I recall reading somewhere about the role that alcohol played in the development of civilization. If I remember correctly, there wasn't much of it in the Western Hemisphere before Columbus. Elsewhere in the world there was wine, mead, Saki, beer, etc. But no native american alcohol. Thus their lack of any evolved tolerance. But I may be remembering this all wrong.
Perhaps this also explains why corn, chocolate, and tomatos used to give me migraines (got better). They're all new-world plants.
There was an article in the Los Angeles Times in 1992 describing the effects of new-world plants on old-world cuisine. (At that time, the French were better cooks than the English and had been for centuries.) Corn, chocolate, tomatos, potatos, vanilla, chili peppers, Jerusalem artichokes, avacados, cassava, sweet potatos, etc., are all used worldwide now.