily for 60 days also appears to improve lipid parameters in some patients (4789,4790,51669). Garlic alone may be more effective than garlic plus fish oil for improving LDL cholesterol levels, but the combination may be useful in patients with elevated levels of total cholesterol, LDL cholesterol, and triglycerides (4789).
• Hypertension. Some clinical research suggests that oral garlic seems to modestly reduce blood pressure in hypertensive and normotensive patients. Details: One meta-analysis of clinical studies show that taking garlic can reduce systolic and diastolic blood pressure by about 5 mmHg and 3 mmHg, respectively, in patients with or without hypertension (16605,51414,96007). However, another meta-analysis found that taking garlic may not impact systolic or diastolic blood pressure in patients with coronary artery disease when compared with placebo (110721). When only patients with hypertension are considered, taking garlic can decrease systolic blood pressure by about 7-9 mmHg and diastolic blood pressure by about 4-6 mmHg. These results are limited by the fact that many of the included studies were of low to moderate quality and short duration (96007,96008,96014). Most clinical research appears to support these findings (278,279,1873,51442,88398). However, conflicting results exist (107238,110721). Some garlic formulations evaluated for hypertension have included a specific garlic powder formulation (Kwai, Lichtwer Pharma) 2400 mg as a single dose or 600 mg daily for 12 weeks and a specific aged garlic extract (Garlic High Potency Everyday Formula 112, Wakunaga/Wagner) 960 mg to 7.2 grams daily in up to three divided doses for up to 6 months (278,279,1873,51442,88398). Other doses used in the available research have included garlic tablets 300-1500 mg in divided doses daily for 24 weeks (88386) and garlic oil 500 mg plus fish oil 600 mg daily for 60 days (51669). Hypotensive effects of garlic have also been examined in population research. A large population study found that eating raw garlic at least twice daily is associated with a reduced likelihood of having prehypertension when compared with eating raw garlic three or fewer times per week. However, any significant relationship was eliminated after adjusting for dietary salt, making conclusions difficult (102677).
• Nonalcoholic fatty liver disease (NAFLD). Oral garlic seems to reduce the severity of hepatic steatosis in patients with NAFLD. Details: A meta-analysis including 4 studies with 186 patients with NAFLD found that taking 800-1600 mg of garlic powder daily may reduce aspartate aminotransferase (AST) and alanine transaminase (ALT) and lower the probability of hepatic steatosis by 2.75 times when compared with placebo (110720). Clinical research in patients with NAFLD shows that taking garlic powder reduces the severity of steatosis in 51% to 62% of patients, compared to 16% to 26% of those taking placebo (102681,103470). Doses of garlic included a specific powder (Amin Pharmaceutical Company) 800 mg twice daily for 12 weeks or an enteric-coated powder 400 mg twice daily for 15 weeks (102681,103479). There was also an improvement in most liver enzymes, other than alkaline phosphatase, and the level of low-density lipoprotein (LDL) cholesterol when compared with placebo (102681). In addition, population research shows a 7% reduction in odds of developing NAFLD with each 1 gram of raw garlic per 1000 kcal consumed. However, this association was not observed in females (102673). NAFLD is strongly and independently associated with an increased risk for prehypertension and hypertension. A clinical study in adults with NAFLD and stable diet- or antihypertensive-controlled blood pressure shows that taking an enteric-coated tablet containing garlic powder 400 mg (Amin Pharmaceuticals), providing allicin 1.5 mg, twice daily for 15 weeks reduces systolic blood pressure, diastolic blood pressure, and mean arterial pressure by 8, 3, and 6 mmHg, respectively, when compared with placebo. High-sensitivity C-reactive protein is also reduced by 16% when compared with placebo (106614).
• Periodontitis. Oral aged garlic extract seems to improve some measures of gum health in people with mild to moderate periodontitis. Details: Clinical research in otherwise healthy patients with mild to moderate periodontitis shows that taking a specific aged garlic extract (Kyolic, Wakunaga) orally 1200 mg twice daily for 18 months improves probing pocket depth, but not gingival recession, when compared with placebo (105760). The validity of these findings is limited by the lack of an intention to treat analysis.

POSSIBLY INEFFECTIVE

• Gastric cancer. Oral garlic does not seem to prevent gastric cancer. Details: Clinical research evaluating the effects of taking aged garlic extract for 7 years failed to show a reduced risk of developing gastric cancer up to 22 years later (14447,51470,102016), although there was a reduction in mortality associated with gastric cancer in subjects followed for 12-22 years (5-15 years after stopping the garlic extract) (102016). Also, a prospective, case-control study of 123,484 adults over a 30-year review period suggests that garlic intake, whether obtained from the diet or via supplementation, is not associated with a reduction in the rate of gastric cancer occurrence (97034). However, some research disagrees. One prospective population study suggests that a 1 kg/year increased increment in garlic intake is associated with a 17% reduced risk in gastric cancer incidence over 22 years. Also, consuming at least 3.25 kg yearly is associated with at least a 12% reduced risk when compared with consuming less than 2 kg each year. A sub-analysis suggests that this potential benefit is associated with garlic stalks, rather than garlic bulbs (111764). Meta-analyses of population research, as well as small population studies, have suggested 23% to 51% lower odds of developing gastric cancer with increased dietary garlic intake when compared with never eating garlic (3320,4775,4776,51209,51460,96005,108604). However, these studies have limited external validity.
• Helicobacter pylori. Oral garlic does not seem to be beneficial for Helicobacter pylori eradication. Details: Despite some promising initial laboratory research suggesting activity against Helicobacter pylori, garlic cloves, powder, or oil does not seem to have any beneficial effect when used to treat patients infected with Helicobacter pylori (3322,4761,4762,4763,4765,4774,97034).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Allergic rhinitis (hay fever). Although there has been interest in using oral garlic for allergic rhinitis (hay fever), there is insufficient reliable information about the clinical effects of garlic for this condition.
• Alopecia areata. Topical garlic may increase hair growth by a small amount. Details: Preliminary clinical research in adults with alopecia areata shows that applying garlic 5% gel four times daily for 3 months, in addition to topical corticosteroid use, increases hair growth by 18% when compared with placebo plus topical corticosteroid (51386).
• Asthma. Although there has been interest in using oral garlic for asthma, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Athletic performance. It is unclear if oral garlic is beneficial for athletic performance. Details: Preliminary clinical research shows that taking a single dose of garlic 900 mg prior to exercise increases endurance when compared with placebo in young athletes (51623). A small preliminary clinical trial shows that taking garlic extract 1000 mg daily for 4 weeks does not reduce the time to cycle 40 km when compared to placebo (111765).
• Benign prostatic hyperplasia (BPH). It is unclear if oral garlic is beneficial for BPH. Details: In patients with BPH, preliminary clinical research shows that taking aqueous garlic extract 1 mg/kg daily for one month decreases prostate mass and urinary frequency and improves symptom scores and urinary flow rates when compared to baseline (10374). The validity of these findings is limited by the lack of a comparator group.
• Bladder cancer. Although there has been interest in using oral garlic for bladder cancer, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Breast cancer. It is unclear if oral garlic prevents breast cancer. Details: The relationship between garlic intake and risk of breast cancer is unclear. Overall, population research suggests that taking garlic does not seem to decrease the risk of breast cancer. However, when garlic and onions are examined together, there is some evidence of an association with a decreased risk of breast cancer (4779,102674). More research is needed.
• Bronchitis. Although there has been interest in using oral garlic for bronchitis, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Cardiovascular disease (CVD). It is unclear if oral garlic is beneficial for reducing CVD risk factors in adults with hypercholesterolemia. Details: A clinical crossover study in adults with moderate hypercholesterolemia shows that taking a specific product (ABG+; PharmActive Biotech Products) containing aged black garlic extract 250 mg, standardized to provide S-allyl-L-cysteine 1.25 mg, daily for 6 weeks does not improve blood pressure, glucose or cholesterol levels, or anthropometric measures when compared with placebo. A subgroup analysis in males with elevated diastolic blood pressure at baseline shows that taking this product reduces diastolic blood pressure by 5-mmHg when compared with placebo (108607). It is unclear if garlic is beneficial in patients with existing CVD.
• Chronic fatigue syndrome (CFS). Although there has been interest in using oral garlic for CFS, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Colorectal cancer. It is unclear if oral garlic prevents colorectal cancer. Details: Several individual population studies have found that higher dietary intake of garlic is associated with a reduced risk of colorectal cancer (3320,4770,4771,4772). However, results from meta-analyses of population research are mixed (96003,102669). Reasons for the discrepancy seem to relate to the type of population study conducted. A meta-analysis of case-control studies supports a preventative effect of garlic. However, this is not supported when cohort studies are analyzed separately (102669). Case-control studies are prone to recall and selection bias, and some do not account for confounding factors associated with colorectal cancer (96003). Two separate meta-analyses of observational research conducted in various countries have found that consumption of garlic and other allium-containing vegetables (onions, leeks, chives and scallions) is associated with a reduced risk of colorectal cancer; however, subgroup analyses suggest improvement is greatest in studies conducted in Asian countries, modest in those conducted in North America, and absent in those conducted in Europe (108604,108605). The reasons for these differing findings are unclear but may be related to regional differences in dietary habits, such as the use of raw or cooked garlic. Few studies have examined the effects of garlic supplements. While a single preliminary clinical study in patients with confirmed colorectal adenomas shows that taking high-dose aged garlic extract 2.4 mL daily for 12 months reduces the risk of developing new adenomas by 29% when compared with a lower dose of 0.16 mL daily (51320), other studies do not support the use of garlic supplements for this purpose (4773,96003).
• Common cold. Oral garlic might reduce the frequency of the common cold when used prophylactically. Details: Preliminary clinical research shows that taking one capsule of garlic daily for 12 weeks during the winter months reduces the number of self-reported colds by approximately 63% when compared with placebo. The duration of symptoms was also reduced by approximately one day (10787). Also, a small clinical trial in older patients living in residential care shows that 12% of those taking one capsule daily of a combination of garlic and onion powder (Aliocare, Domca Sau, Spain) for 36 weeks had one or more common cold episodes compared with 45% of those taking placebo. Each capsule provided 14 mg garlic powder (111768).
• Corns. It is unclear if topical garlic is beneficial for corns. Details: Preliminary clinical research in a small number of patients with corns shows that applying a lipid soluble garlic extract topically to corns on the feet twice daily for 10-20 days results in improvement in most patients when compared with baseline (15030). The validity of this finding is limited by the lack of a comparator group.
• Coronary heart disease (CHD). It is unclear if oral garlic is beneficial for CHD. Details: A meta-analysis of preliminary clinical research in adults with CHD shows that taking garlic orally 800-2000 mg daily for 2-48 weeks reduces total cholesterol levels by an average of 16 mg/dL when compared with placebo. Taking garlic did not affect other cholesterol levels; however, the study may have been inadequately powered to detect a difference between groups. The validity of this study is limited by inclusion of patients with and without dyslipidemia at baseline (107238).
• Coronavirus disease 2019 (COVID-19). It is unclear if oral garlic is beneficial for COVID-19. Details: Clinical research in non-critically ill patients hospitalized with COVID-19 shows that taking garlic extract (Gallecina, Samisaz Pharmaceutical Company, Iran) 90 mg every 8 hours for 5 days or until discharge modestly reduces the proportion of patients requiring supplemental oxygen for at least 1 day when compared with placebo. However, there was no overall effect on clinical status, intensive care admission, or discharge prior to day 6. All patients also took remdesivir (111766). A small preliminary clinical study in patients hospitalized with mild to moderate symptoms of COVID-19 shows that taking garlic essential oil orally 50 mg twice daily before breakfast and dinner for 10 days, in addition to standard COVID-19 treatment, reduces the median duration of fever from 5 to 4 days, cough from 7 to 5 days, and weakness from 9 to 7 days when compared with standard treatment alone. The median time to a negative COVID-19 test decreased from 8 to 7 days (109530). The validity of this study is limited by incomplete randomization, the lack of a placebo comparator, and the exclusion of people with severe symptoms.
• Cystic fibrosis. It is unclear if oral garlic is beneficial for cystic fibrosis. Details: Preliminary clinical research shows that taking garlic oil macerate 625 mg daily for 8 weeks does not improve pulmonary function, symptom scores, or the need for antibiotic therapy when compared with placebo in children with cystic fibrosis and chronic pulmonary infection (51438).
• Dental hypersensitivity. Although there has been interest in using oral garlic for dental hypersensitivity, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Denture stomatitis. It is unclear if topical garlic as a mouthwash is beneficial for denture stomatitis. Details: Preliminary clinical research in patients with oral denture stomatitis shows that using a garlic mouthwash 40 mg/mL three times daily for 4 weeks improves redness when compared to baseline. When compared with nystatin, garlic has a lesser degree of recovery, but better patient satisfaction (51466).
• Diabetic retinopathy. It is unclear if oral garlic is beneficial for diabetic retinopathy. Details: Preliminary research in patients with diabetic retinopathy and macular edema, treated with intravitreal bevacizumab and laser photocoagulation, shows that taking garlic powder 1 gram orally daily for 4 weeks improves the best-corrected visual acuity by 0.18 logMAR (logarithm of the minimum angle of resolution), compared with 0.06 for placebo. It also decreases intraocular pressure by 1 mmHg, compared with 0.3 mmHg for placebo (109529).
• Diarrhea. Although there has been interest in using oral garlic for various types of diarrhea, including travelers' diarrhea and dysentery, there is insufficient reliable information about the clinical effects of garlic for these conditions.
• Dysmenorrhea. Although there has been interest in using oral garlic for dysmenorrhea, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Erectile dysfunction (ED). It is unclear if oral garlic is beneficial for erectile dysfunction. Details: A small clinical study in patients with erectile dysfunction (ED) and poor response to tadalafil shows that adding fresh pressed garlic 5 grams in juice 150 mL twice daily for 4 weeks to a regimen of tadalafil 5 mg daily improves erectile function when compared with placebo plus tadalafil A subgroup analysis suggests that effects are clinically significant in patients with moderate ED but not severe ED (114892).
• Esophageal cancer. It is unclear if oral garlic prevents esophageal cancer. Details: Observational research regarding the use of garlic in preventing esophageal cancer is conflicting. Some evidence suggests that raw garlic consumption does not prevent the development of esophageal cancer (51508). However, other population research suggests that weekly garlic consumption decreases the risk of developing esophageal cancer (51209).
• Exercise-induced muscle soreness. It is unclear if oral garlic is beneficial for exercise-induced muscle soreness. Details: Preliminary clinical research shows that taking allicin, a constituent of garlic, 80 mg daily for 14 days can reduce subjective assessments of exercise-induced muscle soreness in athletes when compared with placebo (51404).
• Fatigue. Although there has been interest in using oral garlic for fatigue, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Familial hypercholesterolemia. Oral garlic does not seem to improve blood lipid levels in children with familial hypercholesterolemia. Details: In children with familial hypercholesterolemia, a small clinical trial shows that taking garlic powdered extract, standardized based on alliin content, does not improve levels of total cholesterol, low-density lipoprotein (LDL) or high-density lipoprotein (HDL) cholesterol, triglycerides, lipoprotein (a), apolipoprotein B-100, homocysteine, fibrinogen, or blood pressure (4796).
• Fibrocystic breast disease. Oral garlic has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking a specific combination product (Karinat, INAT-Farma), containing garlic powder 150 mg, beta-carotene 2.5 mg, alpha-tocopherol 5 mg, and ascorbic acid 30 mg twice daily for 6 months reduces the severity of breast pain, premenstrual syndrome, and menstruation pain, and can cause regression of palpable symptoms of breast fibromatosis (51317). It is unclear if these effects are due to garlic, other ingredients, or the combination.
• Gastritis. Oral garlic has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with gastritis shows that taking a specific combination product (Karinat, INAT-Farma), containing garlic 150 mg, beta-carotene 2.5 mg, alpha-tocopherol 5 mg, and ascorbic acid 30 mg twice daily for 6 months improves digestion, inhibits H. pylori infection, and reduces the risk of precancerous lesion formation when compared with placebo (51308). It is unclear if these effects are due to garlic, other ingredients, or the combination.
• Gout. Although there has been interest in using oral garlic for gout, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Hepatitis. It is unclear if oral garlic is beneficial for hepatitis. Details: Preliminary clinical research shows that taking 3-6 capsules of a product containing garlic oil 50 mg and diphenyl-dimethyl-dicarboxylate 25 mg per capsule daily for 6 weeks improves liver function enzyme levels when compared with placebo in patients with chronic hepatitis (51478). The effects of garlic alone have not been determined.
• Hepatopulmonary syndrome. It is unclear if oral garlic is beneficial for hepatopulmonary syndrome. Details: Preliminary clinical research shows that garlic oil (Garlic Pearls, Ranbaxy, India) 1-2 grams/m² daily in two divided doses for 9-18 months may improve oxygen levels and remission rates when compared with placebo in patients with hepatopulmonary syndrome (51439).
• Influenza. Oral garlic has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in older patients living in residential care shows that 12% of those taking one capsule daily of a combination of garlic and onion powder (Aliocare, Domca Sau, Spain) for 36 weeks had one or more influenza-like episodes compared with 36% of those taking placebo. Each capsule provided 14 mg garlic powder (111768).
• Lead toxicity. It is unclear if oral garlic is beneficial for lead toxicity. Details: Preliminary clinical research shows that taking garlic powder 400 mg three times daily for 4 weeks reduces blood lead concentration when compared with baseline, but not when compared to treatment with D-penicillamine, in patients with mild to moderate lead poisoning (51467).
• Lung cancer. It is unclear if oral garlic prevents lung cancer. Details: Some population research suggests that eating raw garlic is associated with a reduced odds of developing lung cancer. However, other research suggests that eating garlic or taking garlic supplements is not associated with a reduced risk of lung cancer (4778,103482). Reasons for the discrepancy possibly relate to the type of garlic consumed.
• Metabolic syndrome. Meta-analyses of small studies suggest that oral garlic may improve some metabolic parameters in patients with metabolic syndrome and other metabolic disorders. Details: Two meta-analyses of several small clinical studies in adults with metabolic syndrome or metabolic disorders including hyperlipidemia, hypertension, nonalcoholic fatty liver disease, obesity, and type 2 diabetes show that taking various forms of garlic improves triglycerides, total cholesterol, low-density lipoprotein cholesterol, diastolic blood pressure , measures of insulin resistance, and waist circumference when compared with control. However, the meta-analyses reach conflicting conclusions on whether garlic is beneficial for body mass index, high-density lipoprotein cholesterol, fasting blood glucose, or systolic blood pressure when compared with control. Garlic forms studied in the meta-analyses include raw garlic 5000-20,000 mg, aged garlic extract 240-6000 mg, garlic powder tablets 188-6000 mg, and garlic derivative ajoene 2.34 mg, taken daily for 4 to 36 weeks (113617,113619).
• Mosquito repellent. It is unclear if oral garlic is beneficial as a mosquito repellent. Details: Preliminary clinical research shows that taking a single dose of garlic orally does not seem to effectively repel mosquitos (51322). The effect of long-term garlic administration is unclear.
• Multiple myeloma. It is unclear if oral garlic prevents multiple myeloma. Details: A case-control study comparing a small population of adults with and without multiple myeloma has found that increased intake of garlic in the diet may be associated with a decreased risk of developing multiple myeloma (51476).
• Muscle strength. It is unclear if oral garlic is beneficial for muscle strength. Details: Population research has found that increased consumption of raw garlic is associated with increased hand grip strength in healthy adults. Females consuming raw garlic 2-3 times per week were 23% less likely to have low handgrip strength, defined as being below the 20th percentile, when compared to those who almost never eat garlic. In males, the odds of having low handgrip strength were 34% lower. Eating any raw garlic, even less than once per week, was associated with an increased likelihood for having high grip strength (102678).
• Obesity. It is unclear if oral garlic is beneficial for obesity. Details: Clinical research shows that taking garlic powder (Amin Pharmaceutical Company) 1600 mg daily for 12 weeks does not reduce body weight or body mass index when compared with placebo in overweight or obese patients with nonalcoholic fatty liver disease (NAFLD), although there is a small effect on waist circumference (102681). One small clinical study evaluating garlic in combination with multiple other ingredients shows that the combination (Prograde Metabolism) modestly improves body weight, fat mass, and waist and hip circumference when compared with placebo. The other ingredients include raspberry ketone, caffeine, capsicum extract, ginger root extract, bitter orange fruit, L-theanine, and black pepper fruit (40802). However, it is unclear if this benefit is due to garlic, other ingredients, or the combination.
• Onychomycosis. Although there has been interest in using topical garlic for onychomycosis, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Oropharyngeal candidiasis. It is unclear if oral garlic is beneficial for oropharyngeal candidiasis. Details: Preliminary clinical research in patients with oral candidiasis shows that applying a topical garlic paste four times daily for 14 days to affected areas can increase the rate of complete eradication of oral lesions by 23% when compared with clotrimazole solution (51330).
• Osteoarthritis. It is unclear if oral garlic is beneficial for osteoarthritis. Details: Preliminary clinical research in overweight and obese females with knee osteoarthritis shows that taking garlic tablets (Nature Made) 500 mg twice daily for 12 weeks modestly reduces pain scores by an additional 15% when compared with placebo (98813).
• Otitis media. Although there has been interest in using topical garlic for otitis media, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Peripheral arterial disease (PAD). Oral garlic seems to improve pain-free walking distance by a small amount in patients with PAD. However, it does not seem to improve blood pressure. Details: In patients with stage II peripheral arterial occlusive disease, a small clinical trial shows that taking garlic (Kwai) 400 mg twice daily for 12 weeks improves pain-free walking distance by about 15 meters. There was no effect on blood pressure or ankle or brachial pressures (4801).
• Polycystic ovary syndrome (PCOS). It is unclear if oral garlic is beneficial for PCOS. Details: Preliminary clinical research in adults with PCOS shows that taking garlic orally 800 mg daily for 8 weeks reduces low-density lipoprotein (LDL) cholesterol levels by approximately 8% when compared with placebo. Taking garlic did not affect other cholesterol levels; however, the study may have been inadequately powered to detect a difference between groups. Garlic supplementation also modestly reduces body mass index (BMI) and waist circumference in this population. However, there was no change in hip circumference (107238,111763).
• Pre-eclampsia. It is unclear if oral garlic prevents pre-eclampsia during the third trimester. Details: Preliminary clinical research shows that taking a specific garlic extract (Garlet, Cosar Pharmaceutical Company) 800 mg daily during the third trimester of pregnancy does not reduce the risk of developing pre-eclampsia in high-risk patients with first-time pregnancies (9201,51626).
• Premenstrual syndrome (PMS). It is unclear if oral garlic is beneficial for PMS. Details: Preliminary clinical research in adult students with moderate to severe PMS shows that taking a specific garlic supplement (Allium-S, Dineh Pharmaceutical Company) orally 400 mg daily, standardized to contain 1.1 mg allicin, for 3 menstrual cycles improves PMS symptom scores 1.4 times more than placebo. After taking garlic for 3 cycles, 91% of students improved to mild PMS, compared with only 36% in the placebo group (107239).
• Prostate cancer. Observational research on the relationship between garlic intake and prostate cancer risk is conflicting. It is unclear if garlic supplements are beneficial in patients with prostate cancer. Details: Observational research in Chinese males shows that those who eat garlic 2.14 grams/day (about one clove) seem to have a 50% lower risk of developing prostate cancer (9876). Also, a pooled analysis of epidemiological research suggests that garlic consumption may be associated with a 23% decreased odds of developing prostate cancer (88410). A case-control study has also found that garlic, consumed at least twice weekly, may reduce the risk for prostate cancer when compared with lower consumption (4777). However, other population research suggests that garlic consumption has no effect on prostate cancer risk in Iranian males (51454). One very small clinical study in patients with prostate cancer shows that taking garlic extract 1 mg/kg daily for one month might improve prostate specific antigen (PSA) levels, urinary flow, and urinary frequency when compared with baseline (10374). The validity of these findings is limited by the small study size and lack of a comparator group.
• Rheumatoid arthritis (RA). Oral garlic seems to reduce pain by a small amount in patients with RA. Details: Clinical research in females with RA shows that taking dried garlic (Garcin; Goldaru Co.) 500 mg twice daily, providing allicin 5 mg, for 8 weeks reduces pain after activity and improves functional ability by a small amount when compared with placebo. Fatigue and pain were reduced by approximately 13% and tender joint count was reduced by 47% (102680,103481). The long-term effect of garlic supplementation is unclear.
• Scleroderma. It is unclear if oral garlic is beneficial for scleroderma. Details: Clinical research shows that taking garlic 900 mg daily for 7 days does not have an effect on vasomotor function when compared with placebo in females with scleroderma (51374).
• Stress. Although there has been interest in using oral garlic for stress, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Tick repellent. It is unclear if oral garlic is beneficial as a tick repellent. Details: Preliminary clinical research shows that taking garlic 1200 mg daily for 8 weeks reduces the number of tick bites when compared with placebo (3318). However, the effect of garlic when compared with commercially available tick repellents is unknown (8027).
• Tinea capitis. Although there has been interest in using topical garlic for tinea capitis, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Tinea corporis. It is unclear if topical garlic is beneficial for tinea corporis. Details: Applying a gel containing 0.6% ajoene, a constituent of garlic, twice daily for one week seems to be as effective as terbinafine 1% cream for tinea corporis (4767).
• Tinea cruris. It is unclear if topical garlic is beneficial for tinea cruris. Details: Applying a gel containing 0.6% ajoene, a constituent of garlic, twice daily for one week seems to be as effective as terbinafine 1% cream for tinea cruris (4767).
• Tinea pedis. It is unclear if topical garlic is beneficial for tinea pedis. Details: Applying a gel containing 1% ajoene, a constituent of garlic, twice daily seems to be more effective than 0.6% ajoene gel, and seems to be as effective as 1% terbinafine (Lamisil) for tinea pedis infections. Sixty days after completing one week of treatment, mycological cure occurred in 100% of patients using 1% ajoene, 72% of patients using 0.6% ajoene , and 94% of those using 1% terbinafine (8019). Additional research suggests that 0.4% ajoene gel twice daily has a 7-day cure rate of around 80% (4766).
• Trichomoniasis. Although there has been interest in using oral garlic for trichomoniasis, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Tuberculosis. Although there has been interest in using oral garlic for tuberculosis, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Unstable angina. It is unclear if intravenous garlic is beneficial for unstable angina. Details: Preliminary clinical research in patients with unstable angina shows that giving garlicin, 60 mg by intravenous infusion daily for 10 days improves symptoms by 7% when compared with intravenous nitroglycerin (51244).
• Urinary tract infections (UTIs). Although there has been interest in using oral garlic for UTIs, there is insufficient reliable information about the clinical effects of garlic for this condition.
• Vaginal candidiasis. It is unclear if oral or topical garlic is beneficial for vaginal candidiasis. Details: One small clinical study in asymptomatic patients with culture-positive candida infections shows that taking garlic (Garlicin, Nature's Way) 1050 mg (3 tablets) twice daily for 14 days does not improve vaginal symptoms, candida colony counts, or cases of vaginal candidiasis when compared with placebo (88405). Another small clinical study shows that application of a vaginal cream containing garlic and thyme nightly for 7 nights is as effective as clotrimazole vaginal cream for treating vaginal candidiasis (88387). However, it is unclear if this effect is due to garlic, thyme, or the combination.
• Warts. It is unclear if topical garlic is beneficial for warts. Details: Preliminary clinical research shows that applying a specific lipid-soluble garlic extract topically to warts on the hands twice daily results in wart resolution within 1-2 weeks. An aqueous garlic extract applied twice daily also seems to provide modest improvement, but only after 30-40 days of treatment (15030). The validity of these findings is limited by the lack of a comparator group.
• Wound healing. It is unclear if topical garlic is beneficial for wound healing. Details: Based on patient and physician evaluations, preliminary clinical research shows that applying an ointment containing fresh garlic in petroleum jelly twice daily for 2 weeks results in 80% of surgical wounds healing at a faster rate than those treated with petroleum jelly. Most patients also indicated that the wound treated with garlic experienced less discomfort (102676). More evidence is needed to rate garlic for these uses.

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POSSIBLY EFFECTIVE

• Dysmenorrhea. In people with dysmenorrhea, taking oral ginger seems to reduce pain. Clinical research shows that ginger might be comparable to ibuprofen or mefenamic acid. In addition, taking ginger seems to be beneficial when used as an adjunct to mefenamic acid 250 mg twice daily. Details: Clinical research in individuals at least 15 years of age shows that ginger can reduce pain from dysmenorrhea. Clinical studies show that taking ginger powder 500-2000 mg daily usually for the first 3-4 days of a menstrual cycle modestly decreases pain severity by an average of 2.3-2.7 points on a 10-point scale when compared to control groups (89889,89899,91139,91892,96255,106077). However, a meta-analysis of clinical research shows that taking ginger does not reduce pain duration when compared with placebo (106077). Clinical research also shows that ginger might be as effective as some anti-inflammatory agents. Taking a specific ginger extract (Zintoma, Goldaru) 250 mg four times daily for 3 days at the beginning of the menstrual period or until pain relief improves symptoms similarly to ibuprofen or mefenamic acid (17931,96259,106077). Also, taking a ginger extract 200 mg four times daily for 3-4 days at the beginning of pain is equally effective to taking Novafen, a combination of acetaminophen, caffeine, and ibuprofen (99444). Ginger also seems to improve pain when given as an adjunct to anti-inflammatory agents. A small clinical study in young females with dysmenorrhea shows that adding ginger (Vomigone, Dineh Co.) 500 mg daily to mefenamic acid 250 mg twice daily for 5 days further reduces pain when compared with taking mefenamic acid alone (102464).
• Osteoarthritis. Most clinical research shows that taking ginger extract by mouth improves pain in some patients with osteoarthritis. Topical ginger, on the other hand, has not shown benefit for knee osteoarthritis in low quality research. Details: Meta-analyses of clinical research show that taking ginger extract 500-1000 mg daily for 3-12 weeks can modestly improve pain when compared with placebo in some patients with osteoarthritis of the knee or hip (96253,103357). However, a meta-analysis of two clinical studies shows that taking ginger extract about 500 mg daily for 6 weeks does not have an effect on function (103357). One small clinical trial in patients with mild osteoarthritis of the knee also shows that taking steamed golden ginger extract 480 mg daily for 12 weeks moderately improves pain and functional scores when compared with placebo (114784). Some clinical research has also compared ginger to conventional drug treatment. In one clinical trial, there was no significant difference between ginger extract 30 mg daily and ibuprofen 400 mg three times daily for one month in patients with osteoarthritis of the hip or knee (17930). However, taking a specific ginger extract (Eurovita Extract 33; EV ext-33) orally 170 mg three times daily for 3 weeks was significantly less effective than ibuprofen 400 mg three times daily for reducing pain (7048). Since ginger is thought to take several weeks for significant benefit, this trial might not have lasted long enough. Ginger has also been compared with diclofenac. When used orally as 1500 mg daily in two divided doses, ginger is less effective than oral diclofenac 100 mg daily in two divided doses, or the combination of ginger and diclofenac, for 12 weeks (89898). Various studies have evaluated formulations containing ginger with other ingredients. These combinations have all been shown to improve osteoarthritis pain, and in some cases, functionality. Studied formulations include ginger (Eurovita Extract 35; EV ext-35) 340 mg with glucosamine (Zinaxin glucosamine, Ferrosan AS) 1000 mg daily for 4 weeks, a ginger extract with an alpinia (Alpinia galanga) extract (Eurovita Extract 77; EV ext-77) 255 mg twice daily for 6 weeks, a ginger extract with curcuminoids, and extracts of devil's claw, Boswellia serrata, and celery (Tregocel) for 36 weeks, or Ayurvedic shunthi-guduchi formulations containing ginger, Indian gooseberry, and Tinospora cordifolia, either with or without Boswellia serrata (7084,18210,89557,106078). However, it's too early to know if the effects of these combination agents are associated with ginger or other ingredients in the formulations. Topical ginger, alone or in combination with other ingredients, has also been studied for knee osteoarthritis. Although a meta-analysis of two randomized clinical trials shows no evidence of benefit of topical ginger for pain and disability when compared with placebo or standard therapy (103357), some benefits have been shown in individual preliminary studies (20340,20341,89897,96668,97537,97542). These trials have used a specific gel containing ginger and plai 4% by weight (Plygersic gel, Thailand Institute of Scientific and Technological Research) 4 grams/day in four divided doses for 6 weeks (89897), an ointment composed of ginger, cinnamon, mastic (Saghez), and sesame oil twice daily for 6 weeks (20340), or one gram of ginger extract 5% (standardized to 11.18% of 6-gingerol) in a nanostructure lipid carrier three times daily for up to 12 weeks to the affected knee (96668,97537). Some studies have used ginger essential oil in a massage oil, alone or with sweet orange essential oil or standard therapy, twice weekly for 3 or 6 weeks (20341,97542).
• Pregnancy-induced nausea and vomiting. Oral ginger seems to reduce the severity of nausea and vomiting in some people during pregnancy. Ginger seems to be more effective than placebo, comparable to vitamin B6 or dimenhydrinate, and less effective than metoclopramide. Details: Although most clinical studies are small and have methodological limitations, the available research shows that ginger is more effective than placebo, and comparable to vitamin B6 or dimenhydrinate (721,1922,5343,11346,13071,16306,20312,20315,90103,91201,102462). Although ginger is comparable to dimenhydrinate for reducing symptoms of morning sickness, it seems to take about 3 days to reduce vomiting episodes compared to 1 day with dimenhydrinate (16305). In addition, clinical research shows that ginger is less effective than metoclopramide at relieving nausea and vomiting associated with pregnancy (20315). Ginger doses of 500 to 2500 mg daily, divided into two to four daily doses for 3 days to 3 weeks, have been used in clinical research (721,5343,16305,16306,20312,20315,90103,91201). The American College of Obstetrics and Gynecology (ACOG) considers ginger capsules 250 mg 4 times daily a first-line nonpharmacological treatment option for pregnancy-induced nausea based on limited evidence. However, there is no evidence that ginger reduces vomiting (111601).

