The belief that a glass of wine every now and then will help you live longer appears to be no more than a myth, according to a new study. University of Victoria researchers conducted a meta-analysis to investigate the claim that moderate drinkers (people who have up to two drinks per day) have reduced mortality risk, and found that many of them were flawed. A large part of the problem was how “abstainers” have been defined in these studies.
“A fundamental question is, who are these moderate drinkers being compared against?” said Tim Stockwell, the lead researcher and director of the university’s Centre for Addictions Research in British Columbia, Canada. Stockwell explained that among the 87 studies included in the analysis, many of them compared moderate drinkers with “current” abstainers. But they did not account for the possibility that people who quit alcohol because they were in poor health may have been included in the abstainer group.
Without adjusting for these factors, the studies originally showed that moderate drinkers had a reduced mortality risk when compared to heavy drinkers. The researchers wrote: “Estimates of mortality risk from alcohol are significantly altered by study design and characteristics.” When the researchers accounted for these factors, including abstainer “biases” and other study design flaws, they found there was no significant reduction in mortality risk for moderate drinkers when compared to people who drink occasionally or don’t drink at all.
The researchers concluded that moderate alcohol consumption “has no net mortality benefit compared with lifetime abstention or occasional drinking” and that a “skeptical position is warranted in relation to the evidence that low-volume consumption is associated with net health benefits.”
One thing the study did not account for were the effects of different types of alcohol—for example, red wine, which has been studied for its health benefits for years. But if red wine does indeed have certain health benefits, Stockwell says it’s probably not because of the alcohol content.
“There’s a general idea out there that alcohol is good for us, because that’s what you hear reported all the time,” said Stockwell. “But there are many reasons to be skeptical.”
