HME-H by Pure Herbs

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Irritable bowel syndrome (IBS). Preliminary clinical research shows that taking powdered arrowroot 10 mL three times daily with meals for one month modestly improves abdominal pain and reduces diarrhea when compared to baseline in patients with diarrhea-predominant IBS (32448). The validity of this finding is limited by the lack of a comparator group. More evidence is needed to rate arrowroot for this use.

(Read more about ARROWROOT)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Dental plaque. It is unclear if oral Ascophyllum nodosum is beneficial in patients with dental plaque. Details: A small crossover study in adults with moderate to heavy calculus formation shows that taking a specific brand of Ascophyllum nodosum capsules (ProDen PlaqueOff, SDC Swedencar eAB) 500 mg daily for 6 months reduces the buildup of supragingival calculus by 52% when compared with placebo. The buildup of plaque was reduced by 19% in males, but was not reduced in females, when compared with placebo (94996).
• Gastroesophageal reflux disease (GERD). Although there has been interest in using oral Ascophyllum nodosum for GERD, there is insufficient reliable information about the clinical effects of Ascophyllum nodosum for this purpose.
• Gingivitis. It is unclear if oral Ascophyllum nodosum is beneficial in patients with dental plaque. Details: A small crossover study in adults with moderate to heavy calculus formation shows that taking a specific brand of Ascophyllum nodosum capsules (ProDen PlaqueOff, SDC Swedencar eAB) 500 mg daily for 6 months does not reduce gingivitis when compared with placebo (94996).
• Impaired glucose tolerance (prediabetes). Oral Ascophyllum nodosum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults with prediabetes that are overweight or obese shows that taking a specific product (InSea2, InnoVactiv Inc.) containing 500 mg of Ascophyllum nodosum and Fucus vesiculosus extracts daily for 12 weeks reduces postprandial blood glucose but does not improve fasting blood glucose, glycated hemoglobin (HbA1c), body weight, lipids, or blood pressure when compared with placebo (110560).
• Inflammatory bowel disease (IBD). Although there has been interest in using oral Ascophyllum nodosum for IBD, there is insufficient reliable information about the clinical effects of Ascophyllum nodosum for this purpose.
• Iodine deficiency. It is unclear if oral Ascophyllum nodosum is beneficial in patients with iodine deficiency. Details: Ascophyllum nodosum contains iodine, and there is interest in its use for patients with iodine deficiency. A small clinical study in females with iodine insufficiency shows that taking a specific brand of Ascophyllum nodosum capsules (Napiers Hebridean Seagreens (NaHS), Seagreens Ltd) 500 mg daily for 14 days increases urinary iodine excretion by almost three-fold and increases thyroid stimulating hormone levels by 36% when compared with baseline (94997). The validity of these findings is limited by the lack of a control group.
• Metabolic syndrome. Oral Ascophyllum nodosum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Observational research in adults with one or more components of metabolic syndrome has found that taking a specific combination product (Gdue, Aesculapius) containing extracts of Ascophyllum nodosum and Fucus vesiculosus in a 95:5 ratio along with chromium picolinate two to three times daily with meals for around 6 months is associated with reductions in body weight by 7.3 kg, waist circumference by 7.5 cm, fasting blood glucose by 16 mg/dL, glycated hemoglobin (HbA1c) by 0.55%, systolic blood pressure by 7 mmHg, diastolic blood pressure by 4 mmHg, low-density lipoprotein (LDL) cholesterol by 18 mg/dL, and 10-year cardiovascular risk scores by 1.8% when compared to baseline (110559). It is unclear if these effects are due to Ascophyllum nodosum, Fucus vesiculosus, or the combination. Further, the validity of these findings is limited by a lack of control group.
• Obesity. Oral Ascophyllum nodosum has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults with prediabetes that are overweight or obese shows that taking a specific product (InSea2, InnoVactiv Inc.) containing 500 mg of Ascophyllum nodosum and Fucus vesiculosus extracts daily for 12 weeks does not reduce body weight, body mass index (BMI), body fat, lipids, blood pressure, or measures of glycemic control when compared with placebo (110560).
• Peptic ulcers. Although there has been interest in using oral Ascophyllum nodosum for peptic ulcers, there is insufficient reliable information about the clinical effects of Ascophyllum nodosum for this purpose. More evidence is needed to rate Ascophyllum nodosum for these uses.

