What Causes Asian Flush? and what you can do to prevent it


For those who suffer from asian flush syndrome, theres no introduction needed as to its symptoms.

Asian flush 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
  3. Headaches
  4. Rapid 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?
  • Do people with asian flush have a higher risk of developing cancer?
  • Asian flush prevention tips

Asian Flush: What is it?

Is it caused by a deficiency in the ALDH2 (alcohol dehydrogenase) enzyme. This enzyme specifically breaks down acetaldehyde which if left to build up, can cause havoc to your insides.

Acetaldehyde is a by-product of alcohol breakdown which is one of the main causes of hangovers. It is a highly unstable molecule which breaks down to cause free radical damage to the cells of your body.

Our body has an antioxidant system which keeps this process in check, but if we drink too much or suffer from asian flush, this system is quickly overwhelmed.

The problem is acetaldehyde.

Acetaldehyde causes your blood vessels to dilate and allows blood to rush through them which gives the characteristic flush or glowing appearance. AND all the other symptoms that comes with a hangover…

Does this mean asian people are allergic to alcohol?

No, An allergy is an immune response to an allergen.

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

It mounts an inappropriate immune response to this allergen (pollen) and tries to fight it off – when it doesn’t need to. This is a pure allergy. 

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! So only a relatively small population will be at increased risk.

Asian flush 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 od 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 be 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.

Find out more about practical steps to help prevent the worst hangovers..



Lee H1, Kim SS, You KS, Park W, Yang JH, Kim M, Hayman LL.. (2014). Asian flushing: genetic and sociocultural factors of alcoholism among East asians.. Gastroenterol Nurs. 5 (.), 326-336.

Philip J Brooks,* Mary-Anne Enoch, David Goldman, Ting-Kai Li, and Akira Yokoyama*. (2009). The Alcohol Flushing Response: An Unrecognized Risk Factor for Esophageal Cancer from Alcohol Consumption. PLoS Med. 6 (3)

Ryuhei Maejima,1 Katsunori Iijima,1,* Pertti Kaihovaara,2 Waku Hatta,1 Tomoyuki Koike,1 Akira Imatani,1 Tooru Shimosegawa,1 and Mikko Salaspuro2. (2015). Effects of ALDH2 Genotype, PPI Treatment and L-Cysteine on Carcinogenic Acetaldehyde in Gastric Juice and Saliva after Intragastric Alcohol Administration. PLoS One. 10 (4)

Vasdev S1, Mian T, Longerich L, Prabhakaran V, Parai S.. (1995). N-acetyl cysteine attenuates ethanol induced hypertension in rats. Artery . 21 (6), 312-6.

effrey S. Chang,corresponding author#1 Jenn-Ren Hsiao,2 and Che-Hong Chencorresponding author#3. (2017). ALDH2 polymorphism and alcohol-related cancers in Asians: a public health perspective. J Biomed Sci. 24 (19)

6) Miller NS1, Goodwin DW, Jones FC, Gabrielli WF, Pardo MP, Anand MM, Hall TB.. (1988). Antihistamine blockade of alcohol-induced flushing in orientals.. J Stud Alcohol.. 49 (1), 16-20.

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This product does not prevent intoxication or protect against alcohol related damage that may be caused by excessive or long term drinking. AfterDrink is not a Hangover cure. The only way to reliably prevent a hangover is to drink in moderation and within recommended limits. Hangovers are usually caused by drinking too much in a short period of time. If you are pregnant, breastfeeding or taking any prescribed medication or have any medical conditions including food allergies, it is best to consult your doctor before taking food supplements.

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