POSSIBLY INEFFECTIVE

• Chemotherapy-induced nausea and vomiting (CINV). Most clinical research shows that oral ginger does not reduce acute or delayed CINV. The effect of ginger might depend on the dose, the other antiemetics used, or the specific chemotherapy regimen. Details: Most clinical research shows that taking ginger as adjunct to adequate antiemetic therapy does not reduce DELAYED CINV when compared with antiemetic therapy alone (20316,96260,89891,96675,97538,97541,101760,102461,113616). Clinical research from meta-analyses and most individual clinical studies also show that taking ginger 0.5-3.5 grams as an adjunct to standard antiemetic therapy does not reduce the incidence or severity of ACUTE CINV when compared with antiemetic therapy alone (89891,96675,101760,102461,102466,113616). However, conflicting results exist from some individual clinical studies (20316,102466). These individual studies evaluated powdered ginger root or liquid extract of ginger root 0.5-2 grams taken in two to four divided doses daily, starting on either the day of or 3 days before chemotherapy and continuing for 3-5 days after chemotherapy initiation (20316,102466). Also, one small study shows that ginger in doses of 1 gram or less for more than 3 days reduces the likelihood of acute vomiting by 60% (101760). More research is needed to confirm the efficacy of this lower dose. Reasons for the conflicting results are unclear, but several theories have been postulated. One theory is that ginger might help reduce CINV associated with some, but not all, chemotherapy regimens. One preliminary clinical study shows that ginger 500 mg twice daily for 3 days reduces vomiting in patients receiving cyclophosphamide and doxorubicin, but not in patients also receiving 5-fluorouracil or docetaxel (96251). However, since there is limited evidence supporting this theory, additional research is needed to confirm. Another theory is that ginger helps when used with certain antiemetic drugs, but not others. For example, ginger seems to help in cases when optimal antiemetic therapy, such as 5-HT3 receptor antagonists, is not available. Small clinical studies show that ginger reduces the severity of acute nausea when compared with prochlorperazine or metoclopramide, both of which are suboptimal antiemetic therapy for CINV (89891). Another small study shows that ginger is comparable to metoclopramide for improving delayed chemotherapy-induced nausea (13244). On the other hand, several studies show that taking ginger 0.5-2 grams daily along with antiemetic therapy that includes aprepitant does NOT improve acute or delayed CINV (20318,89891,96251,96675). In fact, one study found an association between concomitant use of ginger 2 grams daily with aprepitant and worsened severity of delayed nausea. Ginger is hypothesized to decrease the absorption of aprepitant and reduce its effectiveness for delayed nausea (20318,96675). However, this effect has not been replicated, and aprepitant serum levels were not measured to confirm this hypothesis. Finally, many of the studies showing a benefit of ginger for CINV when used as an adjunct to standard antiemetic therapy are considered to be methodologically flawed (20317,96252,96677). For instance, one study using powdered ginger root 1-2 grams daily during the first three days of chemotherapy in children and adults (20317) has been criticized for inaccurately representing data (89891). Other studies of ginger 500 mg twice daily for up to 10 days used questionable methods to measure outcomes and usually did not differentiate between acute and delayed CINV (96252,96677). Ginger essential oil aromatherapy has also been evaluated. One small study shows that using two drops of ginger essential oil on an aromatherapy necklace for 2 minutes daily for 5 days, starting on the first day of chemotherapy, reduces acute nausea, but not vomiting or delayed nausea, when compared with placebo in females with breast cancer taking standard antiemetics including granisetron, dexamethasone, and metoclopramide (96256).
• Exercise-induced muscle soreness. Most research shows that oral ginger in single or multiple doses does not prevent or treat exercise-induced muscle soreness. Details: Two small studies in healthy adults show that single doses of ginger supplements do not seem to reduce muscle soreness from exercise. Taking capsules of ground ginger 2 grams, 30 minutes before a 30-minute cycling bout, or 24-48 hours after eccentric exercise, does not reduce muscle pain during exercise or within one hour of ingestion when compared with placebo (17932,17934). Taking multiple doses also does not seem to help. One small study in healthy adults shows that taking capsules with ginger powder 4 grams daily for 5 days before high-intensity eccentric exercise does not reduce muscle soreness over 4 days when compared with placebo (96258). Another small study in healthy adults shows that taking capsules of heated or raw ground ginger 2 grams daily for 8 days prior to eccentric exercise, and continuing supplementation for 3 more days, might modestly reduce muscle soreness 24 hours post-exercise, but not at later time points, when compared with placebo (17933,96258). Ginger has also been tested in combination with other ingredients. One small study in healthy adults shows that taking a specific combination product (ReWin(d), Natural Origins) containing a 4:3 ratio of ginger and annatto powder, 2 grams in divided doses daily for 4 weeks before eccentric exercise and continuing for 3 days after exercise, may modestly reduce muscle pain 48 hours after exercise but not at other time points (105057). This study was funded by the supplement manufacturer.
• Motion sickness. Most research shows that oral ginger does not prevent or treat motion sickness. Details: Most clinical research shows that taking ginger 500-1000 mg up to 4 hours prior to travel does not prevent motion sickness (7624,7625,20330,20331). Some patients report subjective feelings of improvement, but in many studies objective measures did not significantly improve (7400). However, one clinical trial suggests that ginger is more effective than dimenhydrinate at reducing gastrointestinal distress associated with motion sickness (20332). Another clinical study seems to show that taking ginger 1-2 grams as a single dose reduces nausea severity and increases the latency before the onset of nausea caused by simulated motion sickness when compared to baseline (20333). The validity of this finding is limited by the lack of a comparator group.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acute respiratory distress syndrome (ARDS). Some small clinical studies show that giving ginger with tube feeds to hospitalized patients might reduce the duration of serious sequelae from ARDS. Details: A small clinical trial in adults with ARDS shows that administering ginger extract 120 mg in three divided doses daily via nasogastric tubing for 21 days increases the number of ventilator-free days and the amount of feeding tolerated and decreases the number of intensive care unit (ICU) days when compared with placebo. However, it does not seem to improve overall mortality (20343). Also, another small clinical study shows that adding ginger extract 120 mg to tube feeds in three divided doses daily for 8-21 days improves blood oxygen levels by 13% to 20%, as well as the ability of the lungs to expand by 17%, when compared with a coconut oil placebo. The duration of mechanical ventilation and stay in the ICU also improved. However, ginger does not affect other measurements of lung function or physical organ damage in these patients (89886).
• Allergic rhinitis (hay fever). It is unclear if oral ginger is beneficial in allergic rhinitis. Details: A small clinical trial shows that taking ginger extract 500 mg daily for 6 weeks is as effective as loratadine 10 mg daily for reducing nasal symptoms of allergic rhinitis (103359).
• Antiretroviral-induced nausea and vomiting. Oral ginger seems to improve nausea and vomiting in patients using antiretroviral agents. Details: A small clinical study in patients with HIV shows that taking ginger 0.5 grams twice daily, 30 minutes prior to each dose of antiretroviral for 14 days, reduces the relative likelihood of nausea and vomiting by about 63% and 79%, respectively, when compared with placebo (89887).
• Asthma. Although there has been interest in using oral ginger for asthma, there is insufficient reliable information about the clinical effects of ginger for this condition.
• Atopic dermatitis (eczema). Topical ginger has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A moderate-sized clinical trial in adults and children with eczema shows that applying a combination topical product containing ginger and cannabidiol twice daily for 5 days moderately improves eczema scores, including erythema, dryness, itching, and scaling, when compared to baseline. It is unclear if this effect is due to ginger, other ingredients, or the combination. The validity of this study is limited by the lack of a comparator group (114783).
• Back pain. Although there has been interest in using oral ginger for back pain, there is insufficient reliable information about the clinical effects of ginger for this condition.
• Burns. Although there has been interest in using topical ginger for burns, there is insufficient reliable information about the clinical effects of ginger for this condition.
• Cancer-related anorexia. It is unclear if oral ginger improves appetite in people with cancer-related anorexia. Details: A small clinical study in patients with cancer-related anorexia and cachexia shows that taking a capsule containing ginger 1650 mg daily for 14 days improves nausea, appetite, reflux, dysmotility, and other gastrointestinal symptoms when compared to baseline (102460). The validity of these findings is limited by the lack of comparator group.
• Chronic obstructive pulmonary disease (COPD). Oral ginger has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking two capsules of a specific combination product (AKL1, AKL International Ltd.) containing ginkgo extract, ginger, and Picrorhiza kurroa twice daily for 8 weeks does not improve respiratory symptoms when compared with placebo in patients with COPD (89702). Another moderate-sized clinical study in adults with COPD shows that taking a combination product containing extracts of ginger, alpinia, cardamom, cinnamon, and saffron in honey 3 times daily for 8 weeks improves confidence in leaving home and the ratio of forced exploratory volume per second to forced vital capacity of the lungs (FEV1/FVC) when compared with placebo. However, the combination product does not improve most measures of respiratory function or symptoms such as cough, phlegm, chest tightness, dyspnea, reduced energy levels, sleeping disorders, or activity limitations when compared with placebo (111542). It is unclear if these effects are due to ginger, other ingredients, or the combination.
• Colic. Although there has been interest in using oral ginger for colic, there is insufficient reliable information about the clinical effects of ginger for this condition.
• Constipation. Although there has been interest in using oral ginger for constipation, there is insufficient reliable information about the clinical effects of ginger for this condition.
• Coronavirus disease 2019 (COVID-19). It is unclear whether oral ginger is beneficial for patients with COVID-19. Details: Clinical research in adults hospitalized with asymptomatic COVID-19 infection shows that taking ginger 1.5 grams twice daily orally until hospital discharge reduces length of stay from around 8.5 days to 6 days, when compared with placebo. The strongest effect is seen in males over 60 years of age (110005). The relevance of these results is reduced by a lack of blinding, and the fact that the subjects were initially asymptomatic. Another small study in adults with COVID-19 treated in the community shows that taking ginger 1000 mg three times a day for 7 days does not improve viral clearance, oxygen saturation, or respiratory rate when compared with placebo. Taking ginger also did not reduce the risk of hospitalization (114779). The efficacy of ginger for treating COVID-19 has also been evaluated in combination with other ingredients. In adults with uncomplicated, moderate COVID-19, taking a combination of ginger, turmeric, ashwagandha, and boswellia (BV-4051, Artovid-20), 1776 mg twice daily orally for 14 days in addition to standard care and starting 48-96 hours after symptom onset, reduces the mean duration of symptoms from about 8 days to 7 days, when compared with placebo (109899). A small open-label study in adults with confirmed mild to moderate COVID-19 shows that taking ginger 1000 mg and ashwagandha 500 mg twice daily for 15 days, along with conventional therapy, leads to a 13.8-fold and 2.6-fold increase in the relative rate of clinical cure at 7 days and 15 days, respectively, when compared with conventional therapy alone. Taking this combination also appears to reduce time to recovery by around 6 days but does not improve the rate of negative COVID-19 tests, chest imaging findings, viral clearance, serum antibodies, or other measures of disease progression when compared with conventional therapy alone (112094). The validity of these findings is limited by a lack of blinding, and the study may have been inadequately powered to detect a difference between groups. Additionally, it is unclear if these effects are due to ginger, ashwagandha, or the combination.
• Diabetes. Some preliminary clinical studies suggest that oral ginger might have a small beneficial effect on glycemic control in patients with type 2 diabetes or gestational diabetes. Details: Meta-analyses of several small clinical trials in adults with type 2 diabetes show that taking ginger 1200-3000 mg daily for 8-13 weeks reduces glycated hemoglobin (HbA1c) by around 0.6% to 1% and fasting blood glucose by 19-21 mg/dL when compared with placebo (96680,107898). However, a recent meta-analysis of randomized clinical trials in adults with type 2 diabetes shows that taking ginger 1200-2000 mg daily for 4-12 weeks does not improve HbA1c or fasting blood glucose when compared with placebo (114780). The reasons for these discordant results are not entirely clear, but they are likely related to heterogeneity of the included populations, treatment dose, and duration of follow up. Additionally, a small clinical study in adults with diabetes on hemodialysis for end stage renal disease shows that taking ginger powder 2000 mg daily for 8 weeks reduces fasting blood glucose and measures of insulin resistance, but not serum insulin levels, when compared with placebo (111543). In patients with gestational diabetes at weeks 24-28 of pregnancy, clinical research shows that taking ginger 1500 mg daily in three divided doses for 6 weeks reduces fasting blood glucose, insulin levels, and measures of insulin resistance by a small amount when compared with placebo, with no effect on postprandial glucose levels (103358).
• Diabetic neuropathy. Topical ginger has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in adults treated with gabapentin for diabetic neuropathy of the foot shows that applying a combination balm containing ginger, menthol, camphor, and other ingredients three times a day for 4 weeks moderately improves pain scores when compared with a placebo balm without ginger but containing menthol, camphor, and other ingredients.(114781). It is unclear if this effect is due to ginger, other ingredients, or the combination.
• Diarrhea. Although there has been interest in using oral ginger for various types of diarrhea, including cholera and acute bacterial dysentery, there is insufficient reliable information about the clinical effects of ginger for these conditions.
• Dry mouth. It is unclear if rinsing the mouth with ginger extract is beneficial for dry mouth. Details: In patients with dry mouth related to type 2 diabetes, clinical research shows that use of a ginger extract 25% mouthwash 20 mL three times daily for 14 days modestly reduces symptoms of dry mouth when compared with rinsing with a saline control mouthwash (106068). Although this study was indicated as being triple-blind, it is unclear how the taste of ginger was masked.
• Dyspepsia. It is unclear if oral ginger is beneficial for dyspepsia. Details: In patients with dyspepsia, a small clinical trial shows that a single dose of ginger root powder 1.2 grams, taken 1 hour prior to eating, does not reduce abdominal discomfort when compared with placebo. However, it increases the rate of gastric emptying (20325).
• Erectile dysfunction (ED). It is unclear if oral ginger is beneficial for erectile dysfunction. Details: Preliminary clinical research in middle-aged males with ED shows that taking two capsules of a specific combination product (Revactin, MD Concepts LLC) containing ginger root 250 mg, muira puama 250 mg, guarana 250 mg, and L-citrulline 800 mg twice daily for 3 months improves scores related to erectile function and intercourse satisfaction, but does not improve sexual desire or orgasmic function scores, when compared to baseline (103224). This study is limited by the lack of a placebo control, the use of per-protocol analysis, and a high dropout rate. In fact, 44% of patients withdrew in order to resume use of phosphodiesterase type 5 (PDE5) inhibitors. Further, it is unclear if these effects are due to ginger, other ingredients, or the combination.
• Gastroenteritis-associated nausea and vomiting. It is unclear if oral ginger is beneficial for children with gastroenteritis-associated vomiting. Details: In children aged 1-10 years with acute gastroenteritis-associated vomiting, clinical research shows that taking a single dose of ginger reduces the risk of vomiting at least once in the subsequent 8 hours by 20% when compared with placebo. The incidence of vomiting over the next 24 and 48 hours was also modestly reduced. The children were given 20 drops of ginger equivalent to 10 mg immediately, followed by every 8 hours until cessation of vomiting. All children were offered hypotonic oral rehydration solution (ORS) 30 minutes after the first dose (106076). The number of children accepting ORS, and the quantity of ORS consumed, was less in the group receiving placebo. It is unclear if this affected the outcomes of this study. Also, the incidence or severity of nausea was not investigated.
• Hangover. It is unclear if oral ginger is beneficial for managing symptoms of hangover. Details: Preliminary clinical research shows that use of a decoction containing a combination of ginger 6 grams, pith of Citrus tangerine 3 grams, and brown sugar decreases symptoms of alcohol hangovers, including nausea, vomiting, and diarrhea, when compared with placebo. The decoction was taken once 5 hours prior to drinking alcohol or four times after drinking alcohol (20320).
• Hyperlipidemia. Oral ginger may be modestly beneficial for some patients with hyperlipidemia. Details: A meta-analysis of preliminary clinical research in adults with and without hyperlipidemia shows that taking ginger 200-3000 mg orally daily for 2-24 weeks reduces triglyceride and low-density lipoprotein cholesterol levels by 12 mg/dL and 5 mg/dL, respectively, and increases high-density lipoprotein cholesterol levels by 1 mg/dL when compared with placebo (109521). However, the validity of this study is limited by high heterogeneity. A clinical study in adults with hyperlipidemia shows that taking ginger powder 1 gram three times daily for 45 days reduces triglyceride and cholesterol levels by an additional 36% and 90%, respectively, when compared with placebo (20327).
• Hypertension. It is unclear if oral ginger is beneficial for lowering blood pressure. Details: A preliminary clinical study in patients with diabetes and elevated systolic blood pressure shows that drinking black tea containing ginger 3 grams three times daily for 8 weeks does not reduce blood pressure by a clinically significant amount when compared with plain black tea (96669).
• Hypothyroidism. It is unclear if oral ginger is beneficial in patients with hypothyroidism. Details: A small clinical study in patients with primary hypothyroidism who are stabilized on thyroid hormone therapy shows that taking ginger powder 500 mg twice daily for 30 days improves symptoms associated with hypothyroidism, including cold intolerance, constipation, dizziness, dry skin, weight gain, and concentration and memory issues, when compared with placebo. However, ginger supplementation does not seem to improve hair loss, hearing, nail fragility, speech, or feelings of depression in these patients (107903).
• Insect bite. It is unclear if topical ginger is beneficial for reducing the size of insect bites. Details: Preliminary clinical research shows that a topical application of Trikatu, which contains ginger, long pepper, and black pepper extracts with 0.074% piperine and 0.046% gingerol, does not reduce the papule size associated with mosquito bites when compared with a control compound containing the same base ingredients of camphor 2%, menthol 2%, and eucalyptus oil 4% (89893).
• Intraoperative nausea and vomiting (IONV). It is unclear if oral ginger is beneficial for preventing IONV. Details: Clinical research in individuals undergoing elective C-section and receiving cimetidine and metoclopramide, shows that taking ginger 1 gram orally 30 minutes prior to anesthesia reduces the number of episodes of intraoperative nausea, but not vomiting, when compared with placebo (89890). In other clinical research in adults undergoing elective surgical procedures, adding ginger to a high calorie drink consumed pre-operatively reduces the incidence of nausea from 40% to 10%, and the incidence of vomiting from 25% to 10% when compared with the high calorie drink alone (110007). The validity of these results is unclear as only patients were blinded to the treatment group.
• Irritable bowel syndrome (IBS). Oral ginger might reduce symptoms of IBS when used in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial shows that taking ginger 1-2 grams daily for 28 days does not improve symptoms or the number of responders when compared with placebo (90102). However, some research shows that ginger might be beneficial in some patients when used along with other herbal ingredients. Taking a capsule containing ginger, boswellia, and yarrow three times daily for 30 days reduces the frequency and severity of abdominal pain, as well as the severity of bloating, when compared with placebo in females, but not males, with mild to moderate IBS (96673). Another clinical study shows that taking an herbal mixture containing ginger, English horsemint, and purple nut sedge tuber three times daily for 8 weeks improves IBS symptoms including abdominal pain, stool frequency, stool consistency, incomplete evacuation, and urgency, when compared to baseline; these improvements are similar to those achieved by taking mebeverine 135 mg three times daily (89900). However, it is unclear if these effects are due to ginger, other ingredients, or the combination.
• Joint pain. Oral ginger has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking a specific combination product (Instaflex Joint Support, Direct Digital) containing glucosamine sulfate 1500 mg, methylsufonlylmethane 500 mg, white willow bark extract 250 mg, ginger root concentrate 50 mg, Boswellia extract 125 mg, turmeric root extract 50 mg, cayenne 40 m H.U. 50 mg, and hyaluronic acid 4 mg in three divided doses daily for 8 weeks reduces joint pain severity by 37% compared to only 16% with placebo. However, it does not improve joint stiffness or function when compared with placebo (89560). It is unclear if these effects are due to ginger, other ingredients, or the combination.
• Menorrhagia. It is unclear if oral ginger is beneficial for menorrhagia. Details: Preliminary clinical research in healthy adults experiencing heavy menstrual bleeding shows that taking ginger 250 mg three times daily for 4 days, starting the day prior to menstruation, and repeating for three menstrual cycles, reduces the amount of menstrual bleeding when compared with placebo (96672).
• Menopausal symptoms. Although there has been interest in using oral ginger for menopausal symptoms such as insomnia, there is insufficient reliable information about the clinical effects of ginger for this purpose.
• Migraine headache. Small clinical studies suggest that oral ginger may modestly reduce migraine pain severity and duration. However, taking ginger doesn't seem to PREVENT migraines. Details: Ginger does not seem to be effective for the prevention of migraines. Clinical research in patients with episodic migraine shows that taking ginger extract 200 mg three times daily for 3 months does not reduce the number of migraine attacks, the use of analgesics, or the number of days with pain, any more than taking placebo (101761). However, ginger may be beneficial for the treatment of migraine. Clinical research shows that taking ginger extract 400 mg orally in the emergency room along with intravenous ketoprofen 100 mg reduces pain over the next 2 hours when compared with ketoprofen and placebo. This combination also resulted in an overall better response with a higher likelihood of having no or mild pain with treatment (101762). Taking ginger 250 mg at the onset of a common migraine headache seems to be as effective as taking sumatriptan 50 mg for reducing headache severity within two hours of treatment (89894). Furthermore, a combination of ginger and feverfew (GelStat Migraine, GelStat Corporation; LipiGesic M, PuraMed BioScience), administered sublingually at the onset of a migraine attack, decreases the duration and intensity of migraine pain when compared with placebo (19357,22602). It is unclear if these effects are due to ginger, feverfew, or the combination. Feverfew alone has demonstrated some benefit in treating migraines.
• Multiple sclerosis (MS). It is unclear if oral ginger is beneficial for MS. Details: A small clinical study in adults with MS shows that taking ginger 500 mg three times daily for 12 weeks reduces disability scores and improves physical and psychological quality of life scores when compared with placebo (111541). Another small clinical study in adults with relapsing-remitting MS shows that taking ginger 500 mg three times daily for 12 weeks reduces the frequency and severity of nausea and constipation and the severity but not frequency of bloating when compared with placebo. However, no improvement was noted in other gastrointestinal symptoms of MS including abdominal pain, anorexia, diarrhea, dysphagia, gas, or heartburn (113614).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral ginger is beneficial for NAFLD. Details: A small clinical study in patients with NAFLD shows that taking ginger 1000 mg twice daily for 12 weeks improves liver steatosis scores but not liver fibrosis scores when compared with placebo. Ginger also modestly improves levels of alanine aminotransferase and gamma-glutamyl transferase but not aspartate aminotransferase (113615). However, it is unclear whether any improvements are clinically significant. Another small clinical study in patients with NAFLD shows that taking ginger root 1500 mg daily for 12 weeks reduces low-density lipoprotein (LDL) cholesterol and fasting blood glucose levels, but does not affect triglycerides, high-density lipoprotein (HDL) cholesterol, insulin resistance, blood pressure, or fatty liver index, when compared with placebo (102465).
• Obesity. Oral ginger has primarily been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Although some individual research disagrees (40802), a meta-analysis and most individual clinical trials show that taking ginger alone or with other ingredients does not reduce weight by a clinically significant amount when compared with placebo in overweight or obese individuals (20346,20347,96676,109521). Ginger has been taken alone or in combination with green tea and capsaicin; rhubarb, astragalus, red sage, turmeric, and gallic acid (Number Ten); or raspberry ketone (Razberi K, Integrity Nutraceuticals), caffeine, capsicum extract (Capsimax, OmniActive Health Technologies), bitter orange fruit (Advantra Z, Nutratech Inc), L-theanine, and black pepper fruit extract (Biperine, Sabinsa Corporation) (Prograde Metabolism) (20346,20347,40802,96676). Due to the various other ingredients contained in available formulations, any effect from ginger is unclear.
• Parturition. It is unclear if bathing in a ginger bath is beneficial for shortening the duration of labor. Details: Preliminary clinical research shows that bathing in 228 liters of water containing 4 drops of ginger essential oil does not shorten the duration of labor when compared with a regular bath (20345).
• Polycystic ovary syndrome (PCOS). It is unclear if oral ginger is beneficial for females with PCOS. Details: Preliminary clinical research in females with PCOS shows that taking ginger 500 mg three times daily orally for 8 weeks decreases body weight, body mass index, and levels of follicle stimulating hormone and luteinizing hormone, when compared with placebo. It does not affect testosterone levels (110006).
• Postoperative nausea and vomiting (PONV). Evidence for the use of oral ginger for preventing PONV is inconclusive and conflicting. Reasons for the conflicting findings may relate to the ginger formulation used and the outcomes measured. It is unclear if ginger aromatherapy is beneficial for PONV. Details: Some individual clinical studies, as well as a large, recent meta-analysis of the available clinical research, show that taking ginger by mouth 1 hour prior to surgery does not reduce the incidence of 24-hour PONV (3452,3453,17369,99445). Also, the meta-analysis found that, although ginger reduces the severity of PONV when measured on a visual analogue scale (VAS), it does not reduce the severity of PONV when measured on a verbal descriptive scale (VDS). Furthermore, ginger does not reduce the use of rescue antiemetic medications (99445). However, some small, individual clinical studies and a meta-analysis of older clinical research show that taking ginger by mouth prior to surgery reduces the incidence of 24-hour PONV by up to 16% to 38% (722,723,1919,13237,20336,20338,20339). In addition, large clinical trials show that the frequency and severity of PONV 2-6 hours after surgery are similar when ginger 1 gram is given orally or when medications such as metoclopramide or dexmedetomidine are given intravenously prior to undergoing anesthesia (103356,103360). However, taking ginger prior to general anesthesia, in combination with other antiemetics like dexamethasone or cimetidine and metoclopramide, does not seem to reduce nausea and vomiting when compared with the other medications alone (20337,89890). In contrast, other research shows that powdered ginger 1-2 grams 30-60 minutes before induction of anesthesia has been used in most studies showing benefit, occasionally followed by 1 gram of ginger administered two hours after surgery (722,723,13237,20336,20338,103356,103360). Ginger aromatherapy has also been evaluated for the prevention of PONV. Application of 5% ginger essential oil to the wrists of patients prior to the induction of general anesthesia seems to prevent PONV in approximately 80% of treated patients (20334). Also, use of ginger essential oil aromatherapy on a gauze pad results in nausea relief in approximately 67% of patients compared with 40% in the placebo group; however, a blend of essential oils including ginger, spearmint, peppermint, and cardamom, results in nausea relief in 82% of patients (89888).These conflicting findings may be due to differences in outcome measures and the chemical compositions of ginger preparations used in the various clinical studies. Some evidence suggests that the efficacy of ginger for preventing PONV differs based on the formulation used. A network meta-analysis of 18 studies evaluating various ginger preparations, including ginger oil, ginger powder, ginger extract, and a combination of ginger powder and antiemetics, for the prevention of PONV suggests that ginger powder and ginger oil are the most effective formulations for preventing nausea and vomiting, respectively. The analysis also shows that while no ginger formulation is superior to another for the prevention of nausea, ginger powder and ginger oil have a lower risk of postoperative vomiting when compared with ginger extract. A subgroup analysis suggests that ginger seems to be most effective in adults over 30 years of age, when administered preoperatively, and when used for gastrointestinal, hepatobiliary, obstetric, or ophthalmic surgeries (112108).
• Postoperative recovery. It is unclear if oral ginger is beneficial for postoperative recovery. Details: One preliminary clinical study in adults who had a tonsillectomy shows that taking a specific ginger supplement (Solgar, Leonia) 500 mg twice daily for 7 days along with acetaminophen and antibiotics modestly improves pain and wound healing when compared with acetaminophen and antibiotics alone (96674).
• Postpartum complications. It is unclear if oral ginger is beneficial in patients with postpartum pain. Details: A small clinical study in patients recovering from vaginal delivery shows that taking ginger powder 500 mg 8-hours post-delivery, followed by 250 mg every 8 hours thereafter for 24 hours, reduces postpartum pain by nearly 1 point on a 10-point rating scale when compared with placebo (107904). It is unclear if this improvement would be considered clinically relevant.
• Radiation-induced nausea and vomiting. It is unclear if oral ginger is beneficial in patients with radiation-induced nausea and vomiting. Details: A very small study in adults with cervical cancer undergoing treatment with cisplatin and radiotherapy shows that taking ginger 250-500 mg twice daily for 6 weeks in addition to standard antiemetic therapy does not reduce acute or delayed nausea and vomiting when compared with antiemetic therapy alone (113616).
• Rheumatoid arthritis (RA). One small clinical study suggests that oral ginger may improve some symptoms of RA. Details: Preliminary clinical research in adults with RA shows that taking ginger powder 1500 mg daily for 12 weeks improves disease activity on the Disease Activity Score-28 when compared with placebo (100697). Another small study in adults with RA shows that taking a combination product containing ginger, ashwagandha, black pepper, and colchicum luteum twice daily for 4 weeks does not improve RA disease scores when compared with celecoxib 100 mg orally twice daily (114785). However, the interpretation of these results is limited by. poor methodology, and the study may have been inadequately powered to detect a difference between groups.
• Smoking cessation. Oral ginger has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A moderate-sized clinical study in adults in India with a history of smoking 5 or more cigarettes daily for at least 3 years shows that taking a specific combination product containing ginger 50 mg, ashwagandha, cowhage, turmeric and other herbal extracts (Smotect, Smotect India) twice daily for 3 months reduces the number of cigarettes smoked by approximately 3 per day when compared with placebo. This product also reduces levels of alveolar carbon monoxide and carboxyhemoglobin but does not improve lung capacity (112115). However, only data from patients who completed treatment were analyzed, which limits the validity of this study. It is also unclear if these effects are due to ginger, other ingredients, or the combination.
• Swallowing dysfunction. The effects of oral ginger for treating swallowing dysfunction are inconclusive. Reasons for the conflicting findings may relate to the route of administration or the number of treatments provided. Details: Clinical research shows that applying a spray containing ginger and clematix root (Tongyan) to the oropharynx for 28 days is more effective than placebo at treating grade 2 or 3 dysphagia in stroke victims. However, there does not seem to be a beneficial effect in patients with grade 1 dysphagia (20342). Other clinical research in elderly patients with dysphagia shows that taking a single dose of ginger 2 mg orally does not improve swallowing but increases saliva (96671). It is possible that a single dose of ginger is not enough to improve swallowing function.
• Toxin-induced liver damage. Oral ginger might help to prevent liver damage in patients using antimycobacterial drugs. Details: Preliminary clinical research shows that a specific ginger supplement (Zintoma, Goldaru) 500 mg taken 30 minutes prior to antimycobacterial drugs daily for 4 weeks reduces the percentage of patients experiencing an increase in liver function enzymes to greater than five times the upper limit of normal by 54% when compared with placebo. Antimycobacterial drugs used for tuberculosis in the study included isoniazid 5 mg/kg, rifampin 10 mg/kg, ethambutol 15 mg/kg, and pyrazinamide 25 mg/kg daily (96670).
• Traumatic brain injury (TBI). Oral ginger has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary research in young adults with subjective memory dysfunction associated with mild TBI, shows that taking a combination of ginger 36 mg and boswellia 360 mg (Memoral) every 8 hours orally for one month improves scores for some, but not all, parameters on an auditory-visual learning test performed at one and three months, when compared with placebo. Total learning scores increased by about 7.5 points with the ginger combination product, compared with 4 points for placebo (110132). It is unclear if these effects are due to ginger, boswellia, or the combination.
• Ulcerative colitis. It is unclear if oral ginger is beneficial for improving symptoms of ulcerative colitis. Details: Preliminary clinical research in adults with ulcerative colitis shows that taking ginger powder 1000 mg twice daily for 12 weeks improves disease activity as measured by the Simple Clinical Colitis Activity Index Questionnaire when compared with taking placebo. However, taking ginger did not improve quality of life, stool frequency, bowel distress, or flatulence when compared with placebo (100694). It is possible that this study was not adequately powered to detect a difference in these secondary outcomes.
• Upper respiratory tract infection (URTI). Although there has been interest in using oral ginger for various upper respiratory tract infections, there is insufficient reliable information about the clinical effects of ginger for this condition.
• Vertigo. It is unclear if oral ginger is beneficial for improving symptoms of vertigo. Details: A small clinical study shows that taking 1 gram of ginger orally as a single dose prior to stimulated vertigo seems to reduce symptoms of vertigo, including nausea, when compared with placebo. However, it does not seem to reduce nystagmus (7623). More evidence is needed to rate ginger for these uses.