(Read more about ASCOPHYLLUM NODOSUM)

POSSIBLY INEFFECTIVE

• Human papillomavirus (HPV). Topical carrageenan gel does not seem to reduce the risk of anal HPV in males who have sex with males. Details: A clinical study in adult males who have sex with males shows that applying 15 mL of carrageenan 1.4% gel to the anus, condom, or partners' penis prior to receptive anal intercourse does not decrease the rate of anal HPV when compared with placebo, regardless of HPV strain, HPV vaccination status, or HIV status. Although patients were enrolled for an intended duration of 1 year, the study was terminated early due to a lack of observed benefit and potential safety concerns, resulting in a median follow-up of 8 months. A total of 60% of patients in the treatment group reported adverse effects, compared with 40% of patients in the placebo group (107851). Additionally, the prevalence of HPV at baseline was 61%, which may have reduced the study's ability to identify an effect.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Common cold. Evidence on the use of intranasal iota-carrageenan for improving symptoms of the common cold is conflicting. Details: A small clinical study in patients with early symptoms of the common cold shows that spraying a saline solution containing iota-carrageenan 0.12% into the nose three times daily for 4 days seems to reduce total symptoms during days 2-4 when compared with using a plain saline spray. However, in a larger clinical trial using the same methods, there were no differences between placebo and treatment groups. Furthermore, neither study noted an improvement in total cold symptoms over 7-10 days (99449,99450). In children with the common cold, spraying a saline solution containing iota-carrageenan 0.12% seemed to be no better for improving cold symptoms than using plain saline spray (99451). Some research suggests that carrageenan might benefit patients with a confirmed viral infection. In a clinical study in patients with symptoms of a common cold and a laboratory-confirmed viral infection, using a specific nasal spray (Coldamaris) containing carrageenan 0.12% three times daily for 7 days reduced symptom duration by about 2 days when compared with using a saline nasal spray. However, there was no difference in disease duration when all patients were considered, regardless of viral infection status (99452). Furthermore, the validity of this study is limited by the changing definitions for disease duration and primary outcome over the course of the study.
• Coronavirus disease 2019 (COVID-19). There is limited evidence on the intranasal use of iota-carrageenan for the prevention of COVID-19. Details: A clinical study in healthcare professionals working with patients hospitalized for COVID-19 shows that using a nasal spray containing iota-carrageenan 0.17% as 1 puff in each nostril 4 times daily (providing 1 mg daily) for 21 days decreases the absolute rate of confirmed, symptomatic COVID-19 to 1%, compared with 5% of patients in the placebo group. This suggests that 25 people would need to use this nasal spray to prevent one infection (107852). The validity of this study is limited due to the lack of baseline viral testing and short duration; additionally, asymptomatic COVID-19 infections may be underreported due to study design.
• Cough. Although there is interest in using oral carrageenan for cough, there is insufficient reliable information about the clinical effects of carrageenan for this condition. More evidence is needed to rate the effectiveness of carrageenan for these uses.

(Read more about CARRAGEENAN)

