I don't know any Jewish people. But, I had a Jewish doctor once who was quick to point out that 'Jews' (Jewish) was a religion and not a race. So...which is it? I suspect this study is of Jews of central or eastern European descent and didn't include Ethiopeans, Jews from Arab countries, converted Indians, etc.
One trait (or a handful of traits) in a somewhat inbred lineage does not make a "race". I'm still not convinced the alcoholism thing isn't cultural, though.
I've read that there is some support for the DNA studies and in fact the family name Cohen shows a strong correlation to a 'position' titled Cohen in ancient times that was passed down through the males of the family. (I think I got that correct)