New report says there’s no safe level for alcohol consumption
By Journal
of Studies on Alcohol and Drugs
Probably everyone has heard the conventional wisdom that a glass of wine a day is good for you—or you’ve heard some variation of it. The problem is that it’s based on flawed scientific research, according to a new report in the Journal of Studies on Alcohol and Drugs.
Over
the years, many studies have suggested that moderate drinkers enjoy longer
lives with lower risks of heart disease and other chronic ills than abstainers
do. That spurred the widespread belief that alcohol, in moderation, can be a
health tonic. However, not all studies have painted such a rosy picture—and the
new analysis sheds light on why.
“There
is simply no completely ‘safe’ level of drinking.” — Tim Stockwell,
Ph.D.
Misleading Comparisons
In
a nutshell, studies linking moderate drinking to health benefits suffer from
fundamental design flaws, said lead researcher Tim Stockwell, Ph.D., a
scientist with the Canadian Institute for Substance Use Research at the University of
Victoria.
The
major issue: Those studies have generally focused on older adults and failed to
account for people’s lifetime drinking habits. So moderate drinkers were
compared with “abstainer” and “occasional drinker” groups that included some
older adults who had quit or cut down on drinking because they’d developed any
number of health conditions.
“That
makes people who continue to drink look much healthier by comparison,”
Stockwell said.
And
in this case, he noted, looks are deceiving.
Analyzing
Data From 107 Studies
For
the analysis, Stockwell and his colleagues identified 107 published studies
that followed people over time and looked at the relationship between drinking
habits and longevity. When the researchers combined all the data, it looked
like light to moderate drinkers (that is, those who drank between one drink per
week and two per day) had a 14% lower risk of dying during the study period
compared with abstainers.
Things
changed, however, when the investigators did a deeper dive. There were a
handful of “higher quality” studies that included people who were relatively
young at the outset (younger than 55, on average) and that made sure former and
occasional drinkers were not considered “abstainers.” In those studies,
moderate drinking was not linked to a longer life.
Instead,
it was the “lower quality” studies (older participants, no distinction between
former drinkers and lifelong abstainers) that did link moderate drinking to
greater longevity.
“If
you look at the weakest studies,” Stockwell said, “that’s where you see health
benefits.”
The
French Paradox
The
notion that moderate drinking leads to a longer, healthier life goes back
decades. As an example, Stockwell pointed to the “French paradox”—the idea,
popularized in the 1990s, that red wine helps explain why the French enjoy
relatively low rates of heart disease, despite a rich, fatty diet. That view of
alcohol as an elixir still seems to be “ingrained” in the public imagination,
Stockwell noted.
Health
Risks of Moderate Drinking
In
reality, he said, moderate drinking likely does not extend people’s lives—and,
in fact, carries some potential health hazards, including increased risks of
certain cancers. That’s why no major health organization has ever established a
risk-free level of alcohol consumption.
“There
is simply no completely ‘safe’ level of drinking,” Stockwell said.
Reference:
“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” by Tim Stockwell, Jinhui Zhao, James Clay,
Christine Levesque and Nitika Sanger, 30 January 2024, Journal of Studies
on Alcohol and Drugs.
DOI: 10.15288/jsad.23-00283