(Read more about GINGER)

EFFECTIVE

• Anemia of chronic disease. Oral and intravenous (IV) iron in combination with erythropoiesis-stimulating agents (ESAs) are effective for treating anemia of chronic disease. Details: Iron supplementation with ESAs is effective for treating anemia associated with chronic kidney disease (CKD) or chemotherapy. During therapy with ESAs, iron levels should be monitored and supplementation provided as needed to ensure that the response is not limited by lack of iron for erythropoiesis (1087,1091,20110,20111,110192). Research shows that IV iron appears to be more effective than oral supplements for this purpose (20112,20113). In patients with CKD, IV iron at total doses from 2232 mg over 6 months to 1020 mg over one week increases hemoglobin levels more than oral doses of 4-6 mg/kg daily or 325 mg daily for up to 6 months (20112). Some research has evaluated the effect of IV or oral iron in patients not treated with ESAs. In patients with cancer or CKD, oral iron supplements have been shown to improve iron status (110184,110192). However, overall benefits of iron alone remain unclear in treated or untreated patients with cancer and more research is needed to rule out an increase in mortality and to determine any effect on blood transfusion requirements (110192). Preliminary clinical research shows that children aged 6 months to 10 years with HIV and anemia who take elemental iron 3 mg/kg daily along with a multivitamin for 3 months have a 41% lower chance of having persistent anemia at 3 months when compared with multivitamins alone (95432).
• Iron deficiency anemia. Oral and intravenous (IV) iron are effective for treating or preventing iron deficiency anemia. The benefits of iron supplementation in people with iron deficiency without anemia are unclear. Details: Oral iron supplements, mainly as ferrous sulfate, are effective for treating and preventing iron deficiency anemia in adults, children, and infants (1089,7135,17495,17496,17497,103806,20114,20115,91183,96621)(104680,104681,112601). Other forms are also effective, including sodium iron ethylenediaminetetra-acetate (NaFeEDTA), iron(III)-hydroxide polymaltose complex (IPC), iron protein succinylate, iron bisglycinate, and lactoferrin with iron (20117,20118,110189). Treatment with iron supplements should increase hemoglobin levels by 1 gram/dL every 2-3 weeks. However, even after hemoglobin has normalized, it may take up to 4 months for iron stores to be replenished (17497). Historically, treatment of iron deficiency anemia with oral iron supplements has typically consisted of a daily dosing regimen, often taken in divided doses to reduce adverse effects. In more recent years, however, intermittent iron supplementation (1-3 doses/week) has become preferred for some patients, particularly those with mild anemia, due to better absorption and a possible reduction in side effects compared to daily dosing. One small clinical study shows that taking ferrous sulfate 60 mg on alternate days in single doses improves iron absorption when compared to once daily dosing (96630). Another small clinical study in females with iron-deficiency anemia shows that fractional iron absorption is 40% to 50% higher with alternate-day dosing compared with daily dosing. Furthermore, total iron absorption was shown to be similar for alternate day dosing of elemental iron 200 mg compared with daily dosing of 100 mg, but the incidence of gastrointestinal adverse effects may be lower for the alternate day dosing regimen (101514). A meta-analysis of 25 clinical trials, including 10,996 menstruating females with or without pre-existing iron deficiency and/or anemia, shows that intermittent iron reduces the risk of anemia and increases hemoglobin and serum ferritin when compared with placebo or no intervention. This meta-analysis did not identify differences in the risk of anemia, hemoglobin, or serum ferritin between intermittent and daily iron supplementation. However, it did show that females receiving intermittent dosing had a 59% reduction in the risk for adverse effects. The validity of these findings is limited by significant heterogeneity in the enrolled populations and selected dosing strategies, including frequency of intermittent dosing, total weekly dose, and duration of follow-up. In addition, the subgroup analyses performed by baseline anemia, hemoglobin, and serum ferritin, as well as duration of follow-up, showed differing overall conclusions when comparing intermittent and daily iron supplementation. While intermittent dosing appears to be beneficial when compared with daily dosing for some patients with iron deficiency anemia, intermittent dosing may be less effective than daily iron supplementation in some patients (103806). For patients with severe anemia, twice daily dosing may be preferred to alternate day dosing due to faster response. A small clinical study in patients with iron deficiency anemia shows that taking ferrous sulfate 200 mg twice daily is more effective at increasing hemoglobin levels by 3 weeks when compared with ferrous sulfate 400 mg taken on alternate days in single doses (102864). Intermittent iron supplementation has also been investigated in children. A meta-analysis of clinical research in children and adolescents with or without pre-existing iron deficiency and/or anemia shows that taking iron supplements 1-2 times weekly is similarly effective as 3-7 times weekly for decreasing iron deficiency and iron deficiency anemia. However, ferritin and hemoglobin levels increased to a greater extent with 3-7 times weekly supplementation (112601). Blood transfusion may be required for some patients with severe iron deficiency anemia who have symptoms such as dyspnea and fatigue (17497). Intravenous iron should be considered in patients who cannot tolerate oral iron or in patients with chronic bleeding or intestinal malabsorption (17497). Guidance from the American Gastroenterological Association and the British Society of Gastroenterology recommends treatment with iron while awaiting investigations to rule out gastrointestinal issues in adults in the absence of an alternative explanation. Ferrous sulfate, fumarate, or gluconate daily are recommended. If adverse effects occur, intake can be reduced to once every other day, or alternative oral or parenteral sources of iron can be used. Parenteral sources should be used if oral sources are contraindicated or ineffective. Treatment should be monitored and continued after hemoglobin levels have normalized (110193,115890). Iron supplementation may also be beneficial in patients with iron deficiency without anemia, which can cause fatigue and reduced well-being, although guidelines are lacking. A meta-analysis of randomized controlled trials in adults with iron deficiency but not anemia shows that supplemental iron improves iron stores and hemoglobin levels. In addition, iron moderately reduces self-reported fatigue, but not physical capacity, when compared with placebo. Oral ferrous sulfate was used in most studies included in the analysis; however, IV or intramuscular iron were also used (104684). Intravenous iron has also been evaluated for the prevention of postoperative anemia. A meta-analysis of several, moderate-quality clinical studies in adults undergoing cardiac surgery, including patients with or without anemia, shows that various types of IV iron (e.g. ferric carboxymaltose, iron sucrose) reduce the risk of red blood cell transfusions by approximately 23%, and improve hemoglobin and iron levels by postoperative day 4, when compared with placebo and oral iron therapy (115898). The validity of these results is limited by heterogeneous methods across clinical studies including patient population, iron formulation, and use of erythropoietin.
• Pregnancy-related iron deficiency. Oral and intravenous (IV) iron are effective for managing pregnancy-related iron deficiency. Details: Clinical research shows that taking iron orally at an average daily dose of 15-225 mg of elemental iron increases maternal hemoglobin levels by up to 1 gram/dL when compared with placebo and reduces the risk of maternal anemia by 50% to 100% (20122,20123,20124,110180,110188,115895). Some clinicians may recommend alternating days of iron administration to reduce gastrointestinal adverse effects. A pooled analysis shows that taking iron supplements, with or without folic acid, on alternating days during pregnancy maintains adequate iron intake and reduces gastrointestinal adverse effects when compared with taking iron daily (96625). Another meta-analysis shows that daily supplementation of iron with folic acid increases hemoglobin levels by 0.24 g/dL when compared with intermittent supplementation, given as 1, 2, or 3 doses weekly. However, clinical significance of this slight increase is unlikely, and no difference in rates of anemia are noted between dosing strategies (115896). Various forms of oral iron seem to be equally effective for raising hemoglobin levels (110185,110188,115895). However, in patients with anemia during pregnancy, meta-analyses of several, moderate-quality clinical studies show that IV iron (e.g. iron sucrose) is more effective than oral iron (e.g. ferrous sulfate) for improving hemoglobin levels and reducing the risk for anemia (110185,115897).

POSSIBLY EFFECTIVE

• Breath-holding attacks. Oral iron seems to be effective for reducing the frequency of breath-holding attacks in children with iron deficiency. Details: The incidence of breath-holding attacks is increased in children with iron deficiency or iron deficiency anemia. Most research shows that oral supplementation with ferrous sulfate 3-6 mg/kg daily for 4-16 weeks reduces the frequency of breath-holding attacks in children aged 1-72 months (20128,104682,104683). The best evidence comes from a meta-analysis of one randomized controlled trial and 11 observational single arm studies (104682). In this analysis, approximately 84% of children experienced at least a 50% decreased frequency of breath-holding attacks (104682). Some preliminary clinical research also shows that administering intramuscular iron reduces the frequency of breath-holding attacks and increases remission in children with iron deficiency anemia (20128).
• Cognitive function. Oral iron seems to be effective for improving cognitive function in children and adolescents with iron deficiency. Details: Taking iron orally seems to improve cognitive function in iron-deficient children and adolescents (20121,112600). For example, ferrous sulfate 650 mg twice daily for 8 weeks improved verbal learning and memory in non-anemic iron-deficient adolescent females (1095). Ferrous sulfate 50 mg twice weekly for 16 weeks appeared to improve attention measures in adolescent females with possible anemia (91186). Iron also appears to reverse developmental and learning deficits caused by iron-deficiency in anemic infants (1104). Some clinical research is focused on children and adolescents from low- and middle-income countries. In children aged 5-19 years with or without iron-deficiency anemia, a meta-analysis of clinical research shows that iron supplementation for 3-8 months dose-dependently improves measured intelligence by a modest amount. However, there was no effect on other measures of cognition, including attention or memory (110181). Another meta-analysis of clinical research in school age children shows that taking iron for 2-12 months modestly improves intelligence, attention, and memory, but not educational achievement, when compared with placebo or no intervention. However, sub-analyses show that any benefits are limited to children with anemia (112600). Most studies included in the analyses evaluated daily iron supplementation, with a few studies assessing iron taken 4-6 times weekly (110181,112600). In contrast, a large clinical trial in schoolchildren in Ethiopia shows that taking iron supplements, providing 42 mg of elemental iron, once weekly for 11 months does not improve working memory, nonverbal intelligence, planning, or problem-solving, and may even worsen one measure of attention and concentration when compared with placebo (113904). These discrepant findings may be related to differences in frequency of dosing (daily vs. weekly) and baseline demographics; only 20% and 4% of children in this study had iron deficiency and iron deficiency anemia, respectively.
• Heart failure. Intravenous (IV) iron seems to be effective for improving certain outcomes in patients with heart failure and iron deficiency. It is unclear if oral iron is effective. Details: Iron deficiency is common in patients with heart failure (17499,112597,112598,112599). A number of large clinical trials and meta-analyses of clinical research in patients with heart failure show that administering IV iron, as ferric carboxymaltose, iron dextran, iron isomaltoside, or iron sucrose, for at least 12 weeks modestly improves quality of life, increases exercise capacity, and reduces hospitalizations when compared with placebo or standard care. However, there was no effect on all-cause mortality or cardiovascular mortality (17498,91179,110176,110187,112597,112598,112599,113900,113901). Based on these results, guidelines from the American Heart Association and European Society of Cardiology support the use of IV iron in patients with heart failure with reduced ejection fraction and iron deficiency to improve symptoms and quality of life. Additionally, IV iron supplementation in these patients is associated with a reduced risk of heart failure hospitalization (115935,115936). Limited research has investigated the effect of oral iron in this population. A small meta-analysis of clinical research shows with low certainty that taking iron orally has beneficial effects on serum ferritin and left ventricular ejection fraction (110178). Most research shows that taking oral iron does not improve hemoglobin levels, quality of life, or exercise capacity when compared with placebo (100970,110178). However, one small clinical trial shows that taking oral iron modestly improves iron status and overall symptoms and increases the 6-minute walking distance by about 46 meters, compared with a reduction of only 14 meters in those taking placebo (110183). Some doses used in individual clinical studies have included iron polysaccharide 150 mg twice daily for 16 weeks and ferrous sulfate 200 mg three times daily for 12 weeks (100970,110183).
• Restless legs syndrome (RLS). Oral and intravenous (IV) iron seem to be beneficial for RLS. The American Academy of Neurology recommends a combination of oral ferrous sulfate and vitamin C or IV ferric carboxymaltose for patients with RLS. Details: RLS is commonly associated with iron deficiency anemia. Some clinical research shows that taking iron in the form of ferrous sulfate 325 mg twice daily for 12 weeks reduces RLS symptoms comparably to pramipexole. Symptoms such as leg discomfort, need to move, and sleep disturbances improved considerably in about half of the patients taking either treatment (91181). Additional clinical research shows that taking ferrous sulfate 325 mg twice daily along with vitamin C 100 mg twice daily for 12 weeks reduces symptoms of RLS when compared with vitamin C alone in patients with RLS and low-normal serum ferritin levels (94189). Based on these results, clinical practice guidelines by the American Academy of Neurology report that taking this combination of oral ferrous sulfate and vitamin C is likely to improve symptoms in patients with RLS and low-normal serum ferritin (93587). Intravenous iron may also reduce symptoms of RLS. Clinical practice guidelines by the American Academy of Neurology report that two doses of IV ferric carboxymaltose 500 mg given 5 days apart are likely to improve symptoms and quality of life within 28 days in patients with moderate to severe RLS, regardless of serum ferritin levels. Iron sucrose, given IV, has also been evaluated in patients with RLS, but there is currently insufficient available evidence to support or refute the use of this form of iron for treating RLS (93587). Additionally, IV and oral iron have been compared in the management of RLS. A clinical study in adults with RLS and iron deficiency anemia shows that administering IV ferumoxytol 1020 mg for 2 doses, 2-7 days apart, reduces self-reported symptom severity and frequency comparably to taking oral ferrous sulfate 650 mg daily for 6 weeks (115894). The validity of these results is limited by methodological concerns, including lack of a placebo control group and failure to obtain all follow-up data.

POSSIBLY INEFFECTIVE

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

INSUFFICIENT RELIABLE EVIDENCE to RATE

• ACE inhibitor-induced cough. It is unclear if oral iron is beneficial in patients with this condition. Details: A small clinical trial shows that taking ferrous sulfate 256 mg daily reduces or eliminates cough induced by ACE inhibitors such as captopril (Capoten), enalapril (Vasotec), lisinopril (Prinivil, Zestril), and others, when compared with placebo (7307).
• Androgenic alopecia. Oral iron has only been evaluated in combination with other ingredients, its effect when used alone is unclear. Details: A moderate-sized clinical study in adults with androgenic alopecia or telogen effluvium shows that taking one tablet daily of a specific product (GFM Oral, Cantabria Labs), providing an unknown dose of iron in combination with selenium, taurine, cysteine, methionine, and hydrolyzed collagen, along with conventional therapy, consisting primarily of finasteride or minoxidil, for 12 weeks improves hair loss when compared with conventional therapy alone (111636). It is unclear if this effect is due to iron, other ingredients, or the combination.
• Attention deficit-hyperactivity disorder (ADHD). It is unclear if oral iron is beneficial in children with ADHD. Details: A meta-analysis of three small, lower quality clinical studies in children and adolescents with ADHD and iron deficiency shows that taking ferrous fumarate 200-400 mg, dependent upon body weight, or ferrous sulfate 80 mg daily for 3 months does not improve hyperactivity and inattention when compared with placebo. However, the results of individual clinical studies are inconsistent (115893). The validity of these results is limited by high heterogeneity across clinical studies, including patient baseline characteristics, use of investigator-, parent-, and teacher-rated ADHD scales, and concomitant use of ADHD medication therapy (e.g. stimulants).
• Child development. It is unclear if oral iron is beneficial for improving development in non-anemic children. Details: Some observational research has found that iron deficiency in infancy is associated with poor verbal performance and social skills in childhood (102862). It is unknown whether iron supplementation can ameliorate these developmental issues. In non-anemic infants and children, clinical research shows that iron does not improve cognitive performance; the evidence for the benefits of iron on psychomotor development is conflicting (20129,20130,91315,96616,96626,115891).
• Esophageal cancer. It is unclear if oral iron is beneficial for esophageal cancer prevention. Details: Population research has found that taking iron supplements is associated with a 32% lower risk of esophageal adenocarcinoma when compared to never taking iron supplements. However, use of iron supplements is not associated with a lower risk of esophageal squamous cell carcinoma (95435).
• Fatigue. It is unclear if oral iron is beneficial in patients with fatigue due to iron deficiency without anemia. Details: A meta-analysis of mainly preliminary clinical research in adults with iron deficiency without anemia shows that iron reduces self-reported fatigue moderately more than placebo (104684). A specific ferrous sulfate supplement (Tardyferon; Pierre Fabre Médicament) providing 80 mg of elemental iron daily for 4-12 weeks was used in two studies included in this analysis (11406,91188).
• Inflammatory bowel disease (IBD). In patients with active IBD, intravenous iron may be more beneficial than oral iron due to impaired absorption. However, it may also increase the risk of infection in these patients. Details: Since the absorption of oral iron may be impaired in patients with active symptoms of IBD, guidelines from the British Society of Gastroenterology suggest that treatment with parenteral iron may be needed in patients with IBD who have moderate to severe iron-deficiency anemia (110193). However, a meta-analysis of clinical research in this population shows that administering IV iron, usually as iron sucrose or ferric carboxymaltose, increases the risk of infection by 73% when compared with oral iron or no iron (110186).
• Postoperative recovery. It is unclear if intravenous (IV) iron is beneficial for recovery following cardiac surgery. Details: A meta-analysis of low- to moderate-quality clinical research in patients with preoperative iron-deficiency anemia shows that treatment with IV iron before cardiac surgery does not improve the rate of transfusions or the length of stay in the intensive care unit or hospital when compared with control groups, including placebo, oral iron, or no treatment. Also, a meta-analysis of clinical research shows that IV iron does not reduce postoperative mortality rates (110182).
• Postpartum depression. Although there has been interest in using iron for postpartum depression, there is insufficient reliable information about the clinical effects of iron for this condition.
• Prematurity. Enteral iron seems to be beneficial for some measures of development in preterm infants. Details: A meta-analysis of clinical research in preterm or low birthweight infants fed human milk shows that enteral iron supplementation increases linear growth and reduces the risk of anemia when compared with control groups receiving no iron supplementation. However, there was no effect on serum ferritin, weight, head circumference, cognitive development, risk of infection, or risk of necrotising enterocolitis (110177). Additional clinical research in infants born at 24-28 weeks' gestation shows that a higher average enteral iron dose by 60 days of age is positively associated with cognitive performance at 2 years of corrected age. However, this association was not present for iron doses received at 90 days of age (110190). More evidence is needed to rate iron for these uses.

(Read more about IRON)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Bladder cancer. It is unclear if consuming kale in the diet can reduce the risk of bladder cancer. Details: Population research suggests that patients with bladder cancer consumed approximately 0.18 fewer cups of cruciferous vegetables, such as cabbage, Brussels sprout, cauliflower, broccoli, kale, or collards, on a weekly basis in the year prior to diagnosis when compared with people without bladder cancer. The effects of kale, specifically, are unclear (14864). Other population research suggests that eating at least five servings per week of cruciferous vegetables, such as cauliflower, Brussels sprout, cabbage, broccoli, and kale, is associated with a 51% reduction in the risk of developing bladder cancer in males when compared with eating up to one serving per week. However, higher intake of kale alone does not seem to be associated with a reduced risk of bladder cancer (26184).
• Breast cancer. It is unclear if consuming kale in the diet can reduce the risk of breast cancer. Details: Population research suggests that the highest dietary intake of cruciferous vegetables, including broccoli, Brussels sprout, cabbage, cauliflower, collards, and kale, is associated with a slight increase in the risk of breast cancer in premenopausal adults when compared with the lowest intake (26188). Cruciferous vegetables might increase urinary levels of 2-hydroxyestrone, and its ratio to 16-alpha-hydroxyestrone, which could reduce the risk of breast cancer. However, research in pre-menopausal adults shows that taking a dried kale and Brussels sprout supplement, 3.3 grams daily for 8 weeks, or increasing dietary intake of Brussels sprout or broccoli by one 40-gram serving daily, does not increase urinary levels of 2-hydroxyestrone, or its ratio to 16-alpha-hydroxyestrone, when compared with placebo (112086). In postmenopausal adults, the highest intake of cruciferous vegetables appears to be associated with a statistically insignificant reduced risk of breast cancer (26188).
• Inflammatory bowel disease (IBD). Although there is interest in oral kale for IBD, there is insufficient reliable information available about the use of kale for this purpose.
• Menopausal symptoms. Although there is interest in oral kale for reducing menopausal symptoms, there is insufficient reliable information available about the use of kale for this purpose. More evidence is needed to rate kale for these uses.

(Read more about KALE)

EFFECTIVE

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

INSUFFICIENT RELIABLE EVIDENCE to RATE

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

(Read more about LACTASE)

INSUFFICIENT RELIABLE EVIDENCE to RATE

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

(Read more about LIPASE)

EFFECTIVE

• Bowel preparation. Various magnesium salts are used for cleansing the bowel prior to procedures such as colonoscopy. Details: Various magnesium salts, including citrate, hydroxide, oxide, and sulfate, are ingredients in bowel preparation products available over-the-counter or by prescription only.
• Constipation. Magnesium salts are effective when used short-term orally to treat constipation and chronic idiopathic constipation (CIC). Details: Magnesium citrate, hydroxide, oxide, and sulfate salts are commonly used as laxatives. Magnesium citrate 11.3-17.45 grams has been used; magnesium hydroxide 2.4-4.8 grams, as 30-60 mL of milk of magnesia, has also been used (113483,113484). Magnesium sulfate, also known as Epsom salt, which seems to have the most potent effect, has been used as 10-30 grams (6430,113485). Magnesium salts should only be used for occasional treatment of constipation, and doses should be taken with a full 8-ounce glass of water. Magnesium oxide seems to be beneficial in adults with CIC when taken short-term. Clinical guidelines published by the American Gastroenterology Association and American College of Gastroenterology in 2023 give a conditional recommendation suggesting the use of magnesium oxide over managing CIC without magnesium oxide based on low-quality studies conducted over 4 weeks. The recommended starting dose is 400-500 mg daily with dose titration per symptom response and side effects (112859). A small clinical study in patients with CIC who are not taking chronic medications shows that taking magnesium oxide 1.5 grams in three divided doses daily for 28 days increases spontaneous bowel movements when compared with placebo (104397). It is unknown if magnesium is beneficial for CIC when used long-term.
• Dyspepsia. Magnesium salts are effective when used orally as antacids. Details: Magnesium carbonate, hydroxide, oxide, or trisilicate salts are used orally as antacids to reduce symptoms of gastric hyperacidity or gastroesophageal reflux. Magnesium hydroxide has the fastest onset of action. The onset for magnesium carbonate is slower due to its crystal structure. Magnesium trisilicate has the slowest onset and longest duration of action due to poor solubility (6844). Doses used include magnesium hydroxide 400-1200 mg (5-15 mL of milk of magnesia) up to four times daily, or magnesium oxide 800 mg daily (15).
• Eclampsia. Magnesium sulfate is considered the drug of choice for control of seizures. Details: Intravenous (IV) and/or intramuscular (IM) magnesium sulfate is considered the agent of choice for seizure prophylaxis during eclampsia by the American College of Obstetricians and Gynecologists (ACOG) (15,12591,12592,61012,61184). Typical doses include 4-6 grams of magnesium sulfate by IV infusion in 250 mL of dextrose 5% or normal saline solution, followed by 4-5 grams of magnesium sulfate IM every 4 hours, or 1-3 grams per hour by continuous IV infusion. Doses should be adjusted according to serum levels and urinary excretion, and should not exceed 30-40 grams of magnesium sulfate daily (15,12591). Meta-analyses of clinical research show that treatment with IV or IM magnesium reduces the risk of seizure recurrence by 33% to 69% when compared with phenytoin, and by 47% to 60% when compared with diazepam (19960,60818,60954,60964,61105). One preliminary clinical study shows that lower doses of IV magnesium sulfate (9 grams loading dose and maintenance of 2.5 grams every 4 hours for 24 hours) are as effective as higher doses (14 grams loading dose and maintenance of 5 grams every 4 hours for 24 hours) for reducing the recurrence of eclamptic seizures (89383). It is generally recommended that treatment be continued for at least 24 hours after the last seizure (15). Oral magnesium has not been evaluated for eclampsia.
• Hypomagnesemia. Hypomagnesemia can be effectively treated with oral or parenteral magnesium. Details: Taking magnesium orally or parenterally is helpful for treating and preventing hypomagnesemia associated with alcoholism, cirrhosis of the liver, congestive heart failure (CHF), severe or prolonged diarrhea or vomiting, kidney dysfunction, inflammatory bowel disease (IBD), pancreatitis, malabsorption syndromes, and other conditions (6280,6281,8088,8089). The dose and salt of magnesium for oral replacement therapy should be chosen carefully to avoid causing diarrhea. The gluconate and chloride salts cause less diarrhea, while the oxide salt is more likely to cause diarrhea and should be avoided. Magnesium chloride should also be avoided due to poor solubility which decreases absorption (6430,8099,10664). Orally, magnesium sulfate 3 grams every 6 hours for four doses has been used for hypomagnesemia (15). Parenteral magnesium doses must be individualized according to serum magnesium levels, but a typical starting dose for mild deficiency is 1 gram of magnesium sulfate intramuscularly (IM) every 6 hours for 4 doses (15). For more severe deficiency, 5 grams of magnesium sulfate may be given as an intravenous (IV) infusion in 1 liter of dextrose 5% or normal saline solution over 3 hours (15).
• Pre-eclampsia. Magnesium sulfate is considered the drug of choice for seizure prophylaxis in patients with pre-eclampsia. Details: Intravenous (IV) and/or intramuscular (IM) magnesium sulfate is considered the agent of choice for seizure prophylaxis during pre-eclampsia by the American College of Obstetricians and Gynecologists (ACOG) (12591,12592,61012,61184). Some meta-analyses show that IV administration of magnesium sulfate reduces the risk of eclampsia when compared with placebo, phenytoin, or diazepam in patients with pre-eclampsia (19960,60818,60960,60979). A typical initial dose is 4-5 grams of magnesium sulfate by IV infusion in 250 mL of dextrose 5% or normal saline solution, followed by 4-5 grams of magnesium sulfate IM every 4 hours, or 1-3 grams of magnesium sulfate per hour by continuous IV infusion. Doses should be adjusted according to serum levels and urinary excretion, and should not exceed 30-40 grams of magnesium sulfate daily (15,12591). The optimal duration of prophylaxis has not been determined. A meta-analysis suggests that using a shorter duration of 12 hours or less is not associated with an increase in risk of eclamptic seizures when compared with regimens of 24 hours or longer (108732). However, studies are likely underpowered due to the low incidence of eclampsia. Oral magnesium has been evaluated for the prevention of pre-eclampsia in healthy adults, but taking magnesium citrate 300 mg daily, starting at 12-20 weeks' gestation and continuing until delivery, does not reduce the incidence of pre-eclampsia when compared with placebo (103724).

LIKELY EFFECTIVE

• Cerebral palsy. Most evidence shows that antenatal magnesium reduces the risk of cerebral palsy in preterm infants, although there are some inconsistent results. Details: Most clinical studies and meta-analyses show that antenatal magnesium sulfate reduces the risk of cerebral palsy by about 32% and the risk of motor dysfunction by about 45% in preterm infants (60915,60927,60931,61001,97485,103734,103754,114675,114681). The lowest effective dose of magnesium sulfate seems to be 4 grams intravenously, with or without a maintenance dose of 1 gram/hour until birth or for 24 hours. In obese females, a higher dose, based on body weight, may be needed (97485,97495,103734,103754). However, some studies have inconsistent results (8093,19998,98293,98295,112784). Giving females at risk of imminent preterm birth (prior to 32 weeks), intravenous magnesium sulfate 4.5 grams over 20 minutes followed by 1 gram per hour until birth or for 24 hours, in addition to a standard treatment protocol, does not reduce the incidence of cerebral palsy (112784). Oral magnesium has not been evaluated for this purpose.
• Seizures. Intravenous magnesium sulfate is used for treating seizures of various etiologies. Details: Intravenous magnesium sulfate may be useful for controlling seizures associated with epilepsy, glomerulonephritis, hypothyroidism, and acute nephritis in children (15). Oral magnesium has not been evaluated for this purpose.
• Torsades de pointes. Intravenous magnesium sulfate is the first-line treatment for torsades de pointes after measures to correct precipitating factors have been unsuccessful. Details: Intravenous magnesium sulfate has been used successfully to treat the life-threatening ventricular tachycardia, torsades de pointes (15,6844). The Advanced Cardiac Life Support (ACLS) guidelines of the American Heart Association recommend a dose of 1 to 2 grams diluted in 50-100 mL Dextrose 5% solution given IV over 5-60 minutes, followed by a continuous IV infusion of 0.5-1 gram/hour.

