Historical Beer Opinions
I’ll be the first to agree with the spirit of George F. Will’s editorial about the historical importance of beer in the growth of urban populations (via Daring Fireball), but there are two issues in this piece of which the reader should be aware:
I.
Mr. Will is committing the fallacy of equivocation when he speaks of the “beer” consumed daily by our urbanizing ancestors. When a brewed beverage had to substitute for water, it was generally a “weak beer” or “small beer” with extremely low alcohol content. (cf. Beer in the Middle Ages)
II.
Alcohol dehydrogenase (ADH) was correctly named in the editorial as the dimer that catalyzes the first step in our digestion of alcohol. Mr. Will asserts that those people who couldn’t process beer due to ADH mutation didn’t survive to reproduce; therefore, alcohol intolerance was selected out of the population. However, the story strays from the truth a bit:
“Most of the world’s population today,” Johnson writes, “is made up of descendants of those early beer drinkers, and we have largely inherited their genetic tolerance for alcohol.”
Johnson’s view is Euro-centric and ultimately incorrect. The issue is this: “European populations express an allele for the alcohol dehydrogenase gene that makes it much more active than those found in populations from Asia or the Americas.” That makes sense: people with European ancestry can digest alcohol faster and safer than those from Asia. However, people in Asia make up over half of the world’s population, so it is silly for Johnson to state that most of the world’s population is tolerant to alcohol.
To reiterate: over half the world has a mutation on the gene encoding for ADH. This causes deficiency in the metabolism of alcohol and results in the well-known alcohol flush reaction. Therefore, the sterilizing power of alcohol in weak beers secured the water supply and in doing so propelled urbanization, but the effects of this beverage didn’t shape humanity’s genetic profile as profoundly as this article would have you believe.