INSUFFICIENT RELIABLE EVIDENCE to RATE

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

(Read more about FUCUS VESICULOSUS)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Androgenic alopecia. Although there is interest in using oral horsetail for alopecia, there is insufficient reliable information about the clinical effects of horsetail for this condition.
• Hypertension. Oral horsetail seems to reduce blood pressure in patients with hypertension. Details: A clinical trial in patients with stage 1 systemic arterial hypertension shows that taking horsetail extract 900 mg daily for 3 months decreases systolic and diastolic blood pressure by 13 mmHg and 8 mmHg, respectively, and is similarly effective to hydrochlorothiazide 25 mg daily (108849). The validity of this finding is limited due to high withdrawal rates and low adherence to treatment protocols.
• Kidney stones (nephrolithiasis). Although there is interest in using oral horsetail for kidney stones, there is insufficient reliable information about the clinical effects of horsetail for this condition.
• Obesity. Although there is interest in using oral horsetail for weight loss, there is insufficient reliable information about the clinical effects of horsetail for this purpose.
• Osteoporosis. It is unclear if oral horsetail is beneficial for osteoporosis. Details: Preliminary clinical research shows that taking two tablets of either dried horsetail extract or a specific combination of horsetail extract with calcium (Osteosil Calcium) daily for 2-month intervals separated by 2 weeks of no treatment for up to one year can increase bone density when compared with no treatment in postmenopausal patients with osteoporosis. The effect of horsetail extract plus calcium (Osteosil Calcium) seems to be greater than the effect of dried horsetail extract alone (55578).
• Tonsillitis. Oral horsetail has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in children with acute non-bacterial tonsillitis shows that taking a specific combination product (Imupret) for 10 days in addition to standard symptomatic therapy accelerates recovery by a small amount when compared with symptomatic therapy alone. Overall treatment response after 10 days occurred in 82% of patients taking the combination product compared with 65% of patients receiving symptomatic therapy alone. Withdrawal from antipyretic drugs occurred approximately one day earlier in children using the horsetail product. Per 100 grams, Imupret provides 29 grams of an alcoholic extract produced from horsetail 0.5 grams, marshmallow root 0.4 grams, chamomile flowers 0.3 grams, walnut leaves 0.4 grams, English walnut leaves 0.4 grams, yarrow 0.4 grams, oak bark 0.2 grams, and dandelion 0.4 grams. In children aged 6-11 years, 15 drops 6 times daily for 5 days and then 15 drops 3 times daily for 5 days was used. In children aged 12-18 years, 25 drops 6 times daily for 10 days was used. (100347). Due to the small difference between the two groups and the open-label design, the clinical relevance of this study is unclear. Also, it is unclear if these benefits are due to horsetail, the other ingredients, or the combination.
• Urinary incontinence. Oral horsetail 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 supplement (Urox, Seipel Group) 840 mg, containing a combination of horsetail stem, three-leaf caper, and lindera root daily with food for 8 weeks modestly decreases urinary frequency, stress incontinence, and urgency incontinence when compared with placebo in patients with urinary incontinence and/or overactive bladder (97575). It is unclear if these effects are due to horsetail, the other ingredients, or the combination.
• Urinary tract infections (UTIs). Although there is interest in using oral horsetail for UTIs, there is insufficient reliable information about the clinical effects of horsetail for this condition. More evidence is needed to rate horsetail for these uses.

(Read more about HORSETAIL)

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).
• Hypercholesterolemia. 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 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); however, doses greater than 10 grams daily don't seem to increase effectiveness (5788). Eating three bowls of oatmeal (28 gram servings) daily can decrease total cholesterol by about 5 mg/dL (4972,4973,4974,4975,4976,4977,5786,5788,6188). 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).

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 has a moderate effect on 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: Observational research has found that consumption of oats as oatmeal or oat cereal does not seem to reduce diastolic blood pressure (DBP) or systolic blood pressure (SBP) in males with minor elevations in blood pressure (2956). 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)

LIKELY SAFE ...when the starch from the root or rhizome is used orally in the amounts found in foods (12). There is insufficient reliable information available about the safety of arrowroot when used in medicinal amounts.

PREGNANCY AND LACTATION: POSSIBLY SAFE
when used in amounts found in foods. There is insufficient reliable information available about the safety of larger amounts used during pregnancy and lactation; avoid using.

(Read more about ARROWROOT)

POSSIBLY SAFE ...when used orally, short-term. Ascophyllum nodosum dried powder has been used with apparent safety at a dose of up to 500 mg daily for up to 6 months (94996,94997,103900). However, marine products such as Ascophyllum nodosum are known to accumulate heavy metals such as arsenic (94997,94999). Some supplement products are prospectively analyzed to confirm a lack of contaminants and that heavy metal levels are below threshold (94997).