POSSIBLY EFFECTIVE

• Arrhythmia. Magnesium sulfate is effective for the specific type of ventricular tachycardia known as torsades de pointes, and seems to be helpful for treating other types of arrhythmias. Evidence for the role of oral or intravenous magnesium in preventing postoperative arrhythmias is conflicting. Details: Administering magnesium intravenously or orally may be helpful for treating atrial and ventricular tachycardia and fibrillation, and supraventricular tachycardia (9497,13352,13354,13355,13356,60804,60829,60877,61113,111696). Arrhythmias associated with congestive heart failure have been treated with magnesium sulfate 8 grams infused over 12 hours (9497). For rate control in atrial fibrillation, magnesium sulfate 2.5 grams IV over 20 minutes, followed by 2.5 grams IV over 2 hours has been used (13356). For paroxysmal supraventricular tachycardia, single doses of 1-4 grams of magnesium chloride have been used (13352). For atrial tachycardia, 2 grams of magnesium sulfate in 10 mL of dextrose 5% solution has been given IV over 1-10 minutes, followed by 5-10 grams of magnesium sulfate in 250-500 mL dextrose 5% solution as an IV infusion over 5 hours (13354,13355). Research on the effects of intravenous magnesium for preventing arrhythmias after cardiac surgery is conflicting. Some meta-analyses show that intravenous magnesium reduces the risk of atrial fibrillation, ventricular arrhythmias, or supraventricular arrhythmias following cardiac surgery by 23% to 48% when compared with placebo (60814,60826,60828,60838,61008,61033,61181,97487,97490). Doses of magnesium sulfate used include 30 mg/kg in 500 mL normal saline (97490), or 80-100 mg/kg added to the cardioplegia solution (97487). Also, one small study in adults after CABG surgery suggests that taking magnesium hydroxide 1600 mg orally reduces arrhythmia as effectively as receiving magnesium sulfate 2000 mg intravenously (99315). However, other meta-analyses that only include higher-quality trials show that magnesium supplementation does not reduce the risk of ventricular or supraventricular arrhythmias following cardiac surgery (61010,61024,61031,105081). A meta-analysis of clinical trials of intravenous magnesium for prevention of new-onset atrial fibrillation after non-cardiac surgeries shows that it does not reduce the incidence significantly when compared with placebo (112778). However, there was a high risk of bias in the analysis, and variability in types of surgery, and the salt and dose of magnesium used.
• Asthma. Parenteral magnesium sulfate can help to reverse severe acute asthma attacks and reduce the need for hospital admission. It is unclear if nebulized magnesium is beneficial for acute asthma attacks. However, oral magnesium does not seem to be beneficial. Details: Overall, a single dose of intravenous magnesium seems to improve pulmonary function in acute asthma exacerbation and reduce the risk of hospitalization, particularly in patients with severe asthma, and those who have failed initial treatment with nebulized albuterol and intravenous corticosteroids (60888,90023,96483,104398,107365). The typical dose used for adults is 2 grams of magnesium sulfate infused over 20 minutes (15). For children, 25-75 mg/kg, to a maximum of 2 grams, infused over 20-30 minutes has been used (15,96483,107365). However, a post-hoc analysis of one large clinical trial (104400) designed to assess nebulized magnesium in children with acute asthma has found that adding IV magnesium to nebulized magnesium is associated with greater odds of hospitalization when compared with no IV magnesium (105919). This post-hoc analysis did not differentiate between precautionary and necessary hospitalizations. Although some clinical research and a meta-analysis in patients with acute asthma exacerbation show that nebulized magnesium in combination with standard treatment improves airway function, respiratory rate, and clinical asthma severity when compared with standard treatment alone, it is unclear whether these findings are clinically relevant (90016,113466). Most evidence, including larger clinical trials and meta-analyses, has not shown benefit of adjunct nebulized magnesium for acute asthma in adults or children (60888,90002,96484,104400,105920,113466,114674). Oral magnesium also does not seem to be beneficial. A meta-analysis of small clinical trials in children and adults with asthma shows that taking magnesium supplements orally does not improve lung function or reduce bronchodilator use when compared with control (104404).
• Colorectal cancer. Increasing dietary magnesium intake seems to lower the risk of colon cancer but not rectal cancer. Details: Epidemiological research shows that increased dietary magnesium intake is associated with a reduced risk of colon cancer, but the risk of rectal cancer is not affected (89387,90017,90027,101355).
• Diabetes. Low dietary magnesium may increase the risk of developing type 2 diabetes, but evidence on the use of supplements for treating type 2 diabetes is conflicting. Details: Higher dietary magnesium intake is associated with lower fasting insulin concentrations and a reduced risk of developing type 2 diabetes in adults and obese children (13369,15548,96473,97486,98294,103736,105918,106920). In people with existing type 2 diabetes, hypomagnesemia is found in 25% to 38% of patients, especially in those with poorly controlled diabetes (1172). Population research in adults with type 2 diabetes also shows that a dietary magnesium intake of less than 250 mg daily is associated with a 56% higher risk of mortality. Preliminary subgroup analyses suggest that the risk of mortality is higher in those with glycated hemoglobin (HbA1C) levels above 7% (110051). A meta-analysis of small, heterogeneous clinical studies in adults with type 2 diabetes suggests that magnesium may modestly reduce HbA1C in patients with hypomagnesemia, but not in patients with normal magnesium levels, when compared with control (105075). Individual clinical studies using magnesium supplements in patients with type 2 diabetes or insulin resistance have shown mixed results. Some research suggests magnesium supplements can decrease fasting blood glucose and improve insulin sensitivity, as well as reduce the risk of developing diabetes in high-risk patients (10664,12582,13376,60854,99313,106920), but other research shows no effect (1171,1172,13379,13380,112780). Discrepancies in these findings might reflect differences in magnesium salts and doses used, or differences in baseline magnesium status in study subjects.
• Hypercholesterolemia. Magnesium may help improve lipid levels by a small amount in people with this condition. Details: There is some evidence that taking magnesium oxide 1 gram orally daily for 6 weeks can produce small decreases in low-density lipoprotein (LDL) and total cholesterol levels, and small increases in high-density lipoprotein (HDL) levels in patients with hypercholesterolemia. However, magnesium does not seem to improve lipoprotein (a) levels (1193). Magnesium may also lower triglycerides in people with hypertriglyceridemia (97494).
• Metabolic syndrome. Low dietary and serum levels of magnesium seem to be associated with the development of metabolic syndrome. Details: Higher magnesium intake from diet and supplements is associated with a 27% lower risk of developing metabolic syndrome in healthy females (13371) and a 31% lower risk in healthy young adults (14304). Additional epidemiological research suggests that people with low serum magnesium levels are 6-7 times more likely to have metabolic syndrome than people with normal magnesium levels (13372). In a population analysis of over 6000 individuals without metabolic syndrome at baseline, the risk of developing this condition over a 6-year follow-up period was reduced by 16% in the highest quintile of dietary magnesium intake (median intake 371 mg daily) when compared with the lowest quintile (median intake 203 mg daily). Some, but not all, research suggests that the hazard ratio for metabolic syndrome in relation to magnesium intake may be U-shaped, with higher risk at intakes below about 150 mg daily and above 600 mg daily (108963). A combination of magnesium 20 mEq daily and potassium 40 mEq daily (magnesium potassium citrate) taken orally for 16 weeks reverses metabolic side effects of chlorthalidone, such as increased fasting plasma glucose and hypokalemia, more effectively than potassium chloride 40 mEq daily alone (112932).
• Osteoporosis. Increased dietary and supplemental magnesium intake seems to increase bone mineral density and decrease bone loss in postmenopausal patients. Details: Preliminary clinical research shows that taking magnesium hydroxide orally, 300-1800 mg daily for 6 months, then 600 mg daily for 18 months, or magnesium citrate orally 1830 mg daily for 30 days, might reduce bone loss and bone turnover in postmenopausal patients with osteoporosis (9104,60928). Some epidemiological research also suggests that magnesium intake is related to increased bone mineral density (12501,12502,12503,12504,90014), although not all studies have found an association (12505,98286).
• Postoperative pain. Injectable magnesium has been used with promising results for reducing pain and the need for other analgesics postoperatively. Details: A meta-analysis of 25 clinical trials shows that intravenous (IV) magnesium sulfate, 5-50 mg/kg bolus followed by a continuous infusion of 6 mg/kg or 500 mg hourly during surgery, seems to reduce the 24-hour postoperative use of IV morphine by 24% when compared with placebo (19968). Adding IV magnesium sulfate 3.7-5.5 grams to patient-controlled analgesia for 24 hours after surgery has also been used (19968). Additionally, meta-analyses support that adjunctive IV or intrathecal administration of magnesium reduces post-operative pain scores, improves pain relief and sensory nerve block, and decreases the need for other analgesics, when compared with control (89390,90012,90015,98287,103728,114676,114677,114678). However, some data are conflicting. In a meta-analysis of 7 trials, IV magnesium was not associated with lower pain scores over the first 48 hours postoperatively. The reasons for these discrepant findings are unclear but may be explained by differences in magnesium regimens, anesthesia protocols, and surgical populations studied. Additionally, IV magnesium appears to be less effective than dexmedetomidine (105082). Two moderate-sized clinical studies in patients undergoing total knee arthroplasty in China show that adding magnesium sulfate 2.5 mg/mL to the periarticular infiltration analgesia (PIA) cocktail or administering IV magnesium sulfate 40 mg/kg before anesthesia induction then as a 15 mg/kg infusion during surgery reduces pain scores, increases comfort levels, limits and delays the use of postoperative opioids, prolongs analgesia, and reduces markers of inflammation when compared with the usual PIA cocktail or control (111181,113677). Administering magnesium intravenously also seems to be helpful for pain control after hysterectomy. A 3-gram IV bolus of magnesium sulfate followed by an infusion of 0.5 grams per hour for 20 hours has been used. Lower doses were not effective (6848). In males undergoing laparoscopic radical resection for gastrointestinal cancer, administering IV magnesium intraoperatively, as a loading dose of 40 mg/kg followed by 15 mg/kg/hour through the end of surgery, reduces postoperative catheter-related bladder discomfort and analgesic requirements, when compared with placebo (112783). However, IV magnesium might not alleviate postoperative pain in children. Two small clinical studies show that administering a magnesium IV infusion does not reduce pain when compared with saline in children after tonsillectomy or after elective strabismus surgery (98282,105077).
• Premenstrual syndrome (PMS). Taking magnesium orally seems to relieve symptoms of PMS. Details: There is some evidence that magnesium supplementation can improve symptoms, including mood changes and fluid retention, in some patients with PMS (1187,1188,6847). Doses used include magnesium oxide 333 mg daily for 2 menstrual cycles, or magnesium pyrrolidone carboxylic acid equivalent to 360 mg elemental magnesium three times daily, from the 15th day of the menstrual cycle until onset of menstrual flow (1187,1188). Taking magnesium orally in a dose of 360 mg (elemental magnesium) three times daily for 2 months seems to prevent premenstrual migraine (1186,6847). A combination of magnesium 200 mg daily plus vitamin B6 50 mg daily seems to reduce anxiety-related premenstrual symptoms, including nervous tension, mood swings, irritability, and anxiety, when compared with placebo (8555).
• Vasospastic angina. Intravenous magnesium seems to prevent coronary spasm in patients with this condition. Details: Clinical research shows that administration of intravenous magnesium sulfate 65 mg/kg infused over 20 minutes dilates coronary arteries and suppresses acetylcholine-induced coronary spasms when compared with infusion of a dextrose solution in patients with vasospastic angina (8091).

