Grapes' resveratrol may help prevent obesity

MONDAY June 16, 2008 (foodconsumer.org) -- Resveratrol, a compound found in grapes and red wine, reduces the number of fat cells and may one day be used to treat or prevent obesity that affects millions of Americans, according to a new study presented at the Endocrine Society's 90th Annual Meeting in San Francisco.

Early research has found that resveratrol protected laboratory mice fed a high fat diet from having health problems associated with obesity by mimicking the effects of calorie restriction, which is known to elongate the lifespan of many animals, probably including humans.

In the current study, researchers at the University of Ulm in Germany wanted to know if resveratrol exerts its anti-obesity effects by changing the size or function of the fat cells.

For the study, the German team used a strain of human fat cell precursors known as preadipocytes, which in the body go on to develop into mature fat cells, according to Pamela Fischer-Posovszky, Ph.D., coauthor of the study and a pediatric endocrinology research fellow in the University's Diabetes and Obesity Unit.

Resveratrol prevented the pre-fat cells from increasing in number and being converted into mature fat cells; it also hindered fat storage, the researchers found.

Additionally, resveratrol reduced certain cytokines (interleukins 6 and 8), which may be linked to the development of obesity-related disorders such as diabetes and clogged coronary arteries, and increased the production of a protein called adiponectin, which is known to decrease the risk of heart attack. Unfortunately, its production is reduced by obesity.

The new findings further the theory that resveratrol in red wine explains the French paradox, the observation that French people eat a relatively high-fat diet but have a low death rate from heart disease.

"Resveratrol has anti-obesity properties by exerting its effects directly on the fat cells," Fischer-Posovszky said. "Thus, resveratrol might help to prevent development of obesity or might be suited to treating obesity."

Fischer-Posovszky cautioned, through, that there is not sufficient knowledge about the effects of long-term treatment with resveratrol, although one study has found that a single dose of up to 5 grams of the compound daily, a dose that is much higher than the amount found in a bottle of red wine, caused no serious side effects in healthy individuals.

However, she pointed out that another study suggested that resveratrol may stimulate the growth of human breast cancer cells, probably because the chemical structure of the compound is similar to a phytoestrogen found in some plants.

By David Liu, Ph.D., and edited by Heather Kelley
Jun 16, 2008 - 1:21:39 PM