Red faces

Did rice wine lead to flushed faces in Asia? - New Scientist

As it happens, today I witnessed this first hand. I convinced an Asian friend, who assured me he did not often drink alcohol because of the severe face flushing it causes him, to at least try a Cascade Premium Lite. (Alcohol content: 2.6%.)

It was still enough to cause a very noticeable flush. It did seem to fade by the end of the schooner, though, but he wouldn't take up my suggestion that he now try a full strength beer to see if he had broken some sort of barrier.

The science behind it is explained in the New Scientist article as follows:

A mutation that causes some Asians to flush red when they down a beer may have evolved to help their ancestors cope with rice wine. A genetic study suggests that the mutation evolved around 10,000 years ago, about the same time as Asians were starting to farm rice and figuring out how to ferment it into boozy drinks....

The mutation causes alcohol to be metabolised at 100 times the speed that it otherwise would be. As the enzyme removes alcohol so quickly from the blood stream, it protects people from the harmful effects of alcohol, and Su believes it confers an evolutionary advantage: a study in the Han Chinese suggests that those carrying the mutation have the lowest risk of alcoholism (American Journal of Human Genetics, vol 65 p 795).

The mutation also causes a by-product of the alcohol's metabolisation to accumulate in the body, which makes those who have the mutation flush red when they drink.

So, this mutation has the embarrassing effect of making you look like a quick drunk, which (like my lunch mate) causes some sufferers enough embarrassment to not want to drink at all, but actually it sounds like they should be capable of drinking with relative impunity. How ironic.