POSSIBLY INEFFECTIVE

• Altitude sickness. Taking magnesium citrate orally does not seem to reduce acute altitude sickness risk. Details: Clinical research shows that taking magnesium citrate 1200 mg daily orally in three divided doses, beginning 3 days prior to mountain ascent and continuing until mountain descent, does not reduce the risk of acute altitude sickness when compared with placebo (60801).
• Athletic performance. Taking magnesium orally does not seem to improve energy or endurance during athletic activity. Details: Most evidence suggests that taking magnesium orally doesn't increase energy and endurance during athletic activity. Magnesium oxide, aspartate, and orotate salts do not seem to improve exercise performance when used alone or in combination with potassium, vitamin B6, or zinc (2825,2826,2828,2829,2830,60751,113655).
• Bronchiolitis. Intravenous or nebulized magnesium is not beneficial in infants with this condition. Details: Clinical research shows that administering a single IV dose of magnesium sulfate 100 mg/kg to infants with acute bronchiolitis does not improve, and may actually worsen, symptoms when compared with placebo (97482). A clinical study in infants with moderate to severe bronchiolitis shows that adding nebulized magnesium sulfate 40 mg/kg to nebulized epinephrine does not reduce hospital stay or the need for ventilator or oxygen support when compared with epinephrine alone (99317). Oral magnesium has not been evaluated for this use.
• Chemotherapy-induced peripheral neuropathy. Research on the effects of intravenous infusions of magnesium and calcium for preventing oxaliplatin neurotoxicity are inconsistent, but higher quality studies seem to show no benefit. Details: Pooled analyses of cohort studies and clinical trials show that calcium and magnesium infusions can decrease the incidence of severe oxaliplatin-induced neurotoxicity (90028,90029,90031). However, when only clinical trials are considered, the infusions do not appear to be helpful (90005,90029,90031,96474,96479).
• Complex regional pain syndrome. Intravenous magnesium is not beneficial in complex regional pain syndrome type 1. Details: Clinical research shows that receiving magnesium sulfate 70 mg/kg intravenously at the rate of 25 mL/hour for 4 hours each day for 5 days does not improve pain or level of impairment when compared with placebo in patients with chronic complex regional pain syndrome type 1 (89395).
• Emergence delirium. The majority of small clinical studies in adults and children undergoing various surgeries suggest that intravenous (IV) magnesium doesn't reduce the risk of emergence delirium. However, most clinical studies in adults suggest that IV magnesium reduces emergence agitation. Details: A small clinical study in adults undergoing surgery for endovascular aortic aneurysm repair shows that administering IV magnesium 30 mg/kg as a loading dose, followed by a 10 mg/kg/hour infusion for the duration of surgery, does not improve agitation or delirium scores when compared with administering saline (111182). Similarly, a small clinical study in children ages 2-5 years undergoing elective strabismus surgery shows that administering IV magnesium during anesthesia does not seem to prevent the occurrence of emergence delirium when compared with administering saline (105077). In a meta-analysis of 8 clinical trials in children aged 2-16 years undergoing general anesthesia for oral or ophthalmic surgery, giving IV magnesium as a 30 mg/kg loading dose followed by a 10 mg/kg/hour infusion, or as a single dose of 15-30 mg/kg, does not reduce emergence delirium scores, and may actually prolong emergence times (108729). However, there is some conflicting evidence. In patients undergoing radical mastectomy, giving intraoperative magnesium sulfate 30mg/kg over 1 hour, followed by 10 mg/kg/hour until the end of surgery, reduces emergence agitation (odds ratio 0.26) when compared with placebo (112781).
• Menopausal symptoms. Oral magnesium oxide does not seem to be beneficial for menopausal hot flashes. Details: A small, low quality study in postmenopausal patients with a history of breast cancer shows that taking magnesium oxide 400-800 mg orally daily reduces hot flashes when compared with baseline (102454). However, a larger, higher quality clinical study using magnesium oxide 800-1200 mg daily did not show any benefit when compared with placebo (98290).
• Muscle cramps. Oral magnesium does not seem to improve muscle cramp frequency or intensity. Details: Meta-analyses of small clinical trials show that magnesium supplementation for 3-6 weeks does not decrease the frequency or intensity of skeletal muscle cramps, whether the cramps are idiopathic or due to liver cirrhosis or pregnancy, when compared with placebo (90022,104395).
• Sickle cell disease. Intravenous magnesium does not add any benefit to standard therapy for sickle cell disease in children. Details: Clinical research shows that giving magnesium sulfate 40-100 mg/kg (maximum of 2 grams per dose) intravenously every hour for 6-8 doses as an adjunct to standard therapy does not decrease hospital stay, pain, or opioid use, or improve quality of life, when compared with standard therapy and placebo in children with sickle cell disease (89399,98283,101356). Oral magnesium has not been evaluated for this purpose.
• Stillbirth. Magnesium administered during pregnancy does not reduce stillbirth risk. Details: A meta-analysis of clinical research shows that magnesium supplementation does not significantly decrease the risk of stillbirths when administered during pregnancy (60925,60978).
• Tetanus. Intravenous magnesium sulfate does not seem to improve outcomes in patients with this condition. Details: A meta-analysis of clinical research shows that intravenous magnesium sulfate does not reduce mortality when compared with placebo or diazepam in patients with tetanus (61020). While some research shows that magnesium reduces the duration of hospitalization and the need for ventilation when compared with diazepam (61170), magnesium does not seem to improve these outcomes when compared with placebo (60860).
• Traumatic brain injury (TBI). Magnesium does not improve clinical outcomes in patients with moderate to severe TBI. Its effect in patients with concussions is unclear. Details: A meta-analysis of four clinical trials shows that treatment with magnesium does not significantly improve neurological outcomes or reduce the risk of mortality when compared with placebo in patients with moderate to severe TBI (60905). A small observational cohort study in adolescents with concussions has found that adding oral magnesium 400 mg twice daily for 5 days to standard treatment with acetaminophen and ondansetron is associated with a trend toward reduced symptom severity when compared with standard treatment alone (104401). The validity of this study is limited by its observational nature and small cohort size.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alcohol use disorder. Intravenous magnesium does not seem to help reduce symptoms of alcohol withdrawal but may reduce the duration of alcoholic delirium. Details: Preliminary clinical research shows that administration of four intramuscular injections of magnesium sulfate 2 grams at 6-hour intervals does not reduce symptoms of alcohol withdrawal when compared with saline (61063). A small observational study in patients with alcoholic delirium has found that administering magnesium sulfate IV 50 mg/kg every 8 hours, in addition to usual sedation, is associated with a reduction of delirium by approximately 2 days, or 4 days when given every 12 hours in addition to dexmedetomidine, when compared with usual sedation alone (111180). However, half of patients had hypomagnesemia at baseline; it is unclear if effects would be similar for patients with normal magnesium levels. Oral magnesium has not been evaluated for this purpose.
• Allergic rhinitis (hay fever). Although there has been interest in using oral magnesium for allergic rhinitis, there is insufficient reliable information about the clinical effects of magnesium for this purpose.
• Attention deficit-hyperactivity disorder (ADHD). It is unclear if oral magnesium is beneficial in children with ADHD. Details: Children with ADHD seem to have lower magnesium levels in their blood and hair (9969,100262,100263). A small clinical study in children aged 7-12 years with ADHD and magnesium deficiency shows that taking magnesium aspartate and lactate 6 mg/kg daily for 6 months might improve hyperactivity and magnesium levels when compared with control (1189). Another small clinical study in children with ADHD but without magnesium deficiency shows that taking magnesium 6 mg/kg daily along with vitamin D 50,000 IU weekly for 8 weeks may modestly improve emotional problems, but not inattention or hyperactivity, as measured on the strength and difficulties questionnaire (SDQ), when compared with placebo (105914).
• Back pain. It is unclear if oral or intravenous magnesium is beneficial for acute or chronic back pain in adults. Details: One open-label clinical study in adults with acute low-back pain shows that taking magnesium 365 mg once daily in addition to taking etodolac 400 mg twice daily for 10 days does not further reduce pain when compared with taking etodolac alone (105913). Magnesium has also been tried for chronic back pain. A small clinical study in patients with chronic low-back pain shows that receiving magnesium sulfate 1 gram in 250 mL normal saline intravenously every 4 hours for 2 weeks, followed by magnesium gluconate 100 mg and magnesium oxide 400 mg by mouth daily for 4 weeks, reduces pain severity when compared with placebo (90035). It is unclear if oral magnesium used alone is beneficial.
• Bariatric surgery complications. It is unclear if oral magnesium supplementation improves metabolic parameters after bariatric surgery. Details: A retrospective study of over 3000 post-bariatric surgery patients suggests that those who take oral magnesium supplements providing 100-450 mg elemental magnesium daily may have improved metabolic parameters over 4 years of follow-up. When patients taking magnesium supplements were compared with those not taking supplements, 11% and 18% had type 2 diabetes, respectively, 30% and 42% had hypertension, respectively, and 16% and 23% had elevated low-density lipoprotein (LDL) cholesterol levels, respectively. For patients with hypomagnesemia at baseline, supplementation seemed to result in greater benefits (108968).
• Bipolar disorder. Taking magnesium orally might improve manic symptoms in some people with bipolar disorder; however, it is unclear how it compares to current standard of care. Details: One preliminary clinical study shows that magnesium 40 mEq daily (Magnesiocard) for 32 weeks has similar effects to lithium in up to 50% of patients treated for rapid cycling bipolar affective disorder (61022). Another preliminary clinical study shows that magnesium oxide 375 mg orally daily plus verapamil 80 mg taken four times daily reduces manic symptoms more effectively than verapamil alone in patients with mania (60742).
• Cancer-related neuropathic pain. It is unclear if intravenous magnesium is beneficial for this condition. Details: Single 500 mg to 1 gram doses of magnesium sulfate seem to relieve neuropathic pain for up to four hours when compared to baseline (6846). The validity of this finding is limited by the lack of a comparator group.
• Cardiac arrest. Intravenous magnesium does not seem to be helpful in cardiac arrest; however, the risk of sudden cardiac death seems to be inversely correlated to higher plasma magnesium levels or dietary intake. It is unclear if magnesium supplementation is associated with similar risk reduction. Details: Administering magnesium intravenously doesn't seem to improve successful resuscitation in people with cardiac arrest (1190). However, higher plasma magnesium levels and higher dietary magnesium intake might reduce the risk of sudden cardiac death, possibly by protecting against fatal ventricular arrhythmias. In the Nurses' Health Study, the risk of sudden cardiac death was 77% lower in females with the highest quartile of plasma magnesium levels when compared with the lowest quartile. Also, the risk was 37% lower in females with the highest quartile of dietary magnesium intake when compared with the lowest quartile (17132).
• Cardiovascular disease (CVD). Evidence regarding the effect of dietary magnesium on CVD risk is conflicting. Details: Epidemiological research in some populations shows that increased dietary magnesium intake is associated with decreased mortality due to strokes, coronary heart disease, ischemic heart disease, and heart failure, but other epidemiological research does not show any effect on these risks (89391,90003,90009,90030,90036,103735). Reasons for the discrepancies may be related to serum levels of magnesium at baseline, risk of cardiovascular disease at baseline, use of concomitant medications such as diuretics, or the presence of concomitant conditions such as kidney dysfunction. A population analysis conducted in Denmark has found that magnesium intake from drinking water may be associated with cardiovascular mortality. The overall risk of cardiovascular death and death due to stroke was reduced by 4% in the lowest 3 quintiles of intake when compared with the highest quintile. However, the risk of death due to acute myocardial infarction was increased by 22% in the lowest quintile when compared with the highest (108726). The relevance of these results is unclear, given that the main dietary source of magnesium is food rather than drinking water.
• Chronic fatigue syndrome (CFS). Limited evidence suggests that magnesium may help improve CFS symptoms, but this is controversial. Details: In people with low red blood cell magnesium, there is some evidence that intramuscular injections of 1 gram magnesium sulfate given once weekly for 6 weeks might improve CFS symptoms (7556). However, there is additional evidence that most patients with CFS have normal magnesium stores, and measurement of red cell magnesium is a poor indicator of total magnesium stores (7557,8084,8085,8086,8087).
• Chemotherapy-induced leukopenia. It is unclear if oral magnesium is beneficial in pediatric patients at risk for cisplatin-induced febrile neutropenia. Details: A small clinical study in children with solid tumors aged 9 years and older shows that taking magnesium 250 mg daily while receiving cisplatin-based chemotherapy reduces febrile neutropenia by 47% and septic shock by 57% when compared with not receiving magnesium. Results from this study suggest that four pediatric patients need to take oral magnesium to avoid one case of febrile neutropenia (104394).
• Chemotherapy-induced nephrotoxicity. It is unclear if intravenous magnesium is beneficial for chemotherapy-induced nephrotoxicity. Details: A meta-analysis of several lower quality clinical studies in adults in Japan with cancer receiving cisplatin shows that pretreatment with intravenous magnesium sulfate 5 to 20 mEq reduces the odds of chemotherapy-induced nephrotoxicity in a dose-dependent manner when compared to standard hydration therapy (115726). The validity of these findings is limited by heterogenous methods between clinical trials, including types of cancer, definitions of nephrotoxicity, and use of other nephroprotective therapies.
• Chronic obstructive pulmonary disease (COPD). Intravenous, but not nebulized, magnesium may be helpful in acute exacerbations of COPD. Details: Administering magnesium sulfate intravenously, 1.2-2.5 grams over 20 minutes, might be helpful for treating acute exacerbations of COPD (1208,6844,103733). Also, giving magnesium sulfate 2 grams intravenously seems to improve exercise capacity when compared with placebo (89384). A meta-analysis of studies using intravenous magnesium sulfate for COPD exacerbations shows that it reduces hospital admission and mean length of stay and improves dyspnea scores when compared with placebo. Based on the relative risk identified in the included studies, seven patients would need to receive intravenous magnesium to prevent one hospitalization. However, intravenous magnesium sulfate does not change the need for non-invasive ventilation and the available research did not evaluate intensive care unit (ICU) admission (108967). Nebulized magnesium has also been evaluated. In patients experiencing a COPD exacerbation, clinical research shows that administering nebulized magnesium sulfate with albuterol three times at 30-minute intervals does not improve pulmonary function as measured by the forced expiratory volume in 1 second (FEV1) when compared with placebo (89393). Also, a meta-analysis of a small number of low-quality studies shows that nebulized magnesium does not reduce hospital admission or the need for ventilatory support, although it might modestly improve dyspnea scores and reduce ICU admissions, when compared with placebo (108967).
• Cluster headache. It is unclear if a single intravenous dose of magnesium sulfate is beneficial for cluster headaches. Details: Administering magnesium sulfate intravenously, 1 gram over 5 minutes, seems to improve cluster headaches when compared with baseline(1184). The validity of this finding is limited by the lack of a comparator group.
• Cognitive impairment. It is unclear if oral magnesium is beneficial for cognitive impairment. Details: A large observational study in adults with end-stage renal disease on hemodialysis suggests that serum magnesium levels of 20.2-22.3 mg/dL are associated with the lowest odds of mild cognitive impairment, while serum magnesium levels below and above that range of values are associated with increased odds of mild cognitive impairment (111695).
• Coronary heart disease (CHD). It is unclear if magnesium supplementation is beneficial for CHD. Details: Clinical research shows that magnesium oxide 800-1200 mg daily for 3 months reduces platelet-dependent thrombosis by 35% when compared with placebo in patients with CHD (60759). It is unclear if this effect improves clinical outcomes. The effect of magnesium supplementation on coronary artery calcium has also been studied. A meta-analysis of 3 clinical studies in 196 patients with chronic kidney disease (CKD) shows that taking magnesium or increasing the concentration of magnesium in dialysate does not improve coronary artery calcification (CAC) scores when compared with standard therapy. However, magnesium reduced carotid intima-media thickness (111179). Similarly, a large clinical study in patients with CKD shows that taking slow-release magnesium hydroxide (Mablet, Denmark) 360 mg twice daily for 12 months does not slow the progression of CAC scores when compared with placebo (111178). This study may not have been adequately powered to detect a difference between groups.
• Coronavirus disease 2019 (COVID-19). It is unclear if oral magnesium is beneficial for COVID-19. Details: A small clinical study in patients hospitalized with moderate COVID-19 shows that taking magnesium 300 mg daily for the duration of hospitalization reduces the number of patients requiring oxygen therapy but not the duration of hospital stay when compared with placebo (114680).
• Depression. It is unclear if magnesium is beneficial for the treatment or prevention of depression in adults. Details: Some population research shows that dietary intake of elemental magnesium between 76-360 mg daily is associated with a reduced risk of depression, but there was no association with greater amounts of magnesium, and other population research shows no association at any intake level (96480,98289). For treatment of mild to moderate depression, one preliminary clinical study shows that taking magnesium chloride 2 grams orally daily for 6 weeks reduces depression scores by 56% and anxiety scores by about 52% when compared to baseline (96477). The validity of these findings is limited by the lack of a comparator group. However, a small clinical study in adults with recurrent depression shows that taking magnesium aspartate 120 mg daily for 8 weeks, along with fluoxetine, does not improve depression scores when compared with patients taking fluoxetine and placebo (111185). Similarly, a very small crossover clinical study in adults with mild or moderate treatment-resistant depression shows that administering a single dose of IV magnesium sulfate 4 grams does not improve depression scores when compared with an infusion of 5% dextrose (96481). However, scores were evaluated 24 hours post-infusion which may be too soon to detect improvement. Guidelines from The World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety Treatments (CANMAT) Taskforce state that elemental magnesium in doses of 100-400 mg is not recommended for adjunctive or monotherapy use in patients with depression (110318).
• Diabetic foot ulcers. Oral magnesium has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with grade 3 diabetic foot ulcers shows that taking magnesium oxide 250 mg plus vitamin E 400 IU daily for 12 weeks modestly reduces ulcer size when compared with placebo (101436). It is unclear if this effect is due to magnesium, vitamin E, or the combination.
• Exercise-induced muscle soreness. It is unclear if oral magnesium reduces muscle soreness in adults after resistance training. Details: A very small study in healthy adults, ages 19-23, shows that taking magnesium glycinate 350 mg daily for 10 days seems to reduce muscle soreness after bench press exercise when compared with placebo (104399).
• Fetal and premature infant mortality. It is unclear if antenatal intravenous (IV) magnesium sulfate administration reduces the risk of fetal and premature infant mortality. Details: Two meta-analyses of up to 7 clinical studies in patients at risk of preterm birth shows that antenatal IV magnesium sulfate administration does not reduce the risk of fetal or neonatal death when compared with placebo (114675,114681).
• Fibromyalgia. It is unclear if oral magnesium is beneficial for this condition. Details: A small clinical study shows that taking magnesium chloride orally 100 mg once daily for one month reduces mild to moderate, but not severe, stress associated with fibromyalgia when compared with placebo. It also reduces pain levels, but not to a clinically significant extent, and it does not affect sleep, fatigue, or quality of life (108964). Another small clinical study shows that taking magnesium citrate 300 mg daily for 8 weeks improves some symptoms of fibromyalgia, such as number of tender points and depression, when compared to baseline (89385). The validity of this finding is limited by the lack of a comparator group. A small clinical study shows that taking a combination of magnesium hydroxide and malic acid (Super Malic tablets) orally decreases fibromyalgia-related pain and tenderness in some patients when compared with placebo (3262). It is unclear if this effect is due to magnesium, malic acid, or the combination.
• Fractures. Population research suggests that higher intakes of magnesium may reduce fracture risk. Details: Observational research has found that higher dietary and supplemental magnesium intake is associated with a 34% lower odds of fracture when compared with lower magnesium intake (101395).
• Gastric cancer. Population research suggests that higher intakes of magnesium may reduce gastric cancer risk. Details: Observational research has found that higher dietary and supplemental magnesium intake is not associated with a reduced risk for gastric cancer when compared with lower intake (103730).
• Hearing loss. Oral magnesium may prevent and improve hearing loss due to environmental factors or loud noises. Details: Clinical research in healthy military recruits shows that taking magnesium aspartate 167 mg daily for 2 months prevents hearing loss from exposure to loud noises during basic military training when compared with placebo (1205). Also, in patients with acute-onset hearing loss that was not caused by environmental factors, taking magnesium aspartate 167 mg daily for 8 weeks seems to improve hearing loss when compared with placebo (60813).
• Hypertension. Oral magnesium supplementation may modestly reduce blood pressure, although these changes are not likely to be considered clinically significant. Details: Most research shows that taking oral magnesium supplements in daily doses that are at least as high as the Recommended Dietary Allowance (RDA) for adults and up to 1000 mg daily can lower diastolic blood pressure by about 2 mmHg in adults with or without hypertension (1192,1199,9465,15165,18111,96482). Significantly lower doses do not seem to have this effect (1180,1195,1197,8098). The effect of magnesium on systolic blood pressure is conflicting. Two meta-analyses shows that taking magnesium 212-970 mg daily does not lower systolic blood pressure in patients with or without hypertension (15165,115728). However, additional meta-analyses show that taking magnesium 120-970 mg daily can lower systolic blood pressure in a dose-dependent manner by about 2-4 mmHg in patients with or without hypertension (18111,96482). The reasons for these discrepant findings are unclear but may be due to heterogenous methods, including dose and duration among clinical studies. In 2022, the US Food and Drug Administration (FDA) approved a qualified health claim stating that inconsistent and inconclusive evidence suggests that diets with adequate magnesium may reduce the risk of high blood pressure. Products bearing this claim must provide at least 84 mg of magnesium daily, but no more than 350 mg daily (107451).
• Hypokalemia. It is unclear if intravenous or oral magnesium is beneficial for hypokalemia in patients with normal magnesium levels. Details: A preliminary retrospective observational study in patients with hypokalemia and unknown serum magnesium levels has found that administering oral or intravenous magnesium is not associated with improved time to normalization of serum potassium levels when compared with no magnesium treatment (110049). However, hypokalemia with concurrent hypomagnesemia can impede potassium repletion and exacerbate hypokalemia-induced rhythm disturbances. Standard of care in patients with hypokalemia and known hypomagnesemia includes prompt treatment with magnesium (110063).
• Impaired glucose tolerance (prediabetes). It is unclear if oral magnesium is beneficial for prediabetes. Details: Preliminary clinical research in patients with prediabetes shows that taking magnesium oxide 250 mg orally daily for 12 weeks does not improve fasting blood glucose levels, insulin resistance, or glycated hemoglobin (HbA1C) levels when compared with placebo. Taking magnesium also did not affect blood pressure, body weight, triglyceride levels, or low-density lipoprotein cholesterol levels; however, it did modestly improve high-density lipoprotein cholesterol levels (110053).
• Insomnia. Oral magnesium may modestly improve sleep complaints in adults, but evidence is conflicting. Details: A meta-analysis of two small clinical studies in healthy older adults with or without insomnia suggests that taking magnesium reduces the time to fall asleep by an average of 17 minutes when compared with placebo (105917). However, it does not increase the time spent asleep. Also, these findings are limited by imprecision and a high risk of bias. Studies included in the analysis used elemental magnesium 500-729 mg daily (as magnesium oxide) for up to 8 weeks (102458,105917). Another small clinical study in patients with poor sleep quality and low magnesium status shows that taking elemental magnesium 320 mg (as magnesium citrate) in divided doses daily for 7 weeks does not improve sleep quality, as measured by the Pittsburgh Sleep Quality Index (PSQI), when compared with a sodium citrate placebo (102456). Magnesium has also been evaluated in combination with other ingredients. A very small crossover clinical study in patients aged 18-40 years without a sleep disorder shows that taking a combination of magnesium 300 mg, L-tryptophan 1000 mg, glycine 3000 mg, tart cherry 220 mg, and theanine 200 mg for 3 days reduces the time to fall asleep by about 24 minutes, increases total time asleep by about 22 minutes, and improves sleep efficiency, but does not improve the total time in bed or wakefulness after falling asleep when compared with cellulose placebo (111184). Another small crossover clinical study in adults with sleep disturbances shows that taking a combination of magnesium 200 mg and melatonin nightly for 4 weeks improves sleep quality, as measured by the PSQI, reduces the length of time it takes to fall asleep by about 17 minutes, and improves some other measures of sleep, such as sleep efficiency and number of awakenings, when compared with placebo. However, despite these improvements, overall sleep quality was still categorized as poor after the intervention (113670). It is unclear if these effects are due to magnesium, other ingredients, or the combination.
• Intraventricular hemorrhage. It is unclear if antenatal intravenous (IV) magnesium sulfate can reduce the risk for intraventricular hemorrhage in neonates. Details: A meta-analysis of clinical research in premature infants shows that if the mother received antenatal intravenous magnesium sulfate, the infant had a non-significant trend toward a reduced risk of intraventricular hemorrhage when compared with infants whose mothers received placebo (103727). This analysis may have been insufficiently powered to detect a difference between groups. Another meta-analysis of up to 6 clinical studies, some of which are included in the previously referenced meta-analysis, in patients at risk of preterm birth shows that maternal antenatal (IV) magnesium sulfate administration does not reduce the risk of intraventricular hemorrhage, but does reduce the risk of severe intraventricular hemorrhage by about 24% when compared with placebo (114681).
• Kidney stones (nephrolithiasis). Taking magnesium orally may prevent the recurrence of kidney stones, although evidence is conflicting. Details: Prophylactic treatment with magnesium hydroxide, 200 mg twice daily for one year, followed by 500 mg daily for another year, might decrease the recurrence rate of calcium stone formation (2007). However, magnesium oxide does not seem to benefit patients considered to be recurrent calcium stone formers when compared with placebo, no treatment, or chlorthalidone (8097,38501,61199). Magnesium oxide 300 mg in combination with vitamin B6 10 mg daily seems to decrease urinary oxalate levels in people with hyperoxaluria who have previously had kidney stones (1201), but it is unclear if this effect translates into a reduced incidence of kidney stones.
• Liver cancer. Increased dietary magnesium intake is linked with a lower risk of liver cancer. Details: Observational research in retired older Americans has found that higher dietary magnesium intake is associated with a 35% lower risk of liver cancer when compared with lower intake. This association was especially strong in persons who were moderate or heavy alcohol users (105080).
• Lung cancer. Supplemental or dietary magnesium intake does not seem to reduce the risk of lung cancer. Details: A large epidemiological cancer screening trial with a mean follow-up of over 12 years suggests there is no association between dietary or supplemental magnesium intake and the risk of lung cancer. However, dietary magnesium seems to play an important yet unclear role in lung cancer prevention when taken as part of the diet with alpha-carotene, vitamin C, vitamin E, lycopene, selenium, lutein, and zeaxanthin (112096).
• Migraine headache. Oral magnesium may help prevent migraine in some adults and children. Also, intravenous magnesium may help treat migraine in adults, but evidence is conflicting. Details: A meta-analysis of 4 low-quality clinical studies, in adults with migraine shows that magnesium 122-600 mg daily for 4-16 weeks modestly reduces migraine frequency and severity when compared with placebo(115730). However, clinical significance is unclear, and the validity of these findings is limited by heterogeneous methods between clinical trials, including type of magnesium formulation and dose, patient population, and duration. In contrast, one small clinical study shows that taking magnesium does not reduce migraine frequency and severity by at least 50% in adults when compared with placebo (10661). Limited evidence suggests that adding oral magnesium to conventional treatment may also be beneficial. A clinical study in adults with migraine living in Iran shows that taking magnesium oxide 250 mg twice daily in addition to sodium valproate 200 mg twice daily for 12 weeks modestly reduces severity and duration of migraine, but not migraine frequency, when compared with taking sodium valproate alone (105915). It is unclear if these improvements would be considered clinically significant. For treatment of migraine, some adults with normal magnesium levels respond to intravenous (IV) magnesium sulfate 1 gram over 5 minutes, but most patients who benefit have low magnesium levels at baseline (1185,6844). Effects of IV magnesium in patients with unknown magnesium levels are conflicting. Some preliminary clinical research shows that magnesium 1-2 grams IV alleviates acute migraine for up to 2 hours, but other research has found no benefit (89388,97493,98285). In children, treatment with magnesium oxide orally 15 mg/kg daily in 3 divided doses for up to 16 weeks reduces the frequency and severity of migraine headaches when compared with placebo (10663). However, adding magnesium sulfate 400 mg orally daily to ibuprofen or acetaminophen does not further reduce migraine severity in children (89396).
• Miscarriage. Oral magnesium has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in pregnant adults with threatened miscarriage between the 6th and 13th week of gestation shows that taking a specific combination product (DAV HA, Lo.Li pharma s.r.l) containing magnesium 450 mg, alpha-lipoic acid, hyaluronic acidvitamin B6, and vitamin D daily in combination with conventional treatment of vaginal progesterone over 2 weeks of observation results in a faster resorption of the subchorionic hematoma and faster decrease of patient-reported vaginal bleeding, abdominal pain, and uterine contractions when compared with vaginal progesterone alone (113893). It is unclear if these effects are due to magnesium, other ingredients, or the combination. Additionally, the validity of these findings is limited by the lack of a placebo in the control group.
• Myocardial infarction (MI). Research on the effects of intravenous or oral magnesium after myocardial infarction are conflicting. Details: Administering magnesium intravenously doesn't seem to reduce mortality after an acute MI (8999,13357,13358,13359,13360,19990,60872,61082), although there is some conflicting evidence from a meta-analysis of clinical research that shows that intravenous magnesium sulfate may reduce short-term mortality by 55% when compared with placebo (60795,60895). Clinical research with oral magnesium supplementation has found no benefit (1198,6844).
• Neonatal encephalopathy. Intravenous magnesium may improve short-term outcomes in neonates with encephalopathy. Details: A meta-analysis of clinical research shows that intravenous magnesium may improve short term outcomes of neonatal encephalopathy (hypoxic ischemic encephalopathy, HIE). However, long term outcomes are not affected (90025).
• Nocturnal leg cramps. It is unclear if oral magnesium is helpful for nocturnal leg cramps. Details: Some clinical research in adults with nocturnal leg cramps shows that taking magnesium oxide 865 mg daily at bedtime for 4 weeks does not reduce the frequency of leg cramping episodes when compared with placebo (96478). However, four weeks may be too short a time to see a benefit. In other clinical research, taking oral magnesium oxide monohydrate 226mg daily at bedtime for 60 days reduces the frequency of leg cramps when compared with placebo. This reduction was not seen after 30 days. Magnesium also reduced cramp duration and improved sleep quality, but did not affect pain scores, at 60 days when compared with placebo (106919).
• Nonalcoholic fatty liver disease (NAFLD). Oral magnesium hydroxide has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults with NAFLD shows that taking magnesium hydroxide 150 mg and L-carnitine 2000 mg daily for 16 weeks does not improve liver stiffness scores when compared with baseline or controls who took placebo for 8 weeks followed by this magnesium and L- carnitine combination for 8 weeks. Taking magnesium and L-carnitine also did not improve levels of aspartate aminotransferase (AST) or alanine transaminase (ALT) when compared to baseline (111177).
• Obesity. Evidence on the use of magnesium for weight loss in obese patients is conflicting; any benefit is likely small at best. Details: A meta-analysis of 7 clinical studies in obese patients shows that taking magnesium reduces body mass index (BMI) by 0.3 when compared with control (103723). Another meta-analysis of 7 studies in obese patients shows that while magnesium supplementation does not reduce weight, it reduces waist circumference by 2 cm when compared with placebo (103729). Interestingly, subgroup analyses did not find that the dose of magnesium or baseline magnesium levels impacted effectiveness. One subgroup analysis found that magnesium supplementation lasting 12 weeks or less seemed to be more beneficial for obesity than supplementation lasting longer than 12 weeks (103723).
• Overall mortality. It is unclear if oral or IV magnesium reduces the risk of overall mortality. Details: A meta-analysis of heterogeneous observational studies has found that increased dietary magnesium intake, but not supplemental magnesium intake, is associated with a modestly reduced risk of overall mortality (105073). A meta-analysis of 3 small, low-quality clinical studies in ICU patients shows that administering IV magnesium 24-30 mmol or as a target-directed dose for 3 days reduces overall mortality when compared with patients who did not receive magnesium (111290). However, some studies included patients with hypomagnesemia; it is unclear if effects would be similar for patients with normal levels of magnesium.
• Osteoarthritis. Population research has not found a link between magnesium intake and osteoarthritis risk. Details: Observational research has found that dietary and supplemental magnesium intake is not associated with the risk of developing osteoarthritis (101395).
• Pain (acute). It is unclear if locally injected or intravenous magnesium is helpful for acute pain. Details: Preliminary clinical research in patients with renal colic shows that intravenous (IV) magnesium sulfate, 50 mg/kg infused over 20 minutes, is as effective as IV morphine sulfate 0.1 mg/kg for controlling acute renal pain at 20 minutes after the dose (107367). Magnesium has also been evaluated in a dental procedure. A single-center clinical study in India in adults with irreversible pulpitis requiring a root canal shows that a local injection of 0.2 mL of 10% magnesium sulfate with lidocaine and epinephrine reduces perioperative pain when compared to lidocaine with epinephrine alone (115729).
• Pain (chronic). Population research suggests that higher intakes of magnesium may modestly reduce the risk for chronic pain. Details: A cross-sectional observational study has found that increased magnesium intake is associated with a 7% to 8% reduced risk for chronic pain. The association was found to be stronger in females than in males (103732).
• Parturition. It is unclear if topical magnesium is beneficial for labor duration. Details: A single-center clinical study in Iranian adults shows that applying 10 mL of a 50% magnesium sulfate solution directly to the cervix during the active phase of labor reduces the time to vaginal delivery by approximately 1.5 hours and improves the childbirth experience, as reported by patients, when compared with placebo. However, clinical significance is unclear (115727).
• Perioperative anxiety. It is unclear if oral magnesium is beneficial for perioperative anxiety. Details: Preliminary clinical research in adults undergoing open heart surgery shows that taking magnesium oxide 250 mg orally twice daily during hospitalization moderately improves anxiety and depression scores when compared with no magnesium therapy. Magnesium therapy was held for the 2 days immediately following surgery (110054).
• Physical performance. Oral magnesium may modestly improve physical performance in otherwise healthy, elderly females. Details: Clinical research in otherwise healthy elderly females shows that taking a magnesium oxide supplement (Easymag, Sanofi-Aventis) 900 mg daily for 12 weeks modestly improves walking speed and chair stand speed in elderly females when compared with no treatment (90026).
• Polycystic ovary syndrome (PCOS). It is unclear if oral magnesium is beneficial for improving metabolic indices in patients with PCOS. Details: Two small clinical studies in patients with PCOS show that taking magnesium oxide orally, 250 mg daily for 8 weeks, does not affect insulin resistance, beta-cell function, lipid levels, or insulin sensitivity when compared with placebo (103725,105887). Other clinical research in patients with PCOS shows that taking magnesium oxide orally, 250 mg daily for 10 weeks, improves subjective measures of quality of life, fatigue, and emotional functioning, but not objective measures such as alopecia, abnormal uterine bleeding, or acne, when compared with placebo (108965). A clinical study using a combination of magnesium 250 mg with vitamin E 400 mg daily for 12 weeks shows a modest reduction in insulin resistance, insulin levels, and triglyceride levels, but not other lipid levels, when compared with placebo (100264). It is unclear if these beneficial effects are due to magnesium, vitamin E, or the combination.
• Postoperative nausea and vomiting (PONV). It is unclear if intravenous (IV) magnesium is beneficial for PONV due to mixed results from clinical research. Details: A meta-analysis of 5 clinical studies in adults undergoing surgery with general anesthesia shows that administering IV magnesium sulfate intraoperatively reduces PONV (114676). However, a meta-analysis of 20 clinical studies in adults undergoing surgery with general anesthesia shows that administering IV magnesium perioperatively does not reduce the incidence of PONV (114678). A moderate-sized clinical study conducted in China in older adults undergoing total knee arthroplasty shows that administering intravenous magnesium sulfate 40 mg/kg prior to anesthesia induction then 15 mg/kg during surgery reduces the incidence of postoperative vomiting but not postoperative nausea when compared with control (113677). The reasons for these discrepant findings are unclear but may be explained by differences in magnesium regimens, anesthesia protocols, and surgical populations studied.
• Postoperative recovery. It is unclear if intravenous (IV) magnesium is beneficial for postoperative recovery. Details: A moderate-sized clinical study conducted in China in older adults undergoing total knee arthroplasty shows that administering IV magnesium sulfate 40 mg/kg prior to anesthesia induction then 15 mg/kg during surgery does not reduce extubation time, time spent in the post-anesthesia care unit (PACU), or duration of hospital stay when compared with control (113677). Additionally, a meta-analysis of 3 different clinical studies in adults undergoing surgery with general anesthesia shows that administering IV magnesium intraoperatively does not reduce extubation time (114676).
• Postoperative sleep disturbance. It is unclear if oral magnesium is beneficial for postoperative sleep disturbances. Details: Preliminary clinical research in adults undergoing open heart surgery shows that taking magnesium oxide 250 mg orally twice daily during hospitalization moderately improves sleep scores when compared with no magnesium therapy. Magnesium therapy was held for the 2 days immediately following surgery (110054).
• Postoperative sore throat. It is unclear if topical magnesium sulfate is beneficial for reducing sore throat pain after endotracheal intubation. Details: Preliminary clinical research in patients undergoing endotracheal intubation for surgery shows that using a gargle containing magnesium sulfate 20% with lidocaine, 20 minutes before anesthesia induction, is less effective for reducing sore throat pain than a gargle containing dexmedetomidine and lidocaine (112779). The study did not include a comparison to lidocaine alone.
• Pregnancy-related leg cramps. It is unclear if oral magnesium reduces leg cramps during pregnancy; evidence is conflicting. Details: One small clinical study in patients with pregnancy-related leg cramps shows that taking magnesium bisglycinate chelate 300 mg daily for 4 weeks reduces the frequency and intensity of leg cramps when compared with placebo (99318). A smaller clinical study in this population shows that taking a specific mixture of magnesium lactate and citrate (Nycoplus Magnesium) providing elemental magnesium 120 mg in the morning and 240 mg in the evening for 3 weeks reduces the frequency of cramps when compared with placebo (1194). However, not all research agrees. One small clinical study using this same supplement and dose for 2 weeks found no benefit when compared with placebo (17463). It is possible that a 2-week duration of treatment is too short to be beneficial. Finally, a meta-analysis of these studies and one other more recent clinical study shows that taking magnesium does not reduce the frequency or improve the resolution of pregnancy-related leg cramps when compared with placebo (105916). This analysis may not have been adequately powered to detect a difference between treatment groups.
• Pre-procedural sedation. It is unclear if intravenous magnesium is beneficial when administered in addition to other medications used for sedation during surgery. Details: A moderate-sized study of adults aged 65-79 years old undergoing endoscopic retrograde cholangiopancreatography (ERCP) shows that administering a single intravenous bolus of magnesium sulfate 40 mg/kg prior to the procedure reduces intraoperative propofol requirements by about 21% and reduces some peri-procedural adverse events including the incidence of respiratory depression and involuntary movement when compared with control. However, there were no differences in recovery time, hemodynamic parameters, or the incidence of hypotension, bradycardia, perioperative nausea or vomiting, lethargy, or arrythmias (111694). Another moderate-sized study in older adults undergoing total knee arthroplasty shows that administering intravenous magnesium sulfate 40 mg/kg prior to anesthesia induction then 15 mg/kg during surgery does not reduce the need for medications used for anesthesia induction, intraoperative maintenance propofol requirements, or recovery time when compared with control. However, magnesium sulfate does seem to reduce the amount of remifentanil required for intraoperative anesthesia maintenance and increase norepinephrine requirements when compared with control (113677).
• Preterm labor. The use of magnesium sulfate to inhibit uterine contractions in preterm labor (tocolysis) is controversial. However, its use for the purpose of fetal neuroprotection for up to 48 hours is supported by the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine. Details: Magnesium is given intravenously (IV) during preterm labor in an effort to improve fetal neurological outcomes, such as to reduce the risk of cerebral palsy and motor dysfunction in the infant (60915,60927,60931,61001,97485,103734,103754,114681). The typical dosage of magnesium sulfate is 4 grams infused IV over 10-30 minutes, followed by a maintenance infusion of 1-4 grams/hour for 48 hours or until birth. Use beyond 5-7 days has been associated with hypocalcemia and bone abnormalities in the fetus (15,12590,12594). Some meta-analyses of clinical research suggest that magnesium sulfate is more effective at delaying delivery by 48 hours when compared with oxytocin receptor blockers, nitrates, beta-mimetics, and/or placebo (20263,61021). However, an additional meta-analysis of several clinical studies shows that magnesium sulfate 4 or 6 grams IV is not more effective at delaying preterm labor by 48 hours when compared with nifedipine (115639). The reason for these discrepant findings are unclear, but may be related to the heterogenous methods between clinical trials, including dose and duration.
• Pseudoxanthoma elasticum (PXE). It is unclear if oral magnesium is beneficial for PXE. Details: Preliminary clinical research in patients with PXE shows that taking magnesium oxide 800 mg (500 mg of elemental magnesium) twice daily for one year tends to reduce calcification of elastic skin fibers when compared with placebo, but the effect is not statistically significant (101393). This study was limited by small size and insufficient power to detect smaller effects.
• Restless legs syndrome (RLS). It is unclear if oral magnesium is beneficial for RLS. Details: Some observational research has found that hypomagnesemia is associated with RLS; however, not all research agrees (8096,9472). Preliminary clinical research in adults with RLS who are beginning treatment with pramipexole shows that also taking magnesium oxide 250 mg orally daily for 2 months moderately improves RLS scores and sleep quality scores when compared with pramipexole and placebo (110052). Other low-quality clinical research in adults with RLS or periodic limb movement during sleep shows that taking magnesium 12.4 mmol orally in the evening for 4-6 weeks decreases movement and increases sleep when compared with baseline (9466). The validity of this finding is limited by the lack of a comparator group.
• Sarcopenia. It is unclear if oral magnesium is beneficial for the prevention or treatment of sarcopenia. Details: Population research in older adults has found that lower dietary intake of magnesium is associated with sarcopenia. However, the effect of magnesium supplementation on sarcopenia prevention or treatment has not been evaluated (110055). Magnesium has been evaluated in combination with other ingredients for treatment of sarcopenia. A small clinical study in elderly individuals with sarcopenia undergoing a diet and exercise program shows that taking a combination supplement containing magnesium 300 mg, carnosine, hydroxymethylbutyrate, lactoferrin, and sodium butyrate daily for 4 months increases muscle mass, as measured by the skeletal muscle index, and improves measures of muscle function, including handgrip muscle strength, chair test, and walking speed, when compared with placebo (114682). It is unclear if these effects are due to magnesium, other ingredients, or the combination.
• Sepsis. It is unclear if intravenous magnesium is beneficial for sepsis. Details: A very large observational study in patients with sepsis and hypomagnesaemia or normomagnesemia in the intensive care unit (ICU) suggests that administering intravenous magnesium sulfate 2 or 4 grams within 24 hours of admission reduces 28-day all-cause mortality from 25% in patients who did not use magnesium sulfate to 20% in those who were administered magnesium sulfate, regardless of baseline serum magnesium level and other baseline characteristics. Administration of intravenous magnesium sulfate in this population may also reduce ICU mortality by 4%, in-hospital mortality by 3%, and the use of renal replacement therapy by 3% but also seems to increase the length of ICU and hospital stay when compared with patients who did not use magnesium sulfate (113676). The validity of these results is limited by the observational nature of the study.
• Sleep deprivation. Oral magnesium has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in sleep-deprived recreational athletes shows that taking a combination of magnesium 1350 mg, zinc 90 mg, and vitamin B6 31.5 mg for 3 nights at bedtime does not change sleep quality, subjective sleepiness, mood, or fatigue the next day when compared with placebo (113655).
• Stroke. Increased dietary magnesium may decrease stroke risk, and using a magnesium-containing salt substitute may improve neurological performance post-stroke. However, intravenous magnesium has not demonstrated benefit. Details: Most population research has found that increased dietary intake of magnesium is associated with decreased stroke risk and decreased mortality from stroke (9001,9002,90013,90030,90036,92107,103736). In patients who have had a stroke, a preliminary clinical study shows that using a salt substitute providing the Dietary Reference Intake (DRI) of magnesium and potassium for 6 months improves neurological performance when compared with using regular salt (97491). However, intravenous (IV) magnesium does not seem to be beneficial in patients who have had a stroke. Large prospective clinical trials show that IV magnesium given within 12 hours of acute stroke does not reduce mortality or disability in most patients when compared with placebo. However, one subgroup analysis suggested that IV magnesium might benefit patients with lacunar (non-cortical) stroke (13361,90021). IV magnesium also doesn't seem to reduce cardiovascular complications after acute stroke. A secondary analysis of a clinical trial in patients after ischemic and hemorrhagic stroke shows that giving IV magnesium does not reduce serious cardiac adverse events when compared with placebo (104393). Another secondary analysis of this trial shows that giving IV magnesium prior to arrival at the hospital and within 2 hours of a hemorrhagic stroke does not reduce hematoma volume on hospital arrival, hematoma expansion during hospital admission, or functional outcomes at 3 months (108733).
• Subarachnoid hemorrhage. Intravenous magnesium sulfate may reduce the risk of adverse outcomes in people with subarachnoid hemorrhage, but evidence is conflicting. Details: There is mixed evidence regarding the effect of magnesium sulfate in managing aneurysmal subarachnoid hemorrhage. One meta-analysis of clinical research shows that intravenous magnesium sulfate 64-144 mmol/day for 10-18 days reduces the risk of poor outcomes following aneurysmal subarachnoid hemorrhage, including death, vegetative state, or dependency, by 46% when compared with control (60932). Also, meta-analyses of clinical research show that intravenous magnesium reduces the risk of delayed cerebral ischemia by 27% when compared with placebo (60944,89398). However, these results were not confirmed in other meta-analyses (60973,90034).
• Thrombocytopenia. It is unclear if intravenous magnesium sulfate is beneficial in patients with thrombotic thrombocytopenic purpura (TTP). Details: Addition of intravenous magnesium sulfate as a 6-gram loading dose followed by 6 grams infused over 24 hours for 3 days, to standard treatment for TTP does not reduce the time to normalization of the platelet count, the incidence of TTP-related organ dysfunction, or the recurrence rate, when compared with standard treatment alone (112777). This study may have been underpowered to detect a difference.
• Urinary incontinence. Although there has been interest in using oral magnesium for urinary incontinence, there is insufficient reliable information about the clinical effects of magnesium for this purpose. More evidence is needed to rate magnesium for these uses.

(Read more about MAGNESIUM)

EFFECTIVE

• Manganese deficiency. Oral and intravenous manganese can prevent and treat manganese deficiency. Details: Taking manganese orally or intravenously is effective for preventing or treating manganese deficiency (15). However, the incidence of manganese deficiency is not well documented. Long-term home parenteral nutrition should provide no more than 55 mcg daily of manganese for adults or 1 mcg/kg daily (up to 50 mcg) of manganese for children unless clinically indicated (96416,99302). A clinical trial in children aged 8-14 months who are manganese deficient shows that taking manganese in addition to other vitamins and minerals in a 30 mL beverage six days per week for up to 14 months promotes growth when compared with placebo (19348).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Allergic rhinitis (hay fever). It is unclear if intranasal manganese is beneficial in patients with allergic rhinitis. Details: A small clinical study in patients with chronic allergic rhinitis shows that using an isotonic seawater nasal spray enriched with manganese (Sterimar Mn, Laboratori Baldacci) four puffs daily for 5 months, in addition to standard treatment with oral antihistamines, nasal corticosteroids, and nasal decongestants, reduces the number of acute exacerbations by about three when compared with the standard treatment alone (99416). However, the effect of the manganese in this product is unclear since nasal lavage with a plain saline nasal spray also helps in allergic rhinitis.
• Chronic obstructive pulmonary disease (COPD). Intravenous manganese has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients being treated for exacerbation of COPD shows that intravenous supplementation with manganese 0.4 mg, selenium 100 mcg, and zinc 2 mg daily may shorten the number of days spent on mechanical ventilation when compared with placebo (61432). It is unclear if these findings are due to manganese, other ingredients, or the combination.
• Metabolic syndrome. It is unclear if oral intake of or environmental exposure to manganese decreases the risk of metabolic syndrome. Details: A meta-analysis of 12 observational studies suggests that increased dietary intake of manganese or higher levels of manganese in the serum, whole blood, or urine are not associated with a lower risk of metabolic syndrome when compared with lower manganese intake or laboratory values (112138).
• Obesity. Oral manganese has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in overweight adults shows that taking a specific combination product (7-Keto Naturalean, Enzymatic Therapy, Inc.) containing manganese 500 mcg, 7-oxo-DHEA 100 mg, L-tyrosine 100 mg, asparagus root extract 100 mg, choline bitartrate 50 mg, inositol 50 mg, copper gluconate 500 mcg, and potassium iodide 100 mcg daily for 8 weeks reduces body weight by around 1.5 kg and body mass index (BMI) by around 0.7 kg/m² when compared with placebo (61581).
• Osteoarthritis. Oral manganese has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Small clinical studies in patients with osteoarthritis of the knee and lower back show that taking a specific combination product (Cosamin DS, Nutramax Laboratories) containing manganese ascorbate 228-304 mg (about 31-41 mg of elemental manganese), glucosamine hydrochloride 1500-2000 mg, and chondroitin sulfate 1200-1600 mg daily for 4 months improves pain and ability to do activities of daily living when compared with baseline or placebo (4237,7169). The amount of manganese in the Cosamin DS formulation used in this study is considerably higher than the 1 mg of elemental manganese per 1500 mg of glucosamine hydrochloride in the current formulation. Since numerous studies show glucosamine with chondroitin without manganese might be effective for osteoarthritis, it is not possible to draw conclusions about the effects of manganese alone.
• Osteoporosis. Oral manganese has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in postmenopausal patients shows that taking manganese 5 mg in combination with elemental calcium 1000 mg, zinc 15 mg, and copper 2.5 mg daily for 2 years reduces spinal bone loss when compared with placebo (1994). Another small clinical study in females with osteopenia shows that taking a specific combination product (Vitrum Osteomag, Unipharm Inc.) containing manganese 1.8 mg, calcium 600 mg, vitamin D (cholecalciferol) 200 IU, magnesium 40 mg, zinc 7.5 mg, copper 1 mg, and boron 250 mcg twice daily for one year improves bone mineral density when compared with no treatment (36840). However, since numerous studies have demonstrated the efficacy of calcium plus vitamin D for osteoporosis, it is not possible to draw conclusions about the effects of manganese alone.
• Premenstrual syndrome (PMS). Oral manganese has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in patients with PMS shows that taking manganese 1.0 mg or 5.6 mg in combination with calcium 587 mg or 1336 mg daily for about 24 weeks improves symptoms of PMS including pain, crying, loneliness, anxiety, restlessness, irritability, mood swings, depression, and tension (2004).
• Wound healing. Topical manganese has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Observational research has found that applying an alginate dressing containing manganese, calcium, and zinc to chronic wounds for 12 weeks is associated with improved wound healing when compared with previous treatments (61327). It is unclear if these findings are due to manganese, other ingredients, or the combination. More evidence is needed to rate manganese for these uses.

(Read more about MANGANESE)

LIKELY EFFECTIVE

• Coronary heart disease (CHD). A diet high in soluble fiber, such as that found in oats, reduces the risk of CHD. Details: Clinical research shows that a diet containing foods high in fiber, such as oats, oat bran, or whole oat flour, reduces the risk of CHD (2737,4960,4962,4963,4964,4965,4966,4967,4968). In 1993, the US Food and Drug Administration (FDA) approved a health claim stating that consuming at least 3 grams of soluble fiber per day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of CHD (102336). However, clinical studies show that at least 3.6 grams of soluble fiber daily is needed to reduce the risk of CHD (5786,5787,5788,5794,5795,5796).
• Dyslipidemia. A diet rich in soluble fiber, such as that found in oats, can reduce cholesterol by a moderate amount. Details: Oats, oat bran, and other soluble fibers can modestly reduce total and low-density lipoprotein (LDL) cholesterol, especially when consumed as part of a diet low in saturated fat. Consuming 56-150 grams of whole oat products such as oatmeal and oat bran, containing 3.6-10 grams of soluble fiber daily, can significantly lower total and LDL cholesterol levels. For each gram of soluble fiber consumed, total cholesterol decreases by about 1.4 mg/dL and LDL by about 1.2 mg/dL. Eating 3-10 grams of soluble fiber daily can reduce total cholesterol by about 4-14 mg/dL (4976,4977,5786,5788,5792,5794,5795,8521,107749,113488,113495). For example, eating 3 bowls of oatmeal (28 gram servings) daily, providing a total of 3 grams of soluble fiber daily, can decrease total cholesterol by about 5 mg/dL (5788). However, consuming more than 10 grams of soluble fiber daily doesn't seem to increase effectiveness (5788). A meta-analysis comparing the effects of oats and isolated beta-glucans shows that both products similarly impact lipid profiles, suggesting that the bioactive component of oats are beta-glucans (113488). Oat bran products, such as oat bran muffins and oat bran flakes, may vary in their ability to lower cholesterol, depending on the total soluble fiber content and other dietary variables (6188). Whole oat products might be more effective for lowering LDL and total cholesterol than foods containing oat bran plus soluble fiber (10145). Although oats are shown to lower total and LDL cholesterol, a meta-analysis and a small clinical study in adults with and without dyslipidemia shows that consuming oatmeal or oat products does not reduce triglycerides or increase high-density lipoprotein (HDL) cholesterol when compared with controls (113488,113495).

POSSIBLY EFFECTIVE

• Diabetes. A diet rich in whole grains, such as oats, may help prevent diabetes or improve blood glucose control in patients with type 1, type 2, or gestational diabetes. Details: Population research shows that for every 16 gram daily serving of whole grains, including oats, there is a 7% to 11% lower risk of developing type 2 diabetes (100622). There is also evidence that consuming oats can decrease blood glucose and insulin levels, as well as lipid levels, in patients with diabetes. The glycemic effects of oats depend on the level of processing of the oat products. Consuming intact oat kernels or thick-cut oats (>0.6 mm) reduces postprandial blood glucose and insulin, but consuming thin-cut, or "quick", oats has no effect (105536). Clinical research shows that consuming oats and oat bran for 4-8 weeks decreases pre-prandial blood glucose, 24-hour plasma glucose, glycated hemoglobin (HbA1c), insulin levels, and low-density lipoprotein (LDL) cholesterol in people with type 2 diabetes (4980,4982,6266,103345). Various doses have been used, including 3 grams of soluble fiber daily, or bread providing 34 grams of total fiber daily (9 grams of soluble fiber) (4961,4980). Additional clinical research in obese adults with type 2 diabetes shows that eating whole grain oats 50-100 grams daily in place of other carbohydrates reduces postprandial blood glucose by 19-27 mg/dL when compared with other carbohydrates in a healthy diet. After 1 year, the groups consuming 50 grams and 100 grams of oats had an additional 0.48% and 0.64% reduction in HbA1c, respectively, when compared with the regular healthy diet group (97520). There is also some evidence that consuming oats 50 grams daily, containing 25 grams of soluble fiber, might be more effective for improving glycemic control and decreasing hyperinsulinemia than the standard moderate fiber diet recommended by the American Diabetes Association (ADA) (6266). Oats have also been evaluated in adolescents with type 1 diabetes. One very small clinical study shows that taking 50 grams of a specific oat product (Betaglucare), providing beta-glucans 6 grams, in three divided doses daily for one week is beneficial for glycemic control and variability when compared with a standard diet without beta-glucans or with taking only 25 grams of the product daily. Maximal, mean, and pre- and post-meal blood glucose levels were modestly lower, and minimal blood glucose levels were modestly higher. Most measures of glycemic variability were statistically different, although there were no differences in the duration of hypoglycemia or hyperglycemia between groups (105261). Oats have also been evaluated in patients with gestational diabetes. A randomized, controlled trial shows that taking 30 grams of a specific oat bran product (OAB; Golden Light Cup Company) orally twice daily at lunch and dinner for 4 weeks improves mean fasting blood glucose and two-hour postprandial glucose when compared with a control group. After 4 weeks, the mean fasting blood glucose and 2-hour postprandial glucose in the treatment group were 85 mg/dL and 104 mg/dL, respectively, compared with 93 mg/dL and 117 mg/dL, respectively, in the control group (107751). The validity of this study is limited by the short treatment duration and lack of follow-up.
• Gastric cancer. A diet rich in soluble fiber, such as that found in oats, might reduce the risk of gastric cancer. Details: Observational research has found that consuming a diet that includes cereal fiber, such as oats and oat bran, might reduce the incidence of gastric cancer (10435).

