Haddock has written up Resveratrol and its presence in red wine over on his blog. I went searching and liked most of what I found ...

Resveratrol is a phytoalexin produced by several plants that is sold as a nutritional supplement. it has a number of beneficial health effects, such as anti-cancer, antiviral, neuroprotective, anti-aging, anti-inflammatory and life-prolonging effects have been reported.

Resveratrol is found in the skin of red grapes and as a constituent of red wine may explain the “French paradox” that the incidence of coronary heart disease is relatively low in southern France despite high dietary intake of saturated fats.