Wednesday, June 25, 2003

Drinking grape juice may reduce blood pressure in hypersensitive men

Drinking Concord grape juice may reduce blood pressure in hypertensive men, according to results from a preliminary study presented at Experimental Biology 2003.

In the study, men with elevated blood pressure who drank Concord grape juice for twelve weeks experienced a five-point drop in both their systolic and diastolic blood pressures versus no significant change in the group drinking a placebo.

"This is one of the first randomized, double-blind, placebo-controlled studies to use a whole juice in this case, Concord grape juice," explained study author Kevin Maki, Ph.D., Director, Nutrition and Metabolism Research Unit, Radiant Research, Chicago. "In our study, blood pressure was measured as part of the basic health information of the study participants. When we reviewed the data, we saw reductions of nearly six points in both systolic and diastolic blood pressure measurements among the hypertensive men drinking Concord grape juice. Those on the calorie-matched placebo showed no significant change."

The study, presented at the annual meeting of the Federation for American Societies of Experimental Biology, looked at 80 healthy males, ages 45 to 70. For 12 weeks, half drank an average of 12 ounces of Concord grape juice per day and half drank the same amount of a placebo beverage designed to look and taste like grape juice. The results presented at FASEB looked at the 19 Concord grape juice drinking and the 17 placebo drinkers who started the study with above-median blood pressure.

"While additional studies are necessary to confirm these results, it is exciting that drinking Concord grape juice every day may be an easy way for hypertensive individuals to significantly lower their blood pressure," noted Maki.

The U.S. National High Blood Pressure Education Program estimates that lowering systolic blood pressure by five points would result in a 14 percent reduction in deaths from stroke and a nine percent reduction from heart disease.

The study authors point to two previous clinical studies showing that consuming Concord grape juice improved arterial wall flexibility (demonstrated by increased flow-mediated vasodilation) as suggesting a possible mechanism of action for the reduced blood pressure. Recent research has also shown the ability of purple grape juice to slow the oxidation of LDL cholesterol as well as inhibit the tendency of blood to clot. Both functions contribute to maintaining healthy cardiovascular function.