Originally posted by Urbanjet:
Is it true that a type of enzyme which breaks down alcohol is missing from many of Asians. The result being that some Asians cannot take alcohol as well as an Irish or German. Also, how does that relate to redness in the skin?
In brief, the answers are 1) well, not really; and 2) yes.
That is, the enzyme you’re talking about is aldehyde dehydrogenase (ALDH), which breaks down acetaldehyde (a byproduct of alcohol), not the alcohol itself. The enzyme’s still there, it’s just a bit different and not as good at getting rid of alcohol byproducts.
Briefly, alcohol dehydrogenase (ADH) converts alcohol (ethanol) to acetaldehyde, which ALDH then converts to acetate. In people with ALDH deficiency, acetaldehyde builds up quickly and causes the “Asian flushing” you mentioned along with others symptoms such as low blood pressure, headache, etc.
Not all Asians have this enzyme “deficiency”, but it’s much more common in Asian than in non-Asian people. People with this defiency are also less likely to become alcoholic, although other factors are obviously involved.
Variations in ADH may also play a role in responses to alcohol, even in non-Asians.
Disclaimer: I’m not a doctor nor do I play one on TV. The information presented here was gathered from various sources of uncertain reliability. That is, I scanned a few abstracts on MEDLINE.