Is moderate alcohol consumption good for you?
Some of us would certainly like to think our nightly tipple is doing us a service. And over the years many studies have backed up the claim that moderate drinkers (those having up to two drinks per day) live longer than abstainers. Indeed, it has been argued that alcohol consumption helps to ward off any number of health concerns, ranging from cancer and dementia to even cirrhosis of the liver.
But a new Canadian study in the Journal of Studies of Alcohol and Drugs has become the focus of controversy within the field of alcohol research, with some of its detractors claiming the study’s negative conclusions about the benefits of alcohol ignore the overwhelming evidence in favour of moderate consumption.
The study argues that much of the research on alcohol and longevity has been plagued by unfortunate study biases, particularly with reference to the role played by so-called abstainers. Led by Dr. Tim Stockwell, director of the Centre for Addictions Research of British Columbia at the University of Victoria in Victoria, BC, the research team looked at 87 studies on alcohol and longevity and found that while many of the studies showed that moderate drinkers fared better health-wise than abstainers, this was shown mostly to be due to the fact that people who used to drink but at the time of study were currently abstaining were often categorized as abstainers.
Effectively, this grouping helped to stack the statistical deck against abstainers, since on the whole, former drinkers are found to have quit due to ongoing health issues (which themselves negatively impact longevity). “We consistently found that former drinkers had significantly elevated risk of all-cause mortality compared with abstainers,” say the study’s authors.
Remarkably, this abstainer bias turned up in 65 of the 87 studies analyzed, leading the researchers to hold suspect many of the claims of alcohol’s health benefits.
After correcting for the abstainer bias, the advantage of moderate drinkers over abstainers disappeared. The researchers did find that in terms of longevity, occasional drinkers -those having one or two drinks per week – fared somewhat better than both moderate drinkers and abstainers but that such a small regular consumption of alcohol was likely not related to the occasional drinker’s incrementally higher health status.
Overall, the authors conclude that “a skeptical position is warranted” in connection with propositions about the benefits of moderate alcohol consumption.
But this conclusion and the research on which it is based have been strongly condemned by the International Scientific Forum on Alcohol Research, a joint project of Boston University School of Medicine and the Alcohol in Moderation (AIM) group in the United Kingdom.
In a review posted on its website the Forum members argue that the study “ignores the immense amount of experimental data, not only animal experiments but trials in humans, that have described the mechanisms by which moderate alcohol and wine intake have been shown to decrease essentially all of the risk factors for cardiovascular disease, including low HDL-cholesterol, elevated LDL-cholesterol, endothelial dysfunction, coagulopathies, inflammation, abnormal glucose metabolism, and many others.”
The Forum members claim that in paring down its analysis from 2,575 identified studies to a mere 87 upon which to base its findings, the study passed over an “overwhelming body of observational scientific data” that shows that a moderate consumption of alcohol can be considered part of a ‘healthy lifestyle’.
According to Health Canada estimates, four to five million Canadians engage in high risk drinking, which is associated with a range of health and social issues including motor vehicle accidents, Fetal Alcohol Spectrum Disorder, family problems, crime and violence. Canadian guidelines for drinking recommend no more than two drinks a day five times a week for women and no more than three drinks a day five days a week for men.