Resveratrol is a phytoalexin found in high concentrations in the skin of red grapes, which helps fight infections by fungi and certain bacteria. The molecule is thought to be an antioxidant, helping to prevent cell damage from powerful oxidants produced during normal metabolism. Although it is already touted as an “anti-aging” drug, the mechanism by which it prolongs life in animals is unknown. 

Alcohol in moderation seems to have health benefits beyond just its “anti-aging” qualities. More than 60 research studies have shown that moderate consumption of alcohol reduces the risk of a heart attack. The benefits occur only if no more than one or two drinks are consumed daily — exceeding the limit increases risks of heart attacks and death. Resveratrol is not the only compound in wine with health benefits. Antioxidants called polyphenols are found in high concentrations in grape skin and are believed to reduce the risk of heart attacks. The highest amounts of polyphenols are in Cabernet grapes and in French wine. Fats that become oxidized are much more likely to accumulate in the wall of arteries, leading to plaques. Not only do polyphenols prevent fat deposition, but they also prevent blood clotting by impairing the ability of platelets to stick to damaged arteries. These antioxidants also appear to reduce inflammation in blood vessels, decreasing cholesterol deposition and the risk of spasm if an artery becomes partly blocked. 

Recently, a substance called saponin, also found in red wine, has been shown to raise the good or HDL cholesterol and modestly reduce the bad or LDL cholesterol. Saponin binds cholesterol and prevents its absorption into the bloodstream from the bowel. Some maintain that saponin is the most potent agent in red wine. Its concentration is highest in California zinfandels.