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

(Read more about ASCOPHYLLUM NODOSUM)

LIKELY SAFE ...when undegraded carrageenan is used orally in the amounts found in foods (11). Carrageenan has Generally Recognized as Safe (GRAS) status in the US (4912,102538).

POSSIBLY SAFE ...when used intranasally, short-term. Saline solution containing iota-carrageenan 0.12% has been sprayed into the nose with apparent safety three times daily for up to 7 days (99449,99450,99451,99452,99466). Also, saline solution containing iota-carrageenan 0.17% has been sprayed into both nostrils with apparent safety four times daily (providing 1 mg daily) for up to 21 days (107852).

POSSIBLY UNSAFE ...when the degraded form, called poligeenan, is used orally. Poligeenan contains a lower molecular weight product that is partially absorbed. There is concern about the safety of this form because it has been linked to colonic lesions, neoplasms, and bleeding in animals (40065,40047). Due to public concern that commercial carrageenan contains poligeenan or can be degraded to poligeenan in the stomach, the United States Food and Drug Administration (FDA) reevaluated the safety of carrageenan and reaffirmed its status as GRAS in 2012 (99466). Carrageenan that is not degraded has an average molecular weight of 453-652 kDA, while degraded carrageenan is usually 20-30 kDA. In order to limit potential safety concerns, the European Commission Scientific Committee on Food advises that the total weight of any carrageenan food additives contain no more than 5% of a molecular weight below 50 kDa (99901). There is insufficient reliable information available about the safety of carrageenan when used topically.

PREGNANCY AND LACTATION: LIKELY SAFE
when used in food amounts (11). There is insufficient reliable information available about the safety of using larger amounts; avoid using.

(Read more about CARRAGEENAN)

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

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

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

(Read more about FUCUS VESICULOSUS)

POSSIBLY UNSAFE ...when horsetail products containing thiaminase are used orally, long-term. Thiaminase is an enzyme that destroys thiamine, which could theoretically lead to thiamine deficiency. In Canada, horsetail products are required to be thiaminase-free (105301).

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

(Read more about HORSETAIL)

LIKELY SAFE ...when used orally and appropriately in food amounts (4960,4969,5792,5797). Oat bran has Generally Recognized as Safe (GRAS) status in the US (4912). Whole grain oats 50-100 grams daily have been used for up to 1 year without serious adverse effects (97520).

POSSIBLY SAFE ...when used topically and appropriately (12). Lotion containing colloidal oat 1% has been used topically without adverse effects for up to 6 weeks (97518,103340). There is insufficient reliable information available about the safety of oats when used orally in medicinal amounts.

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in food amounts (5792,5797).

(Read more about OATS)

(Read more about ARROWROOT)

AMIODARONE (Cordarone) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, combining Ascophyllum nodosum with amiodarone might cause excessively high iodine levels.  Details Ascophyllum nodosum contains iodine (94997,95000,95102), although the bioavailability of iodine from Ascophyllum nodosum is lower than that of potassium iodide (94997). Amiodarone contains 37.3% iodine and can increase iodine levels. Concomitant use might increase the risk of having excessive iodine levels and adversely affecting thyroid function (7135,17574). Monitor thyroid function.

ANTITHYROID DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Due to its iodine content, Ascophyllum nodosum might alter the effects of antithyroid drugs.  Details Ascophyllum nodosum contains iodine (94997,95000,95102), although the bioavailability of iodine from Ascophyllum nodosum is lower than that of potassium iodide (94997). Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking Ascophyllum nodosum while using antithyroid drugs could alter the effects of the antithyroid drugs (17574).

THYROID HORMONE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Due to its iodine content, Ascophyllum nodosum might alter the effects of thyroid hormone.  Details Ascophyllum nodosum contains iodine (94997,95000,95102), although the bioavailability of iodine from Ascophyllum nodosum is lower than that of potassium iodide (94997). Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking Ascophyllum nodosum while using thyroid hormone could alter the effects of thyroid hormone (17574).

