Most people are probably familiar with the common belief that consuming a glass of wine daily can be beneficial for one’s health – or have come across some version of this statement. However, this belief has now been challenged by a new report in the Journal of Studies on Alcohol and Drugs.
While past studies suggested that moderate drinkers tend to live longer lives with reduced risk of heart disease and enjoy longer lives compared to abstainers, the new analysis raises questions about the validity of such claims. The new analysis sheds light on the reasons behind this discrepancy.
Lead researcher Tim Stockwell, Ph.D., from the Canadian Institute for Substance Use Research at the University of Victoria, highlighted fundamental design flaws in studies linking moderate drinking to health benefits.
The primary issue lies in the fact that these studies have predominantly focused on older adults and have not taken into consideration people’s lifetime drinking habits. This led to a comparison of moderate drinkers with “abstainer” and “occasional drinker” groups that included some older adults who had stopped or reduced their alcohol intake due to various health conditions.
“That makes people who continue to drink look much healthier by comparison,” Stockwell said. He observed that appearances can be misleading in this instance.
In their analysis, Stockwell and his team reviewed 107 published studies that tracked individuals over time to investigate the correlation between alcohol consumption and lifespan. The aggregated data suggested that moderate drinkers (i.e., those consuming one to two drinks per day) had a 14% lower risk of death compared to abstainers.
However, a closer examination revealed a different story. A select few “higher quality” studies focused on younger participants and made efforts to distinguish former and occasional drinkers from abstainers. In these studies, moderate drinking did not demonstrate a connection to longer life.
Interestingly, it was the “lower quality” studies, which involved older participants and failed to differentiate between former drinkers and lifelong abstainers, that indicated a link between moderate drinking and increased longevity.
“If you look at the weakest studies,” Stockwell said, “that’s where you see health benefits.”
The widely held belief that moderate drinking contributes to a longer, healthier life has been around for many years. For instance, it was once popular to attribute the relatively low rates of heart disease in France to the consumption of red wine despite their rich, fatty diet. However, recent research suggests that moderate drinking may not actually extend life expectancy and could even pose health risks, such as an increased likelihood of certain cancers. As a result, major health organizations have refrained from establishing a risk-free level of alcohol consumption.
“There is simply no completely ‘safe’ level of drinking,” Stockwell said.
Journal reference:
- Tim Stockwell, Jinhui Zhao, James Clay, Christine Levesque, Nitika Sanger, Adam Sherk, Timothy Naimi. Why Do Only Some Cohort Studies Find Health Benefits From Low-Volume Alcohol Use? A Systematic Review and Meta-Analysis of Study Characteristics That May Bias Mortality Risk Estimates. Journal of Studies on Alcohol and Drugs, 2024; DOI: 10.15288/jsad.23-00283
