WASHINGTON—Many believe that a glass of wine a day may lead to a longer, healthier life. However, according to a new research analysis published in the Journal of Studies on Alcohol and Drugs, solid scientific evidence of the health benefits of moderate alcohol consumption is negligible.
"There's a general idea out there that alcohol is good for us, because that's what you hear reported all the time," said Tim Stockwell, lead researcher on the analysis and director of the Centre for Addictions Research at the University of Victoria. "But there are many reasons to be skeptical."
Numerous studies and news reports have linked moderate drinking to health benefits ranging from longer life to lower risk of heart disease. However, researchers found that out of 87 studies reviewed, a large number (74) were flawed, containing design biases that implied benefits that were not likely real.
A crucial problem identified by the research team in many studies is how they defined “abstainers.” Most studies compare moderate drinkers (those who have one or two drinks per day) with individuals who were abstinent at the time. However, according to Stockwell, the abstainer group may include people who are in poor health or have recently stopped drinking.
"A fundamental question is, who are these moderate drinkers being compared against?" said Stockwell.
After correcting for biases related to abstainers and other design issues, Stockwell and his research team found that individuals who drank alcohol in moderation were not more likely to live longer than those who abstained from drinking.
Out of the 87 studies, 13 did not include some sort of bias related to the abstainer group. None of these remaining studies showed health benefits from moderate alcohol consumption.
Moreover, according to Stockwell, before researchers corrected for biases and design flaws, “occasional” drinkers (individuals who consumed less than one drink per week) were likely to live longest. He noted, however, that it was unlikely that the small amount of alcohol consumed during their occasional drinking was the reason for their longevity.
"Either alcohol is a panacea," Stockwell said, "or moderate drinking is really a marker of something else."
The study did not distinguish between types of alcohol and did not look at whether certain types (like red wine) are associated with the probability of living longer.
