Grapes Reduce Metabolic Syndrome

Ann Arbor, Mich.Eating grapes could reduce high blood pressure and insulin resistance and thus, help prevent heart disease and type 2 diabetes, according to scientists at the University of Michigan Health System. They are testing the effect of grapes in reducing risk factors related to cardiovascular disease (SVD) and metabolic syndrome. The effect is thought to be due to phytochemicals naturally occurring antioxidants that grapes contain.

Findings from a new animal study was presented today at the Experimental Biology convention in Anaheim, CA, and showed encouraging results of a grape-enriched diet preventing risk factors for metabolic syndrome, a condition affecting an estimated 50 million Americans and is often a precursor to type 2 diabetes.

Researchers studied the effect of regular table grapes (a blend of green, red and black grapes) that were mixed into a powdered form and integrated into the diets of laboratory rats as part of a high-fat, American style diet. All of the rats used were from a research breed that is prone to being overweight. Researchers added calories and sugars to the control group to balance the extra calories and sugars gained from getting the grape powder.

After three months, the rats that received the grape-enriched diet had lower blood pressure, better heart function, and reduced indicators of inflammation in the heart and the blood than rats who received no grape powder. Rats also had lower triglycerides and improved glucose tolerance. Rats who consumed the grape powder also had lower levels of inflammation, oxidative damage and other molecular indicators of cardiac stress than rats who did not receive grapes.  The effects were seen even though the grape-fed animals had no change in body weight.

Reducing these risk factors may delay the onset of diabetes or heart disease, or lessen the severity of the diseases, said E. Mitchell Seymour, Ph.D., lead researcher and manager of the U-M Cardioprotection Research Laboratory. Ultimately it may lessen the health burden of these increasingly common conditions.

Rats were fed the same weight of food each day, with powered grapes making up 3 percent of the diet. The study was supported in part by the California Table Grape Commission, which also supplied the grape powder.