The following is a comprehensive overview of Asian Flush intended as a reference for anyone wanting to understand this complex and embarrassing problem.
Table of Contents
- Alcohol Flush Reaction - (i.e. Asian Flush or Asian Glow)
- Symptoms of Alcohol Flush Reaction
- What Can Trigger Asian Glow?
- Related Conditions
- Health Risks
- Using Antihistamines for Asian Flush
- Experiences with Asian Flush
- Want to Learn More About Asian Flush?
Alcohol Flush Reaction - (i.e. Asian Flush or Asian Glow)
The phenomenon we’re talking about here is when you get a red face shortly after consuming alcohol. This embarrassing problem occurs because of a genetic deficiency in the way we metabolise alcohol in our liver.
When our body tries to break alcohol down, it gets flooded with a metabolic by-product of alcohol called acetaldehyde.
In a healthy liver, acetaldehyde is broken down into a harmless, non-toxic substance called acetate. However, in alcohol flush sufferers, it isn't broken down adequately and ends up passing through the liver and into our system.
This metabolic dysfunction is called ALDH2 deficiency. It causes all kinds of unpleasant symptoms that detract from the enjoyment of alcohol, including red facial flushing.
This statement coincides with results of a 1989 study that looked at the link between acetaldehyde accumulation and alcohol flush reaction. The study found that:
The alcohol-flush reaction is the result of excessive acetaldehyde accumulation, and the unpleasant symptoms tend to reduce alcohol consumption.
Let's take a closer look at acetaldehyde to understand what is happening in our body when we react negatively to this toxin.
What is acetaldehyde?
Acetaldehyde is produced by a liver enzyme when the body breaks down alcohol. It has been shown to irritate the skin, eyes, mucous membranes, throat, and respiratory tract when consumed at a high enough dosage.
In this regard, it is little surprise that the symptoms of Asian glow include redness of the skin, redness and glazing of the eyes and difficulty breathing.
This toxin also poses longer-term dangers, being flagged in a 1999 study by Dr Carreón-Valencia of the International Agency for Research on Cancer as "possibly carcinogenic to humans". In 2009, the IARC confirmed this and distributed a press release in which they stated:
"Carriers of the inactive enzyme are extremely slow to metabolise acetaldehyde, as a result, they experience higher internal levels of acetaldehyde and have much higher risks of oesophageal cancer and cancers of the head and neck compared with individuals with the active enzyme."
As you can see, the toxic substance responsible for the alcohol flush reaction also has some serious long-term risks.
These warnings followed research out of the University of Minnesota Cancer Center in Minnesota that drew a causal link between acetaldehyde exposure and DNA damage.
These findings were later confirmed in a 2006 study by a group of researchers from Kyoto University that concluded:
These results provide molecular evidence that the ALDH2 genotype affects the genotoxic damage caused by acetaldehyde.
In other words, the mere fact that someone experiences Asian flush can affect the degree of DNA damage caused by acetaldehyde from alcohol consumption.
The seriousness of this increased DNA damage was the topic of a recent 2018 study by researchers from the MRC Laboratory of Molecular Biology at Cambridge.
The researchers were able to show that subjects with the Asian flush gene suffered four times more DNA damage from alcohol than subjects without the gene mutation.
For more information about this toxin, you can check out our Expert's Guide to Breaking Down Acetaldehyde.
Why can't people with Asian flush break down acetaldehyde like regular consumers of alcohol? The problem originates from an obscure enzyme that goes by the name of ALDH2.
What is the ALDH2 enzyme?
“Your face may flush from alcohol for two reasons: because of an enzyme deficiency or because of rosacea. Both are tied to your ethnicity,”
Approximately 50% of East Asians are born with an ALDH2 deficiency, with a smaller percentage of Caucasians being affected. That said, the alcohol flush reaction in Caucasians is not as uncommon as one might think. In fact, according to a 1986 study looking at the racial differences in alcohol sensitivity, approximately 3 to 29 per cent of Caucasians get a red face from alcohol.
Regardless of one's race, people have an alcohol flush reaction because they inherit a deficient ALDH2 gene from their parents, who inherited it from their parents, and so on.
Given its genetic origin, people generally accept that there is nothing that can solve ALDH2 deficiency. They are usually told to abstain from alcohol if they don't like going red in the face.
However, this doesn’t mean the enzyme can’t receive support to enable it to break down acetaldehyde like a regular healthy liver.
To understand this further, we must examine the symptoms of Asian flush and what triggers them.
