Why do you blush when drinking?

Blushing after drinking is something that most people will encounter, but the severity is different. Some people are as red as ripe shrimp when they touch wine, and some people have to drink a lot to blush; Some people just blush, and some people have red skin all over.

Blushing after drinking (picture from the internet, deleted)

Blushing after drinking is actually a manifestation of vasodilation of skin mucosa. This phenomenon mainly occurs in Asian yellow people, so it is also called "Asian flush". The reason for blushing is the mutation of the gene of the enzyme that metabolizes alcohol in Asians, which leads to the accumulation of toxic acetaldehyde in the body, causing vasodilation and blushing reaction.

What does alcohol experience in the human body? Copy the contents of the last article:

After alcohol enters the human body, it can be absorbed in about 10 minutes and enter the blood, reaching a peak in 60-90 minutes. 20% alcohol is absorbed by the stomach and 80% by the small intestine. After entering the blood, alcohol is transported to the liver. Alcohol dehydrogenase in the liver converts ethanol into acetaldehyde, and acetaldehyde is converted into acetic acid by acetaldehyde dehydrogenase. Acetic acid is completely converted into carbon dioxide and water by liver drug enzyme (cytochrome P450) and excreted.

The decomposition process of alcohol in human body

Let me briefly talk about alcohol dehydrogenase (ADH). Alcohol dehydrogenase is abundant in human and animal livers, plants and microbial cells, and its function is to produce acetaldehyde through a series of complex ethanol oxidation reactions. There are at least six different alcohol dehydrogenases in human body. The activity of alcohol dehydrogenase varies from person to person. For example, young women can't decompose alcohol as quickly as young men, because the activity of alcohol dehydrogenase in young women is not as high as that in men. However, this situation will reverse after middle age.

If a person's body lacks alcohol dehydrogenase, then his drinking performance is: the capacity for drinking is poor, and he will fall down after one cup, but he is very drunk when he obviously has only a little.

ALDH gene is located on chromosome 12, the normal allele is named ALDH2* 1, and the allele with single base mutation is named ALDH2*2. In the enzyme translated from the mutant gene, glutamic acid of residue 487 was converted into lysine, resulting in the basic loss of catalytic activity. Generally speaking, ALDH2*2 can't decompose acetaldehyde quickly. ALDH2*2 is distributed in different races of human beings and basically appears in Asians.

Distribution of ALDH2*2

People who lack ALDH2* 1 can't quickly decompose acetaldehyde into acetic acid, which will accumulate in the body, leading to vasodilation of skin and mucosa, thus causing blushing. Acetaldehyde is very harmful to the body, which can cause discomfort symptoms such as blushing, palpitation and blood pressure drop. Dizziness and headache after hangover are caused by acetaldehyde, and the accumulation of acetaldehyde can also lead to anemia, audio-visual hallucinations, mental decline and mental disorders.

Process of ethanol, acetaldehyde and acetic acid

Based on the above, we should be clear that blushing when drinking has nothing to do with the quality of drinking. Please don't use the phrase "red-faced man, a catty and a half" to explain that drinking is good.

Drinking blush has nothing to do with drinking quality, but drinking blush actually belongs to an evolutionary mechanism. This is the body reminding you that the acetaldehyde content in your body has seriously exceeded the standard and you can't drink any more. Just shut up. In other words, blushing after drinking is actually a powerful protection mechanism evolved by some Asians! It allows this group to bring their own "abstinence gene", which excludes alcohol and is not easy to produce side effects such as alcohol dependence.

Facial comparison of patients with ALDH2*2 deficiency before and after drinking.

Without this protection mechanism, whites and blacks are very prone to alcohol dependence or alcoholism. There is a famous drug in America called tubbs, which is actually an acetaldehyde dehydrogenase (ALDH) inhibitor. Using it will artificially cause the accumulation of acetaldehyde, resulting in a "face-lifting effect", which makes alcoholics feel very uncomfortable, thus inhibiting their dependence on alcohol.

People who blush after drinking can confidently announce when they don't want to drink: "I blush, and you still let me drink." Alcohol allergy, can't drink! "

Look, others need to rely on "tools" to call the police, and you will bring your own "alarm system" when you blush after drinking. Isn't this a better evolution?

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