POSSIBLY INEFFECTIVE

• Colorectal cancer. Regular consumption of oats does not seem to reduce the risk of colorectal cancer. Details: Observational research has found that consuming oat bran or oats orally doesn't seem to reduce the risk of colon cancer. Additionally, consuming fiber, including oat-bran fiber, is not associated with a reduction in the risk for recurrence of colorectal adenomas (4820,5104).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Although there is interest in using topical oats for acne, there is insufficient reliable information about the clinical effects of oats for this purpose.
• Anxiety. Although there is interest in using oral oats for anxiety, there is insufficient reliable information about the clinical effects of oats for this purpose.
• Atopic dermatitis (eczema). Topical colloidal oatmeal cream may be beneficial in patients with atopic dermatitis. Details: Preliminary clinical research shows that applying a cream containing colloidal oatmeal 1% daily for 2 weeks moderately reduces the severity of atopic dermatitis when compared with baseline (103344). The validity of this finding is limited by the lack of a comparator group. Other research suggests that colloidal oatmeal may be beneficial when used in combination with topical steroids. Clinical research shows that the benefits obtained from applying an ointment containing fluocinolone 0.025% to the hands for 2 weeks were better maintained in the patients who also used a cream containing colloidal oatmeal 1% during this time period and for an additional 4 weeks when compared with patients using fluocinolone and the cream base without colloidal oatmeal. Quality of life was also improved in the patients using colloidal oatmeal (103340).
• Breast cancer. Observational research suggests that regular oatmeal intake may be associated with reduced mortality from breast cancer. Details: Population research in postmenopausal patients has found that those who have eaten 50 grams of oatmeal daily prior to a breast cancer diagnosis have a 20% reduced risk of all-cause mortality in the 7 years following the diagnosis when compared with patients who have not eaten oatmeal. However, no benefit was seen when post-diagnostic oatmeal intakes were examined (103343).
• Burns. Although there is interest in using topical oats for burns, there is insufficient reliable information about the clinical effects of oats for this purpose.
• Chronic fatigue syndrome (CFS). Although there is interest in using oral oats for CFS, there is insufficient reliable information about the clinical effects of oats for this purpose.
• Cognitive function. It is unclear if oral oats are beneficial in healthy adults with mild memory impairment. Details: Preliminary clinical research in healthy middle-aged adults with self-reported memory decline shows that consuming a specific wild green-oats extract (Neuravena, Frutarom) 800 mg as a single dose improves overall speed, but not overall accuracy, of cognitive performance when compared with placebo. However, a higher dose of 1600 mg was ineffective (97519).
• Dry skin. It is unclear if applying lotion containing colloidal oat extract improves dry skin to a greater extent than other lotion products. Details: Preliminary clinical research shows that applying a lotion containing colloidal oat extract (Aveeno Active Naturals Skin Relief 24Hr Moisturizing Lotion, Johnson & Johnson) twice daily for 2 weeks improves itchiness, cracking, scaling, dryness, and roughness when compared to baseline in females with dry skin (91458). Additional preliminary clinical research shows that applying a colloidal oatmeal lotion to the legs twice daily for three weeks reduces skin dryness and improves skin integrity when compared to baseline in adults with dry skin (97518). The validity of these findings is limited by the lack of a comparator group.
• Exercise-induced muscle soreness. It is unclear if oral oats are beneficial for exercise-induced muscle soreness. Details: A small clinical trial shows that eating two cookies containing oat flour 60 grams daily for 8 weeks reduces muscle soreness 48 or 72 hours after downhill running when compared with baseline (103341).
• Fat redistribution syndrome. It is unclear if oral oats are beneficial for fat redistribution syndrome. Details: Consumption of a high fiber diet, including oats, with adequate energy and protein might prevent fat deposition in patients with HIV. A one-gram increase in total dietary fiber may decrease the risk of fat deposition by 7% (12517).
• Gallbladder disease. Although there is interest in using oral oats for gallbladder disease, there is insufficient reliable information about the clinical effects of oats for this purpose.
• Hypertension. It is unclear if oral oats are beneficial for hypertension. Details: A meta-analysis of 21 clinical studies in healthy adults and those with a variety of metabolic conditions including hypertension shows that consumption of oat products reduces systolic blood pressure (SBP) by 3 mmHg but has no effect on diastolic blood pressure (DBP) when compared with control. Subgroup analysis suggests that consuming oat products reduces SBP by 10 mmHg in patients with hypertension at baseline. An additional subgroup analysis suggests that consuming at least 5 grams of beta-glucan-enriched oats daily or consuming oats for a duration at least 8 weeks reduces SBP and DBP (113494). Observational research has found that consumption of oats as oatmeal or oat cereal does not seem to reduce DBPor SBP in males with minor elevations in blood pressure or patients with dyslipidemia (2956,113495). A randomized, controlled trial in patients with stage 1 hypertension receiving dietary guidance shows that taking 30 grams of oat bran, providing 8.9 grams of dietary fiber, once daily with breakfast or in between meals for 3 months improves various blood pressure measures when compared with dietary guidance alone. After 3 months of treatment, 24-hour maximum SBP and DBP decreased by 14 mmHg and 11 mmHg, respectively, and office SBP and DBP decreased by 15 mmHg and 10 mmHg, respectively. Oat consumption may also have impacted antihypertensive medication use. Two patients in the control group increased doses of antihypertensive medications, whereas 6 patients in the treatment group decreased doses and 1 patient discontinued use (107750). The effect of oral oat bran on patients with stage 2 hypertension or pre-hypertension is unknown.
• Irritable bowel syndrome (IBS). Although there is interest in using oral oats for IBS, there is insufficient reliable information about the clinical effects of oats for this purpose.
• Metabolic syndrome. Limited research suggests that oats may not be beneficial for metabolic syndrome. Details: Preliminary clinical research in adults with metabolic syndrome shows that adding oat bran 40 grams daily for 6 weeks to a low-calorie diet does not reduce the incidence of metabolic syndrome. Oat bran also does not improve body weight, blood pressure, low-density lipoprotein (LDL) cholesterol, triglycerides, or blood glucose levels when compared with a low-calorie diet alone in patients with metabolic syndrome (103342).
• Osteoarthritis. Although there is interest in using oral oats for osteoarthritis, there is insufficient reliable information about the clinical effects of oats for this condition.
• Pruritus. Applying oat lotion topically may improve some types of pruritus. Details: Preliminary clinical research shows that applying an oat lotion (Espanol) twice daily for up to 2 weeks can decrease itching intensity by about 20% when compared to baseline in patients with pruritus associated with chronic kidney disease (uremic pruritus). This decrease is similar to the effects of applying vinegar 5% solution or taking hydroxyzine 10 mg orally. However, applying the oat lotion does not appear to decrease the frequency of itching (91457).
• Psoriasis. Although there is interest in using topical oats for psoriasis, there is insufficient reliable information about the clinical effects of oats for this purpose.
• Rheumatoid arthritis (RA). Although there is interest in using oral oats for RA, there is insufficient reliable information about the clinical effects of oats for this purpose.
• Stroke. It is unclear if oral oats are beneficial for reducing the risk of stroke. Details: Population research suggests that consuming oatmeal for breakfast once weekly might reduce the incidence of stroke by a small amount when compared with consuming white bread or eggs for breakfast (103337).
• Ulcerative colitis. Oral oats have only been evaluated in combination with other ingredients; their effect when used alone is unclear. Details: Preliminary clinical research shows that taking a specific oat-based product (Profermin, Nordisk Rebalance) containing fermented oat flour, Lactobacillus plantarum, barley malt flour, and lecithin, 250 mL orally twice daily for 8 weeks, reduces disease activity and increases remission in about two-fold more patients with relapsing ulcerative colitis, when compared with treatment with a specific nutritional beverage (Fresubin Original, Fresenius Kabi) (90271).
• Wound healing. Although there is interest in using topical oats for wound healing, there is insufficient reliable information about the clinical effects of oats for this purpose. More evidence is needed to rate oats for these uses.

(Read more about OATS)

POSSIBLY EFFECTIVE

• Scarring. Clinical research in adults and children shows that topical application of onion extract, often as part of combination products, for 10 weeks to 6 months is beneficial for preventing scarring; however, the most effective combination of ingredients, dosage form, and dose are unclear. Details: Many small clinical trials show that using topical onion extract improves the appearance, as well as pain and itching, associated with postburn hypertrophic scars, keloidal scars, scars following tattoo removal, scars following Cesarean delivery, or scars following surgical removal of tissue when compared with control (66895,66918,66939,66951,66987,67089,67104,95151,95156,95159,104773). Products evaluated in clinical research have included gels containing a combination of onion extract, heparin, and allantoin (Contractubex, Merz Pharmaceuticals) (66895,66987,67089,67104,104773); a combination of onion extract and a silicone derivative (Cybele scagel, Bangkok Botanica) (95156,95159); a combination of onion extract, allantoin, pentaglycan, and a solution of glycosaminoglycans (Kaloidon gel, Laboratori Farmacologici Milanesi) (95151); and a transdermal patch containing a combination of onion extract and allantoin (104771). However, not all research agrees. A meta-analysis of randomized controlled trials using onion extract gel for scar management demonstrated mixed results when compared with control. However, the validity of the study is limited by high heterogeneity (109511). In addition, a specific product containing onion extract and allantoin (Mederma, Merz Pharmaceuticals) for 4-11 weeks does not appear to improve the appearance of new surgical scars (66742,66883). Similarly, observational research has found that a topical patch containing onion extract and allantoin is not associated with improved provider- or patient-assessed appearance of scars following cesarean-delivery after 4 weeks when compared with those using no scar treatment (104771). It is possible that the duration of treatment in these studies was inadequate to identify improvement.

POSSIBLY INEFFECTIVE

• Obesity. Clinical research does not support the use of dietary onion or onion supplements for weight loss. Details: Clinical research in overweight patients shows that taking capsules containing steamed onion (Oniro, Kunpoong Bio Co., Ltd) 300 mg orally three times daily for 12 weeks does not reduce body mass index (BMI), fat distribution, or fat mass when compared with placebo (101747). In addition, one clinical study in overweight and obese patients with polycystic ovary syndrome (PCOS) shows that eating raw red onion 80-120 grams daily can actually increase BMI by 0.36 kg/m2 when compared with eating 20-30 grams of raw red onion (95155). Clinical studies have also used onion products standardized by quercetin content. Preliminary clinical research in overweight and obese patients shows that taking onion peel extract providing quercetin 100 mg orally daily for 12 weeks reduces body weight by up to 1.1 kg and BMI by up to 0.4 kg/m2 when compared to baseline, but not when compared with placebo (95152,101748). Another small clinical study in healthy, overweight Japanese adults shows that taking an onion powder containing quercetin 60 mg orally daily for 12 weeks does not reduce body weight, BMI, abdominal circumference, or abdominal fat when compared with the same quantity of quercetin-free onion powder (104772).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alopecia areata. It is unclear if topical onion is beneficial in patients with alopecia areata. Details: Preliminary clinical research in children and adults with alopecia areata shows that topical application of raw onion juice twice daily for 8 weeks improves hair growth when compared with placebo. Hair regrowth was demonstrated in 74% of subjects using onion juice, compared with 13% using placebo (66797).
• Angina. Although there has been interest in using oral onion for angina, there is insufficient reliable information about the clinical effects of onion for this purpose.
• Asthma. Although there has been interest in using oral onion for asthma, there is insufficient reliable information about the clinical effects of onion for this purpose.
• Atherosclerosis. Although there has been interest in using oral onion for atherosclerosis, there is insufficient reliable information about the clinical effects of onion for this purpose.
• Bruises. Although there has been interest in using topical onion for bruises, there is insufficient reliable information about the clinical effects of onion for this purpose.
• Diabetes. It is unclear if oral onion is beneficial in patients with diabetes. Details: Preliminary clinical research in adults with type 2 diabetes shows that taking fresh onion 20 grams orally three times daily, in addition to consuming a controlled diet, for 8 weeks decreases blood glucose levels by 5% when compared with a controlled diet alone (67072).
• Dyspepsia. Although there has been interest in using oral onion for dyspepsia, there is insufficient reliable information about the clinical effects of onion for this purpose.
• Gastric cancer. It is unclear if oral onion is beneficial for preventing gastric cancer. Details: Population research has found that the highest dietary intake of onion is associated with a 48% reduced odds of gastric cancer when compared with the lowest intake (51460).
• Hypertension. It is unclear if oral onion is beneficial in patients with hypertension. Details: Preliminary clinical research in overweight or obese adults with prehypertension or hypertension shows that taking onion skin extract 132 mg orally three times daily for 6 weeks reduces 24-hour systolic blood pressure by 4 mmHg, but does not affect diastolic blood pressure, when compared with placebo (95149). Other preliminary clinical research in patients with hypertension shows that taking a specific product (Campo di mele formula, Phyt-Immun) containing onion 2.5 grams, olive oil 5 mL, grape skin extract 50 mg, L-carnitine 30 mg, vitamin E 3 mg, vitamin C 2 mg, lycopene 1 mg, and folic acid 44 mcg, once daily for one week, decreases systolic and diastolic blood pressure by 5 mmHg and 2 mmHg, respectively, when compared with placebo (66766). It is unclear if this effect is due to onion, other ingredients, or the combination.
• Hypothyroidism. It is unclear if oral onion is beneficial for preventing hypothyroidism. Details: Population research in females has found that high dietary intake of onion is associated with a lower risk of subclinical hypothyroidism when compared with low dietary intake, However, this association was not identified in males. The association of dietary onion intake with symptomatic hypothyroidism was not evaluated (109512).
• Insect bite. Although there has been interest in using topical onion for insect bites, there is insufficient reliable information about the clinical effects of onion for this purpose.
• Insomnia. It is unclear if oral onion is beneficial in patients with poor sleep quality. Details: Preliminary clinical research in healthy adults that were unsatisfied with their current sleep quality shows that taking onion extract 500 mg orally three times daily for 5 days may slightly improve sleep latency and waking after sleep onset, but does not change self-rated sleep quality, when compared with placebo (104774).
• Polycystic ovary syndrome (PCOS). It is unclear if oral onion is beneficial in patients with PCOS. Details: Clinical research in overweight or obese adults with PCOS shows that eating 80-120 grams of raw red onion daily does not improve levels of fasting blood glucose, cholesterol, triglycerides, or lipoprotein (a), and can increase body mass index (BMI) by 0.36 kg/m2, when compared with eating 20-30 grams of raw red onion daily (95155).
• Prostate cancer. It is unclear if oral onion is beneficial for preventing prostate cancer. Details: Population research has found that high dietary intake of onion is not associated with a lower odds of developing prostate cancer when compared with low dietary intake of onion (88410).
• Respiratory tract infections. Although there has been interest in using oral onion for respiratory tract infections, including the common cold, there is insufficient reliable information about the clinical effects of onion for this purpose.
• Stretch marks (striae distensae). Topical onion has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adult females shows that applying a specific cream (Mederma For Stretch Marks, Merz Pharmaceuticals) containing onion extract, gotu kola, and hyaluronic acid to striae rubra twice daily for 12 weeks improves stretch mark scores, including color, softness, and texture, when compared with no treatment (95154).
• Warts. Although there has been interest in using topical onion for warts, there is insufficient reliable information about the clinical effects of onion for this purpose. More evidence is needed to rate onion for these uses.

(Read more about ONION)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Cancer. Although there has been interest in using oral papain for cancer, there is insufficient reliable information about the clinical effects of papain for this purpose.
• Dental caries. It is unclear if topical papain gel is beneficial for reducing procedure time or pain in children having caries removed by a dentist. Details: A small clinical study in children 3-9 years of age with dental caries shows that application of a specific papain gel (Brix3000, Brix Medical Science) 3000 U/mg during atraumatic restorative treatment (ART) by a dentist actually increases the time required to remove caries tissue, with no effect on pain, when compared with ART alone (107434).
• Diabetic foot ulcers. Although there has been interest in using topical papain for diabetic foot ulcers, there is insufficient reliable information about the clinical effects of papain for this purpose.
• Exercise-induced muscle soreness. Oral papain has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in healthy males shows that taking a combination enzyme tablet containing papain 50 mg, trypsin 75 mg, bromelain 50 mg, amylase 10 mg, lipase 10 mg, lysosome 10 mg, and chymotrypsin 2 mg, four times in one day before downhill running, improves recovery of contractile muscle function and decreases muscle soreness when compared with placebo (67838). It is unclear if these findings are due to papain, other ingredients, or the combination.
• Herpes zoster (shingles). Although there has been interest in using oral papain for shingles, there is insufficient reliable information about the clinical effects of papain for this purpose.
• Insect bite. It is unclear if topical papain is beneficial in individuals with fire ant stings. Details: A small clinical study in individuals with fire ant stings shows that applying gauze soaked with a specific papain-containing meat tenderizer (Adolph's meat tenderizer) to the sting for 20 minutes does not reduce pain or itching when compared with placebo (67845).
• Intestinal parasite infection. Although there has been interest in using oral papain for intestinal parasite infections, there is insufficient reliable information about the clinical effects of papain for this purpose.
• Jellyfish stings. It is unclear if topical papain is beneficial in individuals with jellyfish stings. Details: A small clinical study in individuals with jellyfish stings shows that submerging affected skin into a solution with a papain-containing meat tenderizer (Adolph's meat tenderizer), starting two minutes after a jellyfish sting and continuing for at least 20 minutes, is less effective than hot water alone in decreasing pain caused by the jellyfish sting (67835).
• Ocular floaters. Oral papain has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A moderate-sized clinical study in patients with symptomatic ocular floaters shows that taking 1, 2, or 3 capsules daily of an oral mixed fruit enzyme product containing papain 95 mg, ficin 95 mg, and bromelain 190 mg for 3 months leads to 55%, 63%, and 70% of floaters completely disappearing, respectively, when compared to baseline, as well as significant improvements when compared with vitamin C. Additionally, in patients with vitreous hemorrhage-induced symptomatic ocular floaters, taking 3 capsules daily of the same mixed fruit enzyme product for 3 months leads to 56% of floaters completely disappearing and improves visual acuity when compared to baseline, as well as significant improvements when compared with vitamin C (111650). It is unclear if these effects are due to papain, other ingredients, or the combination.
• Pressure ulcers. Although there has been interest in using topical papain for pressure ulcers, there is insufficient reliable information about the clinical effects of papain for this purpose.
• Radiation dermatitis. Oral papain has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study in patients receiving pelvic radiotherapy shows that taking three capsules of a specific combination product (Wobe-Mugos E, Mucos Pharma) containing papain 100 mg, trypsin 40 mg, and chymotrypsin 40 mg per capsule, four times daily, beginning 3 days prior to radiotherapy and continuing until the last day of therapy, does not attenuate skin deterioration when compared with placebo (67834). However, another small, open-label clinical study in patients with uterine carcinoma shows that taking three capsules of the same combination product four times daily, beginning 7 days before radiotherapy and continuing for 9 weeks, reduces skin reactions when compared with control (67831). It is unclear if these findings are due to papain, other ingredients, or the combination.
• Radiation-induced cystitis. Oral papain has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with uterine carcinoma receiving radiotherapy shows that taking three capsules of a specific combination product (Wobe-Mugos E, Mucos Pharma) containing papain 100 mg, trypsin 40 mg, and chymotrypsin 40 mg per capsule, four times daily, beginning 7 days before radiotherapy and continuing for 9 weeks, reduces genitourinary symptoms when compared with control (67831).
• Radiation-induced nausea and vomiting. Oral papain has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients receiving pelvic radiotherapy shows that taking three capsules of a specific combination product (Wobe-Mugos E, Mucos Pharma), containing papain 100 mg, trypsin 40 mg, and chymotrypsin 40 mg per capsule, four times daily, beginning 3 days prior to radiotherapy and continuing until the last day of therapy, does not reduce radiation-related nausea or vomiting when compared with placebo (67834).
• Tonsillopharyngitis. Oral papain has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Two small clinical studies in patients with pharyngitis and/or tonsillitis shows that use of throat lozenges containing papain 2 mg, lysozyme 5 mg, and bacitracin 200 IU daily for 4 days reduces pain and inflammation of the throat and lymph nodes when compared with placebo or disinfectant alone (964,968). It is unclear if these findings are due to papain, other ingredients, or the combination.
• Traumatic oral ulcers. Although there has been interest in using topical papain for traumatic oral ulcers, there is insufficient reliable information about the clinical effects of papain for this purpose.
• Venous leg ulcers. Although there has been interest in using topical papain for venous leg ulcers, there is insufficient reliable information about the clinical effects of papain for this purpose.
• Wound healing. Topical papain has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with purulent wounds shows that applying papain 1% solution plus dimethylsulfoxide (DMSO) followed by phonophoresis, a process by which ultrasound is used to increase topical drug delivery, improves wound healing when compared to baseline (67843). The validity of this finding is limited by the lack of a comparator group. Also, it is unclear if these findings are due to papain, DMSO, or the combination. More evidence is needed to rate papain for these uses.

(Read more about PAPAIN)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Abortion. Although there has been interest in using oral parsley to induce abortion, there is insufficient reliable information about the clinical effects of parsley for this purpose.
• Constipation. Although there has been interest in using oral parsley for constipation, there is insufficient reliable information about the clinical effects of parsley for this purpose.
• Diabetes. Although there has been interest in using oral parsley for diabetes, there is insufficient reliable information about the clinical effects of parsley for this purpose.
• Dry skin. Although there has been interest in using topical parsley for dry skin, there is insufficient reliable information about the clinical effects of parsley for this purpose.
• Dyspepsia. Although there has been interest in using oral parsley for dyspepsia, there is insufficient reliable information about the clinical effects of parsley for this purpose.
• Hypertension. Although there has been interest in using oral parsley for hypertension, there is insufficient reliable information about the clinical effects of parsley for this purpose.
• Insect bite. Although there has been interest in using topical parsley for insect bites, there is insufficient reliable information about the clinical effects of parsley for this purpose.
• Kidney stones (nephrolithiasis). Although there has been interest in using oral parsley for kidney stones, there is insufficient reliable information about the clinical effects of parsley for this purpose.
• Melasma. It is unclear if topical parsley is beneficial for melasma. Details: A small clinical study in adults with melasma shows that applying a brewed parsley water to the face with a cotton ball on 6 days of each week for 8 weeks is as effective as hydroquinone 4% cream for improving dark spots (96828).
• Nonmelanoma skin cancer. Although there has been interest in using topical parsley to prevent nonmelanoma skin cancer, there is insufficient reliable information about the clinical effects of parsley for this purpose.
• Osteoarthritis. Although there has been interest in using oral parsley for osteoarthritis, there is insufficient reliable information about the clinical effects of parsley for this purpose.
• Urinary tract infections (UTIs). Although there has been interest in using oral parsley for UTIs, there is insufficient reliable information about the clinical effects of parsley for this purpose. More evidence is needed to rate parsley for these uses.

(Read more about PARSLEY)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aging skin. In patients with deep wrinkles, preliminary clinical research shows that taking zinc citrate 50 mg and phytase 3,000 units daily for four days prior to a botulinum toxin treatment increases the patient-reported duration of botulinum toxin effects by approximately 25%, compared with no improvement in patients taking zinc gluconate 10 mg or placebo. The efficacy of botulinum treatment was also improved (101913). Whether this reported benefit is due to the dose or form of zinc, citrate, phytase, the combination, or other factors, is unclear (101913,101914).
• Blepharospasm. In patients with blepharospasm, preliminary clinical research shows that taking zinc citrate 50 mg and phytase 3,000 units daily for four days prior to a botulinum toxin treatment increases the patient-reported duration of botulinum toxin effects by approximately 25%, compared with no improvement in patients taking zinc gluconate 10 mg or placebo. The efficacy of botulinum treatment was also improved (101913). Whether this reported benefit is due to the dose or form of zinc, citrate, phytase, the combination, or other factors, is unclear (101913,101914).
• Child growth. Clinical research in infants consuming a corn-based diet shows that taking a fat- and micronutrient-based food supplement containing phytase, docosahexaenoic acid (DHA), arachidonic acid, and lysine increases linear growth at age 8 and 10 months and improves locomotor development when compared with not taking this supplement. In contrast, a similar fat- and micronutrient-based supplement without phytase, DHA, arachidonic acid, and lysine does not improve these indices when compared with not taking a supplement. The phytase-containing supplement did not affect linear growth, weight for age, or hand-eye coordination at 12 months (101902). These reported benefits to child growth are likely to be due to the combination of provided essential and non-essential nutrients. Any role of phytase is expected to be minimal.
• Iron deficiency anemia. Taking phytase with a meal containing phytate and iron increases iron absorption (101903,101904,101906). However, the effect of phytase specifically for the treatment of iron deficiency anemia remains unclear (101902). Phytase is sometimes added to the diet to increase the absorption of iron from food. In a small study of women, some with iron deficiency anemia, incubating wheat as a source of phytase with a traditional grain high in phytate increased iron absorption from the meal to 8.3% from 2.6% (101904). Also, adding microbial phytase to whole wheat rolls containing phytate increases iron absorption from a meal by approximately 82% when compared with rolls without added phytase (101906). In another small study, the addition of a microbial phytase to a single corn meal with added micronutrients increases iron absorption and incorporation into red blood cells after 14 days by 1.85-fold when compared with the meal without added phytase (101903). However, consuming white wheat rolls with added wheat bran as a source of phytase does not increase iron absorption from the meal when compared to consuming rolls with added wheat bran with deactivated phytase (101906). The use of phytase as treatment for iron deficiency, with or without anemia, has rarely been investigated. However, clinical research in infants consuming a corn-based diet shows that taking a fat- and micronutrient-based food supplement containing phytase, docosahexaenoic acid (DHA), arachidonic acid, and lysine for 6 months does not seem to be more effective for reducing anemia than taking the food supplement without phytase (101902).
• Zinc deficiency. Preliminary clinical research shows that adding phytase 20.5 units to a millet-based porridge with added zinc immediately prior to consumption increases zinc absorption by approximately 68% in children aged 12-24 months (101911). Some of these children had low plasma levels of zinc at baseline. However, the use of phytase specifically for the treatment of zinc deficiency has not been investigated. More evidence is needed to rate phytase for these uses.

(Read more about PHYTASE)

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 EFFECTIVE

• Benign prostatic hyperplasia (BPH). Taking oral pumpkin seed or pumpkin seed oil may improve symptoms of BPH. Details: One study in patients with BPH shows that taking pumpkin seed 5 grams twice daily for 12 months may be more effective for controlling symptoms than pumpkin seed extract 1000 mg twice daily (92383). A specific pumpkin seed extract (Prosta Pink Forte) 1-2 capsules daily for 12 weeks has also been used (11231). Some preliminary clinical research also suggests that taking pumpkin seed oil (Prostafit, EuRho Vital) two tablets daily for 6 months may be as effective as the medication prazosin (92382). Pumpkin seed oil has also been compared with tamsulosin. A clinical study comparing pumpkin seed oil 360 mg twice daily to tamsulosin 0.4 mg once nightly for 3 months shows that both treatment groups report improvements in BPH symptoms and quality of life when compared with baseline, although improvement appears greater in the tamsulosin group, specifically when measured at 1 month and 3 months. In the pumpkin seed oil group, adverse effects were reported in 0% of patients, compared with 15% of patients taking tamsulosin (107842). The validity of this study is limited due to the short duration of treatment. Pumpkin seed oil or extracts have also been studied in combination with saw palmetto (6777), with saw palmetto, nettle root, and lemon extracts plus beta carotene (5093), and with saw palmetto, small flowered willow herb, lycopene, and pygeum (92379).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Androgenic alopecia. Oral pumpkin seed oil might improve hair regrowth in males with mild to moderate hair loss. Details: Clinical research in males with mild to moderate hair loss shows that taking pumpkin seed oil (Octa Sabal Plus, Dreamplus Co. Ltd.) 400 mg daily in divided doses for 24 weeks increases hair count by 30% when compared with placebo. Self-rated improvement and satisfaction scores were 62% and 52% with pumpkin seed oil and placebo, respectively (92378). Clinical research in patients with female pattern hair loss shows that applying 1 mL of pumpkin seed oil to the scalp daily for 30 days improves hair regrowth similarly to minoxidil 5% foam, 1 mL daily (104974).
• Interstitial cystitis. Although there is interest in using oral pumpkin for interstitial cystitis, there is insufficient reliable information about the clinical effects of pumpkin for this condition.
• Intestinal parasite infection. Although there is interest in using oral pumpkin for intestinal parasite infection, there is insufficient reliable information about the clinical effects of pumpkin for this condition.
• Overactive bladder. Oral pumpkin seed oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in females with overactive bladder shows that taking a specific combination product (Granu Fink femina, Omega Pharma) containing pumpkin seed oil 227 mg, sweet sumac bark extract 56 mg, and hops cone extract 18 mg three times daily for 12 weeks decreases the frequency of urination and leakage and improves quality of life when compared to baseline (103253). The validity of these findings is limited by the lack of a control group. Additionally, it is unclear if these findings are due to pumpkin seed oil, other ingredients, or the combination.
• Urinary tract infections (UTIs). Although there is interest in using oral pumpkin for UTIs, there is insufficient reliable information about the clinical effects of pumpkin for this condition. More evidence is needed to rate pumpkin for these uses.

(Read more about PUMPKIN)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Obesity. Preliminary clinical research in healthy overweight males shows that consuming a bread providing quinoa flour 20 grams daily for 4 weeks does not affect anthropometric measures, blood pressure, or plasma levels of glucose or cholesterol when compared with consuming a refined wheat bread (99147).
• Postmenopausal conditions. One small clinical study in postmenopausal adults shows that consuming quinoa flakes 25 grams daily for 4 weeks does not improve glycemic or lipid indices or anthropometric measures when compared with consuming corn flakes (99148). More evidence is needed to rate quinoa for these uses.

