Alcohol, health, and the ruthless logic of the Asian flush

But many studies do account for that scenario of "sick quitters". The statistical correlation still showed that light moderate drinkers had lower mortality rates.

The study itself may still be flawed but the point is that the researchers were aware of "sick quitters" being categorized as "non-drinkers" and thus distorting the results.

Excerpt from 90+ Study publication https://pubmed.ncbi.nlm.nih.gov/17350977/ :

>The greater proportion of surviving participants in our study who reported not drinking at follow-up compared to baseline is probably due to a combination of the cohort’s becoming older and drinking less, secular changes in alcohol consumption with time, and survival selection effects. Decline in consumption is also associated with the development of ill health, particularly cardiovascular disease. This accumulation of ill health and higher mortality risk in ‘sick quitters’ increases the observed benefit in drinkers if non-drinkers include these ex-drinkers [6, 24, 26]. In addition, regular light drinkers tend to have characteristics advantageous to health [26, 27]. Thus, controlling for baseline disease is important, particularly if alcohol history is unknown. With adjustment for baseline medical history as well as body mass index, exercise, and smoking, the lower risks of death among light and moderate alcohol drinkers observed in our study did not change substantially and remained statistically significant although those associated with heavier drinking were reduced.

> ...An unexpected, highly significant finding was observed: the AA rats, bred for high voluntary ethanol drinking, lived much longer than the ANA rats, bred for ethanol avoidance. The death rate by 24 months in the AA line was less than one-third of that in the ANA line.

> Conclusions: Lifelong ethanol consumption increased neither the mortality nor the morbidity of AA and ANA line of rats. Genes selected in the development of the high drinking AA line have additional effects producing rats that are healthier and living longer than the ANA rats possessing genes resulting in alcohol avoidance.

https://pubmed.ncbi.nlm.nih.gov/14745306/

So what if people who drank were simply _genetically_ healthier to begin with, and moderate drinking has no effect on health outcomes whatsoever? The study seems to suggest that.

I am not an apologist. I have come to dislike alochol, and I’m trying to cut it from my life. But, at least here in scandinavia, having work, a love life and friends can be dependant on you drinking.

A fun thing i’ve noticed though, is that Tinder has alleviated this dependancy on alcohol quite a bit.

I don't drink, mostly due to not liking the taste. But I thought wine and whisky had something in there that is good for you / antioxidant?

And in terms of lactose intolerance, I lived in Asia and milk is amazingly popular with young kids. And I’ve almost never heard of much lactose intolerance beyond what you’d hear in the west.

I guess you could flip the hypothesis and suggest maybe East Asians didn't (have the time to) evolve to digest alcohol sufficiently and hence the Asian flush. /joke

This seems super unlikely.

It is at least as likely that the mutation which causes the "Asian flush" is protective against something else while losing the ability to consume whopping quantities of alcohol is simply a side effect.

Historically, people have drunk surprising amounts of alcohol – we may not have been as collectively sober as today for millennia (depending on the exact location, to be sure); beer and wine have the big advantage that they're reasonably safe to drink even if the primary source of water isn't (due to the fermentation process and the alcohol content), and that it's easier to tell when they aren't (because if fermentation doesn't work right, you definitely notice). In some of the more remote areas in the alps, even children still drank lots of diluted wine as late as the 1950s, for precisely that reason. That sort of thing was the rule, not the exception, for Europe pre-industrialization.

Evolutionary pressure on humans also doesn't usually involve everyone with allele X dropping dead right away, because people are pretty creative at avoiding that outcome, and it's often (probably, likely) not about small-ish effects under good, stable conditions, but outsize ones in exceptional circumstances.

There have been bad years and very bad years all the time; even as late as the 19th century, agrarian societies were pretty much helpless if harvests failed on a large scale (think Irish Potato Famine), and that's after 6000-ish years of working on that existential problem. When bad years become bad decades, and lots and lots of people die, that's when things like alcohol tolerance and lactose tolerance can make a big difference.

Being able to tolerate alcohol may mean access to a cleaner source of fluid, less pathogens for weakened immune systems to deal with, and access to nutrients that store pretty well. There may have been a social component as well – getting drunk together has been an extremely important vehicle for networking and bonding for literal ages. Finally, being able to get drunk relatively safely may have kept people functioning through highly traumatic experiences as well. Not saying that's what happened for sure, but a few ways this could have played a decisive role.

Taking a quick glance at the literature, it's... super complicated. This paper (https://doi.org/10.1002/jcla.10076) suggests that women have lower gastric ADH but higher liver ADH. There's some animal studies that suggest men have higher ALDH, but also some contradictory human studies that suggest that everything is just the same.

Argh, biology.

Early European civilisations kept their water safe by making it lightly alcoholic - Early Asian civilizations just boiled their water to make tea.

That makes a good environment for mutations that protect people from alcohol consumption, but such mutations still has to randomly appear, and that it happened to appear in East Asia is probably just random.

The fact that populations who have never had alcohol succumb to rampant alcoholism when first getting access implies that even the eurasian populations without the Asian Flush genes probably has some less obvious genetic protection. You can also think of it as the most alcoholic prone genes have been weeded out over the centuries.

Is it really required that these genes are equally selective everywhere? If the adaptation theory were true, that would depend on how widely available alcohol was, as well as how harmful it is to lose the extra calories from rotting fruit, etc. No particular reason to think it would be equal everywhere.

There’s variations going on all the time, maybe they’re random, maybe they’re not. But the ones that stick in a population are the ones that get selected by outcompeting hosts without the variation.

1. People with the gene variant drink slightly less than people without it, but otherwise their drinking patterns follows everyone else's.

2. alcoholism does not cause the gene variant in individuals (obviously).

3. The gene variant is invisible. Within a reasonable population group, it seems basically random who carries it or not (I.e, you can predict that Koreans are more likely to carry it than Americans, but within a group of Americans, or a group of Koreans, it's basically impossible to guess who carries it or not). It's even been used for Mendelian randomization studies, because as far as we can tell, it affects nothing else than alcohol digestion.

A better explanation for the relative lack of success of disulfiram is that you don't take it from birth without choosing to. You have to want to take it to gain the benefit of it, but if you need it, you don't really want to take it. You want to drink. It's the big problem of addiction, you want things that contradict each other, and you want the bad things more.

The drug researcher and philosopher Ole-Jørgen Skog wrote a lot of interesting things on this topic, on "The weakness of will" and time preferences:

"If the consumer's sole motive for changing his level of patience is to escape an allocation that is dictated by his first order preference (including time preference), but that contradicts his second order preferences, he will not be able to achieve this by rational means. This is to put the cart before the horse." (But he thought that if you sought patience for its own sake, rather for the sake of not wanting to be an alcoholic, there was maybe a way. Since deciding to value patience for its own sake is not strictly speaking a rational decision.)

Evolution isn't a perfect machine. If those variant genes don't pop up at the right place at the right time, they might just not happen to catch on.