Dietary supplement boosts insulin sensitivity

Dietary supplements made of resistant starch can help improve the body's response to the sugar-processing hormone insulin, a new study shows.

Loss of insulin sensitivity, also called insulin resistance, is a key step in the development of diabetes. The researchers found the supplement improved sensitivity in healthy people by up to one-third, and a similar effect in people with full-fledged diabetes could have a significant beneficial effect on their health, said Dr. M. Denise Robertson of the University of Surrey in Guilford, UK.

She and her colleagues are now planning to test the supplement in diabetic patients. "The challenge will be if we can actually get the same result from this group of subjects - we're quite confident that we can but it remains to be seen," she said.

Robertson and her colleagues conducted the current study in 10 healthy people, who consumed either 30 grams of the resistant starch supplement or the same amount of a supplement that did not contain resistant starch. They mixed the supplement with water and added it to milk or other drinks.

After taking the supplement daily for four weeks, healthy people showed up to a one-third increase in insulin sensitivity. Study participants tolerated the supplement well, the team reports in the American Journal of Clinical Nutrition.

Resistant starch is thought to exert its effects because "good" bacteria in the colon break it down into short-chain fatty acids, which are then released into the circulation. These special fats are very different from the fatty acids people eat, Dr. Robertson noted.

While most strategies for increasing insulin sensitivity require major changes in diet and exercise, Robertson noted, the current study shows "we could actually improve people's health without having to change their lifestyle."

SOURCE: American Journal of Clinical Nutrition, September 2005.