The Ultimate Asian Flush Guide : What causes it and can it be prevented?
By James Petra
Updated on January 16, 2019

If you’re on this article, chances are, you are all too familiar with asian flush. Some people experience the negative effect of alcohol very severely and its due to an enzyme deficiency (more on this later).

So who’s affected by asian flush?

It effects 40% of those originating from east asia (China, Japan, Korea, Vietnam) and it occurs after drinking small quantities of alcohol causing symptoms of:

  1. Facial flushing – rose red cheeks as well as other body areas
  2. Nausea and vomiting
  3. Headaches
  4. Fast heart rate

But what exactly causes it? and more importantly, is there a way of stopping it?

In this article we’ll tell you all about:

  • What causes asian flush?
  • Is asian flush genetic?
  • Are there any other negative health effects?
  • Asian flush prevention tips

Asian Flush: What is it?

Is it caused by a deficiency in the ALDH2 (alcohol dehydrogenase) enzyme. This enzyme breaks down acetaldehyde which is one of the main by-products of alcohol break down and responsible for the majority of the symptoms of a hangover. 

So how does acetaldehyde cause damage and hangovers?

Acetaldehyde is a highly unstable and toxic by-product of alcohol break down. Your body has a sophisticated method of keeping it in check. The enzyme ALDH2 will break it down into less harmful molecules before clearing it from your body.

So in people who lack this enzyme, acetaldehyde is left to build-up in the system which causes significant damage to the cells it comes into contact with.

Symptoms including headache, nausea and facial flushing (Rosy looking cheeks) are all mainly caused by acetaldehyde.

Is asian flush an allergy?

No, An allergy is your immune system responding inappropriately to a non-harmful thing. 

For example, people with hay fever inhale pollen, the immune system picks this up and sees it as a foreign invader.

Your immune system then mounts an immune response to this allergen (pollen) and tries to fight it off. However pollen is not harmful and the immune system doesnt need to attack it. 

The typical symptoms of an “allergic reaction” are:

  • hives: red itchy patches that develop on the skin.
  • itchy throat / eyes
  • watery eyes
  • Swelling of the lips / throat / airways – this occurs in severe cases only.

Asian flush syndrome is caused by a buildup of acetaldehyde which has nothing to do with allergies.

Is Asian flush genetic?

Genes play a huge role. If both of your parents carry the gene which produces less of the ALDH2 enzyme then this is more likely to be passed onto their children who will have more severe asian flush symptoms. 

Those who receive only one from their parents will be able to tolerate larger quantities of alcohol and experience symptoms to a less severe extent.

Cancer and asian flush syndrome: The facts

Studies have shows that individuals with asian flush syndrome who drink moderate to high quantities of alcohol are at increased risk of developing squamous cell oesophageal cancer.

First of all, what is meant by moderate to high quantities?

There are lots of definitions available online but the most accepted is from the NIAAA (National institute on alcohol abuse and alcoholism):

Moderate: Up to 2 alcoholic drinks per day in men and 1 in women

High:  up to 4 alcoholic drinks per day in men and 3 in women

Therefore the studies suggest that those with asian flush who drink daily are at increased risk of oesophageal cancer. This link has been attributed to the buildup of acetaldehyde but the exact mechanism isn’t yet clear.

Other Studies have also been carried out to determine a link between asian flush syndrome and other cancers but have so far been inconclusive in bowel, breast and head and neck cancers.

An important thing to note is that people with asian flush tend to drink much less anyway because of the negative effects they experience! 

Asian flush survival tips:

So what can be done to prevent the symptoms of asian flush?

1) Amino acids – N-Acetyl-cysteine (NAC)

This amino acid is commonly used in hospitals around the world as an antidote to paracetamol overdose. It is believed that NAC is used by the liver to produce more glutathione, known as the master antioxidant which swoops around the body to clear up free radicals.

The breakdown of acetaldehyde will produce huge amounts of free radicals which glutathione will help clear up before too much damage is done.

Some animal studies have shown that giving NAC can significantly reduce the amount of acetaldehyde produced from alcohol consumption. Although there is not much research on its use in asian flush syndrome specifically, it could have a role to play.

2) Antihistamines

These medications can be purchased over the counter and are commonly used to treat allergic reactions by blocking the affects of histamine.

Histamine is released by certain white blood cells when they sense the body is under attack. As explained earlier, asian flush syndrome is not an allergic reaction but this white blood cell response can be initiated by a buildup of certain chemicals in our system. Acetaldehyde may again have an important role here.

a study into using antihistamines for asian flush has shown improvement in their flushing symptoms.

It is important to note that some antihistamines have a sedating effect and can make you sleepy. This is particularly important if you plan to drive or if you work with heavy machinery in which case you need to be cautious. It is advisable to speak to the pharmacist to check before taking antihistamines.

3) Slow down

As the symptoms are as a result of acetaldehyde buildup, giving your liver a chance to process the alcohol you are consuming is a good way of flushing out the toxin from your system and potentially reducing the flushing.

4) Antioxidants

Free radicals play a huge role in making you feel awful after drinking in general. The process of free radical production goes into overload in asian flush as acetaldehyde builds up the body.

Antioxidants such as Vitamin C and E, as well as alpha lipoid acid and coenzyme Q10 can help by supporting your body’s natural antioxidant system to clear up as many free radicals as possible.

5) Rehydrate

The oldest trick in the book: drink plenty of fluids

keeping hydrated is key for several reasons. Firstly alcohol is a diuretic meaning that it can stimulate your kidneys to lose more fluid than your actually consuming.

In fact, after drinking a 250ml glass of wine, you will lose an extra 120mls of fluid.

Secondly, the more hydrated you are, the more dilute the toxins in your system will be which will allow your kidneys to flush away the harmful by-products more easily.

Can Asian Flush be prevented?

People with asian flush syndrome will experience the negative effects of alcohol with only small amounts of alcohol. Because its caused by a deficiency in the enzyme that breaks down acetaldehyde, it’s not possible  to prevent it from happening in the first place.

Anything else to consider?

We’ve covered some steps above which go some way to help reduce some of the symptoms of asian flush. However its important to note that the benefits may only be marginal and the research in this are is still lacking.

If you experience the symptoms of asian flush, it’s probably best to stick to very small quantities of alcohol or even better, avoid completely.

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James Petra

James is a beer loving, mountain bike riding, EDM dancing lad from Hull, which is in Yorkshire, England. James loves his wife and his beautiful daughter, but also loves a good party with the lads on a Friday/Saturday (Wednesday??) night. After one-too-many wild nights followed by down days, James decided to find a real cure to the dreaded hangover and he details all his findings here!

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