Why do some people turn red after drinking alcohol?
13 December 2021
Healthy Pilipinas

Some people drink alcohol like it’s water—nothing happens to them. And yet, some people only have to drink a glass or two before their face, their neck, and even their arms and back, start turning red.

This is what’s commonly referred to as the “Asian Flush.” And no, it is not just a “normal” reaction—there is actually a scientific explanation behind it.
Like everything we eat and drink, alcohol—whether it be wine, beer, tequila, gin, or what have you—also needs to be digested by our body. To do so, our body first breaks down alcohol into the compound known as acetaldehyde. Acetaldehyde is then further broken down into the compound known as acetyl CoA using the enzyme acetaldehyde dehydrogenase. If this sounds complicated, think of alcohol as a big rock. When it enters our body, that big rock (alcohol) is turned into smaller pieces of rock (acetaldehyde), which are broken down further into even smaller pieces (acetyl CoA) using a special hammer (acetaldehyde dehydrogenase).

The problem is, for some unexplainable reason, many Asian people apparently have a genetic deficiency that makes the acetaldehyde dehydrogenase (the special hammer) in their body less functional. That means they cannot readily digest or break down acetaldehyde, which results in an accumulation of acetaldehyde in the body. It is this excess amount of acetaldehyde that causes the symptoms of Asian flush, such as redness, as well as the sensation known as a hangover.

So this coming holiday season, when you see a friend or family member turning very red after having a drink, just know that it’s not because they’re suddenly “embarrassed” or “blushing.” It’s actually genetics at work!