No Net Health Benefits from Moderate Drinking.
Will that glass of wine with dinner help you to live longer? Not likely, according to a new study co-authored by a School of Public Health researcher.
The paper, published in the Journal of Studies on Alcohol and Drugs, reanalyzed data from 87 long-term studies on alcohol use and mortality, which included nearly 4 million people and documented causes for 367,103 deaths. At first glance, the studies showed that low-volume drinkers—those who had up to two drinks a day—had lower mortality risks than those who abstained from alcohol. But once the authors adjusted for errors such as how “abstainers” are defined, they found that the protective effect of light drinking disappeared.
“Our study suggests that a skeptical position is warranted in relation to the evidence that low-volume consumption is associated with net health benefits,” said the study team, which includes Timothy Naimi, associate professor of community health sciences and of medicine at the School of Medicine.
The study also found that before removing errors in how abstainers were defined, it was “occasional drinkers” who consumed less than one drink per week who live the longest. The international team of authors argued that such a tiny consumption level was unlikely to provide any physiological benefits, and so occasional drinkers may be the best group against which to compare other drinkers.
This new paper builds on the work of a landmark 2006 study, co-authored by lead author Tim Stockwell of the Centre for Addictions Research of BC at the University of Victoria, which first highlighted how the majority of published studies on alcohol and mortality make the mistake of comparing moderate drinkers to those who currently abstain. Such “current” abstainers include many people whose poor health has led them to cut down or completely abstain. They make the health and life expectancy of moderate drinkers look good by comparison.
Only 13 of the 87 studies avoided biasing the abstainer comparison group—and these did not show significant health benefits.
The updated study reinforces the 2006 findings and could have major implications for crafting alcohol policies and giving advice about low-risk drinking, the authors said.
They suggest that new, improved methods are required to make unbiased estimates of alcohol’s health impacts and that, to date, research has tended to over-estimate possible health benefits while under-estimating health risks. This means that while alcohol is recognized by international health authorities as a leading cause of preventable death, illness, and injury, the extent of this is underestimated, the study says.