Study: No, a glass of wine a day is not good for your heart
The protective power of a glass of wine a day may be other good habits in disguise.
Is a little alcohol good for you? You may have encountered a chirpy news story or two indulging the idea that a glass of red wine with dinner is an acceptable vice. There are antioxidants in wine after all, right? So is there any truth to this health advice?
Now, a study of the health records of more than 370,000 people, published last month in JAMA Network Open, pours some old water on this notion. The authors estimated that the better health outcomes may not be due to any protective power of booze but rather to other healthy lifestyle factors more common to people who temper their drinking than those who overdo it.
How They Did It — Researchers from Massachusetts General Hospital and the Broad Institute of Massachusetts Institute of Technology and Harvard accessed the records of 371,463 individuals, who gave health data to the UK Biobank, a longitudinal in the United Kingdom that began in 2006 investigating the connections between genetic predispositions and environmental factors in contributing to disease.
The researchers put them into five categories of drinkers by levels of weekly alcohol consumption:
- light drinkers, who had up to 8.4 drinks
- moderate drinkers, 8.4 to 15.4 drinks
- heavy drinkers, 15.4 to 24.5 drinks, and
- abusive drinkers, more than 24.5 drinks
One “drink” was defined by the classic standard of 14 grams of alcohol, which translates to 5 ounces of wine, or 12 ounces of a beer with five percent alcohol, or a 1.5 ounce shot of distilled alcohol, like rum or whiskey.
What’s New — Echoing the results of other studies, the researchers found that light-to-moderate drinkers had the lowest prevalence of heart disease, even lower than abstainers.
Any alcohol consumption was associated with greater risk of cardiovascular disease.
But the light and moderate drinkers also showed better habits in other areas: They smoked less, had lower body mass indexes, exercised more, and ate more cooked vegetables and less red meat.
Once the researchers adjusted the data to remove these healthy lifestyle factors — as well as the biobank participants’ overall rating of their health — the heart health benefits of being in the light and moderate categories disappeared. Any alcohol consumption was associated with greater risk of cardiovascular disease.
The authors noted that the correlation was a J-shaped curve, meaning the risks shoot up exponentially with heavy alcohol use.
For example, the risk of coronary artery disease for men, after other health factors were eliminated, was about 75 percent higher for light and moderate drinkers compared to non-drinkers, 225 percent higher for heavier drinkers, and 660 percent for abusive drinkers.
Why It’s Important — Other health researchers have proposed this explanation for the so-called “French paradox.”
The study authors write that “the observed cardiac benefits of alcohol have been hypothesized to be the product of residual confounding because of favorable lifestyle, socioeconomic, and behavioral factors that tend to coincide with modest alcohol intake.”
In other words, someone who drinks moderately may be showing some self-concern that manifests in other areas of their life and have some socioeconomic advantages over the average person going on a bender, which may obscure the actual health impacts of alcohol.
So how much alcohol is a “healthy” amount? Maybe none is ideal. In 2018, a hulking study published in The Lancet looked at the risk factor for death and disability from alcohol from 694 data sources from around the world, stretching from 1990 to 2016. One of its conclusions: “The level of alcohol consumption that minimized harm across health outcomes was zero standard drinks per week.”
One could look at the findings of the new study and conclude that all alcohol is detrimental to cardiovascular health. Another takeaway is that the health factors considered — exercise, healthy eating, weight maintenance, and abstaining from smoking — have impressive power to counterbalance some more self-gratifying behaviors, like the occasional beer.