I think there's definitely potential for this to be correlation and not causation. My first thought is that the type of person who would have a glass of wine with dinner, or a whiskey every evening, tend to be more affluent, and that people with money tend to be healthier. Obviously, money doesn't make you healthy. But it gives you better access to health care and medicine. And, the type of person that is driven to become financially successful is also more likely to take care of themselves, see a doctor on a regular basis, etc. There's nothing particularly scientific about any of that, but then again as far as I can see there's nothing particularly scientific about epidemiological studies, either.
Having said that, there are apparently many such studies saying the same thing, as opposed to the handful of studies that condemned fat in the middle of last century. Rip, do you have any thoughts on what mechanism might cause this decreased mortality?