This is a very interesting idea. Here's a non-PC take on this:

Consider the fact that the highest rates of alcoholism in the world are in the northern latitudes, Inuits, Finns, Russians, etc, and that these peoples historically relied more on protein and fat for the their calories and less on carbs. They were late to the "benefits" of the agricultural age.

This could also tie in with the other article today about which states in the US have the fastest growth rates of obesity. Are the states with the largest number of poor, whose diets are heavy on carbs, the states with the highest rates of alcoholism?