Drinking a glass of red wine a day may cut the risk of prostate cancer in half, according to a study reported September 22 in the online edition of the International Journal of Cancer.
Researchers at Fred Hutchinson Cancer Research Center in Seattle also found that the protective effect of red wine appears to be strongest against the most aggressive forms of prostate cancer.
Study author Janet Stanford, Ph.D., and her colleagues found that men who consumed four or more four-ounce glasses of red wine per week reduced their risk of prostate cancer by 50 percent and had about a 60 percent lower incidence of the more aggressive types of prostate cancer.
The researchers found no significant positive or negative effects associated with the consumption of beer or hard liquor and no consistent risk reduction with white wine, which suggests a beneficial compound in red wine that other types of alcohol lack.
The key ingredient in red wine may be an antioxidant called resveratrol, which is abundant in the skins of red grapes but much less so in the skins of white grapes. The compound is also found in peanuts and raspberries and is available as a dietary supplement.
While the researchers found that the risk of prostate cancer decreased six percent for every glass of red wine consumed per week, Stanford said the law of diminishing returns comes into play when consumption increases beyond moderation.
"But for men who already are consuming alcohol, the results of this study suggest that modest consumption of red wine - four to eight 4-ounce drinks per week - is the level at which you might receive benefit,” said Stanford. “Clearly other studies show that more than that may have adverse effects on health."
