Alcohol… People have been imbibing beer and wine for millennia, enjoying alcohol ever since someone discovered the altered sensations from fermented fruits and grains. In fact, archeologists recently announced the discovery of an Egyptian brewery from the time of the great pyramid. Does anyone else have ‘Walk Like a (drunk) Egyptian’ running through their minds?
What exactly does alcohol do in our bodies? And why do people react differently to alcohol? (yep – it’s genetic!)
First, alcohol is absorbed through the stomach into our bloodstream, making its way to our brain and to our liver.
In the liver, alcohol is first broken down with an enzyme called alcohol dehydrogenase, which helps to convert it into acetaldehyde.
In the second step of this elimination process, the enzyme acetaldehyde dehydrogenase helps convert the acetaldehyde into acetate. The acetate then can easily be excreted.
This is a simplified explanation, but it covers the majority of alcohol metabolism.[ref]
Alcohol dehydrogenase is coded for by the ADH genes. The ALDH gene family produces acetaldehyde dehydrogenase.
There are two well studied genetic variants which have different ways of reaching the same endpoint:
~ an alcohol dehydrogenase (ADH1B) variant that speeds up the conversion to acetaldehyde, thus creating a buildup of acetaldehyde
~ an acetaldehyde dehydrogenase (ALDH2) variant that slows down the conversion from acetaldehyde to acetic acid, again creating a buildup of acetaldehyde.
In addition to the beer, wine, and other alcohol that we might drink, the alcohol dehydrogenase enzyme also breaks down alcohols produced by bacterial fermentation in the intestines. (yep – some of your bug guts could be fermenting that apple you ate this morning.)
Retinol (vitamin A) and bile acids are also metabolized by alcohol dehydrogenase.[ref]
So what is the big deal about too much acetaldehyde? Why does it make you feel cruddy and make you flush? Acetaldehyde increases skin temperature, making you feel hot and flushed. It also causes nausea, headache, and allergy-like histamine release. Top it off with being carcinogenic and damaging to your DNA. Moreover, it may also be causing catecholamine release in your brain, giving you feelings of euphoria. Your body wants to get rid of it as soon as possible since it is toxic, but the euphoria makes you want to drink again.[ref]
Check your genetic data for rs1229984 (23 and Me v4, v5):
Studies of this genetic variant show:
Check your genetic data for rs2066702 (23andMe v4 only; AncestryDNA):
Check your genetic data for rs698 (AncestryDNA):
Check your genetic data for rs671 (23andMe v4, v5; AncestryDNA):
Studies on ALDH2 show:
The simple answer is that alcohol is toxic to everyone. Drinking a lot is simply not good for your body.
I know that most people are going to ignore the ‘don’t drink’ advice, so below are ways to help your body in the clearance of acetaldehyde.
MitoQ, a mitochondrial supplement, has been shown in studies to enhance acetaldehyde clearance in the liver. “This study demonstrated that speeding up acetaldehyde clearance by preserving ALDH2 activity critically mediates the beneficial effect of MitoQ on alcohol-induced pathogenesis at the gut-liver axis.” [ref]
Zinc and niacin (B3) are both co-factors for acetaldehyde dehydrogenase. [ref] Make sure you have sufficient levels of both through foods or supplements.
Glutathione is also needed for the conversion of acetaldehyde into acetic acid. NAC is a precursor to glutathione.
H2 blockers such as Tagamet can help reduce the flushing symptoms of the ALDH2 variant. Note that this is just helping the flushing and not moving out the acetaldehyde faster. [ref]
There is a supplement called Sunset Asian Flush that is formulated to prevent the reactions from ALDH2 variant. It has NAC, Quercetin (a natural antihistamine), and a couple of other supplements in it.
Originally published June, 2018. Revised Feb. 2020