Gymnema and Diabetes
Gymnema sylvestre is a woody climbing plant that grows in the tropical forests of central and southern India. The leaves are used in herbal medicine preparations. The leaves, when chewed, interfere with the ability to taste sweetness, which explains the Hindi name gurmar—“destroyer of sugar.” It has been used in India for the treatment of diabetes for over 2,000 years. The leaves were also used for stomach ailments, constipation, water retention, and liver disease.
The hypoglycemic (blood sugar-lowering) action of its leaves was first documented in the late 1920s. This action is gradual in nature, differing from the rapid effect of many prescription hypoglycemic drugs. The leaves raise insulin levels, according to research in healthy volunteers. Based on animal studies, this may be due to regeneration of the cells in the pancreas that secrete insulin. Other animal research shows that it can also improve uptake of glucose into cells and prevent adrenaline from stimulating the liver to produce glucose, thereby reducing blood sugar levels.
The leaves are also noted for lowering serum cholesterol and triglycerides. While studies have shown that a water-soluble acidic fraction of the leaves provides hypoglycemic actions, the specific constituent responsible for this action has not been clearly identified. Some researchers have suggested gymnemic acid as one possible candidate. However, further research is needed to clearly determine which constituent is responsible for this effect. Gurmarin, another constituent of the leaves, and gymnemic acid have been shown to block the ability in humans to taste sweets.
Double-blind clinical trials in India have used 400 mg per day of a water-soluble acidic fraction of the gymnema leaves. In type 2 diabetics, ongoing use for periods as long as 18 to 24 months has proven successful. In type 1 (insulin-dependent) diabetes patients, a similar amount has been used successfully as an adjunct to ongoing use of insulin. The extract used in these trials contains approximately 2,990 gymnemic acids. Consult closely with a physician, as insulin amounts may need to be lowered while taking gymnema. Traditionally, 2–4 grams per day of the leaf powder is used.
Side effects or Interactions
Used at the amounts suggested, it is generally safe and devoid of side effects. The safety during pregnancy and breast-feeding has not yet been determined. People with diabetes should only use it to lower blood sugar under the clinical supervision of a healthcare professional. It cannot be used in place of insulin to control blood sugar by people with either type 1 or type 2 diabetes.
Gymnema & Diabetes