Symptoms of Alcohol Flush Reaction
Other symptoms include:
- Redness of the face and upper body
- Swelling of the cheeks
- Red eyes
- Difficulty breathing
- Rapid heart rate
Looking well presented and attractive is challenging enough without having to do so with a swollen red face. Most of us put effort into looking our best for business lunches, dinner dates or any public social gatherings. It is a shame to have this reversed by a bright red face.
Not only that, but you can also throw in a pair of bloodshot red eyes. This kind of physical appearance is not a good look, especially if you’re trying to maintain a well-presented image in a business context.
Despite this, a 1991 study looking at the subjective feelings of people with Asian flush concluded that:
This alcohol sensitivity reaction that many Asian flushers experience may contribute to their lower tendency to drink excessively, even though their response to alcohol is not predominantly negative.
In this study, researchers divided subjects into two groups. One group with a functioning ALDH2 enzyme and another with the enzyme deficiency that causes alcohol flush reaction.
After administering alcohol to both groups, researchers asked the subjects to rate how they felt. Surprisingly, the results showed that subjects with alcohol flush reaction reported more positive feelings of intoxication than the non-flushing group:
Following alcohol, flushers reported experiencing significantly more positive feelings of intoxication than nonflushers, despite equivalent blood alcohol concentrations. These data suggest that Asians who flush after drinking, particularly those with ALDH2*1/2*2 genotype, have a more intense, although not necessarily a more negative, response to alcohol than comparable nonflushing Asians.
Despite these conclusions, the success of alcoholism medication Disulfiram seems to contradict these findings. Its purpose is to intentionally cause symptoms of Asian flush in people with alcoholism. This makes drinking alcohol sufficiently unpleasant for them that many refrain from drinking.
Furthermore, we have surveyed thousands of people with Asian flush. The truth is, this is not a positive experience. The symptoms are usually sufficiently negative to turn them off drinking alcohol altogether.
We have dealt with thousands of people who have managed to stop their flushing symptoms. Out of this group, the overwhelming feedback is that their enjoyment of alcohol was dramatically improved when their Asian flush went away - not the other way around as the above study suggests.
Now that we've looked at the symptoms of Asian flush, let's direct our attention to its various triggers.
What Can Trigger Asian Glow?
A release of histamines triggers the symptoms of Asian glow. If the liver could process alcohol-related toxins properly, the body would release fewer histamines and alcohol flush reaction would not happen.
Luckily, the number of toxins our bodies are required to process can be controlled by managing the triggers at all stages of the flushing process.
What are you drinking?
There are many additives used in the production of alcohol that can worsen the effects of Asian flush. Avoiding these additives can reduce the histamine load the body is required to handle.
One example is aged spirits stored in wooden barrels. These spirits tend to accumulate molecules called tannins that have been shown to cause a minor histamine re-action in some people. These tannins can exaggerate symptoms in people with Asian glow.
Another example is red wine, which contains high amounts of tannins because of the oak barrels used in its production. White wine can also have tannins too, however, there are some low-tannin varieties of wine such as Beaujolais and Tempranillo.
Another alcohol additive to watch out for is sulfites. Beer and cider both contain sulfites that have been shown to cause some people unpleasant symptoms such as headaches and flushing. Therefore, alcoholic beverages containing sulfites could potentially increase the severity of the Asian flush.
If aged spirits, wine and beer are all potential triggers of Asian flush, what is there left to drink? This question confronted the guys at SRQ labs when dissecting the additives in these common alcoholic beverages.
In answer to this, they put together a list of low flush alcoholic beverages designed explicitly with alcohol flushing in mind.
Deficient liver enzymes
As mentioned earlier, the flush inducing toxins in alcohol are usually broken down by the ALDH2 enzyme. People who flush from alcohol have a deficiency in this liver enzyme, and this triggers a flow-on effect that causes Asian flush.
A naturally occurring antioxidant called glutathione has been shown to support this deficiency.
In a 2007 study, researchers affirmed the role of glutathione in breaking down the toxins from alcohol consumption. However, they also concluded that it gets depleted when alcohol enters the body.
In 2015, researchers at the Brandenburg University of Technology Cottbus-Senftenberg in Germany confirmed this. In their study, they looked at how alcohol consumption affects the body's natural ability to regenerate levels of glutathione in the liver. They concluded that long-term ethanol exposure does affect our body's ability to regenerate glutathione.
Therefore, it is vital to replenish the body's glutathione levels before and during the consumption of alcohol. This replenishing ensures that the body has enough of it to compensate for the shortcomings of its deficient liver enzymes.
