MONDAY, June 11 , 2001 (HealthDayNews) -- If you've been toasting to good health with purple grape juice, you may be onto something.
The substances in the grapes called flavonoids have been proven capable of keeping your arteries free of disease-causing plaque.
Now, a new study says the lip-staining liquid also has the ability to increase the antioxidants in your body while decreasing the level of free radicals. Antioxidants are vitamins like C, E and A that trap free radicals, which are potentially destructive molecules.
"We know purple grape juice inhibits clotting," which helps keep arteries free and clear, says Dr. Jane E. Freedman, assistant professor of medicine and pharmacology at Georgetown University and the study's lead author.
But the flavonoids, which give the juice its purple color, also "reduce production of the free radicals, increase production of nitric oxide, which inhibits clot formation, reduce the size of clots and inhibit platelet activity," adds study co-author John Folts, director of the Coronary Artery Thrombosis Research and Prevention Laboratory at the University of Wisconsin Medical School.
The 20 people enrolled in the study each drank about two cups of juice a day for 14 days and were then found to have significantly decreased platelet activity. Platelets are the culprits that can turn sticky, clog up the arteries and lead to heart disease, the nation's No. 1 killer.
In addition, the study participants' levels of nitric oxide production in the blood, the substance that keeps the arteries expanded, increased by 70 percent, researchers say. White grape juice, which was used as a control, did not yield the same results.
"The 'antioxidant protective' effect we see with the grape juice is new information that, when added to what we already knew about grape juice's other benefits, helps us better understand the mechanism by which grape juice works in the body," says Freedman.
"This is consistent with a growing body of literature demonstrating components in grapes, flavonoids, have a salutary effect on platelets," says Dr. John Keaney, associate professor of medicine at the Boston University School of Medicine. "However, such findings in isolated blood or isolated cells can't necessarily be extrapolated to reduced cardiovascular outcomes, heart attacks and strokes."
The study, funded by the National Institutes of Health and by an unrestricted grant from Welch Foods, Inc., appears in the latest issue of Circulation.
What To Do
If you're looking for this benefit, don't think that a pill is as good as whole food. "
Taking a pill that has a bunch of flavonoids in it, unless it's been studied and shown to have biological properties
could be harmful," says Freedman.
If you want the benefits of the purple grape, Freedman suggests, "whole foods are probably better than a pill, and you'd be better off drinking the juice."
Here's more on flavonoids.
Learn the warning signs of heart attack and stroke and what you can do to prevent them.
For more HealthDay stories on antioxidants, click here.