(Read more about QUINOA)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aging skin. Topical red raspberry leaf has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in females aged 30-65 years shows that applying a specific liquid (Antioxidant and Collagen Booster Serum, Max Biocare Pty Ltd.) containing red raspberry leaf cell culture extract 0.0005%, vitamin C 20%, and vitamin E 1% to the face nightly for 8 weeks, in addition to regular facial skin products, improves skin color, elasticity, radiance, smoothness, and appearance of wrinkles when compared with regular facial skin products alone (102355).
• Cardiovascular disease (CVD). Although there has been interest in using oral red raspberry leaf for CVD, there is insufficient reliable information about the clinical effects of red raspberry for this purpose.
• Congestive heart failure (CHF). Although there has been interest in using oral red raspberry leaf for CHF, there is insufficient reliable information about the clinical effects of red raspberry for this purpose.
• Diabetes. Although there has been interest in using oral red raspberry leaf for diabetes, there is insufficient reliable information about the clinical effects of red raspberry for this purpose.
• Dysmenorrhea. Although there has been interest in using oral red raspberry leaf for dysmenorrhea, there is insufficient reliable information about the clinical effects of red raspberry for this purpose.
• Hypertension. Although there has been interest in using oral red raspberry leaf for hypertension, there is insufficient reliable information about the clinical effects of red raspberry for this purpose.
• Influenza. Although there has been interest in using oral red raspberry leaf for influenza, there is insufficient reliable information about the clinical effects of red raspberry for this purpose.
• Labor pain. Some research suggests that oral red raspberry leaf does not reduce analgesic use during labor. Details: Clinical research shows that taking red raspberry leaf 2.4 grams daily, beginning at 32 weeks' gestation and continuing until delivery, does not decrease the need for analgesics in the perinatal time period when compared with placebo (9796). A systematic review of retrospective studies also supports these findings, showing no improvement in perineal outcomes in patients consuming red raspberry leaf prior to labor (108005).
• Menorrhagia. Although there has been interest in using oral red raspberry leaf for menorrhagia, there is insufficient reliable information about the clinical effects of red raspberry for this purpose.
• Obesity. It is unclear if oral red raspberry fruit is beneficial in patients with obesity. Details: Preliminary clinical research in overweight and obese adults shows that consuming frozen red raspberry fruit 280 grams daily for 8 weeks does not reduce body mass index or waist circumference when compared with control (105873).
• Osteoarthritis. It is unclear if oral red raspberry leaf extract is beneficial for knee osteoarthritis. Details: A moderate-sized clinical study in patients with knee osteoarthritis shows that taking red raspberry leaf extract 200 or 400 mg once daily for 12 weeks reduces pain at the higher dose when measured by the visual analog scale, but does not improve physical performance, physical activity, walking distance, or Western Ontario McMaster osteoarthritis index (WOMAC) global score or pain, stiffness, and function subscores when compared with placebo (112127).
• Parturition. Some research suggests that oral red raspberry leaf does not shorten the duration of labor. Details: Clinical research shows that taking red raspberry leaf 2.4 grams daily, beginning at 32 weeks' gestation and continuing until delivery, does not reduce the length of labor when compared with placebo (108005). Traditionally, doses of up to 4 grams daily have been recommended for this purpose; however, doses greater than 2.4 grams daily have not been evaluated for safety or efficacy. Further high-quality research is needed to determine the optimal dose, duration, and formulation, if any, of red raspberry leaf for this purpose.
• Pharyngitis. Although there has been interest in using topical red raspberry leaf for pharyngitis, there is insufficient reliable information about the clinical effects of red raspberry for this purpose.
• Pregnancy-induced nausea and vomiting. Although there has been interest in using oral red raspberry leaf for pregnancy-induced nausea and vomiting, there is insufficient reliable information about the clinical effects of red raspberry for this purpose.
• Respiratory tract infections. Although there has been interest in using oral red raspberry leaf for respiratory tract infections, there is insufficient reliable information about the clinical effects of red raspberry for this purpose. More evidence is needed to rate red raspberry leaf for this use.

(Read more about RED RASPBERRY)

EFFECTIVE

• Ariboflavinosis. Oral riboflavin can treat and prevent low riboflavin levels.

POSSIBLY EFFECTIVE

• Hyperhomocysteinemia. Oral riboflavin reduces homocysteine levels in individuals with the MTHFR 677 TT genotype. It does not seem to provide benefit in individuals with other genotypes. Details: Population research has found that poor riboflavin status is associated with high homocysteine levels in individuals with the 677 TT genotype for the MTHFR enzyme (71386,71403,71409). Taking riboflavin 1.6 mg daily for 12 weeks reduces homocysteine levels by 22% to 40% in individuals with the 677 TT genotype of MTHFR when compared with pretreatment. However, riboflavin supplementation does not seem to reduce homocysteine levels in individuals with the 677 CC or CT genotypes (71443).
• Migraine headache. Oral riboflavin modestly reduces migraine attack frequency and severity in adults. The benefits of oral riboflavin in children are unclear. Details: A meta-analysis of 5 small clinical trials in adults with migraine shows that taking riboflavin 100-400 mg daily, alone or in combination with other natural ingredients, for three months modestly reduces migraine duration, frequency, and pain scores when compared with control (105480). These findings are limited by significant heterogeneity. Most clinical studies compared riboflavin 400 mg daily with placebo, no treatment, or an active control (1396,1397,1398,12387,105480). Limited evidence also suggests that taking riboflavin 400 mg daily might be no different for migraine prevention than certain conventional treatments such as bisoprolol 10 mg, metoprolol 200 mg, propranolol 80 mg, or valproate 500 mg (1396,105480). These findings are limited due to small study size and a lack of power to detect a difference between groups. Limited research has also evaluated riboflavin in children. A network meta-analysis of 3 small clinical trials in children with migraine shows that taking oral riboflavin 100-200 mg daily for 4-12 months does not significantly reduce incidence of migraine when compared with placebo. However, there was a non-significant trend towards reduced migraine frequency. Furthermore, conventional treatments such as propranolol, pregabalin, valproate, and topiramate were not shown to be significantly better than riboflavin for migraine prevention (105484). These findings are limited by small population sizes and insufficient power to detect differences between groups. Although riboflavin 100-200 mg has been used in prospective clinical studies, small observational studies have found some benefit in children taking riboflavin doses as low as 10-40 mg daily and as high as 400 mg daily for 3-4 months (105481,105485). Riboflavin has also been studied in combination with other ingredients, with research suggesting potential benefit. Specifically, riboflavin 400 mg has been combined with magnesium 600 mg and coenzyme Q10 150 mg daily (Dolovent; Linpharma Inc.) (92101), and also with magnesium 300 mg and feverfew 100 mg daily (12389).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Although there is interest in using oral riboflavin for acne, there is insufficient reliable information about the clinical effects of riboflavin for this purpose.
• Alzheimer disease. Although there is interest in using oral riboflavin for Alzheimer disease, there is insufficient reliable information about the clinical effects of riboflavin for this condition.
• Anxiety. It is unclear if oral riboflavin is beneficial for anxiety. Details: A large observational cohort study in adults suggests that a dietary riboflavin intake above 2.1 mg daily is associated with a 5% lower prevalence of anxiety when compared with a riboflavin intake less than 1.6 mg daily. Subgroup analysis suggests that this association is especially strong in males (111209).
• Cardiovascular disease (CVD). It is unclear if oral riboflavin can prevent mortality due to CVD. Details: Epidemiological research has found that dietary and supplemental riboflavin intake in the highest quartile, around 3.4 mg daily, is associated with a 47% lower risk of CVD mortality when compared with riboflavin intake in the lowest quartile, around 1 mg daily. The reduction in CVD mortality with riboflavin was enhanced by higher folate intake (110727). The validity of this finding is limited by the fact that dietary riboflavin intake was based on 2-day dietary recall.
• Carpal tunnel syndrome. Although there is interest in using oral riboflavin for carpal tunnel syndrome, there is insufficient reliable information about the clinical effects of riboflavin for this purpose.
• Cataracts. It is unclear if oral riboflavin is beneficial in patients with cataracts. Details: Observational research has found that high dietary intake of riboflavin is associated with a reduced risk of nuclear cataracts and age-related lens opacification (6378,14301). Furthermore, a clinical study in Chinese patients with nutrient deficiencies shows that taking a combination of riboflavin 3 mg plus niacin 40 mg daily also seems to reduce the risk of developing nuclear cataracts when compared with no supplementation (4885). It is unclear if the benefit is due to riboflavin, niacin, or the combination.
• Cervical cancer. It is unclear if oral riboflavin helps to prevent cervical cancer. Details: Epidemiological evidence has found that increased riboflavin intake from dietary and supplement sources, along with other B vitamins, is associated with a reduced risk of precancerous cervical lesions (11074).
• Cognitive function. Oral riboflavin has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A moderate-sized clinical study in healthy adults aged 40-65 years shows that taking a combination supplement containing riboflavin 70 mg, other group B vitamins, ginkgo leaf, and bacopa daily for 12 weeks does not improve measures of memory, attention, cognition, mood, or stress reactivity when compared with placebo (111334).
• Colorectal cancer. It is unclear if oral riboflavin reduces colorectal cancer risk. Details: Epidemiological evidence in a Chinese population suggests that increased dietary intake of riboflavin is associated with a reduced risk of developing colorectal cancer (105482).
• Depression. It is unclear if oral riboflavin is beneficial for depression. Details: A large cross-sectional study in middle-aged adults suggests that dietary riboflavin intake above 2.1 mg daily is associated with an 8% lower prevalence of depression when compared with a riboflavin intake less than 1.6 mg daily. Subgroup analysis suggests that this association is especially strong in males (111209).
• Diabetes. It is unclear if oral riboflavin reduces the risk of developing gestational diabetes. Details: A large prospective cohort study in pregnant adults shows that supplementation with riboflavin at doses over 2.5 mg daily during the first trimester and 2.1 mg daily in the second trimester is associated with a lower risk of developing gestational diabetes when compared with riboflavin doses under 1.1 mg daily. However, this effect was not found for dietary intake of riboflavin, only supplementation. Additionally, the participants were mostly Han Chinese adults, limiting the generalizability of the findings to other populations (111680).
• Diabetic neuropathy. Intravenous and oral riboflavin have only been evaluated in combination with other ingredients; riboflavin's effect when used alone is unclear. Details: Clinical research in patients with type 2 diabetes shows that intravenous administration of a specific combination product containing succinic acid, inosine, nicotinamide, and riboflavin (Cytoflavin, Polysan) daily for 10 days followed by an oral formulation of the same product, taken daily for 76 days, reduces symptoms of diabetic neuropathy including paresthesia, numbness, and burning when compared with placebo (110503). It is unclear if these findings are due to riboflavin, other ingredients, or the combination.
• Esophageal cancer. It is unclear if oral riboflavin reduces esophageal cancer risk. Details: Population research in Iranian patients has found that low riboflavin status is associated with a two-fold increase in the risk of esophageal cancer (71439). However, not all evidence agrees. Preliminary clinical studies in Chinese individuals with esophageal dysplasia shows that taking riboflavin, alone or in combination with calcium or niacin, for 3-5 years does not seem to reduce the risk of esophageal cancer in patients when compared with baseline or control (4679,63576,71488). Taking riboflavin 200 mg weekly, in combination with retinol 15 mg and zinc 50 mg, also does not seem to be beneficial in this patient population (71501). It is unclear if these findings are generalizable to geographic locations other than China and Iran.
• Gastric cancer. It is unclear if oral riboflavin reduces colorectal cancer risk. Details: Low quality clinical research in a Chinese population shows that taking riboflavin in combination with niacin does not reduce the risk of gastric cancer when compared with control (4679).
• Hypertension. There is limited evidence on the oral use of riboflavin for reducing blood pressure in patients with the MTHFR 677 TT genotype. Details: A 677 C to T polymorphism on the MTHFR gene has been associated with hypertension. In patients with a confirmed MTHFR 677 TT genotype and premature cardiovascular disease, preliminary clinical research suggests that taking riboflavin 1.6 mg daily for 16 weeks reduces systolic blood pressure (SBP) by 9 mmHg and diastolic blood pressure (DBP) by 6 mmHg when compared with placebo. This decrease in blood pressure is larger than that reported in other trials, which may be due to the fact that only patients with the 677 TT genotype were included. These patients seem to respond to riboflavin therapy more so than patients with 677 CC or 677 CT genotype (92102). Additional clinical research in patients with the 677 TT genotype but without cardiovascular disease shows that taking riboflavin 1.6 mg daily for 16 weeks reduces SBP by 5.6 mmHg but does not reduce DBP (92103). There is also interest in using dietary riboflavin for reducing the onset of hypertension. Some epidemiological evidence in a Chinese population has found that increased dietary intake of riboflavin is associated with a reduced risk of developing hypertension (105483).
• Liver cancer. Oral riboflavin has only been evaluated in combination with niacin; its effect when used alone is unclear. Details: Preliminary clinical research in Chinese individuals older than 55 years shows that taking riboflavin in combination with niacin does not seem to prevent liver cancer mortality when compared with control. However, there was a reduced risk of liver cancer mortality in people aged less than 55 years when compared with control (63470).
• Lung cancer. Oral riboflavin has only been evaluated in combination with niacin; its effect when used alone is unclear. Details: Preliminary clinical research in Chinese individuals shows that taking riboflavin in combination with niacin does not appear to reduce the risk of lung cancer when compared with control (34539).
• Malaria. Oral riboflavin has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in children ages 5-14 years living in Gambia and at high risk for malaria exposure suggests that taking riboflavin, in combination with iron, thiamine, and vitamin C, for 3 months does not reduce the frequency or severity of malaria infections when compared with placebo (56730).
• Malnutrition. There is limited evidence on the oral use of riboflavin with other ingredients in children at risk for kwashiorkor. Details: A clinical study in Malawian children at risk for kwashiorkor, a severe form of malnutrition, suggests that taking riboflavin, vitamin E, selenium, and N-acetyl cysteine at a dose of three times the recommended dietary allowance does not prevent kwashiorkor, reduce edema, increase physical growth, or reduce infection when compared with placebo (71433).
• Mitochondrial myopathies. Although there is interest in using oral riboflavin for mitochondrial myopathies, there is insufficient reliable information about the clinical effects of riboflavin for this condition.
• Multiple sclerosis (MS). It is unclear if oral riboflavin slows the progression of MS-related disability. Details: A small clinical study in patients with relapsing-remitting MS or secondary progressive MS who are undergoing treatment with disease-modifying therapies suggests that taking oral riboflavin 10 mg daily for six months is no more effective for improving disability than placebo (91752). The validity of this finding is limited by the small study sample size.
• Oral leukoplakia. It is unclear if oral riboflavin prevents or slows progression of oral leukoplakia. Details: Population research in people living in Uzbekistan suggests that low blood levels of riboflavin are associated with an increased prevalence of oral leukoplakia (71502). However, clinical evidence in patients with a high occurrence of oral and esophageal cancer who are living in Uzbekistan suggests that taking riboflavin 80 mg weekly for 20 months does not improve the prevalence or progression of oral leukoplakia when compared to baseline (71565). The validity of this finding is limited by the lack of a placebo group and unusual once weekly dosing. Furthermore, it is unclear if these results are generalizable to other geographic locations.
• Pre-eclampsia. Although there is interest in using oral riboflavin for pre-eclampsia, there is insufficient reliable information about the clinical effects of riboflavin for this purpose.
• Pregnancy-related iron deficiency. It is unclear if oral riboflavin is beneficial in patients with iron deficiency due to pregnancy. Details: Preliminary clinical research in pregnant patients in China suggests that adding riboflavin 1 mg daily to supplemental iron and folic acid does not improve iron status when compared with taking iron and folic acid alone (71480).
• Sickle cell disease. It is unclear if oral riboflavin is beneficial in patients with sickle cell disease. Details: One small clinical study in patients with sickle cell disease suggests that taking riboflavin 5 mg twice daily for 8 weeks increases serum iron and transferrin saturation when compared to baseline; however, riboflavin does not seem to improve serum ferritin or circulating hemoglobin levels (71566).
• Stroke. Oral riboflavin has only been evaluated in combination with niacin; its effect when used alone is unclear. Details: Preliminary clinical research in Chinese individuals with poor nutritional status who are at risk for stroke suggests that taking riboflavin 5.2 mg daily in combination with niacin 40 mg daily does not reduce the risk of stroke-related mortality (2673). More evidence is needed to rate riboflavin for these uses.

(Read more about RIBOFLAVIN)

POSSIBLY EFFECTIVE

• Hypertension. Oral sesame oil seems to reduce blood pressure by a small amount. Details: Meta-analyses of clinical research involving patients with or without hypertension show that taking sesame, or the sesame constituent sesamin, can reduce both systolic blood pressure (SBP) and diastolic blood pressure (DBP) (96179,108355,108357). One meta-analysis of eight clinical studies shows that sesame or sesamin can reduce SBP by 8 mmHg and DBP by 6 mmHg when compared with control. In a subgroup analysis of patients with hypertension, reductions in SBP and DBP were 11 mmHg and 9 mmHg, respectively. In a subgroup analysis by formulation, sesame oil was shown to reduce SBP and DBP by 13 mmHg and 10 mmHg, respectively, while whole sesame seed, ground seed, or sesame supplement lowered SBP by only 3 mmHg and did not lower DBP (96179). Another meta-analysis of clinical studies involving patients with hypertension, metabolic syndrome, or kidney failure shows that taking sesame oil reduces SBP and DBP by 3 mmHg and 2 mmHg, respectively, although benefits were limited to studies of less than 8 weeks (108355). Some research on sesame oil involved replacing other cooking oils with a specific brand of sesame oil (Idhayam Gingelly oil, V.V.V. & Sons) 35 grams daily for about 6-9 weeks. Patients included in these studies were also using atenolol, nifedipine, and/or hydrochlorothiazide as antihypertensives (27652,27654,27655). Other preliminary clinical research shows that using a 20:80 blend of sesame oil and rice bran oil (Vivo, Adani Wilmar) as cooking oil for 8 weeks improves blood pressure and lipid profile in patients with hypertension. In patients using nifedipine, using the oil blend seems to reduce systolic and diastolic blood pressure by an additional 2 to 2.2-fold over nifedipine alone (96180).

POSSIBLY INEFFECTIVE

• Cough. Oral sesame oil does not seem to be beneficial for cough in children. Details: Clinical research in children with an acute cough due to common cold shows that taking sesame oil 5 mL by mouth at bedtime for 3 consecutive days does not reduce cough strength or cough frequency when compared with placebo (27647).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aging skin. Although there is interest in using topical sesame oil for aging skin, there is insufficient reliable information about the clinical effects of sesame for this purpose.
• Alzheimer disease. Although there is interest in using oral sesame for Alzheimer disease, there is insufficient reliable information about the clinical effects of sesame for this condition.
• Anemia of chronic disease. Although there is interest in using oral sesame for anemia of chronic disease, there is insufficient reliable information about the clinical effects of sesame for this condition.
• Anxiety. Although there is interest in using topical sesame oil for anxiety, there is insufficient reliable information about the clinical effects of sesame for this purpose.
• Bowel obstruction. It is unclear if oral sesame oil is beneficial for bowel obstruction. Details: Preliminary clinical research in adults with adhesive small bowel obstruction shows that giving sesame oil 150 mL through a nasogastric tube along with standard treatment reduces the need for surgical intervention when compared with standard treatment alone. Also, the resolution time of the obstruction was 6 hours faster and the duration of hospitalization was 4 days shorter for patients treated with sesame oil plus standard treatment when compared with standard treatment alone (27645). Standard treatment consisted of stopping oral intake of food, performing nasogastric tube decompression, administering intravenous fluids with electrolytes, and providing parenteral antibiotics if leukocytosis was present.
• Burns. It is unclear if topical sesame oil is beneficial for burns. Details: Preliminary clinical research in adults and children with partial thickness thermal burns covering less than 40% of body surface area shows that topical application with a moist exposed burn ointment (MEBO) containing sesame oil, beta-sitosterol, berberine, and other unspecified plant ingredients every 4 hours reduces the median time to 75% healing by 3 days (17 days vs. 20 days) and improves analgesic effects during the first 5 days of treatment when compared with a control group receiving cleansing with chlorhexidine 0.05%. The MEBO was left on the burn for 5 days, followed by removal and reapplication at 4 hourly intervals on day 5, to be left on until day 14 (13526).
• Cardiovascular disease (CVD). Although there is interest in using oral sesame for CVD, there is insufficient reliable information about the clinical effects of sesame for this condition.
• Cataracts. Although there is interest in using oral sesame for cataracts, there is insufficient reliable information about the clinical effects of sesame for this condition.
• Chemotherapy-induced phlebitis. It is unclear if massage with topical sesame oil is beneficial for chemotherapy-induced phlebitis. Details: Preliminary clinical research in patients with colorectal cancer and chemotherapy-induced phlebitis shows that applying 10 drops of sesame oil within a 10 cm radius of the affected veins as part of a 5-minute, twice-daily massage reduces pain after 7 days when compared with massage alone (103227).
• Child growth. It is unclear if massage with topical sesame oil is beneficial for child growth. Details: Preliminary clinical research in full-term healthy infants shows that administering a daily massage with sesame oil 20 mL for 4 weeks improves infant length by 1 cm, midarm circumference by 0.9 cm, and midleg circumference by 0.7 cm when compared with a control group that did not receive a massage (29722). It is unclear if these effects are due to sesame oil, massage, or the combination.
• Cognitive impairment. It is unclear if oral sesame is beneficial for cognitive impairment. Details: Clinical research in older adults with memory impairment shows that taking sesame oil cake extract (Keukdong H-Pharm Co., Ltd.) 500 mg three times daily for 12 weeks modestly improves some, but not all, measures of cognitive function when compared with placebo (108351). In addition, preliminary clinical research in patients with mild cognitive impairment shows that taking two capsules of a combination product containing the sesame constituent sesamin 5 mg and astaxanthin 3 mg daily for 12 weeks increases psychomotor and processing speed when compared with placebo. However, there was no effect on memory, attention, or overall severity of cognitive symptoms (99863). It is not clear if these effects are due to sesamin, astaxanthin, or the combination.
• Dental plaque. It is unclear if rinsing the mouth with sesame oil or pulling the oil through the teeth is beneficial for dental plaque. Details: Preliminary clinical research in children 12-14 years of age shows that rinsing with 10 mL of ozonated or non-ozonated sesame oil for 10 minutes daily for 15 days reduces plaque when compared with baseline. The ozonated sesame oil was superior to non-ozonated sesame oil, showing a similar improvement in plaque when compared with chlorhexidine mouthwash (103226). A small clinical study in healthy adults shows that pulling sesame oil 10 mL through the teeth for 15-20 minutes twice daily for 4 days has similar effects on full-mouth prevention of plaque regrowth, tooth staining, gingival index, and bleeding when compared with pulling coconut oil through the teeth (106038).
• Diabetes. It is unclear if oral sesame oil is beneficial for diabetes. Details: Meta-analyses suggest that taking sesame for 6-12 weeks modestly reduces levels of fasting blood glucose and glycated hemoglobin (HbA1c), but not insulin levels or insulin resistance, when compared with placebo, baseline, or other control. Sesame oil and seed flour, tahini, and sesamin were used in the included research (108350,108352,108355). Although most studies included in these meta-analyses were conducted in patients with type 2 diabetes, one study (103231) was conducted in patients with metabolic syndrome. One small clinical trial included in these meta-analyses shows that replacing other cooking oils with a specific brand of sesame oil (Idhayam Gingelly oil, V.V.V. & Sons) 35 grams daily for 45 days reduces blood glucose levels and HbA1c when compared with baseline in patients with diabetes who are also using glibenclamide (27654). Sesame oil has also been investigated in combination with rice bran oil. One preliminary clinical trial in patients with type 2 diabetes not using antidiabetes medications shows that using a specific 20:80 blend of sesame oil and rice bran oil (Vivo, Adani Wilmar) as the only cooking oil for 8 weeks reduces levels of fasting blood glucose by 14% and reduces HbA1c when compared with baseline. In patients taking glibenclamide 5 mg daily, using this oil blend reduces fasting blood glucose and HbA1c when compared with glibenclamide alone (96177). The use of sesame oil has also been investigated for improving cardiometabolic markers in patients with type 2 diabetes. Clinical research in adults taking antidiabetes medications shows that replacing regular dietary oils with sesame oil or a blend of sesame and canola oils for 9 weeks does not improve most cardiometabolic markers when compared with canola oil or sunflower oil as a control (108353).
• Gastric cancer. Although there is interest in using oral sesame for gastric cancer prevention, there is insufficient reliable information about the clinical effects of sesame for this purpose.
• Gingivitis. It is unclear if pulling sesame oil through the teeth is beneficial for gingivitis. Details: Preliminary clinical research in adolescent males with plaque-induced gingivitis shows that oil pulling with sesame oil for one minute daily each morning prior to brushing for 10 days reduces dental plaque and gingivitis when compared with baseline (27648). The validity of this finding is limited by the lack of a comparator group.
• Hemorrhoids. Topical sesame oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small study in adults with symptomatic mild to moderate (first- and second-degree) internal hemorrhoids shows that application of a cream containing sesame oil and aqueous extracts of guggul and Allium ampeloprasum as a thin layer to the anus twice daily for 3 weeks improves anal irritation and itching, bleeding, pain, defecation discomfort, and swelling sense when compared with baseline. In contrast, patients using a placebo cream experienced an improvement only in anal itching (105751). The poor study methodology and lack of statistical comparison to the placebo group limit the validity of these findings.
• HIV/AIDS-related wasting. Oral sesame has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with HIV shows that consuming 300 grams of a chickpea and sesame-based food supplement daily for 3 months, along with routine sulfamethoxazole-trimethoprim, improves weight gain, body mass index, and mid-upper arm circumference in 73% of patients, and results in improved physical performance in 78% of patients, when compared to baseline (27657). The validity of these findings is limited by the lack of a comparator group.
• Hyperlipidemia. It is unclear if oral sesame is beneficial for hyperlipidemia. Details: A meta-analysis of a limited number of clinical studies that included mainly patients without hyperlipidemia shows that consuming sesame 25-50 grams daily or using sesame oil 3.5-35 grams daily for up to 10 weeks does not reduce levels of total or low-density lipoprotein (LDL) cholesterol when compared with baseline (96181). However, a more recent meta-analysis with similar studies shows that consuming sesame reduces levels of total cholesterol by 16 mg/dL, although there is no effect on levels of LDL cholesterol or high-density lipoprotein (HDL) cholesterol (108357). Both analyses show that taking sesame reduces triglyceride levels by about 21 mg/dL (96181,108357). Significant heterogeneity of the included studies and patient populations limits the validity of these results.
• Insect repellent. Although there is interest in using topical sesame oil as an insect repellent, there is insufficient reliable information about the clinical effects of sesame for this purpose.
• Male infertility. It is unclear if oral sesame is beneficial for male infertility. Details: Preliminary clinical research in males with infertility shows that taking sesame 0.5 mg/kg daily for 3 months modestly improves sperm count and motility, but not sperm morphology, when compared with baseline (108356). The validity of these findings is limited by the lack of a comparator group.
• Menopausal symptoms. Although there is interest in using oral sesame for menopausal symptoms, there is insufficient reliable information about the clinical effects of sesame for this purpose.
• Metabolic syndrome. It is unclear if oral sesame oil is beneficial for improving metabolic parameters in adults with metabolic syndrome. Details: Preliminary clinical research in patients with metabolic syndrome shows that taking sesame oil 30 mL with or without vitamin E 400 mg daily for 8 weeks improves levels of fasting blood glucose, lipids, and blood pressure when compared with sunflower oil. In those taking sesame oil alone, total cholesterol and triglycerides were reduced by about 13 mg/dL, while low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol were not affected. In those also taking sesame oil with vitamin E, total cholesterol and triglycerides were reduced by 17 mg/dL and 21 mg/dL, respectively, while HDL cholesterol was increased by 4 mg/dL. Additionally, systolic and diastolic blood pressure were reduced by 10 mmHg and 8 mmHg, respectively, in those taking sesame oil alone, versus 15 mmHg and 9 mmHg, respectively, in those taking sesame oil with vitamin E (103231).
• Miscarriage. It is unclear if oral sesame is beneficial for the management of an incomplete miscarriage. Details: Preliminary clinical research in patients with incomplete abortion related to miscarriage shows that taking sesame seed twice daily for 5 days results in complete resolution of retained products of conception in 84% of individuals, based on a sonographic assessment, compared with 26% of those receiving expectant management as control. There was also a 2-day reduction in the duration of vaginal bleeding when compared with control. Each dose of ground sesame seed powder 30 grams was boiled in 200 mL water for 4 minutes and then filtered before drinking (108346).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral sesame oil is beneficial for NAFLD. Details: Clinical research in females with NAFLD shows that taking sesame oil 30 grams daily for 12 weeks reduces the severity of fatty liver in 89% of patients taking sesame oil, compared with 58% of those taking sunflower oil. There were also modest reductions in levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), but not alkaline phosphatase (ALP), when compared with sunflower oil. All patients were also consuming a 500-kcal hypocaloric diet (108354).
• Obesity. It is unclear if oral sesame is beneficial for weight loss. Details: Meta-analyses of clinical research show that taking sesame or sesame oil in doses of at least 35 grams daily reduces body weight by up to 2 kg and body mass index by up to 1 kg/m² when compared with no oil or a control oil. Clinical studies included in these meta-analysis enrolled patients with type 2 diabetes, hypertension, hypercholesterolemia, and others, and were not limited to overweight or obese individuals (108355,108357). A small clinical study in overweight individuals shows that replacing regular dietary oil with sesame oil for 9 weeks does not improve levels of most cardiometabolic risk factors, although there were modest beneficial effects on insulin (108349).
• Osteoarthritis. It is unclear if topical sesame oil is beneficial for knee osteoarthritis. Details: Preliminary clinical research in patients with osteoarthritis of the knee shows that applying sesame oil 1.5 mL to the affected knee three times daily for 4 weeks reduces pain and improves physical function when compared to baseline. These improvements were similar to those seen in patients applying diclofenac topical gel (103228).
• Osteoporosis. Although there is interest in using oral sesame for osteoporosis, there is insufficient reliable information about the clinical effects of sesame for this condition.
• Pain (acute). It is unclear if massage with topical sesame oil is beneficial for acute pain caused by blunt trauma. Details: One small clinical study shows that using a specific sesame oil (Saman sesame oil, Saman sesame oil Co.) topically as part of a light massage for 5 minutes twice daily for 9 days moderately reduces acute pain caused by blunt trauma to an extremity by day 6 when compared with a light massage with placebo oil. However, the sesame oil massage does not reduce the use of nonsteroidal anti-inflammatory drugs when compared with placebo oil (96178). A similar clinical study in the same population shows that using sesame oil extracted from tahini topically as part of a light massage for 5 minutes 3 times a day for 2 days improves pain severity, pain sensitivity, and heaviness of the painful site by about 20% when compared with baseline (106034). The lack of statistical comparison to the placebo group limits the validity of these findings.
• Peptic ulcers. Although there is interest in using oral sesame for peptic ulcers, there is insufficient reliable information about the clinical effects of sesame for this purpose.
• Rheumatoid arthritis (RA). It is unclear if oral sesame is beneficial for RA. Details: Preliminary clinical research in females with RA shows that taking the sesame constituent sesamin (Sesamin, Scivation, Inc.) 200 mg daily for 6 weeks improves physical function and reduces pain, the number of tender and swollen joints, and markers of inflammation such as C-reactive protein when compared with placebo (103230).
• Stroke. Although there is interest in using oral sesame for stroke, there is insufficient reliable information about the clinical effects of sesame for this purpose. More evidence is needed to rate sesame for these uses.

(Read more about SESAME)

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)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• HIV/AIDS. Preliminary clinical research in HIV patients using antiretroviral therapy shows that taking a specific product containing sorghum extract and other ingredients (Jobelyn, Health Forever Product Ltd.) orally twice daily for 12 weeks improves CD4+ T cell count when compared with antiretroviral therapy alone. Hemoglobin levels were increased compared with baseline in patients ineligible for antiretrovirals (97674).
• Iron deficiency anemia. Preliminary clinical research shows that taking a specific product containing sorghum extract and other ingredients (Jobelyn, Health Forever Product Ltd.) orally once daily for 3 weeks does not improve red blood cell indices in patients with anemia who were also taking iron 600 mg daily and folic acid 5 mg daily (97675).
• Obesity. Preliminary clinical research in overweight and obese men shows that eating extruded sorghum cereal 40 grams each morning along with a calorie restricted diet for 8 weeks reduces body fat by around 2%, but does not appear to improve body weight, body mass index, or waist circumference, when compared with extruded wheat cereal plus calorie restriction (103898). More evidence is needed to sorghum for these uses.

(Read more about SORGHUM)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Cognitive function. It is unclear if consuming spinach is beneficial for cognitive function. Details: Preliminary clinical research in healthy adults shows that consuming spinach 200 grams with lunch does not improve attention or memory after 150 minutes when compared with a rice milk control (96852).
• Muscle strength. It is unclear if oral spinach is beneficial for muscle strength. Details: A small, preliminary clinical study in healthy adults over 50 years of age shows that taking an aqueous spinach extract, 1 gram orally twice daily, in conjunction with a moderate-intensity exercise program, 3 sessions per week of 1 hour each for 12 weeks, improves several measures of muscle strength and quality in both sexes, and increases lower leg muscle mass in males, when compared with placebo (109546).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral spinach can reduce the risk of developing NAFLD. Details: A large observational study has found that raw, but not boiled, spinach consumption is inversely associated with the risk of developing NAFLD (106566).
• Obesity. It is unclear if consuming spinach is beneficial for weight loss. Details: Preliminary clinical research in overweight or obese middle-aged and older females shows that taking a specific spinach product (Appethyl, Greenleaf Medical AB) 5 grams daily before breakfast for 12 weeks increases weight loss by an additional 1.5 kg when compared with placebo. However, fat loss, waist circumference, and blood lipids are not improved when compared with placebo (96856,96857).
• Polycystic ovary syndrome (PCOS). It is unclear if oral spinach-derived thylakoids are beneficial for PCOS. Details: A small clinical study in premenopausal adults with PCOS and obesity shows that adding 5 grams orally daily of spinach-derived thylakoids to a low-calorie diet for 12 weeks reduces weight and body mass index (BMI) by 8%, compared with 4% with placebo and the low-calorie diet. Insulin resistance is also improved among those receiving spinach extract. These changes are unlikely to be clinically significant (106568). More evidence is needed to rate spinach for these uses.

