Study Suggests Why Red Wine Does A Heart Good - By Suzanne Rostler

NEW YORK (Reuters Health) - UK researchers have zeroed in on compounds in red wine that battle a protein linked to heart disease--a finding that provides clues to why the French have relatively low rates of heart disease despite a national diet rich in creamy cheese and buttery desserts.

The investigators found that polyphenols--compounds in grape skins and present in red wine--decrease the production of a protein that causes blood vessels to constrict and reduces the flow of oxygen to the heart. The protein, endothelin-1, is believed to play a key role in the development of heart disease, explain Dr. Roger Corder and colleagues from Queen Mary University of London.

Their findings support the results of earlier studies showing that a moderate intake of red wine may lower the risk of heart disease. But while these studies focused on the antioxidant properties of polyphenols--their ability to quench disease-causing free radicals in the body--the results of the new study suggest a new mechanism by which red wine might bring benefits. According to the report in the December 20/27th issue of Nature, red wine polyphenols inhibit protein tyrosine kinases, a group of enzymes that play a key role in cell regulation. Compounds that inhibit these enzymes have been shown to suppress endothelin production, Corder told Reuters Health.

We believe that red wines contain specific polyphenols that inhibit protein tyrosine kinases, and that this effect leads to suppression of endothelin synthesis,” he said in an interview. “The effects we describe are completely unrelated to any antioxidant properties of polyphenols.'”

White wine is made without the use of grape skins, while red wine is made by fermenting the juice from grapes along with the skins. Grape skin provides red wine with its color, and also contains the highest concentration of polyphenols. Other alcoholic beverages do not contain these compounds. “Consumption of one to two glasses of red wine per day with food might be considered part of a diet to reduce heart disease, provided there are no health grounds for avoiding alcohol, and that the person is not going to drive or operate equipment,” Corder said.

The study findings are based on experiments with cow artery cells treated with alcohol-free extracts of various red, white and rose wines. The researchers also tried an extract of red grape juice, which inhibited endothelin production, but much less so than red wine did.

Source : Nature 2001;414:863-864.