Here’s an interesting human biodiversity article from the Washington Post news section:

‘Asian glow’ from alcohol isn’t just a discomfort. It’s a severe warning.

By Meeri Kim
August 15, 2023 at 6:00 a.m. EDT

Growing up in Taiwan, Joseph Wu watched his parents and grandparents enjoy alcohol on occasion, their faces turning a glaring shade of red after only one or two drinks. When trying alcohol for himself years later, he experienced the phenomenon firsthand.

“My heart rate goes up to 130 beats per minute, I get facial flushing, and three to four hours later, I’ll probably get a headache,” said Wu, director of the Stanford Cardiovascular Institute and president of the American Heart Association, who studies the genetic mutation that causes what is known as alcohol flush reaction.

About 560 million people, or 8 percent of the global population, carry this mutation, with the vast majority being of East Asian descent—hence the nickname for the reaction, “Asian glow” or “Asian flush.”

An estimated 45 percent of East Asians get the “glow” when drinking. For some, the unpleasantness is enough to abstain from alcohol. Many others push through the discomfort, sometimes with the help of an antihistamine to lessen the effects.

Experts such as Wu, however, say that people who experience alcohol flush reaction should drink as little as possible or ideally not at all. The redness and other symptoms may be thought of as a severe warning from the body that alcohol is extremely toxic to this individual, much more so than to many others.

The associated mutation, known as the ALDH2*2 variant, has been linked to a staggering number of diseases in those who consume moderate to large quantities of alcohol.

“This is one of the most common hereditary disorders in the world, and people in our societies like to drink,” said Ronald G. Crystal, chair of genetic medicine at Weill Cornell Medical College. “But the combination of these two things puts these individuals at risk for cardiovascular disease, osteoporosis, esophageal cancer and more.”

For example, someone with the ALDH2*2 variant who drinks in moderation—defined as two drinks a day for men and one drink a day for women—has a risk of esophageal cancer 40 to 80 times higher than a person without the mutation who consumes the same amount.

Yeesh.

… This ALDH2 deficiency leads to alcohol not being metabolized normally, and acetaldehyde—essentially, a poison—builds up in the blood.

My vague impression is that different East Asian countries have different cultural adaptations to this genetic skew: the Chinese don’t drink that much, while South Koreans drink more and Japanese tend to ostentatiously get drunk in public (although I’m not sure how much they are really gulping down).

The ALDH2*2 variant was thought to originate from a single founder in Southeast China who lived 2,000 to 3,000 years ago. From there, the mutation spread to other East Asian countries. Today, the proportion of carriers varies across countries such as South Korea (30 percent), China (35 percent), Japan (40 percent) and Taiwan (49 percent).

Alcohol intake continues to increase despite the widespread nature of alcohol flush reaction in these populations. The prevalence of drinkers in East Asia has risen from 48.4 percent in 1990 to 66.9 percent in 2017. South Korea notably has a binge-drinking problem, while China has seen a surge in alcohol consumption over the past three decades.