Gymnema Research

Researchers at India's University of Madras in the early 1990s found that high doses (40 gm of dried herb daily) of gymnema extracts may actually help to repair or regenerate the pancreas's beta cells, which play a crucial role in the production and secretion of insulin. Few other substances, synthetic or natural, offer such promise for reversing beta cell damage and at least partially reducing diabetics' need for insulin and other drugs. On the other hand, studies indicate that animals that do not have diabetes do not produce more insulin after consuming gymnema.

Suppression of glucose absorption by some fractions extracted from Gymnema sylvestre leaves. Division of Veterinary Pharmacology, Nippon Veterinary and Animal Science University, Tokyo, Japan.
Conclusion: it is suggested that some of the extracts containing gymnemic acids from GS leaves suppress the elevation of blood glucose level by inhibiting glucose uptake in the intestine on the guinea-pig and rat.

A study conducted by Diabetes Educators, under the protocols established by Diabetes in Control and Inform lab of Omaha, NE. Gymnema Sylvestre supplementation appears to improve glycemic control in patients with type 2 diabetes. Reducing postprandial blood glucose significantly caused a decrease of HbA1c, therefore reducing the complications from diabetes.
Conclusion: It appears that the largest effect occurs from decrease of postprandial glucose levels.

http://www.diabetesincontrol.com/studies/gymnema1_2.shtml

In one controlled study, by Himalaya Healthcare Company, a standardized gymnema extract was given to 27 people with Type I diabetes, all receiving a dosage of 400 mg daily for periods ranging from 6 months to 2 and ½ years. 37 of the other people in the study continued to take the usual insulin therapy without the addition of gymnema. Among those who took the herbal extract, researchers found that insulin requirements fell off dramatically. In addition, there was a statistically significant decrease in the blood sugar markers that tests long-term blood sugar. Those in the control group showed no significant decreases in blood sugar or insulin requirements.

In a second study, 22 people with Type II diabetes were given 400 mg of gymnema extract every day for 18 to 20 months while they also continued to get their usual medication for hypoglycemia. Average blood sugar levels improved significantly in the group, along with another sugar related factor (glycosylated hemoglobin). Results also showed that there was an increase in pancreatic release of insulin among the people who got gymnema. People in the study were able to reduce their medication, and five were able to discontinue their drugs completely.