Reviewed By Michael Smith, MD on Tuesday, November 11, 2003 WebMD Medical News
Nov. 11, 2003 (Orlando, Fla.) -- The real beer argument is not "Tastes great" vs. "Less filling." It's dark vs. light, and the winner, according to a University of Wisconsin heart researcher, is dark brew because it can help prevent blood clots.
John D. Folts, PhD, professor of medicine and director of the coronary thrombosis research laboratory at the University of Wisconsin in Madison, tells WebMD that dark beer is rich in flavonoids, which have powerful antioxidant effects.
"It's about color. You can see the flavonoids in products on the shelf," he says. The rich flavonoid content makes red wine more heart friendly than white wine and purple grape juice a better choice for toddlers than white grape juice, he says.
Folts presented his dark beer-light beer study at the American Heart Association's Scientific Sessions 2003. Folts and his colleagues fed dark and light beer to dogs that had narrowed arteries in their hearts, similar to the narrowing observed in people with heart disease.
Only dogs fed dark beer had less stickiness of their blood clotting cells, says Folts. This was true even though the blood alcohol level in the dogs was the same.
He says he is currently conducting similar tests in humans. In that study, volunteers drink two bottles of either light or dark beer a day. Early indications are that dark beer again is more active at fighting blood clots than light beer, he says.
"We are also testing purple grape juice and non-alcoholic red wine," he says. In each case, the dark beverage demonstrates superiority to light colored beverages.
Are Flavonoids the Key?
Valentine Fuster, MD, PhD, director of the cardiovascular institute at Mount Sinai Medical Center in New York, says he is not convinced that flavonoids add anything to the already well-known heart protective effect of alcohol. "We know alcohol works," he tells WebMD. In order to prove that flavonoids add anything to the alcohol benefit, human studies are needed.
Also, Fuster, who was not involved in the study but who has studied the relationship between alcohol and reduced risk for heart disease, says all alcohol studies should be approached with caution. "There is always the risk that the data will be misinterpreted and people will consume too much. Any more than two drinks a day is too much."
For those who are dark beer drinkers -- or drinkers of red wine or purple grape juice -- Folts says they can gain the maximum heart benefit by "drinking these beverages with meals" so that they can fight the increase in free radicals that occurs when the body begins to metabolize food. Free radicals trigger oxidative stress, which has been linked to heart disease and inflammation, says Folts.