'Consistent evidence from numerous studies indicate that moderate alcohol consumption one or two drinks a day) is associated with a lower risk of heart disease, diabetes, stroke, and premature death. But research is conflicting as to whether red wine is actually more beneficial than other forms of alcohol.
Red wine’s alleged advantages are often attributed to an antioxidant called resveratrol, which is found in grape skins. (Because white wine is generally produced without the skins, it contains little if any resveratrol.) Studies in animals and test tubes suggest that the compound may have cardiovascular benefits, including relaxing blood vessels, preventing blood clots, and reducing inflammation.
There’s evidence that other substances in red wine, such as flavanols–which are in dark chocolate as well–may also be good for the heart.'