I researched alcohol a while ago.
If you have a genetic predisposition to alzheimer's, you might want to be really careful as alcohol may increase the risk by a lot. And there is actually a specific gene to test for (23andme?), but I'm afraid of all this genetic testing.
Also, those old fogies in Sardinia live to over 100, and they drink 1 and maybe even 2 glasses of wine a day. But I wonder if it's because something else in their diets protects them from any negative effects of alcohol.