Asian flush

Evidence based

The Asian Flush – Everything You Need To Know

Afterdrink Author Dewey Jhon
Dewey Jhon


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Evidence based

Ever had one or two alcoholic drinks and developed red rosy cheeks and felt hot very quickly?

Well – you may have experienced the Asian flush reaction.

Asian flush describes a combination of signs and symptoms which typically occur soon after consuming a small amount of alcohol.

For those that are familiar with the flush reaction, you’ll know that it can be tricky to manage especially during social occasions.

In this article, we’re going to take an in-depth look at the asian flush reaction including the causes, symptoms and most importantly, what you can do to stop it from happening.

Table of contents

What is the Asian Flush Reaction?

The Asian flush reaction affects 30-50% of people from Asia.

And given the population of Asia is around 4.5 billion people – that makes a huge number of people potentially affected by Asian flush.

It is caused by a deficiency in the enzyme acetaldehyde dehydrogenase 2 (ALDH2).

To understand what causes Asian flush, we’ll need to go over some of the science behind alcohol metabolism.

Alcohol to acetaldehyde
The first step of alcohol metabolism involves your liver breaking down alcohol to acetaldehyde.

The second step involves acetaldehyde being broken down further to acetate which can be used by the cells in your body as energy.

Acetaldehyde, on the other hand, is highly toxic. It breaks down rapidly to form “free radicals” which wreak havoc on your insides.

In people with Asian flush, they lack the enzyme for ALDH2, meaning they aren’t able to break down acetaldehyde into acetate which.

Therefore you get a buildup of acetaldehyde which is the cause of the Asian Flush reaction.

In summary, asian flush is caused by a deficiency in an enzyme which breaks down alcohol. As a result you get a buildup of acetaldehyde which is toxic and causes all the classical symptoms

asian flush symptoms infographic

Asian Flush Symptoms

The main symptoms of Asian Flush are:

1.Red rosy cheeks and skin
acetaldehyde dilates blood vessels which makes the skin turn red. It is thought that acetaldehyde does this by stimulating histamine release from your white blood cells. Histamine is also released during allergic reactions which cause blood vessels to dilate. (we’ll cover more on this later)

2. Nausea and vomiting

As levels of acetaldehyde rise in your bloodstream, your body tries to expel as much alcohol and its by-products from your body.

It’s a natural safety mechanism that your body has when it detects a harmful substance in your body.

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3. Headache
There are many theories about why people get headaches. One of the best-accepted ones is that headaches are caused by dilated blood vessels in the brain.

We know that alcohol and acetaldehyde cause dilation of blood vessels and therefore this could be the cause of the headaches.

In addition to this, the free radical damage caused by acetaldehyde stimulates an inflammatory response. This inflammation could also be a cause of your headaches.

4. High heart rate

As your blood vessels dilate, your heart needs to pump more blood around the body to maintain the same blood pressure.

5. Muscle aches

Similar to inflammation causing headache, this also occurs in your muscles.

You’ve probably noticed that most of the symptoms of Asian flush are the same as having a really bad hangover.

Well, that’s because most of the symptoms of a hangover are caused by acetaldehyde too.

The difference in Asian flush is that the reaction occurs soon after drinking alcohol and the side effects are more severe.

Asian Flush Genetics

Asian flush is inherited from your parents.

The genes which cause ALDH2 deficiency are passed down from generation to generation.

In some people, the Asian flush reaction is so severe from small amounts of alcohol that these people often don’t drink at all because of the side effects.

On the other hand, there are people who have some degree of ALDH2 deficiency but still have a small amount.

These individuals will still have a flush reaction but may not be so severe that they stop drinking.

It’s in this group of people where the dangerous long term effects of drinking are most applicable.

Are asians allergic to alcohol?

Asian flush is not an allergic reaction.

It is an intolerance to alcohol due to the lack of an enzyme called ALDH2 which causes a buildup of acetaldehyde.

We mentioned earlier that histamine is released in response to acetaldehyde which causes blood vessels to dilate.

Although histamine is also released during allergic reactions as well, it’s a completely different mechanism and should not be confused with Asian flush.

Asian flush is not an allergy. Moreover it’s a deficiency in the enzyme ALDH2 which metabolizes acetaldehyde

How to stop asian flush

If you have the Asian flush reaction to alcohol, the only real way to completely stop it is to not drink at all.

That being said, there are ways in which you can reduce the severity and support your liver in clearing alcohols toxic by-products which we will cover next.

Asian flush common remedies – Do they work?

A quick search online will bring up loads of different ways to cure Asian flush. Next, we’re going to take a look at the most popular remedies to see whether they actually work.

Zantac (Ranitidine) and Pepcid (Famotidine) for asian flush
Zantac and Pepcid are histamine receptor 2 blocker (H2 blocker) and works specifically on the cells that control acid release in your stomach.