(Read more about SPINACH)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Cardiovascular disease (CVD). Pooled analyses of clinical research show that taking freeze-dried strawberry powder or eating fresh strawberries for 3-12 weeks can reduce levels of C-reactive protein, a marker of inflammation and risk factor for CVD, by 0.47-0.63 mg/L when compared with placebo. These analyses report conflicting effects on blood pressure and lipid levels (103881,103882), with one analysis reporting small improvements that are not clinically significant (103881). It is unclear whether strawberry can prevent CVD or related outcomes.
• Diabetes. Preliminary clinical research in adults with type 2 diabetes shows that taking freeze-dried strawberry powder 50 grams daily for 6 weeks reduces glycated hemoglobin (HbA1c) by 0.47% compared to an increase of 0.15% with placebo. However, there were no changes in serum glucose, anthropometric measurements, blood lipids, or blood pressure. Also, the short duration of supplementation makes it unclear whether the change in HbA1c was due to strawberry (100113,100119).
• Hyperlipidemia. Data on the effects of strawberry on serum lipids are conflicting. Clinical research in adults with abdominal obesity and elevated serum lipids shows that taking freeze-dried strawberry powder 50 grams daily for 12 weeks reduces total and low-density lipoprotein (LDL) cholesterol when compared with either placebo or taking 25 grams of freeze-dried strawberry daily. In those taking 50 grams daily, levels of LDL cholesterol decreased by approximately 21% from baseline, compared with a 2% reduction in those taking placebo. However, strawberry did not improve levels of high-density lipoprotein (HDL) cholesterol or triglycerides (100109). Another study also reported reduced levels of total and LDL cholesterol (112318), while others report no changes in any lipid levels (112320,112321). In a meta-analysis, strawberry was associated with mean decreases of 11 mg/dL in LDL levels, and 12 mg/dL in total cholesterol, as well as increases in high-density lipoprotein (HDL) cholesterol (112323).
• Hypertension. Preliminary clinical research in postmenopausal women with pre- or stage I hypertension shows that taking freeze-dried strawberry powder 25 or 50 grams daily for 8 weeks does not reduce blood pressure when compared with placebo. However, over 50% of the included women were also taking at least one blood pressure lowering medication (100111).
• Obesity. Clinical research in adults with obesity or abdominal obesity and elevated serum lipids shows that taking freeze-dried strawberry powder 50 grams daily for 12 weeks does not reduce body weight or adiposity when compared with either placebo or freeze-dried strawberries 25 grams daily (100109,100116). Similarly, preliminary clinical research in adults with type 2 diabetes who are overweight or obese shows that taking freeze-dried strawberry powder 50 grams daily for 6 weeks does not improve weight loss when compared with placebo (100113). Evidence from mainly small, lower-quality studies is mixed as to whether taking strawberries has beneficial effects on cardiovascular risk factors when compared to control in obese individuals (100109,100116,100118).
• Osteoarthritis. Preliminary clinical research in obese adults with osteoarthritis shows that taking freeze-dried strawberry powder 50 grams daily for 12 weeks reduces some, but not all, measures of pain by up to 45%, compared to no change in those taking placebo (100116). More evidence is needed to rate strawberry for these uses.

(Read more about STRAWBERRY)

POSSIBLY EFFECTIVE

• Coronary heart disease (CHD). The U.S. Food and Drug Administration (FDA) allows a qualified health claim stating that using high-oleic acid sunflower oil as a replacement for other dietary fats and oils higher in saturated fat may reduce the risk of CHD. Details: A meta-analysis of clinical studies shows that replacing 7.5% of energy from partially hydrogenated vegetable oils with high-oleic acid sunflower oil can reduce CHD risk by about 9% to 19%. Furthermore, analysis of results from observational studies found that replacing partially hydrogenated oil with high-oleic acid sunflower oil is associated with a 16% to 35% reduction in the risk of CHD events (95745). The FDA allows for a qualified health claim that replacing dietary fats and oils higher in saturated fat with high-oleic acid sunflower oil may reduce the risk of CHD. To achieve this benefit, the use of high-oleic acid sunflower oil should not increase total daily energy intake. The suggested daily dietary intake is about 20 grams (1.5 tbsp) of high-oleic sunflower oil in place of other fats and oils (98563). Sunflower oil that contains high amounts of linoleic acid rather than oleic acid does not appear to improve cholesterol levels or reduce the risk of cardiovascular events in patients with CHD (96205).
• Hypercholesterolemia. Consuming sunflower oil in the diet may reduce low-density lipoprotein (LDL) cholesterol levels in some patients. Details: There is evidence that using sunflower oil in the diet as 45-50 grams daily for up to 12 weeks is more effective than olive oil for decreasing LDL cholesterol and apolipoprotein B levels in healthy individuals (9780). Also, clinical research in patients with mild hyperlipidemia or moderate hypercholesterolemia shows that consuming specific brands of mid-oleic acid (NuSun) or high-oleic acid (Sunola, Meadow Lea Foods) sunflower oils as 15% to 20% of dietary calories for up to 5 weeks is more effective than olive oil or saturated fat for decreasing total cholesterol, LDL cholesterol, and apolipoprotein B levels (76697,76698). Also, consuming a high-oleic sunflower oil-rich diet for 3 weeks decreases total cholesterol levels to a greater extent than diets enriched with palm oil or medium-chain triglycerides in patients with mild hypercholesterolemia (67569). Other preliminary clinical research in patients with moderate hypercholesterolemia shows that consuming a diet rich in sunflower oil for 3 weeks decreases total cholesterol and LDL cholesterol levels when compared with baseline. However, levels of high-density lipoprotein (HDL) cholesterol appear to be lowered as well (76714). Despite these beneficial effects, sunflower oil might be less effective than some other dietary oils. Taking sunflower oil for 3 months appears to be less effective than rice bran oil for lowering cholesterol in patients with hypercholesterolemia (76699). Also, while consuming sunflower oil 45 grams daily, as part of the diet and as a supplement, for 12 weeks reduces levels of total cholesterol and LDL cholesterol when compared to baseline, it appears to be less effective at reducing total cholesterol levels than flaxseed oil in certain patients at risk for atherosclerosis (76696). In addition, taking sunflower oil 15.1 grams daily for 4 months does not appear to reduce levels of total or LDL cholesterol in patients with peripheral vascular disease (76691).

POSSIBLY INEFFECTIVE

• Hypertension. Oral sunflower oil does not seem to lower blood pressure. Details: Preliminary clinical research in adults with hypertension shows that taking sunflower oil 30-40 grams daily for one year is less effective than extra-virgin olive oil for reducing blood pressure (5091). Also, clinical research in elderly adults with hypertension shows that taking 60 grams of sunflower oil daily for 4 weeks is less effective than virgin olive oil for reducing systolic blood pressure (76692).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Atherosclerosis. It is unclear if oral sunflower oil is beneficial for atherosclerosis; some clinical research suggests that it may provide less benefit than other dietary oils. Details: Some preliminary clinical research in individuals with overweight and obesity shows that taking sunflower oil 30 mL (about 27 grams) daily for 90 days decreases carotid intima-media thickness (CIMT) by 3.5% when compared to baseline, but not when compared with olive oil or flaxseed oil. Sunflower oil also improves flow-mediated vasodilation by 73% when compared to baseline, compared with no improvement in those taking flaxseed oil or olive oil (99303). Other preliminary clinical research in individuals waiting for carotid endarterectomy shows that taking sunflower oil 6 grams daily for up to 189 days is less effective than the same dose of fish oil, and equivalent to control oil, for improving the status of atherosclerotic plaques (76688).
• Atopic dermatitis (eczema). Although there is interest in using topical sunflower oil for atopic dermatitis, there is insufficient reliable information about the clinical effects of sunflower oil for this condition.
• Child growth. It is unclear if topical sunflower oil is beneficial for early child growth. Details: A large preliminary clinical trial in newborn infants in India shows that exclusive topical application of 10 mL of high-linoleic acid sunflower oil, an average of 2.7 times daily for about one month, increases weight gain by 1.3 gram/kg daily when compared with a control group exclusively given traditional vigorous massage with mustard oil an average of 2.4 times daily. The increase in weight gain was highest for infants weighing less than 1500-2000 grams at birth (108141). However, it is unclear if any beneficial effects are due to the sunflower oil, the massage, their combination, or the lack of mustard oil.
• Dry mouth. It is unclear if rinsing the mouth with sunflower oil is beneficial for dry mouth. Details: Preliminary clinical research in adults with moderate dry mouth associated with medication use shows that using a sunflower oil mouth rinse and gargling for 5-8 minutes before spitting it out twice daily for 7 days improves dry mouth scores by 23% when compared to baseline. Sunflower oil also improves the ability to swallow and sleep with dry mouth, but not other dry mouth symptoms or saliva flow rate, when compared with control (105523). This study may have been inadequately powered to detect a difference between groups.
• Dry skin. It is unclear if topical sunflower oil is beneficial for dry skin in infants. Details: Preliminary clinical research in full-term, newborn infants shows that topical application of 4 drops of sunflower oil to each of three parts of the body twice daily for 4 weeks improves skin hydration, but not skin barrier function or the presence of redness or rash, when compared with not using topical oil. Furthermore, use of sunflower oil may impede the normal development of skin barrier function that occurs during the first four weeks of life (96144).
• Fetal and premature infant mortality. It is unclear if topical sunflower oil is beneficial for preventing early mortality in premature infants. Details: A large clinical trial in newborn infants in India shows that exclusive topical application of 10 mL of high-linoleic acid sunflower oil, an average of 2.7 times daily for about one month, reduces infant mortality by 58% when compared to a control group exclusively given traditional vigorous massage with mustard oil an average of 2.4 times daily. A subgroup analysis of premature infants also shows a 52% reduction in mortality with the use of high-linoleic acid sunflower oil when compared with control (108143). However, it is unclear if any beneficial effects are due to the sunflower oil, the massage, their combination, or the lack of mustard oil.
• Prematurity. Small to moderate-sized clinical studies suggest that topical sunflower oil might increase body weight, reduce length of hospital stay, and improve skin hydration and skin integrity in preterm neonates. Details: Preliminary clinical research in preterm infants with low birth weight shows that massaging for 5-10 minutes using sunflower oil 10 mL/kg three times daily for 2 weeks increases weight gain by approximately 35% over 2 months when compared with massage using no oil. Sunflower oil massage does not appear to increase length or head circumference (96145). A small clinical study in premature infants in the intensive care unit (ICU) shows that a similar massage with sunflower oil three times daily for 5 days shortens ICU stay by about 5 days when compared with no massage. Furthermore, over the ICU stay, infants in the sunflower oil massage group gained an average of 15 grams, whereas infants in the control group experienced weight loss (98479). The effect of sunflower oil on skin hydration and integrity in preterm infants has also been assessed. A clinical trial of 90 preterm infants in a Turkish neonatal ICU shows that whole body skin treatment (not massage) with either sunflower oil or almond oil 4 mL/kg four times daily for 5 days improves measures of skin hydration and skin integrity when compared with control infants that did not receive oil treatment. The sunflower and almond oil treatments are equally effective (105524). Another clinical study in 90 infants (42% preterm) in a Turkish neonatal ICU shows that whole body skin treatment (not massage) with sunflower oil or liquid Vaseline 3-4 mL for preterm and 5-6 mL for full-term infants daily for 16 days improves measures of skin integrity when compared with control infants that did not receive any oil treatment. Skin integrity scores were better in the sunflower oil group than liquid Vaseline at some time points (111726).
• Psoriasis. Although there is interest in using topical sunflower oil for psoriasis, there is insufficient reliable information about the clinical effects of sunflower oil for this condition.
• Rheumatoid arthritis (RA). Although there is interest in using oral sunflower oil for RA, there is insufficient reliable information about the clinical effects of sunflower oil for this condition.
• Tinea pedis. It is unclear if topical sunflower oil is beneficial for tinea pedis. Details: Preliminary clinical research shows that topical application of a specific brand of ozonized sunflower oil (Oleozon) twice daily for 6 weeks is as effective as ketoconazole for curing athlete's foot (76687). More evidence is needed to rate sunflower oil for these uses.

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POSSIBLY EFFECTIVE

• Athletic performance. Most available research suggests that oral tart cherry modestly improves muscular strength and endurance when compared with control. However, most studies are limited by a high risk of selection bias. Details: A meta-analysis of 14 small studies involving a total of 303 trained athletes and untrained healthy adults shows that tart cherry might modestly improve recovery of muscular strength and power when compared with control. Also, some subgroup analyses show that tart cherry may improve recovery of jump height and sprint time when compared with control (105629). In another meta-analysis of 10 studies involving 147 marathon runners, cyclists, or triathletes at various levels of training, taking tart cherry juice concentrate or powder 1.5 hours before exercise, or for up to 7 days prior to exercise, seems to improve exercise endurance, as measured by the time to complete an exercise trial, when compared with control (102340). However, both analyses have a high risk of selection bias and some analyses have high heterogeneity. Specific products assessed in the meta-analyses include tart cherry juice (CherryActive, Active Edge Nutrition) 60 mL, 90 minutes prior exercise (98699); a specific tart cherry concentrate (CherryActive, Active Edge Nutrition) 30 mL twice daily for 8 days (93149); and a specific freeze-dried tart cherry supplement (CherryPURE, Shoreline Fruit LLC) 480 mg daily 7 days before, on the day of, and 2 days after exercise (93158).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aromatase inhibitor-induced arthralgia. It is unclear if oral tart cherry is beneficial in patients with aromatase inhibitor-induced arthralgia (AIIA). Details: Preliminary clinical research in a small group of females with non-metastatic, hormone-receptor positive breast cancer and AIIA after taking aromatase inhibitors for at least 4 weeks shows that taking tart cherry juice concentrate 30 mL daily for 6 weeks reduces pain scores on a visual analog scale by about 35%, compared with 1% in those taking placebo (109657).
• Attention deficit-hyperactivity disorder (ADHD). It is unclear if oral tart cherry juice is beneficial in children with ADHD. Details: A small clinical study in children and adolescents aged 6 to 18 years with ADHD shows that consuming tart cherry juice concentrate 75 mL twice daily for 2 weeks with standard treatment does not improve ADHD symptoms including cognitive impairment, hyperactivity, impulsivity, or oppositional behavior when compared with placebo (112815).
• Cognitive function. It is unclear if oral tart cherry improves cognitive function. Details: Preliminary clinical research in healthy, middle-aged adults shows that taking tart cherry juice concentrate 30 mL orally twice daily for 3 months reduces mental fatigue and improves performance on tests evaluating sustained attention, psychomotor speed, and alertness when compared with placebo. However, it does not affect sleep quality or cerebral blood flow (109655).
• Exercise-induced muscle soreness. Research on the use of oral tart cherry juice or supplements for the reduction of exercise-induced muscle soreness is conflicting. Details: A meta-analysis of 12 small studies in trained athletes and untrained healthy adults shows that tart cherry might modestly attenuate delayed muscle soreness after exercise involving maximal muscle contractions or maximal effort sprints when compared with control. However, tart cherry juice seems to be no better than placebo for improving delayed muscle soreness after prolonged aerobic exercise (105629). These findings are limited by a high risk of selection bias, high heterogeneity, and imprecision. Some products assessed in the meta-analysis include a specific Montmorency tart cherry concentrate (Holland & Barrett Ltd.) 30 mL twice daily for 5 days before, on the day of, and for 2 days after intermittent sprint exercises (102341); a specific freeze-dried tart cherry supplement (CherryPURE, Shoreline Fruit LLC) 480 mg daily for 7 days before, on the day of, and 2 days after running a half-marathon or doing back squats (93157,93158); a specific Montmorency tart cherry juice concentrate (CherryActive, Active Edge Nutrition) 30 mL diluted in water and taken twice daily for 8 days (93149,93151,101880,102344); and a specific juice (Sour cherry juice, Cherrypharm Inc.) containing 90% tart cherry juice and 10% apple juice as a sweetener, twice daily (93152,93154). Some individual clinical studies have yielded mixed findings. One clinical study in professional rugby players shows that taking a Montmorency tart cherry juice concentrate gel, 30 mL (equivalent to 100 cherries) twice daily for 2 days before, on the day of, and for 2 days after a match does not improve muscle soreness when compared with placebo (102339). Similarly, in male professional soccer players, taking tart cherry juice, 60 mL before and after a 90-minute match and then 12 and 36 hours later, does not improve subjective muscle soreness when compared with placebo (102342). Also, a small study in healthy males shows that taking a specific tart cherry supplement (Tart Cherry Extract Powder NordicCherry, Specnova, LLC.) 500 mg daily for 7 days prior to performing resistance exercise does not reduce muscle soreness when compared with placebo (105631). In contrast, a small clinical study in recreational long-distance runners shows that drinking a specific tart cherry juice (Cherrish, Cherrish Corp.) 10.5 ounces twice daily for 7 days prior to a long-distance race decreases post-race muscle pain by around 65% when compared with placebo (93156). Reasons for the discrepancies may include differences in tart cherry products, the small number of subjects, and heterogeneity in study populations and evaluated endpoints. In some studies, the subjects' normal diets were continued during the study, whereas in others, a reduced polyphenol diet was consumed for the duration of the study (102342,105629).
• Exercise-induced respiratory infections. It is unclear if oral tart cherry juice reduces the risk of exercise-induced respiratory infections. Details: A small clinical study in recreational athletes shows that drinking a specific juice blend (Sour cherry juice, Cherrypharm Inc.), containing 90% tart cherry juice and 10% apple juice as a sweetener, 8 ounces twice daily for 5 days before, on the day of, and 2 days after running a marathon, decreases the risk for upper respiratory tract symptoms such as cough, sore throat, congestion, and sneezing when compared with placebo (93168).
• Fibromyalgia. It is unclear if oral tart cherry improves symptoms in patients with fibromyalgia. Details: A very small clinical study in females with fibromyalgia participating in an eccentric exercise program shows that taking a specific tart cherry concentrate (Cherrish, Cherrish Corp.) 10.5 ounces twice daily for 14 days does not improve pain or muscle strength when compared with placebo (93192).
• Gout. It is unclear if oral tart cherry juice reduces symptoms of gout; research is conflicting. Details: Preliminary clinical research shows that tart cherry juice lowers serum urate and increases urinary urate excretion in healthy people, as well as people with hyperuricemia that has not progressed to gout (93166,102338). However, in patients with gout, taking Montmorency tart cherry juice concentrate (Cherryvite) in doses of 7.5-30 mL twice daily for 28 days does not affect urate excretion or the frequency of gout flares (102343). A small, unblinded clinical study in adults with chronic gout shows that taking a combination product (GoutFighter, MaxBiocare Pty Ltd.) containing tart cherry fruit extract 100 mg, celery seed extract 300 mg, devil's claw tuber extract 150 mg, folic acid 90 mcg, potassium citrate 50 mg, and ascorbic acid 50 mg orally, as 2 tablets twice daily for 45 days, modestly reduces mean serum uric acid levels and reduces perceived pain and frequency of joint swelling when compared to baseline (106488). The validity of these findings is limited by the lack of a comparator group. Additionally, it is unclear if any effects are due to tart cherry, other ingredients, or the combination.
• Hypertension. It is unclear if oral tart cherry juice reduces blood pressure; research is conflicting. Details: A very small clinical study in males with mild hypertension shows that taking 60 mL of a specific tart cherry concentrate (CherryActive, Active Edge Nutrition) modestly decreases systolic, but not diastolic, blood pressure 1-3 hours after consumption when compared with placebo (93155). This finding is limited by the small study size and the use of a single dose. Another small study in healthy adults without hypertension shows that drinking 30 mL of Montmorency tart cherry concentrate (Cherry Marketing Institute) diluted in 240 mL of water daily for 3 months does not reduce blood pressure when compared with baseline or placebo (105633).
• Insomnia. Some small clinical studies suggest that oral tart cherry juice may modestly improve sleep and reduce insomnia. This effect might be due to the melatonin content in tart cherry juice. However, the evidence is conflicting. Details: A small clinical study in healthy adults less than 40 years of age shows that consuming a specific tart cherry juice concentrate (CherryActive, Active Edge Nutrition) 30 mL standardized to contain 1.42 mcg/mL of melatonin twice daily for 7 days modestly increases total sleep time and efficiency when compared with placebo (17199). Another small clinical study in adults aged 65 years and older with chronic insomnia shows that drinking a specific juice blend (Sour cherry juice, Cherrypharm Inc.), containing 90% tart cherry juice and 10% apple juice as a sweetener, 8 ounces twice daily for 14 days, modestly improves insomnia severity, but not sleep latency, when compared with placebo (17403). However, another very small clinical study in healthy adults shows that taking Montmorency tart cherry juice 240 mL twice daily or powdered Montmorency tart cherry capsules 1000 mg daily for 30 days does not improve sleep quality, sleep time, or serum melatonin concentration when compared with placebo (112813). The effects of tart cherry on sleep measures have also been evaluated in combination with other ingredients. A very small crossover study in healthy adults without a sleep disorder shows that taking a combination product containing tart cherry powder 220 mg, tryptophan, glycine, magnesium, and L-theanine 2 hours before bedtime for 3 nights decreases the time to fall asleep by about 24 minutes, increases total sleep duration by about 22 minutes, improves sleep efficiency, and reduces morning sleepiness, but does not improve the total time in bed or wakefulness after falling asleep when compared with placebo (111184). It is unclear if these effects are due to tart cherry, other ingredients, or the combination.
• Metabolic syndrome. Oral tart cherry juice does not seem to improve cardiovascular or metabolic biomarkers in patients at risk for or with metabolic syndrome. Details: Two meta-analyses of small, moderate-quality clinical studies in healthy adults, patients with metabolic syndrome, or those with risk factors for metabolic syndrome, that include many of the same studies, show that drinking tart cherry juice 30-480 mL daily for 1-12 weeks does not improve fasting blood glucose, insulin levels, lipid profiles, blood pressure, body weight, body mass index, fat mass, percentage body fat, or waist circumference when compared with placebo (112812,112814).
• Osteoarthritis. It is unclear if oral tart cherry juice is beneficial in patients with osteoarthritis. Details: A small clinical study in patients with osteoarthritis shows that drinking a specific juice blend (Sour cherry juice, Cherrypharm Inc.) containing 90% tart cherry juice and 10% apple juice as a sweetener, 8 ounces twice daily for 6 weeks, does not improve pain, stiffness, function, walking speed, or acetaminophen use when compared with placebo (93160). The validity of this finding is limited because the trial was not adequately powered to detect small differences between groups. More evidence is needed to rate tart cherry for these uses.

(Read more about TART CHERRY)

POSSIBLY INEFFECTIVE

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

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Aging skin. It is unclear if tomato improves skin appearance. Details: A small study of females aged 35-55 shows that taking a certain tomato pulp product (Lumenato, Lycored) 1 capsule daily for 12 weeks improves patient reported skin appearance scores when compared to baseline (110523). The interpretation of this result is limited by the lack of a placebo group.
• Benign prostatic hyperplasia (BPH). Oral tomato powder has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in patients with BPH shows that taking 5 grams of a whole tomato food supplement consisting of tomato powder and polyphenols extracted from olives daily for 2 months improves quality of life and reduces lower urinary tract symptoms including urinary frequency, urinary urgency, and nocturia when compared to baseline. No improvements in these symptoms were reported with placebo (106656). It is unclear if these findings are due to tomato, olive polyphenols, or the combination.
• Cardiovascular disease (CVD). It is unclear if consuming tomato-based foods reduces the risk of cardiovascular events. Details: Observational research has found that increased consumption of tomato-based foods is associated with an insignificant trend towards a reduced risk of myocardial infarction, stroke, and other cardiovascular events (10418,102178).
• Cataracts. It is unclear if consuming tomatoes reduces the risk of cataracts. Details: Observational research has found that eating more than 3 servings of tomatoes each week may decrease the risk of developing cataracts (9439).
• Cervical cancer. It is unclear if consuming tomatoes reduces the risk of cervical cancer. Details: Observational research has found that increased tomato intake is associated with a decreased risk of cervical cancer (2407).
• Colorectal cancer. Research on the benefits of consuming tomatoes or tomato-based products for the prevention of colorectal cancer is conflicting and limited to observational studies only. Details: Some observational research has found that increasing tomato or tomato-based product intake is associated with a reduced risk of colorectal cancer (2404,2407). However, higher quality observational research has found that tomato-based product intake is not associated with risk of colorectal cancer (15747).
• Exercise-induced asthma. It is unclear if oral tomato extract is beneficial in patients with exercise-induced asthma. Details: A small clinical study in patients with exercise-induced asthma shows that taking a specific tomato extract (Lyc-O-Mato, LycoRed Ltd) 30 mg daily for 1 week seems to reduce exercise-induced asthma when compared with placebo. The tomato extract seems to prevent decreases in forced expiratory volume (FEV1) in response to exercise (7898).
• Gastric cancer. Research on the benefits of consuming tomatoes or tomato-based products for the prevention of gastric cancer is conflicting and limited to observational studies only. Details: Some observational studies have found that increasing tomato or tomato-based product intake is associated with a reduced risk of gastric cancer in some subgroups of patients (2407,15747,102480). However, other observational research has found that tomato-based product intake is not associated with risk of gastric cancer (15747). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim regarding tomatoes and gastric cancer risk. However, the FDA concludes that it is highly unlikely that tomatoes reduce the risk of gastric cancer (102375).
• Hyperlipidemia. Small clinical studies suggest that consuming tomato sauce or semi-dried tomatoes may modestly reduce low-density lipoprotein (LDL) cholesterol levels in patients with hyperlipidemia. Details: One small, open-label clinical trial in patients with hyperlipidemia shows that consuming a specific vine-ripened tomato sauce (OsteoCol, C.G. Food, SRL) 150 mL daily for 6 weeks reduces total cholesterol and LDL cholesterol levels when compared to baseline. Patients adherent to the tomato sauce regimen showed an 11 mg/dL and 12 mg/dL reduction in total and LDL cholesterol, respectively, while those consuming a sterol-enriched yogurt saw total and LDL cholesterol levels decrease by 18 mg/dL and 16 mg/dL, respectively. Patients with a baseline LDL cholesterol level of greater than 152 mg/dL saw the greatest benefit from this tomato sauce (106653). Another small clinical study in Japanese patients with borderline high cholesterol shows that taking 50 grams of a semi-dried tomato containing lycopene 22-27.8 mg daily for 12 weeks modestly reduces LDL cholesterol levels but does not affect high-density lipoprotein (HDL) cholesterol levels when compared with taking 50 grams of a tomato without lycopene (102180). This suggests that any benefit of tomato on blood lipid levels is likely due to its lycopene content.
• Hypertension. Small clinical studies and observational research suggest that oral tomato extract or dietary tomato consumption may modestly reduce blood pressure in patients with hypertension. Details: Several small clinical trials in patients with hypertension show that taking a specific tomato extract product (Lyc-O-Mato, LycoRed, Ltd.), providing lycopene 15-30 mg daily, for 6-8 weeks, reduces systolic blood pressure by around 7-13 mmHg and diastolic blood pressure by around 4-6 mmHg when compared to baseline (14287,60415,102182). The validity of these findings is limited by the lack of a comparator group. Additionally, a large observational study, conducted over 3 years, suggests that moderate consumption of tomato-based products (i.e., 44-82 grams daily) is associated with marginally lower blood pressure when compared with higher and lower consumption in older adults with grade 1 hypertension. However, this association is not seen in patients with grade 2 or 3 hypertension (113145). Interpretation of these results is limited by self-reported data and lack of generalizability outside of confounders relating to a Mediterranean lifestyle. Evidence on the use of tomato in patients with pre-hypertension is mixed. One small clinical study in patients with pre-hypertension shows that taking a specific tomato extract (Fruitflow, Provexis Plc, UK.) 150 mg as a single dose seems to modestly reduce blood pressure over a 24-hour period when compared with placebo (102478). This study is limited by its small size and short duration. Another small clinical study in pre-hypertensive patients shows that taking a specific tomato extract (Lyc-o-Mato, LycoRed Ltd) containing lycopene 15 mg daily for 8 weeks does not reduce blood pressure when compared with placebo (42079). The impact of dietary tomato consumption on preventing hypertension has also been evaluated. A large prospective observational study in Chinese adults without a history of smoking or myocardial infarction suggests moderate dietary intake of tomatoes (i.e. up to 33.3 grams daily) is associated with a 49-58% reduction in the risk of developing new onset hypertension when compared with no consumption after about 6 years' follow up. However, the associated risk reduction was less with higher consumption (110525). These results may not apply to patients in countries where dietary trends are different, and the validity of these findings is limited by the potential for confounding. Another large observational study, conducted over 3 years in older adults at high cardiovascular risk, suggests that higher consumption (i.e., at least 1 large-sized tomato daily) is associated with reduced risk of hypertension by 36% when compared with moderate and lower consumption (113145). However, interpretation of these results is limited by self-reported data, and lack of generalizability outside of confounders relating to a Mediterranean lifestyle.
• Lung cancer. It is unclear if consuming tomatoes reduces the risk of lung cancer; the available research is conflicting. Details: Some observational studies have found an association between increased tomato and tomato-based product consumption and a reduced risk of lung cancer; however, many of these studies were not stratified based on the patient's smoking status. Higher quality, large-scale observational studies have not found any association between tomato product intake and lung cancer risk (15747).
• Muscle strength. It is unclear if consuming tomatoes improves muscle strength or attenuates declines in muscle strength. Details: A small observational study in Japanese adults 22-68 years of age found that more frequent tomato consumption (2 or more times weekly) is associated with an attenuated rate of handgrip strength decline over 3 years when compared with less frequent tomato consumption (102473).
• Ovarian cancer. Research on the benefits of consuming tomatoes or tomato-based products for the prevention of ovarian cancer is conflicting and limited to observational studies only. Details: Some observational research has found that increased tomato or tomato juice intake is not associated with risk of ovarian cancer; however, consuming tomato sauce two or more times weekly is associated with a decreased risk (2407). Other observational research has found that increased dietary intake of lycopene, particularly from tomato sauce, is associated with a reduced risk of ovarian cancer in premenopausal patients (10133). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim regarding tomato sauce and ovarian cancer risk. However, the FDA concludes that it is highly uncertain that tomato sauce reduces the risk of ovarian cancer (102375).
• Pancreatic cancer. Research on the benefits of consuming tomatoes or tomato-based products for the prevention of pancreatic cancer is conflicting and limited to observational studies only. Details: A large-scale observational study have found that that tomato or tomato-based product intake is not associated with a decreased risk of pancreatic cancer (15747). However, other observational studies have found that raw tomato intake, and high tomato intake in general, is associated with a reduced risk of pancreatic cancer (2407,15747,15750). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim regarding tomatoes and pancreatic cancer risk. However, the FDA concludes that it is highly unlikely that tomatoes reduce the risk of pancreatic cancer (102375).
• Prostate cancer. Consuming tomatoes or tomato-based products may slightly lower the risk of prostate cancer; however, observational research is mixed and high-quality clinical trials addressing tomato intake and prostate cancer risk are lacking. Details: Some observational studies have found that consuming tomato products, including tomatoes, tomato sauce, pizza, or tomato juice, one time or more per week, is associated with a modest reduction in the risk of prostate cancer (2406,7772,7895,12878,15747,102476). However, other observational research has found that tomato consumption is not associated with a reduced risk of prostate cancer (14125,15172,15747,92171). One small clinical study in patients with high-grade prostatic intraepithelial neoplasia shows that taking tomato extract capsules containing lycopene 30 mg daily for 6 months does not impact benign tissue endpoints when compared with placebo (102471). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim stating that one-half to one cup of tomatoes or tomato sauce weekly may reduce the risk of prostate cancer. However, the FDA concludes that there is little scientific evidence to support this claim (102375).
• Radiation dermatitis. It is unclear if drinking tomato juice is beneficial in patients with radiation dermatitis. Details: One small, uncontrolled clinical trial in patients undergoing radiotherapy for breast cancer shows that drinking tomato juice 160 mg daily for 6 months after radiotherapy improves the severity of dermatitis within 1 month of treatment when compared to baseline (106654). The lack of a comparator group limits the validity of these findings; it is unclear how tomato juice consumption compared with the natural resolution of radiation dermatitis. More evidence is needed to rate tomato for these uses.