Many people believe that a glass of wine with dinner is good for your health and will help protect from heart disease. But this could well be a myth.
A review of the evidence finds little support for the notion that moderate drinking helps prevent heart disease, according to new research in the Journal of Studies on Alcohol and Drugs.
Over the years, studies have found that adults who drink moderately have lower heart disease than non-drinkers – which has spurred the widespread belief that alcohol in moderation does the heart good.
But analysis of 45 previous studies reveals the flaws in that assumption. The main issue is that "non-drinkers" may actually be former drinkers who quit or cut down because of poor health.
In other words, rather than abstaining leading to poorer health, non-drinkers may have chosen to abstain because their health was already poor.
In their analysis, the researchers found that overall, "current" moderate drinkers (up to two drinks per day) did have a lower rate of heart disease death than non-drinkers.
However, that was not the case in studies that looked at people's drinking habits at relatively young ages - ages 55 or younger - and followed them to their older years when heart disease might strike.
Similarly, studies that accounted for people's heart health at baseline indicated no benefits from moderate drinking.
By contrast, "healthy" seniors who enjoy a glass of wine with dinner, the review suggests, are not healthy because they drink, but rather older people who are already in good health are simply more likely to enjoy a glass of wine with dinner because they have no reason not to.
"We know that people generally cut down on drinking as they age, especially if they have health problems," said researcher Tim Stockwell, director of the Centre for Addictions Research at the University of Victoria, Canada.
"People who continue to be moderate drinkers later in life are healthier. They're not sick, or taking medications that can interact with alcohol."
An additional factor that the review brought to light is education. Non-drinkers were found to be less educated overall – and education is known to lead to better health and increased longevity.
"We can't 'prove' it one way or the other," Stockwell said. "But we can say there are grounds for a healthy skepticism around the idea that moderate drinking is good for you."