It’s used for people with gastritis and reflux as it reduces stomach acid production.

Does it work for Asian flush? – No, it doesn’t.

We mentioned before that part of the Asian flush reaction is inflammation caused by acetaldehyde which can stimulate the release of histamine by your white blood cells.

Histamine dilates blood vessels as well as causes itchiness of the skin.

Although it may seem logical that blocking histamine will reduce the severity of flushing, you have several different histamine receptors which have different functions.

The ones in your stomach only control stomach acid production – Zantac and Pepcid only block these histamine receptors. It may help reflux that you may get after drinking alcohol, but it won’t help asian flush.

Zyrtec (Citerizine) for asian flush
Zyrtec is another anti-histamine which blocks H1 receptors. It’s very different to Zantac and Pepcid because it targets the histamine receptors that cause dilation of blood vessels and itchiness of the skin.

Therefore Zyrtec should help in reducing some of the symptoms of asian flush.

In summary, asian flush is caused by a deficiency in an enzyme which breaks down alcohol. Pepcid and Zantac won’t help with preventing or treating asian. On the other hand, Zyrtec could help

Asian flush prevention – top tips

If you’re someone who suffers from Asian flush, there are ways to give your body the best chance of metabolizing alcohol.

It’s important to note that none of the tips mentioned below are cures to the problem. However, sticking to the basics should go a long way in reducing the severity of your Asian flush symptoms.

1. Rehydration
One of the best ways to avoid the worst flush reactions is to keep well hydrated. Drinking plenty of water between each alcoholic drink will also increase the amount of time your liver has to process alcohol and its toxic by-products.

2. Fructose containing snacks
Having a snack high in fructose could help clear more alcohol from your body. It may sound strange but there are studies which have shown that the rate of alcohol breakdown increases by up to 80%.

Fructose is the main sugar found in fruit. It’s found in particularly high amounts in dried fruit.

3. Antioxidants
Acetaldehyde is a “free radical” which is normally neutralized by antioxidants. Taking an antioxidant supplement before and after your last drink could help restore depleted stores.

4. Slow down
As the problem causing Asian flush is a build-up of acetaldehyde, taking your time before moving onto your next alcoholic beverage is always a good idea.

5. Anti-histamines
If you’re going to take anti-histamines, make sure you get hold of H1 receptor blockers. The most common ones are cetirizine and loratadine which you can buy over the counter.

It’s important to note that some antihistamines can make you sleepy or drowsy but it’s not usually the case with the ones mentioned above. You can always ask your pharmacist if you’re unsure.

6. Stick to lighter coloured drinks
Lighter coloured drinks like gin and vodka contain fewer congers compared to whisky and red wine. Congeners like acetaldehyde make the flush reaction a lot worse. We’ll cover how congeners do this later on in this article.

How to treat asian flush

Currently, there are no specific Asian flush treatments. As it occurs become of a lack of the enzyme ALDH2, the only way you could treat it is to replace this enzyme in your liver.

Unfortunately, this is not a possibility yet but who knows what the future holds.

Can people who aren’t asian have flush reaction?

Yes! It all depends on whether you lack the enzyme ALDH2.

Although it’s called “Asian Flush”, you don’t have to be Asian to have it.

It’s only called Asian flush because it’s a lot more common in Asia.

Which alcohol is worse for Asian flush?

Asian flush occurs in response to any alcohol so drinks which have higher concentrations of it will give the worst reaction like spirits.

But of course, this is proportional. You could have a large glass of beer which will have more alcohol in it than a shot of vodka.

So it all depends on the total amount of alcohol being consumed.

Darker drinks will also exacerbate the Asian flush reaction because they contain more congeners.

Congeners are typically found in high concentrations in dark coloured drinks like whisky and red wine.

Studies have shown that congeners can cause worse hangover symptoms in a similar way to acetaldehyde.

That’s why most people have worse hangovers if drinking dark coloured drinks! If you’ve ever had a hangover after a night of drinking whisky, you’ll know exactly what we mean.

If you add this to Asian flush, it’s a double whammy.

Asian flush and cancer

There are several studies which have looked at the relationship between an increased risk of esophageal (food pipe) cancer.

Most notably, a Japanese study found that people with Asian flush who drink 33 units of alcohol (1 unit = 1 vodka shot) a week have an 89 fold increased risk of developing esophageal cancer.

Thankfully, most people who have severe Asian flush don’t actually drink that much so the risks are less.

Nevertheless, it’s important to be aware of the associations found.

Asian flush – Final words

That brings us to the end of our Asian flush guide.

We’ve walked you through all the signs of Asian flush and covered some tips which could help reduce the severity of your symptoms.

Unfortunately, there’s no cure or treatment for Asian flush and the best way to prevent it is to not drink at all.

If you’re someone who suffers very severe symptoms even after small amounts of alcohol, it’s best to consider avoiding drinking altogether.

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