Less Wrong: Open Thread, September 2010

matt

This thread is for the discussion of Less Wrong topics that have not appeared in recent posts. If a discussion gets unwieldy, celebrate by turning it into a top-level post.

The journalistic version:

[T]hose who abstain from alcohol tend to be from lower socioeconomic classes, since drinking can be expensive. And people of lower socioeconomic status have more life stressors [...] But even after controlling for nearly all imaginable variables - socioeconomic status, level of physical activity, number of close friends, quality of social support and so on - the researchers (a six-member team led by psychologist Charles Holahan of the University of Texas at Austin) found that over a 20-year period, mortality rates were highest for those who had never been drinkers, second-highest for heavy drinkers and lowest for moderate drinkers.

The abstract from the actual study (on "Late-Life Alcohol Consumption and 20-Year Mortality"):

Controlling only for age and gender, compared to moderate drinkers, abstainers had a more than 2 times increased mortality risk, heavy drinkers had 70% increased risk, and light drinkers had 23% increased risk. A model controlling for former problem drinking status, existing health problems, and key sociodemographic and social-behavioral factors, as well as for age and gender, substantially reduced the mortality effect for abstainers compared to moderate drinkers. However, even after adjusting for all covariates, abstainers and heavy drinkers continued to show increased mortality risks of 51 and 45%, respectively, compared to moderate drinkers. Findings are consistent with an interpretation that the survival effect for moderate drinking compared to abstention among older adults reflects 2 processes. First, the effect of confounding factors associated with alcohol abstention is considerable. However, even after taking account of traditional and nontraditional covariates, moderate alcohol consumption continued to show a beneficial effect in predicting mortality risk.

(Maybe the overlooked confounding factor is "moderation" by itself, and people who have a more relaxed, middle-of-the-road attitude towards life's pleasures tend to live longer?)

These are fine conclusions to live by, as long as moderate drinking doesn't lead you to heavy drinking, cirrhosis and the grave. Come visit Russia to take a look.

1Vladimir_M16y

The discussion of the same paper on Overcoming Bias has reminded me of another striking correlation I read about recently: http://www.marginalrevolution.com/marginalrevolution/2010/07/beer-makes-bud-wiser.html It seems that for whatever reason, abstinence does correlate with lower performance on at least some tests of mental ability. The question is whether the controls in the study cover all the variables through which these lower abilities might have manifested themselves in practice; to me it seems quite plausible that the answer could be no.

5Vladimir_M16y

The study looks at people over 55 years of age. It is possible that there is some sort of selection effect going on -- maybe decades of heavy drinking will weed out all but the most alcohol-resistant individuals, so that those who are still drinking heavily at 55-60 without ever having been harmed by it are mostly immune to the doses they're taking. From what I see, the study controls for past "problem drinking" (which they don't define precisely), but not for people who drank heavily without developing a drinking problem, but couldn't handle it any more after some point and decided themselves to cut back. Also, it should be noted that papers of this sort use pretty conservative definitions of "heavy drinking." In this paper, it's defined as more than 42 grams of alcohol per day, which amounts to about a liter of beer or three small glasses of wine. While this level of drinking would surely be risky for people who are exceptionally alcohol-intolerant or prone to alcoholism, lots of people can handle it without any problems at all. It would be interesting to see a similar study that would make a finer distinction between different levels of "heavy" drinking.