What is Acetaldehyde? Asian Flush Explained
The main reason you turn red when you drink alcohol is because of a chemical called acetaldehyde. However, there are numerous sources of this chemical that can upset the human body. It can be found in certain foods (such as fermented food), alcohol, cigarette smoke and gasoline. Unfortunately, it’s even found in the air.
But what is acetaldehyde, really? And is it dangerous?
Acetaldehyde is a organic, toxic chemical oftentimes compared to formaldehyde. Sometimes it is abbreviated as MeCHO or referred to as ethanal. After extended exposure to it, acetaldehyde can irritate the skin, eyes, throat and respiratory tract of the individual. It’s not surprising then that symptoms of acetaldehyde buildup can include a stuffy nose, red flushing of the skin, itchy eyes and even hives.
The most common exposure to MeCHO happens through alcohol consumption. This can be the cause of getting a bright red face whenever you have alcoholic drinks.
Acetaldehyde and alcohol
Your body experiences acetaldehyde primarily when drinking alcohol. Normally, the body breaks down alcohol into acetaldehyde when the individual is drinking. This is done by the alcohol dehydrogenase (ADH) enzyme. Because this chemical is so toxic, acetaldehyde is broken down further into a harmless component of vinegar called acetate. This is completed by the aldehyde dehydrogenase (ALDH2) enzyme. Finally, all traces of alcohol are eliminated from the body.
You do not want acetaldehyde hanging around in the body for any longer than necessary.
Usually, the individual drinking alcohol is unaware that such a complex process has occurred. Most people don’t even know what acetaldehyde is, or that their body breaks down acetaldehyde when drinking alcoholic beverages. They continue to enjoy their night out at the bar without realizing that their system is working hard to eliminate acetaldehyde.
However, if you have issues with metabolising alcohol, you’re going to be very aware of the acetaldehyde in your system.
Asian Flush, or Alcohol Flush Reaction
Some people cannot break down alcohol properly. This is usually referred to as Asian Flush, or alcohol flush reaction. This means that the process starts off normal with alcohol broken down into acetaldehyde. However, due to an ineffective liver enzyme, or an ALDH2 deficiency, the body is unable to break down acetaldehyde further. This means the toxic chemical begins to build up in the body and causes some nasty symptoms, such as a bright red face or headaches.
While this condition is commonly called Asian Flush, it can happen to anyone with the liver enzyme deficiency. It’s called Asian Flush because a large proportion of Asians experience this condition, especially those of East Asian descent. This condition is usually passed down through generations as well. So if your parent has it, it’s likely you’ll have it as well.
Even though everyone who drinks alcohol is exposed to MeCHO, it don’t impact us all equally. Those with an ineffective liver enzyme will be effected the most. And it’s these people that need to be extra careful about their MeCHO exposure.
Is acetaldehyde dangerous?
It’s important to understand that simple exposure to acetaldehyde isn’t necessarily dangerous, but continued exposure over long periods of time can cause various health concerns. This can include an increased risk of certain cancers.
A recent study by researchers at Cambridge University found a possible link between acetaldehyde and DNA damage, specifically blood stem cells. Their research looked into the features of DNA damage caused by acetaldehyde.
The International Agency for Research on Cancer sent out a report regarding alcohol, acetaldehyde and the impacts these have on those with Asian Flush. They reported that those with the ineffective liver enzyme have “much higher risks of esophageal cancer and cancers of the head and neck compared with individuals with the active enzyme.” It has also been concluded that acetaldehyde from alcohol consumption is categorized as carcinogenic to humans.
Other studies completed in Japan have shown that those with the ineffective liver enzyme are about 6-10 times more likely to develop esophageal cancer compared to those with the fully active enzyme. Of course, this is comparing people who drink similar amounts of alcohol.
Alcohol is so regularly consumed that nearly 2 billion adults around the world drink alcohol regularly, with about one drink being the average daily amount consumed. We also know that alcohol consumption has been linked to increase risk of liver and breast cancers. This risk is present even in those without the ineffective liver enzyme.
While this sounds scary, we already know that alcohol is damaging to the human body. Now we know just how damaging it can be.
There's also been research that acetaldehyde may be the main cause of painful hangovers the following day. Of course we know everyone can experience hangovers, even those without an ALDH2 deficiency
While it’s unlikely that everyone will stop drinking alcohol completely, even with all of these health risks, it’s still important to understand what alcohol does and how it can impact your health over time.
Other sources of acetaldehyde
Other than alcohol, this chemical can be found in a variety of situations, both organically and artificially.
Tobacco smoke: Acetaldehyde can be found in cigarette smoke and enters the body through the individual’s saliva when smoking. Of course, the type of cigarette and filters used will impact how much of the chemical gets into the individual’s system. More recently, it’s also been found in cannabis smoke.
Candida overgrowth: Candida albicans is a type of yeast that is commonly found in the stomach, gastrointestinal tract and mouth in about 50% of healthy adults. This yeast found in patients with potentially carcinogenic oral conditions has shown to create acetaldehyde in fairly high quantities.
Both outdoor and indoor air: Unfortunately for humans, this toxic chemical can be found in both indoor and outdoor air. Indoor sources come from flooring materials like laminate, linoleum and wooden varnished flooring. It is also found in certain household paints and in wood ceilings. When outside, acetaldehyde is used in a variety of different work environments and can be released into the air through production or transportation.
So while a plant is using acetaldehyde to crate laminate flooring, some of the chemical is released into the outdoor air. We are then exposed to it again when we use that laminate flooring inside our homes.
MeCHO can also be released into the air through car exhaust. Unfortunately, it’s hard to avoid in day-to-day life.
If I have Asian Flush, should I stop drinking?
There’s a few things to take away regarding acetaldehyde and whether you have an ALDH2 deficiency:
- - Acetaldehyde is carcinogenic and harmful to the body
- - Increases risks of certain health issues and cancers
- - Those with Asian Flush, or an ALDH2 deficiency, are exposed to more acetaldehyde than those with a functioning enzyme. This means they are more affected by MeCHO buildup in their system
- - Those with Asian Flush who drink alcohol 6-10 times more likely to develop esophageal cancer
- - We are all exposed to acetaldehyde, but some are more impacts than others
It’s really up to the individual on whether they feel comfortable drinking alcohol, or whether they want to stop completely. A compromise would be to limit the amount of alcohol you consume, thus limiting your exposure to acetaldehyde.
No matter what you decide, it’s always important to understand the health risks when consuming alcohol, whether you have Asian Flush or not.