(Read more about ASCOPHYLLUM NODOSUM)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, carrageenan may increase the risk of bleeding in patients taking anticoagulant or antiplatelet drugs.  Details Laboratory research suggests that carrageenan has anticoagulant effects (6002). However, this has not been reported in humans.

(Read more about CARRAGEENAN)

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

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

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

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

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

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

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

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

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

(Read more about FUCUS VESICULOSUS)

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking horsetail with antidiabetes drugs might increase the risk of hypoglycemia.  Details Equisetum myriochaetum has demonstrated hypoglycemic activity in clinical research (13576). In an animal diabetic model, Equisetum giganteum had hypoglycemic effects (105300). It is unclear whether other horsetail species have hypoglycemic effects.

DIURETIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking horsetail with diuretic drugs might increase potassium loss and the risk of hypokalemia.  Details Laboratory research shows that various species of horsetail have diuretic properties (13574,13575). Due to its diuretic effects, there has been concern that taking horsetail along with potassium-depleting diuretics might increase the risk for hypokalemia. However, pharmacokinetic research in humans shows that taking horsetail 900 mg daily for 4 days does not affect urinary excretion of electrolytes, including potassium and sodium, despite having a diuretic effect similar to taking hydrochlorothiazide 25 mg daily (92288). It is unclear if taking horsetail for a longer duration would affect electrolyte levels. Until more is known, use with caution.

EFAVIRENZ (SUSTIVA) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, horsetail might decrease the levels and clinical effects of efavirenz.  Details In two case reports, patients were found to have detectable viral loads when taking horsetail-containing supplements along with an antiretroviral regimen that included efavirenz. In one case, the antiretroviral regimen included zidovudine, lamivudine, and efavirenz; in the other case, the regimen consisted of emtricitabine, tenofovir disoproxil fumarate, and efavirenz. One month after discontinuing horsetail, the viral loads became undetectable in both cases. The exact mechanism of this interaction is unknown (97573). It is also unclear if this interaction is specific to efavirenz or if it is related to various components of antiretroviral therapy.

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, horsetail might increase the levels and adverse effects of lithium.  Details Animal research suggests that horsetail has diuretic properties (13574). Theoretically, due to these potential diuretic effects, horsetail might reduce excretion and increase levels of lithium. The dose of lithium might need to be decreased.

NUCLEOSIDE REVERSE TRANSCRIPTASE INHIBITORS (NRTIs) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, horsetail might decrease the levels and clinical effects of NRTIs.  Details In two case reports, patients were found to have detectable viral loads when taking horsetail-containing supplements along with an antiretroviral therapy. In one case, the antiretroviral regimen included zidovudine, lamivudine, and efavirenz; in the other case, the regimen consisted of emtricitabine, tenofovir disoproxil fumarate, and efavirenz. One month after discontinuing the supplement, the viral loads became undetectable in both cases. The exact mechanism of these interactions is unknown (97573). It is also unclear if these interactions are specific to NRTIs or if they are related to various components of antiretroviral therapy.

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ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, oats may have additive effects with antidiabetic agents and might increase the risk of hypoglycemia.  Details Consuming oats can decrease blood glucose in patients with diabetes (4980,4982,6266,103345). In those who require insulin, taking oats 100 grams daily for 2 days reduces the insulin dose required to achieve metabolic control (103336).

INSULIN Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Concomitant use of oats and insulin might increase the risk of hypoglycemia.  Details In patients with insulin-dependent type 2 diabetes, taking oats 100 grams daily for 2 days reduces the insulin dose required to achieve metabolic control (103336).

(Read more about OATS)

General ...Orally, arrowroot starch from the root or rhizome is well tolerated when used in the amounts found in foods (12). There is a limited amount of information available about the adverse effects of arrowroot when used in medicinal amounts. In one clinical trial, it was reported to cause dyspepsia, constipation, and dark stools (12,32448).

Gastrointestinal ...Orally, arrowroot has been reported to cause dyspepsia, constipation, and dark stools in one clinical trial (32448).

