h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Is there a genetic component to alcohol tolerance? How important is it compared with body mass and whether a resistance has been developed through frequent drinking?

Apparently so:

http://www.nature.com/tpj/journal/v7/n4/full/6500420a.html

F

I only skimmed it, but surely that's a study of genetics affecting how likely someone is to become alcohol independent, rather than how much of a lightweight they are?

I have read at various points things about certain people not possessing the correct enzymes (?) to break down alcohol, and thus getting drunk quickly and then staying drunk for a long time. Don't know if there's any truth to it.

*alcohol dependent

Not alcohol independent, which is the natural state of affairs, I would hope.

I had a Chinese friend many years ago who became absolutely falling-over, giggling-idiotically drunk after the smallest intake of alcohol. At the time I thought it was odd, as the rest of us, after drinking a similar amount, were hardly affected at all. Years later, I read something about the genetic tendency of people from China, to have an alcohol intolerance. I can't remember where I read this - probably in a dentist's or doctor's waiting room ancient copy of National Geographic or Readers Digest.

So the Chinese get pissed easily?

Since they account for about 1/6 of the planet's population, I'm not sure what that means with regard to the initial question.

I've heard the race one before; Asians developed the ability to boil water to purify it. Europeans brewed alcohol (low strength) to purify water. Therefore, Europeans are genetically more able to tolerate alcohol because we've been at it longer.

Unfortunately, that's a bit of folklore I've picked up, and I don't have any sources to quite.

King Bomba>>Since they account for about 1/6 of the planet's population, I'm not sure what that means with regard to the initial question.<<

I can't quite see what the size of the affected population has to do with it. If it's a difference between one group of people and another group of people caused by a difference in their genes, then it's genetic - whether the size of the group is 60 or 6 billion.

Your initial question was: "Is there a genetic component to alcohol tolerance?"

Am I missing something?

The story about boiling water and brewing alcohol rings a bell Vip. Maybe we read the same article.

King Bomba. I owe you an apology. I've just noticed that this forum is specially for asking scientists questions. Clearly, I'm not a scientist. I came in via the back door, so to speak and didn't notice it was just for asking questions of specialists. I was trespassing.

I vaugely remember watching a tv program about this , probably on the OU . In it they did indeed say there was a genetic factor in alcohol tolerance . ie. many ethnic chinese had low tolerance to alcohol and could get drunk much cheaper than europeans ! . The same program took a mix of people and tested to see how tolerant they where of cold . They did this , by getting each subject to put his arm in a bowl of iced water and then seeing how quickly it warmed up again , using a thermal camera . Well the Scotish docker hardly felt any discomfort at all and warmed up almost instantly and the african guy was almost in tears he was so cold . So it would seem that there is a genetic factor in what we can and cannot tolerate .

best fishes.......tod

TibleyBobley, no apology necessary. SEx (Science EXplained) isn't for scientists only, the idea is that scientifically-minded among us answer questions from the rest of us laymen - of which I'm one.

Anyway I'll explain what I meant by the size of the population. Although they are all 'Chinese', that is a political/geographical term rather than a genetic or biological one. For such a vast population in a vast geographical area, it is likely that there is a lot more divergence in the genetic make-up than might be assumed.

"Well the Scotish docker hardly felt any discomfort at all and warmed up almost instantly and the african guy was almost in tears he was so cold . So it would seem that there is a genetic factor in what we can and cannot tolerate ."

Well, a Scottish docker would be more used to cold than someone living on the edge of the Sahara. It doesn't imply anything genetic. If the Scottish docker's son was brought up at equatorial lattitudes, would he respond to cold more like the African guy or the Scottish docker?

Hi King Bomba. I've sneaked back in. There were no doormen on duty.

I wasn't using 'Chinese' to mean a political/geographical (not political at least) term. But (not sure it this is the right scientific term) an ethnic group. Certainly it's a very big population and there will be a considerable variety within the genetic makeup of such a group. The thing is, there seems to be a *genetic* difference between the alcohol tolerance of people from that part of the world and this part of the world. So that, take my old friend of Chinese origin. She was actually born in Ghana (where her parents fled from the revolution) and had spent her early adult (student) years in Wales. I don't know how she would have compared to the people in her country of birth, but she could not compete in a pub-crawl with the average Welsh girl of her age/size. That was not a cultural or political difference (or just lack of practise), it was a difference in her genes as a result of evolutionary forces. I think Vip's memory of the explanation is right. It was thought to be because people from that part of the world purified things by boiling whereas our ancestors used alcohol. Under those circumstances genes that enabled a higher tolerance of alcohol would have been favoured, pushing evolution in the direction British politicians are so concerned about today. Anyway, I think I can see what you're getting at: genetic differences *within* ethnic groups that make some people more alcohol tolerant than others.

I'll go away now, before the bouncers turn up

Shall the politicians confine their anti drink proposals to those in the south who cannot manage.

Alcohol dehydrogenase, the enzyme that catalyses the oxidation of ethanol to acetaldehyde, is not universily expressed amongst humans.

People of (east)Asian descent has it to less degree and thus are unable to digest larger voulmes of alcohol.

The evolutionary reason for alcohol dehydrogenase is thought to be to digest the small amounts of alcohol created by yeast and bacteria occasionally intaken.

As all enzymes, alcohol dehydrogenase can be induced, i.e. be upregulated if used frequently. Not to any levels and not for a prolonged time though.

"The evolutionary reason for alcohol dehydrogenase is thought to be to digest the small amounts of alcohol created by yeast and bacteria occasionally intaken."

How is that the evolutionary reason? The way you phrase that it sounds as if you mean it was designed for that reason.

An interesting thing that has emerged from this thread is that there seems to be a bit of Lamarckism in the back of people's heads, too.

King Bomba>>Is there a genetic component to alcohol tolerance?<<

I found this BBC News article entitled "Gene 'key' to alcohol's effects": http://news.bbc.co.uk/1/hi/health/3311245.stm

Apparently these scientist chappies have recruited a worm to help them to find a treatment for alcoholism because it shares about ten thousand genes with us.

If you look at the bottom of the article, it says "Worms with a mutated slo-1 gene were much harder to get drunk, the researchers found."

Any good?

Evolution works in a most unkind, relentless way. If some places in the world have people who have a higher tolerance for alcohol it's because the people there started drinking earlier and it killed those who had a low tolerance. The survivors passed genes for tolerance.

Here, in the so called New World, Europeans, who had for a long time been sacrificing ancestors to drink, found that the aboriginals had a very low tolerance and could be exploited this way.

Something like this is also found with lactose intolerance. People, such as Europeans, with a herding tradition can drink milk as adults, others tend to lose the necessary enzyme when they grow to adulthood.

an interesting question arises from the ...fact? that women for most of our human history have not been big alcohol drinkers... i dunno if this is true.. just thinking of recent history mainly... whereas it has always been okay for men to get outrageously schnockered.

so ...evolutionarily speaking... how would THIS fit in?


btw i am a major lightweight... after the first or second drink my common sense takes a holiday.

An unlimited supply of sauce is a modern phenomenon. Used to be, we're bigger and stronger so we got to hog it all. Drinking makes you want more. Watching someone else drink makes you not. "Do I look that stupid when I drink? Maybe I'll pass"