You can read more about glutathione and Asian flush in our article: The Science Behind Asian Flush Prevention.
While glutathione does an excellent job of assisting the deficient ALDH2 enzyme, it is not perfect. As a result, there’s always some toxins left behind that causes our body to release histamines.
This finding was confirmed in a 1998 study looking at the effect of acetaldehyde on mast cells. The study concluded that:
...acetaldehyde, already at a concentration of 50 μM, significantly increases the release of histamine from mast cells. Ethanol has a similar effect but only at molar concentrations. These results indicate that acetaldehyde may contribute to the development of various hypersensitivity reactions by directly increasing histamine release from mast cells.
These findings could explain why many people with alcohol flush reaction partake in the dangerous off-label use of antihistamines to alleviate their symptoms.
As we will discuss later, using antihistamines such as Pepcid AC and Zantac for Asian flush is severely outdated and poses unnecessary risks.
As mentioned above, there are many additives in alcohol that can cause unwanted side effects independent from alcohol flush reaction itself. Because of this, many people have incorrectly classified Asian flush as an allergy to alcohol.
The more likely explanation for a reaction to alcohol is sensitivity to one of the ingredients used in its production.
Many beverages contain traces of yeast, wheat and even dairy. Therefore, for people with food sensitivities, it is imperative to be aware of the contents of every alcoholic beverage consumed.
Up until now, we’ve focused on the short-term symptoms of Asian flush in the form of a red face, headaches, restricted breathing, etc. These symptoms come in the way of enjoying alcohol, and therefore it’s no surprise that they usually command the spotlight of most of the discussion about the topic.
However, the severe longer-term risks of Asian flush require more attention. We’ll assume you’re all aware of the long-term risks of alcohol consumption in general. These are essential considerations for anyone consuming alcohol regularly. But what a lot of people don’t know about are the additional long-term risks specific to people with ALDH2 deficiency (i.e. Asian flush).
These risks arise mostly from exposure to acetaldehyde. According to Dr Tan Ek Khoon, a consultant at the Department of Hepato-pancreato-biliary and Transplant Surgery at Singapore General Hospital:
“Acetaldehyde can trigger inflammation in the upper gastrointestinal tract, cause DNA damage, and increase one’s risk for gastrointestinal diseases, namely oesophageal and stomach cancers as well as peptic ulcers,”
In 2009, scientists from the National Institute on Alcohol Abuse and Alcoholism (NIAAA) and Japan's Kurihama Alcohol Center conducted a study. They showed a chilling link between alcohol flushing and cancer, concluding that:
“ALDH2 eficiency resulting from the ALDH2 Lys487 allele contributes to both the alcohol flushing response and an elevated risk of squamous cell esophageal cancer from alcohol consumption.”
This research was subsequently picked up and released to the public by the National Institutes of Health in a press release, going on to say:
“Dr. Brooks cites the high mortality from esophageal cancer and the large number of individuals with the deficient enzyme, known as aldehyde dehydrogenase 2 (ALDH2).”
These findings have also been confirmed by the International Agency for Research on Cancer (IARC). Not only that, but they go on to describe various other dangers of sustained acetaldehyde exposure such as DNA damage and abnormal muscle development.
With this public health issue in the spotlight, it is surprising that many Asian flush sufferers are unaware of the long term dangers of Asian flush.
In 2009, Lisa Ye at the University of Guelph wrote a literary review titled Alcohol and the Asian Flush Reaction. In her report, she reiterates these severe warnings and calls for governments to come together to educate the population about this public health issue:
Due to severity of the public health implications, it is important to educate and raise awareness of this health risk and explore a harm reducing method in order to facilitate safe alcohol consumption for affected individuals.
This report emphasises the importance of being conscious of the number of toxins entering our bodies when we drink alcohol and the various methods we can use to prevent alcohol flushing.
This discussion brings us to an important question: Why consume alcohol in the first place? Especially if one is subject to higher health risks as a result of their alcohol flush reaction. Does it not make sense to abstain from drinking?
The answer to this is explored in a 2005 study looking at the relationships between alcohol, aldh2 and oesophagal cancer. In this study, the researchers found:
...strong evidence that alcohol intake increases the risk of esophageal cancer and individuals whose genotype results in markedly lower intake, because they have an adverse reaction to alcohol are thus protected.
In other words, the researchers in this study are saying that, even if you have an alcohol flush reaction, you can avoid these health risks by avoiding alcohol consumption.
