For some people, a few sips of alcohol can quickly turn their face red. Often called 'Asian glow' or 'Asian flush', the reaction may be treated as an amusing side effect of drinking. But doctors warn that the redness can signal something more significant about how the body processes alcohol.

The alcohol flush reaction is a form of alcohol intolerance, not an alcohol allergy. It is particularly common among people of East Asian ancestry because certain inherited variations can affect enzymes responsible for breaking down alcohol.

Why Does 'Asian Glow' Happen?

After alcohol enters the body, an enzyme called alcohol dehydrogenase converts it into acetaldehyde, a toxic compound. Another enzyme, aldehyde dehydrogenase 2 (ALDH2), normally breaks acetaldehyde down into less harmful substances.

People with reduced ALDH2 activity cannot clear acetaldehyde as efficiently. As the compound accumulates, it can trigger blood-vessel dilation and histamine release, causing facial flushing and other symptoms.

These can include a racing heart, nausea, hives, low blood pressure, headaches and worsening asthma symptoms.

The genetic variants responsible are particularly common among people of East Asian ancestry. Research has estimated that around 36% of East Asians, including Japanese, Chinese and Korean populations, experience the characteristic flushing response. However, the variants can occur in people from other ethnic backgrounds too.

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The Bigger Concern Is Acetaldehyde

The redness itself is not what causes cancer. The concern is the acetaldehyde accumulating in the body after drinking.

Acetaldehyde is classified as a carcinogenic compound, meaning it can damage DNA and contribute to cancer development. The National Cancer Institute says people who experience alcohol flushing and continue drinking have a higher risk of certain cancers, including oesophageal and breast cancer.

Research has particularly linked alcohol consumption in people with ALDH2 deficiency to an increased risk of oesophageal squamous cell carcinoma, a type of oesophageal cancer.

The risk is influenced by how much alcohol a person consumes. Having a reduced-function ALDH2 variant does not mean someone will inevitably develop cancer, but continuing to drink can increase exposure to acetaldehyde.

Should You Take Something to Stop the Redness?

Some people use antihistamines or other medicines to make flushing less noticeable before drinking.

However, making the redness disappear does not mean the underlying alcohol metabolism problem has been corrected. The NIAAA warns that medicines used to suppress flushing do not prevent the damaging effects of acetaldehyde. Masking the reaction could also make it easier to drink more.

In other words, a less red face does not necessarily mean less biological exposure to acetaldehyde.

What Should You Do if You Flush?

If your face becomes noticeably red after drinking, particularly alongside nausea, a rapid heartbeat, or headaches, it is worth discussing the reaction with a healthcare professional.

The safest way to prevent the alcohol flush reaction in people with impaired alcohol metabolism is to avoid alcohol or limit consumption.

Importantly, 'Asian glow' is not a diagnosis by itself, and facial redness can have other causes. But if alcohol consistently triggers the reaction, it may be worth treating it as a biological warning rather than simply a cosmetic effect.

The message is not that every person who turns red after a drink is destined to become ill. Rather, the reaction can provide a visible clue that the body is handling alcohol differently, potentially leaving it exposed to higher levels of a toxic compound.

Frequently Asked Questions

  • What causes the 'Asian glow' after drinking alcohol?
    The 'Asian glow' is caused by a genetic variation that affects the enzymes responsible for breaking down alcohol, leading to the accumulation of acetaldehyde, a toxic compound.
  • Is the redness from alcohol flush reaction harmful?
    The redness itself is not harmful, but it indicates that the body is exposed to higher levels of acetaldehyde, which is linked to an increased risk of certain cancers.
  • Can medications prevent the health risks associated with alcohol flush reaction?
    Medications may reduce the redness but do not prevent the harmful effects of acetaldehyde. It is advisable to limit or avoid alcohol consumption.
  • Should I be concerned if I experience alcohol flush reaction?
    If you consistently experience alcohol flush reaction, it is advisable to consult a healthcare professional to discuss potential health risks and management strategies.
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