NDRI research challenges health benefits of alcohol
A team of researchers from Canada, the USA, and the National Drug Research Institute in Australia, has found that contrary to the popular belief that a glass of wine with dinner will help lead to a longer and healthier life, the scientific evidence is shaky at best.
Countless news stories have reported on research linking moderate drinking to a range of health benefits—including lowering the risk of heart disease and longevity. But new research, published in the March 2016 issue of the Journal of Studies on Alcohol and Drugs, which reanalyzed data from 87 long-term studies on alcohol use and mortality, found that many were flawed, with designs suggesting benefits where there are likely none.
A key issue is how studies have defined “abstainers,” explained NDRI’s Professor Tanya Chikritzhs. Most often, studies have compared moderate drinkers (people who have up to two drinks per day) with “current” abstainers. The problem is that “current” abstainers can include many people whose poor health has led them to cut out alcohol. They make the health and life expectancy of moderate drinkers look good by comparison.
When the research team corrected for those abstainer “biases” and certain other study-design issues, moderate drinkers no longer showed a longevity advantage. Further, only 13 of the 87 studies avoided biasing the abstainer comparison group - and these showed no health benefits.
What’s more, Chikritzhs said, before those corrections were made, it was actually “occasional” drinkers—people who had less than one drink per week—who lived the longest. And it’s unlikely that such infrequent drinking would be the reason for their better health as they would be getting a biologically insignificant dose of alcohol.
This new research builds on the work of a landmark 2006 study, co-authored by Chikritzhs, 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. The current expanded study reinforces the 2006 findings, and could have major implications for alcohol policy and advice about low-risk drinking.
Stockwell, T., Zhao, J., Panwar, S., Roemer, A., Naimi, T., & Chikritzhs, T. (March 2016). Do “moderate” drinkers have reduced mortality risk? A systematic review and meta-analysis of alcohol consumption and all-cause mortality. Journal of Studies on Alcohol and Drugs, 77(2), 185–198. Link to paper