(Read more about ARROWROOT)

General ...Orally, Ascophyllum nodosum seems to be generally well-tolerated.

Endocrine ...Orally, taking Ascophyllum nodosum powder 500 mg daily for 14 days has been reported to cause elevated levels of thyroid stimulating hormone (TSH) in 2 of 22 women in a clinical trial. The powder contained 356 mcg iodine per 500 mg. Levels of free thyroxine (T4) were unaffected (94997).

Gastrointestinal ...Orally, Ascophyllum nodosum has been reported to cause stomach discomfort in one clinical trial (94996).

(Read more about ASCOPHYLLUM NODOSUM)

General ...Orally, carrageenan is well tolerated in amounts found in foods. Intranasally, carrageenan seems to be well tolerated.
Most Common Adverse Effects: None known.

Dermatologic ...Topically, when carrageenan gel was applied to the penis or anus prior to anal intercourse in one clinical study, it was reported to cause discomfort or adverse reactions in 59% of males, compared with 44% of those using placebo (107851).

Genitourinary ...Intravaginally, carrageenan gel has been associated with mild vaginal itching and burning, a vaginal abrasion, bladder fullness, and urinary hesitancy. However, it is unclear if carrageenan was the causal factor of these symptoms (40044,40068).

Hematologic ...In one clinical study in males, carrageenan gel applied topically to the penis and anus prior to anal intercourse was reported to cause rectal bleeding that was not directly related to anal intercourse in 8% of patients, compared with 0% of patients using placebo (107851).

Oncologic ...Observational research has found that increased consumption of carrageenan is associated with an increase in breast cancer incidence (40046).

(Read more about CARRAGEENAN)

General ...When used orally, Fucus vesiculosus may be unsafe due to its iodine content. Topically, Fucus vesiculosus appears to be well tolerated.
Most Common Adverse Effects:
Orally: Goiter, hyperthyroidism, hypothyroidism.
Serious Adverse Effects (Rare):
Orally: Thyroid cancer.

Cardiovascular ...In one report, a young adult with obesity developed palpitations and syncope after taking an oral weight loss supplement containing a combination of Fucus vesiculosus, dandelion, and boldo for 3 weeks. The patient was found to have a prolonged QT interval on ECG and frequent episodes of sustained polymorphic ventricular tachycardia (14321). It is not clear whether Fucus vesiculosus, another ingredient, or the combination of ingredients is responsible for this adverse effect. The product was not analyzed to determine the presence of any potential toxic contaminants.

Endocrine ...Orally, Fucus vesiculosus can cause or exacerbate hyperthyroidism due to its high iodine content (12789,13061,74217). One case of hyperthyroidism has been reported for a 60-year-old patient taking lithium for bipolar disorder and a combination product containing Fucus vesiculosus 0.125 grams, cascara 0.170 grams, and Frangula 0.222 grams per tablet for laxative purposes. The patient had been taking one tablet of the combination laxative product daily for several years. Following discontinuation of the supplement, thyroid levels normalized (74217). Similar cases of hyperthyroidism have been reported for patients taking other seaweed-containing herbal supplements (Dream Shape; Ever Youth). Analyses of these supplements shows that these products contain triiodothyronine 1 mcg and thyroxine 3-4 mcg. In addition to seaweed, Dream Shape also contains hydrangea vine, maltose, chrysanthemum, Chinese matrimony vine, and sucrose, while Ever Youth contains radish, lotus leaf, chrysanthemum, hawthorn, senna tea, and Chinese matrimony vine (13061).
Orally, prolonged use of Fucus vesiculosus has been associated with hypothyroidism (13664). The iodine in Fucus vesiculosus can cause idiosyncratic reactions.
According to the Institute of Medicine Food and Nutrition Board, prolonged, high dietary intake of iodine is associated with goiter and an increased risk of thyroid cancer (7135).

