One man's side-effect is another man's effect. At this point in the resveratrol research, it's heartening to see that resveratrol is in fact doing something in humans - since we didn't have much evidence even for that. Hopefully this pilot study will justify bigger or at least longer-term research which can characterize what exactly the resveratrol is doing.
Control group: Those whose drink of choice does not have resveratrol.
Experimental group: Those who drink almost exclusively red wine.
Both groups will have ill health due to the alcoholism, but the experimental factor, the consumption of red wine vs. other alcohols, should show a correlative difference, if one exists.
http://en.wikipedia.org/wiki/French_Paradox
A healthy intake of red wine seemed to be a common factor in the French story, and from chemical analysis of wines we found resveratrol.