From Science:
More than a decade ago, a landmark study drove home a message that resonated with wine lovers everywhere: Drink red wine in moderation to lower your risk for a heart attack. Now, new results suggest that some white wines protect the heart just as well, at least in rats. The study, which was partially funded by the grape industry, suggests that more heart-protective chemicals exist in grapes than scientists had suspected.
Wine lovers got their first big boost in 1992, when researchers reported that French people, who drink more red wine, suffered less from coronary heart disease than people in other developed countries, even though they ate food that was just as fatty. To explain this phenomenon, dubbed the French Paradox, others have identified chemicals in red grapes and red wines that neutralize oxygen radicals, chemical saboteurs that harm the heart by damaging key cellular components. Those chemicals, called resveratrol and anthocyanins, are concentrated in the skin of the grape rather than the fruit. Researchers therefore suspected that white wines, which are made without the skin of the grape, would not protect hearts. But in 2002, cardiovascular scientist Dipak Das of the University of Connecticut School of Medicine in Farmington and colleagues reported that some white wines protected rat hearts as well as red wine did.
More here.