Genitourinary ...A case of hemorrhagic cystitis characterized by dysuria and polyuria has been reported in a young adult who took a specific product (Slim-Kombu, Balestra and Mech) containing Fucus vesiculosus and 19 other herbal extracts orally for weight loss. Upon discontinuation, symptoms improved (46959). It is unclear if this effect was due to Fucus vesiculosus or other ingredients in the supplement.

Renal ...A case of hemorrhagic cystitis characterized by dysuria and polyuria has been reported in a young adult who took a specific product (Slim-Kombu, Balestra and Mech) containing Fucus vesiculosus and 19 other herbal extracts orally for weight loss. Upon discontinuation, symptoms improved (46959). It is unclear if this effect was due to Fucus vesiculosus or other ingredients in the supplement. Nephrotoxicity has been associated with oral intake of Fucus vesiculosus that was contaminated with arsenic (12800).

(Read more about FUCUS VESICULOSUS)

General ...There is limited clinical research evaluating the safety of horsetail.
Most Common Adverse Effects:
Orally: Abdominal distension, increased bowel movements, and nausea.

Dermatologic ...In one case report, a patient developed seborrheic dermatitis after topical application of horsetail, requiring treatment with local epinephrine and oral antihistamines. The nicotine component of horsetail was determined to be the likely cause of this reaction (13563).

Gastrointestinal ...Orally, horsetail has been associated with mild gastrointestinal side effects including abdominal distension, increased frequency of bowel movements, and nausea (55576). Orally, chronic consumption of horsetail infusion has been associated with acute pancreatitis. In a case report, a 56-year-old female presenting with recurrent mild acute pancreatitis every 6-7 months, previously thought to be drug-induced, discontinued ingesting horsetail infusions. The patient had a history of bilateral adrenal gland removal and was being treated for hypertension, dyslipidemia, and hormone replacement, and then self-medicated with horsetail infusions. After discontinuing horsetail infusions, there were no further recurrences of pancreatitis during a 14-month follow-up (97574).

Hepatic ...In one case report, a patient with asymptomatic hepatitis B developed symptomatic liver failure following consumption of boiled horsetail juice 500 mL daily for 2 weeks. Liver enzymes returned to normal following discontinuation of the juice (92291). It is not known if the horsetail juice was contaminated or mixed with other ingredients.

Immunologic ...Horsetail has been associated with cross-allergenicity with carrots (13577).

Renal ...There are at least 4 case reports of hyponatremia thought to be at least partially associated with horsetail consumption. In one case report, an elderly patient who had taken oral horsetail 15 mg daily for 10 years presented with hyponatremia and syndrome of inappropriate secretion of antidiuretic hormone (SIADH) secondary to reduced oral intake and nausea for the previous 2 days. Horsetail was thought to be a contributing factor. The patient's symptoms resolved after 5 days of treatment with oral sodium chloride and fluid restriction (108851).

Other ...Crude horsetail contains thiaminase, which can cause thiamine deficiency with prolonged consumption. Canadian Equisetum arvense products are required to be certified as free from thiaminase-like activity (55579,105301). In one case report, the development of autism in a child exposed to both horsetail and alcohol during pregnancy was thought to be caused by thiamine deficiency attributed to this combination (92292). However, it is not known if other genetic or environmental factors were involved in the development of this condition in utero.

(Read more about HORSETAIL)

General ...Orally, oats are well tolerated.
Most Common Adverse Effects:
Orally: Abdominal distension, bloating, flatulence, and unpleasant taste.
Topically: Burning, contact dermatitis, itching, and redness.

Dermatologic ...Topically, oat-containing preparations can cause contact dermatitis (12515). Redness, burning, and itchiness have also been reported (103340).

Gastrointestinal ...When consumed orally, oats provide fiber. Increasing fiber in the diet can cause flatulence, bloating, abdominal distention, and unpleasant taste. To minimize side effects, doses should be slowly titrated to the desired level. These adverse effects usually subside with continued use (12514).
In patients who have difficulty chewing food, or those with conditions that decrease small bowel motility, oat bran may cause bezoars (concretions) and intestinal obstruction. Oats and oat bran are unlikely to cause obstruction without other causative factors (4979,4985).

(Read more about OATS)