Complementary and Alternative Medicine (CAM) Supplement Use in People with Diabetes: A Clinician's Guide. Laura Shane-McWhorter

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СКАЧАТЬ baseline of 11.9% to 8.5% (P < 0.001), and average fasting glucose decreased from 174 mg/dl (9.7 mmol/l) at baseline to 124 mg/dl (6.9 mmol/l) after 18–20 months (P < 0.001). Notably, five individuals were able to discontinue sulfonylurea treatment. Lipids also significantly declined in this study. A control group of 25 patients on sulfonylureas plus placebo had no significant changes in A1C, fasting glucose, or lipids.

      Summary

      Gymnema has been studied for up to 2 years in both type 1 and type 2 diabetes. Target goals for A1C and fasting glucose have not been achieved in published studies. Gymnema has a variety of actions that may stimulate glucose uptake and utilization as well as stimulate β-cell function. If gymnema is used, a standardized extract should be chosen. This product has not been studied in pregnant or lactating women, children, or elderly and therefore should not be used in these populations. The main potential adverse effect is hypoglycemia; hence it is important that medical providers supervise their patients’ use of this product and possibly consider decreasing the dose of concomitant secretagogues. A standardized gymnema extract is being studied in the U.S. A typical dose is 400 mg/day, standardized to contain 24% gymnemic acids.¹⁹

FENUGREEK (Trigonella foenum-graecum L.)

      Fenugreek is a member of the Leguminosae, or Fabaceae, family and grows well in India, Egypt, and other parts of the Middle East.⁷⁵ The leaves are ingested as a vegetable in India.⁷⁶ The part used medicinally is the seed.

      Not only has fenugreek been used to treat diabetes, but since it tastes and smells like maple syrup, it has also been used as a cooking spice and flavoring agent in foods and tobacco. It has been used to mask the taste of medicines.⁷⁵ Other uses include treatment of constipation and hyperlipidemia, and postpregnancy use to promote lactation.⁷⁵ There are no studies supporting its use in lactation.

      Chemical Constituents and Mechanism of Action

      Fenugreek contains many different chemical components, including saponins and several glycosides.⁷⁵ The seeds contain alkaloids, including trigonelline, gentianine, and carpaine compounds. Fiber, 4-hydroxyisoleucine, and fenugreekine, components that may have hypoglycemic activity, are also found in the seeds. The mechanism is thought to involve delay of gastric emptying, slowing carbohydrate absorption, and inhibition of glucose transport.⁷⁷ Fenugreek may also increase the number of insulin receptors in red blood cells and improve glucose utilization in peripheral tissues; thus demonstrating potential antidiabetic effects in both the pancreas and other sites.⁷⁸ A constituent of the seeds, 4-hydroxyisoleucine, may directly stimulate insulin secretion.⁷⁹

      Adverse Effects and Drug Interactions

      The main side effects include diarrhea and gas, or flatulence, which subside after a few days of use. A caution for women of childbearing age is that fenugreek consumption may cause uterine contractions and thus cause problems with pregnancy.⁷⁵ Hypersensitivity reactions have occurred, including rhinorrhea, wheezing, and fainting after inhalation of the seed powder. Wheezing and facial angioedema were reported in a patient with chronic asthma after application of a topical fenugreekpaste.⁷⁶

      A theoretical adverse effect is an allergic reaction in people with a peanut allergy, since peanuts are also members of the Leguminosae family.⁷⁶ However, this reaction has never been reported. All of these side effects may occur in the infants of nursing mothers who use fenugreek, since the fenugreek may be secreted in the milk.

      Fenugreek contains some coumarin constituents, and thus may increase the effects of anticoagulant, or blood-thinning, drugs such as warfarin (Coumadin) or herbs with blood-thinning activity (such as ginkgo biloba, garlic, or ginger). A case report of an interaction between warfarin and a product containing the digestive agent boldo in combination with fenugreek resulted in an increase in international normalized ratio (INR).⁸⁰ Fenugreek may also enhance the activity of diabetes medications; thus, when used in combination with insulin or oral diabetes agents, the patient may experience hypoglycemia.

      Clinical Studies

      There are only a few published studies using fenugreek. Most of these are short-term, involve very few patients, and do not adequately report details. In one study, 10 patients on insulin (with type 1 diabetes) were included in a 10-day evaluation.⁸¹ The patients were assigned to either placebo or twice-daily 50 g fenugreek defatted seed powder, used in unleavened bread. Fasting glucose decreased from an average of 272 mg/dl (15.1 mmol/l) at baseline to 196 mg/dl (10.9 mmol/l; P < 0.01). Total cholesterol decreased (P < 0.001), as did LDL and triglycerides (P < 0.01 for both).

      A larger study involved a 6-month trial of fenugreek in 60 patients with inadequately controlled type 2 diabetes.⁸² Fenugreek seed powder, 25 g daily, was given in two equal doses at lunch and dinner. The average fasting glucose decreased from 151 mg/dl (8.4 mmol/l) to 112 mg/dl (6.2 mmol/l) after 6 months. Glucose values 1 and 2 hours after meals also declined. Mean baseline 1-hour glucose measured by oral glucose tolerance test (OGTT) was 245 mg/dl (13.6 mmol/l) at the start of the study and decreased to 196 mg/dl (10.9 mmol/l) after 6 months (P < 0.001). Mean 2-hour glucose decreased from 257 mg/dl (14.3 mmol/l) to 171 mg/dl (9.5 mmol/l; P < 0.001). Average A1C decreased from 9.6% to 8.4% after 8 weeks (P < 0.001).

      In a different study, 25 newly diagnosed type 2 diabetes patients were given a hydroalcoholic fenugreek extract or placebo plus usual care of diet and exercise for 2 months.⁸³ The group assigned to fenugreek was given 1 g/day of the seed extract. The fenugreek group did not differ from the placebo group in fasting or postprandial glucose, although they had improved area under the curve blood glucose and insulin levels (P < 0.001) and an improved lipid profile for triglycerides and HDL.

      Summary

      In the U.S., fenugreek has GRAS (generally recognized as safe) status⁸⁴ and has been used in both type 1 and type 2 diabetes. However, there are few studies confirming its efficacy. It may have beneficial effects in pancreatic and other tissues and may affect glucose and carbohydrate absorption, as well as affect insulin resistance. Side effects are mostly uncomfortable gastrointestinal effects that may resolve in a few days. Pregnant women should not take fenugreek, since they may experience uterine contractions.⁷⁵ Women who use fenugreek as a galactogogue should be aware that it may appear in breast milk, and their infant may experience the side effects of this botanical. Caution is warranted in those who have a peanut allergy or are allergic to chickpeas, soybeans, or green peas. Individuals who take antiplatelet agents, anti-inflammatory drugs, or herbs that have blood-thinning effects should not use fenugreek. Although the dose used is variable, a typical amount is 10–15 g/day, as a single dose or divided with meals, or 1 g of a hydroalcoholic extract.¹⁹ If fenugreek is combined with insulin or other diabetes medications, the patient may experience hypoglycemia; thus doses of diabetes medications may have to be adjusted.

BITTER MELON (Momordica charantia)

      Bitter СКАЧАТЬ