Study debunks the link between moderate alcohol consumption and a longer life

Everyone has probably heard the conventional wisdom that a glass of wine a day is good for you, or you’ve heard some variation on it. The problem is that it is 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 live longer lives and have a lower risk of heart disease and other chronic diseases than teetotalers. This stimulated the widespread belief that alcohol, in moderation, can have a health-promoting effect. However, not all studies have painted such a rosy picture – and the new analysis sheds light on why.

In short, studies linking moderate alcohol consumption to health benefits suffer from fundamental design flaws, says lead researcher Tim Stockwell, Ph.D., a scientist at the Canadian Institute for Substance Use Research at the University of Victoria.

The main problem: These studies have generally focused on older adults and have not taken into account people’s drinking habits throughout their lives. So moderate drinkers were compared with the ‘non-drinkers’ and ‘occasional drinkers’ groups, which included some older adults who had stopped or reduced their drinking because they had developed some health problems.

“That makes people who continue to drink look much healthier by comparison,” Stockwell said.

And in this case, he noted, appearances are deceptive.

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 appeared that 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 to abstainers.

However, things changed when the researchers dug deeper. There were a handful of ‘higher quality’ studies among people who were relatively young at onset (under 55 on average) and ensured that 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 linked moderate drinking to longer lifespan.

“If you look at the weakest studies,” Stockwell said, “you see health benefits.”

The idea 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 have relatively low rates of heart disease, despite a rich, fatty diet. That view of alcohol as an elixir still seems “ingrained” in the public imagination, Stockwell noted.

In reality, he said, moderate drinking probably doesn’t extend people’s lives — and in fact carries some potential health risks, 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’ drinking level,” Stockwell said.