Is Light Drinking Protective? |
July 30th, 2023 |
| alcohol, health |
The study finds:
Compared with lifetime abstainers, current infrequent, light, or moderate drinkers were at a lower risk of mortality from all causes, CVD, chronic lower respiratory tract diseases, Alzheimer's disease, and influenza and pneumonia. Also, light or moderate drinkers were associated with lower risk of mortality from diabetes mellitus and nephritis, nephrotic syndrome, or nephrosis.
To get this association they analyzed data from the NHIS survey, which includes questions on drinking habits, and the linked death records.
As you might expect, lifetime abstainers look quite different from light and moderate drinkers. For example, 26% of lifetime abstainers had less than a high school education, while only 10% of light or moderate drinkers did. The lifetime abstainer group is also a lot older (22% 65+ vs 10% or 13%), more female (66% vs 50% or 27%), more Black (17% vs 9% or 8%), more Hispanic (19% vs 12% or 10%), more nonsmoker (82% vs 56% or 44%), and more physically inactive (69% vs 48% or 43%). See the full table. Visually:
These are really big!
Now, they did adjust for these, along with many other differences between these groups:
The above-mentioned associations were investigated by adjusting for the following covariates: age, sex, race, or ethnicity (model 1); model 1 plus education level, physical activity, body mass index, smoking status, hypertension, heart disease, stroke, cancer, diabetes, asthma, emphysema, or chronic bronchitis in a separate model (model 2).
The problem is, there could easily be other important confounders. If something they are not adjusting for leads to both abstinence from alcohol and higher mortality, they aren't able to distinguish that from the causal effect of alcohol on mortality.
They do explicitly list this concern, the first one in their list of limitations, and it's always something I'm worried about with correlational studies. But this is worse than usual: the known differences between these groups going into the study are so large that I am very skeptical that adjusting for these is enough to cover the unknown differences. So I haven't updated my views appreciably from this study.
(I don't drink, but not for health reasons.)
I do not understand why they adjusted for cancer; other studies have found a strong association between drinking and cancer, and even they show that for heavy and binge drinkers when they look at cause-specific mortality. You can't adjust for something that's caused by the thing you're investigating!
A common reason I've heard from lifetime abstainers is that a family member drank excessively and they are worried they would do the same if they started. I wonder if there are related health effects there.
Crystal yeah, without controlling for the causes of lifelong teetotaling this seems very suspect. For example, religion is a common cause of lifelong abstention, but neither religion nor religious observance level were among the control var…
I wonder if you'd get some mileage out of running a study in Europe or somewhere the religious aspect is less prominent.
Crystal In Europe what's the most common reason someone might choose to never drink?
Jeff Kaufman I have no idea! Not religion, though
Elliot my impression was that moderate drinkers were more common in Europe but heavy drinkers were more rare. Either way, teetotalers might be hard to find.
As I think about this more, there’s one other factor that seems conspicuously missing from this control list: income. Alcohol costs money and those demographic statistics about the lifelong-teetotaler population vs everyone else are suggesting that affordability is a pretty big contributor to why people never drink. Of course, drinking alcohol also affects income, in both directions (by helping you get connections or by screwing up your career) but whether you’re too poor to afford alcohol seems more exogenous than, say, whether you have a health condition that alcohol may plausibly cause.
Elliot are there really many Americans who have had fewer than 12 drinks ever in their life primarily because they couldn't afford it? It is certainly possible to spend a lot of money on alcohol, but a 12 pack of cheap beer is under $10.
I would also think people who don't drink because they realize they can't afford it would have sufficiently exceptional impulse control to lead to success that would come with enough money to drink.
Oh wait I forgot the marshmallow experiment was debunked. I revoke my claim.
Jeff Kaufman very true, but these other demographic numbers are strongly suggestive of some sort of income effect. Maybe there are more poor people who just never develop a taste for the stuff due to less access to others providing it for free?
FWIW the covariate that I'd think was important is religion. My sense is that there's a large segment of fundamentalist Christianity that thinks drinking alcohol is sinful, and they could plausibly be a large portion of the bucket of people who never d…
Daniel Daniel yes, I think the main problem with that control is that there are probably significant but hard-to-measure systematic differences between people who adhere to a religious prohibition on alcohol and people who are willing to vi…
Religion does seem like something worth controlling for anyway, but I think there’s something really important that it’s not capturing.
That is a really odd set of factors to control for. Treating physical activity, BMI, and [long list of health conditions] as independent variables seems like controlling for the very thing you’re trying to measure.
There's a very relevant Huberman Lab podcast on the topic: https://hubermanlab.com/what-alcohol-does-to-your-body.../
Has anyone described a plausible mechanism by which alcohol it self (rather than, say, antioxidants in wine) could improve health? I'm not aware of any plausible mechanism but I'm not very well informed.
I agree with Michael's default hypothesis. Now, it's not always true that a bad thing in large quantities is slightly bad in small quantities. For example, sodium is bad in large quantities, but it's also bad to have no sodium. There, there's a p…
Could be a general "alcohol in small quantities slightly stresses your body, which can be good, like fasting or exercising. Alcohol in large quantities starts killing parts of your body, like starving or over-exercising until you hurt yourself"
Claire another thing that makes me really skeptical is that the upper bound of “moderate” drinking in this study is an astronomical 14 drinks per week for men. That’s two drinks *every day*, or getting absolutely trashed every Friday *and* Satur…
Elliot That's a good point, though possibly most people in that bucket were in practice drinking much less?
Two drinks every day is easy if you enjoy the taste of the drinks. Especially with liquor, I would guess one serving of bourbon is two "drinks".
a) "Drinking to excess, the way low-class drunks do, is bad for you. Drinking a little bit, the way classy people who appreciate expensive wines/whiskeys do, is good for you." strikes me as a *memetically fit* claim. One you would expect to hear amplified a lot, irrespective of its truth value. b) "Ethanol hurts your body. Small amounts of it hurt your body less than large amounts, but the sign does not change." strikes me as a *simple* claim. It seems like it ought to be the default hypothesis absent strong countervailing evidence.
As others have said in various ways, I have yet to hear a version of the claim that alcohol is good for you that seems plausible. Correlation seems overwhelmingly more likely to be driving any study findings indicating such.