However, this safety comes at a social cost, given how prevalent alcohol is in our societies today. Understandably, people with alcohol flush reaction may want to continue consuming responsible amounts of alcohol in a social context.
Luckily our bodies provide us with a warning signal by exhibiting the unpleasant symptoms of Asian flush. These signs indicate when acetaldehyde exposure is too high.
You can read more about the health risks specific to people with Asian flush in our article titled: Asian Flush Cancer - Debunking the Myth.
Using Antihistamines for Asian Flush
There is one study that found a link between the use of such antihistamines and the severity of a person’s alcohol flush response. However, the problem with using antihistamines to mask your alcohol flush reaction is that it ignores the root cause of why it is happening in the first place.
As we discussed above, the root cause of the flushing is acetaldehyde exposure. By masking the unpleasant side effects of Asian flush, the body can accumulate more toxins than usual. This shortcut could increase various health risks associated with Asian flush.
This assertion was confirmed in a 1988 study looking at the effect of antihistamines on ethanol metabolism. It found that the active compounds in Zantac and Pepcid had little impact on blood acetaldehyde after drinking alcohol.
This study confirms that the off-label use of these antihistamines is misguided. While some users report favourable symptomatic effects, experts suggest that this could lead to undetected acetaldehyde accumulation in people with alcohol flush reaction.
To find out more, please read our article about the dangers of abusing Pepcid AC, Zantac and Zyrtec for Asian flush.
If you suffer from Asian flush, you’ll know exactly how embarrassing it is.
You’re not alone. With a large percentage of Asians and a notable portion of non-Asians experiencing a red face from alcohol, the problem is widespread and relatively understudied.
We asked Jeik, a member of the SRQ Labs team, what it was like the first time he experienced the Asian glow:
“I remember the first time my face went red from alcohol. It was about 15 years ago and I was at a house party trying to get the interest of a girl.
The night was progressing pretty well. We were chatting and all signs were pointing in a positive direction. That was until she offered me a beer. A simple, innocent, cold, refreshing beer.
I downed it with manly gusto, trying to hide the fact that i’d never drunk a full bottle of beer before. Little did I know, this would start a 20 minute count down to me becoming the focus of the room for all the wrong reasons.
It didn’t take long before I began to feel the skin on my face heating up and beginning to tingle. Not long after that it became harder to breath and I could feel my eyes becoming bloodshot.
I could tell something was wrong by the concerned look on the girl's face. Then I heard a voice from across the room yell out “Look how smashed he is!”.
At this point everyone’s eyes were on me, my face was pulsating and quickly becoming the centre of everyone’s attention. “Are you on drugs?” she asked as she distanced herself from the laughing stock of the room.”
What a curse. Alcohol is fundamentally rooted in most societies as a means of celebration, bonding and courtship. A glass of wine on a dinner date, after-work drinks, a client lunch, a bar full of hopeful singles, the list goes on. These are all situations where having bloodshot eyes, a red face and looking like you’re on drugs will not go down well.
In the biggest Asian Flush survey, responders shared their thoughts and experiences with Asian Flush:
"I avoid alcohol completely - don't socialise if alcohol is involved"
"I’m not Asian, so a lot of people don’t understand what’s happening. It’s embarrassing and extremely uncomfortable and has gotten worse and more unpredictable with age."
"I am never able to fully enjoy myself as much when I go out compared to my friends with the symptoms I experience from flushing."
To complicate things further, complete abstinence from drinking alcohol usually doesn’t go down too well either. Many Asian flush sufferers report feeling left out or excluded when they turn down an offer for a drink. In fact, in some cultures turning down an alcoholic beverage can be overtly rude and offensive to the person offering.
To make matters even more uncomfortable, most people are unaware that Asian flush exists. This lack of awareness can cause people to make incorrect assumptions about the drinker that can potentially cause embarrassment and social awkwardness.
A recent 2018 study analysed data from 2912 undergraduate students from 13 universities in China. The researchers found that only 11.6% of students understood the link between alcohol flushing and impaired alcohol metabolism.
This lack of awareness, especially in western countries, contributes a lot to the social hindrance experienced by people who get a red face when they drink alcohol.
What to Learn More About Asian Flush?
Not sure where to start? Check out our article that covers all the basics: Your Top Question about Asian Flush ANSWERED.
We completed the first-ever research survey in 2019 asking real people how they felt (and struggled) with Asian Flush: Asian Flush Research Survey 2019
Have Asian Flush but still want to drink sometimes? Check out: The Best Low-Alcohol Drinks For Asian Flush