CONCORD GRAPE JUICE LOWERED BLOOD PRESSURE IN PRELIMINARY CLINICAL STUDY; ALSO LOWERED PB, CHOLESTEROL AND INHIBITED ATHERSCLEROSIS IN
LAB STUDY
-- Concurrent studies point to positive effect on blood pressure, other cardiovascular risk factors --
San Diego, CA, April 4, 2005—Three current studies point to a positive effect of Concord grape juice consumption on blood pressure, adding to the growing body of scientific evidence that drinking Concord grape juice assists with healthy cardiovascular function. In a preliminary study published in the current issue of Biofactors, drinking Concord grape juice lowered the blood pressure of mildly hypertensive men by almost seven points.
In addition, two laboratory studies presented today at the Experimental Biology meeting in San Diego complement the Biofactors study; one offers a possible mechanism of action for the blood pressure effect, the other shows similar effects in a laboratory model that closely mimics human cardiovascular behavior.
The Biofactors study tested 40 Korean men with mild hypertension (blood pressure averaging 146/94 mm Hg). In a double-blinded study, half drank Concord grape juice for eight weeks while the other half drank a calorie-matched placebo drink. At the end of the study, the grape juice group had a significant decline of 7.2 mm systolic and 6.2 diastolic compared to baseline. The placebo group saw a lesser decrease in both measurements.
“It is exciting to see complementary research presented at the same time on a topic as important as blood pressure,” explains John D. Folts, Ph.D., Professor of Medicine at the University of Wisconsin School of Medicine and an author of one of the laboratory studies. “Nonetheless, we need to be cautious when interpreting preliminary data such as from the Korean study. For example, the placebo group also saw a small drop in blood pressure, although not a significant one, and while the Concord grape juice group’s numbers were significant compared to baseline, they did not reach significance when compared group to group. A larger trial will be necessary to confirm the blood pressure lowering effect.
On the other hand, our study also saw the lowering of blood pressure in a laboratory model, as well as the lowering of cholesterol and the inhibition of atherosclerosis—all significant versus a placebo group and all of which adds credence to the Korean study, suggesting that the Concord grape juice is functioning on a number of levels in the cardiovascular system.”
In the second laboratory study presented at Experimental Biology, researchers from the Louis Pasteur University in Strasbourg, France, led by Valerie Schini-Kerth, Ph.D., found that Concord grape juice produced arterial relaxation by increasing the activity of a nitric oxide synthase in cells lining the arterial wall.
“Dr. Schini-Kerth’s data certainly suggest a mechanism whereby Concord grape juice-based polyphenols may reduce blood pressure by encouraging the relaxation of the artery wall,” notes Dr. Folts. “Previous studies by my group have shown that Concord grape juice enables the brachial arteries to expand to accommodate increased blood flow. Likewise, other researchers have shown that nitric oxide production from platelets may well be the mechanism behind Concord grape juice’s ability to reduce the tendency for the blood to clot. So there are a lot of supporting data in this area.”
The U.S. National High Blood Pressure Education Program estimates that lowering systolic blood pressure by five points would results in a 14% drop in deaths from stroke, a 9% drop in heart disease deaths, and a 7% drop in overall mortality.
Experts also note that all foods should be consumed in moderation, and that a healthy diet should include a wide range of colorful fruits and vegetables, and complemented by regular physical exercise.
The Concord grape juice for these studies was provided by Welch Foods Inc. The laboratory studies were partially supported by grants from Welch Foods Inc.
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The study was underwritten, in part, by Welch Foods Inc.
