Science

Does Alcohol Cause Cancer? (If It Makes You Flush, Yep)

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Transcript:

As I mentioned in another recent video, I’m doing “dry January.” I’ve done it the past two or three years as a way to reset after, let’s be honest, two to three months of unfettered Dionysian intoxication that lasts from my birthday in mid-October straight through to the New Year. The liver is, after all, a highly regenerative organ but only if you give it a minute to get its shit together.

So it is that from up here in the fresh air I breathe from atop my sober high horse that I read a recent press release proclaiming “New genetic study confirms that alcohol is a direct cause of cancer.” Oh, no, I’m so sorry to all of you hopeless drunkards out there. Your fate is sealed. Cheers.

Okay, in line with copious amounts of research that shows that you need to get the debunking out of the way early if you don’t want people to walk away only remembering the misinformation, allow me to edit this headline to be a bit more accurate: “New genetic study confirms that alcohol is a direct cause of cancer IN CHINESE MEN WITH A GENETIC VARIANT RARELY SEEN OUTSIDE OF EAST ASIAN POPULATIONS.” And here’s a bonus fact: regardless of what this study shows, there’s still loads of evidence from past studies that suggests alcohol is absolutely bad for you in every way, even in moderation, and yes that does include the fact that it probably causes cancer. Got all that? Great. Let’s dive in!

This study, published this month in the International Journal of Cancer, IS a really interesting and thorough one: researchers examined the genetic data of 150,000 Chinese people, surveyed them on their drinking habits, and then followed their medical travails for 11 years to see who got cancer and who didn’t. 

Most subjects (about 60%) were women, but none of that data offered any insights, mostly because Chinese women just don’t drink very much (or at least, the female subjects in this study didn’t). So the results were only concerned with the remaining 60,000 men.

The men who drank less had a reduced risk of developing cancer, but that’s not the really interesting bit. You see, loads and loads of previous studies suggest that the more you drink, the more you risk getting cancer, but it’s difficult for those studies to prove causality: does drinking more directly lead to the development of cancer, or do people who drink more also tend to have worse diets, get less exercise, and smoke more, all of which ALSO may have a causal link to cancer? Tough to say!

That’s where we come to the reason this study was based in China. If you have enough East Asian friends, you may be familiar with the “alcohol flush reaction” that many people experience: for 30-50% of the East Asian population (and a very small percentage of other populations), consuming just a small amount of alcohol is extremely unpleasant, resulting in red splotches on the face, neck, and shoulders, plus nausea, headache, and an increased heart rate.

The condition is due to two quite annoying genetic variants that a person can have: ALDH2, which interferes with the body’s ability to break down acetaldehyde, a toxic compound our body produces when we digest alcohol, and ADH1B, which makes the body turn alcohol into acetaldehyde even more quickly. So if you have ALDH2 you are likely to have a bad time when drinking alcohol. If you also have ADH1B, you’re likely to have an even worse time.

Interesting sidenote: no one is really sure why so many Chinese, Japanese, and Korean people have these alleles while it’s pretty rare (less than 4%) in the rest of the world (with the possible exception of Southeast Asian and Inuit populations). Researchers suspect it developed around the time East Asians began growing rice. Could be random, or it could have been selected for due to the same allele providing protection against certain parasites that came along with rice domestication. Evolution: sometimes it sucks!

Anyway, as you might predict, this study found that men with at least one of those genetic variants were less likely to drink alcohol frequently or in great quantities, and those guys enjoyed about a 25% lower risk of developing all kinds of cancer, and men with both variants enjoyed a 14% lower risk of all kinds of cancer and, interestingly, a 31% lower risk of developing cancers that have previously been linked specifically to alcohol: cancers of the head and neck; esophagus, colon, rectum and liver. This held true even for men who still occasionally had a drink here and there.

But a subset of the men with ALDH2 didn’t let a little flushing and nausea and headache and heart palpitation stop them from boozing it up. For those guys, who had the variant and still drank to excess often, their risk of developing those alcohol-linked cancers increased significantly, even over men who drank to excess and didn’t have those genetic variants. 

(All of this, I should note, was controlled in regards to those other cancer-related lifestyles like smoking, bad diet, weight, and lack of exercise, as well as for family history of cancer.)

While this study’s immediate applicability is to the significant portion of East Asian people who have these gene variants, and only to the 4% or so of other populations with the gene variants, it goes a long way toward showing how alcohol may directly cause cancer in everyone. Yes, things are definitely bad for drinkers who have more trouble breaking down alcohol, but there’s a good chance alcohol is affecting everyone in this way, just to a lesser extent.

So remember, kids, if drinking causes you a great amount of discomfort, that is probably your body saying “Hey, please stop, this is killing me in a rather long and drawn out way.” And even if it doesn’t bother your body to get shit-faced every night, maybe reconsider what you’re doing to yourself. Alcohol remains the 2nd deadliest drug in America after tobacco, and that doesn’t even take into consideration drunk driving and alcohol-fueled homicides, let alone cancers.

If you think you might be drinking too much and are having trouble controlling it, please have an honest talk with your doctor. There are plenty of evidence-based, secular ways to control addictions these days – no need to relinquish anything to an imaginary higher power.

As for me, well, in February I will go back to the occasional drink on the weekend. But I swear to god, if a new COVID variant shows up I reserve the right to consider Wednesdays part of the weekend.

Rebecca Watson

Rebecca is a writer, speaker, YouTube personality, and unrepentant science nerd. In addition to founding and continuing to run Skepchick, she hosts Quiz-o-Tron, a monthly science-themed quiz show and podcast that pits comedians against nerds. There is an asteroid named in her honor. Twitter @rebeccawatson Mastodon mstdn.social/@rebeccawatson Instagram @actuallyrebeccawatson TikTok @actuallyrebeccawatson YouTube @rebeccawatson BlueSky @rebeccawatson.bsky.social

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