Purple Grape Juice Improves Flow-Mediated Vasodilation

WESTPORT, Sep 08 (Reuters Health) - The benefits associated with drinking red wine may derive from the effect of purple grape juice on flow-mediated vasodilation and on inhibition of oxidation of LDL cholesterol, a team at the University of Wisconsin reports in the September 7th issue of Circulation: Journal of the American Heart Association.

Dr. James H. Stein and colleagues had 15 patients with angiographically documented coronary artery disease ingest 7.7 mL/kg per day of purple grape juice for 14 days. At baseline, flow-mediated vasodilation, as measured by high-resolution ultrasound of the brachial artery, was impaired.

The investigators found that at the end of the study period, flow-mediated vasodilation increased from 2.2% to 6.4%. LDL oxidation, measured by the lag time to conjugated diene formation after exposure to copper chloride, increased from 87 to 117 minutes.

The investigators note that the positive effects of the ingestion of purple grape juice took place "...despite use of lipid-lowering and antioxidant therapies," as shown by linear regression analysis.

The Madison, Wisconsin, investigators conclude, "Improved endothelium-dependent vasodilation and prevention of LDL oxidation are potential mechanisms by which flavonoids in purple grape products may prevent cardiovascular events, independent of alcohol content."

Circulation 1999;100:1050-1055.