My face didn't turn red when I drank before, why does it turn red now?

Drinking is a common phenomenon and is required in many social occasions. Different people have different physical conditions, and their alcohol tolerance and reactions after drinking are also different. For example, many people will blush after drinking. Some people say that blushing after drinking is good, as it means that the person has a fast metabolism. Others think that blushing after drinking is bad, as it may indicate that the person has esophageal cancer. So, what is the reason for blushing when drinking?

1. The phenomenon of blushing after drinking

Alcohol flushing reaction is caused by a malfunction in acetaldehyde dehydrogenase, which leads to excessive accumulation of acetaldehyde. Acetaldehyde is much more toxic than ethanol, and even a small amount can make a person drunk, with symptoms such as flushed face, dizziness, and vertigo. Some people have a high alcohol tolerance, but in fact it is just that this enzyme is relatively sufficient. For people with less enzyme, alcohol cannot be metabolized quickly, causing acetaldehyde accumulation.

2. Causes of blushing

Blushing after drinking is actually a sign that you can't drink. Many people believe that "blushing means that you have a fast metabolism and can drink a lot", but there is actually not much basis for this. The specific reason has to do with alcohol metabolism. When people drink alcohol, whether it is liquor, beer or wine, what they mainly drink is alcohol, that is, ethanol. As a chemical, alcohol is broken down in the liver. First, alcohol dehydrogenase "breaks it apart" into acetaldehyde. Acetaldehyde has the function of dilating capillaries, and the dilation of facial capillaries is the reason for blushing; then acetaldehyde dehydrogenase converts acetaldehyde into acetic acid. Finally, acetic acid is converted into carbon dioxide, water and fat - fat is the form in which the energy produced by alcohol metabolism is stored in the body. This is also the reason why drinking causes beer belly and fatty liver.

People who blush when drinking alcohol can quickly convert ethanol into acetaldehyde, which means they have highly efficient alcohol dehydrogenase. However, there is another enzyme, aldehyde dehydrogenase. People who blush after drinking alcohol have only the first enzyme but not the second enzyme, so acetaldehyde accumulates rapidly in the body and cannot be metabolized for a long time, so their face will remain red for a long time. After 1-2 hours, the red color will gradually fade away. This is because the P450 in the liver slowly converts acetaldehyde into acetic acid, which then enters the TCA cycle and is metabolized.

3. The harm of blushing after drinking

For those who blush when drinking, they may be facing more than just the direct toxicity of ethanol. Researchers have found that blushing may indicate an increased risk of esophageal cancer. The blushing may be accompanied by nausea and a rapid heartbeat. Blushing is mainly caused by a genetic defect in an enzyme called ALDH2. For such people, just half a bottle of beer can cause this blushing reaction. This defect can cause problems in alcohol metabolism and lead to the accumulation of acetaldehyde in the body. Carrying two defective genes will cause this reaction, and such people will be unable to drink large amounts of alcohol.