A little alcohol may not be good for you after all

The widespread belief that one or two alcoholic drinks per day is associated with living longer rests on flawed research, concludes a recent analysis of 87 previously-published studies.

Why it matters:

The debate over whether a drink or two per day is good for overall health and longevity has raged for years.

Although headlines claim “Moderate Alcohol Drinking May Boost Heart Health,” and respected dispensers of advice such as the Harvard School of Public Health have spread the idea, many medical groups (such as the American Heart Association) have refused to jump on the booze-fueled bandwagon. One concern of skeptics has been that alcohol raises the risk of cancer.

If the new analysis — published in the Journal of Studies on Alcohol and Drugs and led by Dr. Timothy Stockwell of Canada’s University of Victoria — is right, then people who imbibe self-congratulations with their chardonnay are deluding themselves.

You’ll want to know:

The flaw in scores of alcohol-and-longevity studies is that the vast majority classify not only lifetime teetotalers as abstainers, they also classify ex-drinkers that way. That’s a problem because many people stop drinking when they get ill or old. Indeed, a 2005 study found that 27 of 30 risk factors for heart disease, including being overweight, were more common in these abstainers than in moderate drinkers. Comparing moderate drinkers to a group of unhealthy abstainers obviously makes the drinkers look healthier and longer-lived.

That’s what Stockwell’s team found: the 13 of 87 studies that were free of “abstainer bias” showed “no significant reduction in mortality” for moderate drinkers compared with true lifetime abstainers or only-on-special-occasions drinkers.

What they’re saying:

Dr. Peter Thompson, a cardiologist and professor of medicine at the University of Western Australia, who has argued that the benefits of moderate drinking are real, called the new paper “very well written and important.” It shows “quite clearly that former drinkers have a higher mortality risk than very occasional drinkers, and that this may have biased the [estimates]” of the longevity benefits of moderate drinking.

But keep in mind:

The credibility of studies linking moderate drinking to longevity and lower risk of death from cardiovascular disease has long been debated. A 2011 analysis found cardiovascular benefits from moderate drinking even after correcting for the unhealthy-abstainers problem.

Thompson cautioned that by focusing on overall mortality, not heart attack and stroke, the new paper might obscure the heart-protective effects of drinking. Stockwell agreed: “Our conclusion that there is no net benefit [from moderate drinking] might still allow for cardiovascular benefits,” he told STAT.

Bottom line:

Dr. Russell Luetker, a cardiologist in Minneapolis and spokesman for the American Heart Association, told STAT that even in studies claiming a benefit from moderate drinking, “they’re not big effects.” He added, “people who drink moderately have a whole bunch of characteristics that are protective against heart disease” — all of which could be making alcohol look healthier than it actually is.