Is alcohol good for your heart? It’s complicated, despite new insights

On Nutrition

We’re almost a month out from the end of Dry January, and I can’t help but wonder how February went for those who consciously abstained from alcohol for a month. How many people resumed their former drinking habits? How many resumed drinking at a lower level? How many decided to stay alcohol-free, at least for now?

Curious if there was any actual data on this, I went sleuthing and dug up a 2023 study that found 7% of “emerging adults” (ages 18-29) had participated in Dry January or another temporary alcohol abstinence challenge in the previous year, with half reporting drinking less after the challenge and 15% remaining abstinent. A British study published in 2016 found that six months after participating in Dry January, people drank alcohol one fewer day per week, on average, and consumed nearly one fewer drink less on each day they did drink, compared with their previous alcohol use.

Who’s more likely to participate in an alcohol abstinence challenge? Females with a higher education and income level, according to a 2022 review of six published studies and seven reports on one-month abstinence challenges. Temporary abstainers are also likely to be heavier drinkers and be more concerned about the effects of alcohol on health. Those concerns have merit.

It’s long been thought that moderate alcohol consumption — or at least red wine consumption — had benefits for heart health. After all, red wine is part of the Mediterranean diet. However, that belief was supported by research that observed associations between moderate intake and better heart health, and sometimes other aspects of health. But associations can’t prove cause-and-effect in the way that randomized control trials can, and the reality is it would be unethical to randomly assign people to drink moderately, heavily or not at all for months or years. It’s also important to ask the question: Who are moderate drinkers, and what other factors in their lives could promote heart health? Are they more likely to have higher socioeconomic status, to be physically active, to eat a lot of vegetables?

What was also missing was a real understanding of what mechanisms might connect alcohol intake to health or disease. Some recent research is helping to fill that in. For example, a study from Boston and Tufts universities published last fall found that alcohol consumption may either benefit or harm heart health, depending on what metabolites — small molecules produced by many cellular processes — are produced in response to drinking.

A number of previous studies had looked at associations between alcohol consumption in a single drinking episode and metabolites circulating in the blood. For this new study, to look at potential effects of habitual or long-term alcohol consumption, researchers used data from 2,428 participants to look for connections between cumulative average alcohol intake over 20 years with circulating metabolites. Then they looked at the connection between alcohol-associated metabolites and new cases of cardiovascular disease.

The average age of the group of participants was 56 at the time their metabolites were measured. The researchers found that among the 60 metabolites associated with alcohol consumption, some may reduce risk of cardiovascular disease, while others (such as certain triglycerides) may increase risk — and that the positive and negative effects seemed to cancel each other out. However, the authors noted that if other lifestyle or environmental factors disrupt the balance of metabolites, it’s possible that one effect may prevail, for better or for worse. Future research will hopefully find more conclusive answers.

More intriguing research came from researchers at Massachusetts General Hospital last year, suggesting that stress might be the link between moderate alcohol consumption and lower heart disease risk. Brain imaging showed lower levels of stress signaling in the amygdala — the region of the brain associated with stress responses such as increased blood pressure and heart rate — in light-to-moderate drinkers, compared with study participants who abstained or drank little. Importantly, these effects were longer term (not only right after having a drink) and appeared to account for much of the reduction in heart disease risk, including fewer heart attacks and strokes, observed in the light-to-moderate drinkers.

Now for a big “but.” The researchers aren’t advocating for drinking as a mode of stress relief, largely because of alcohol’s other potential negative health effects. For example, the study found that among people who consumed more than 14 alcoholic beverages per week, risk of heart attack increased and overall brain activity decreased. It also found that any amount of alcohol increased the risk of cancer.

According to the World Cancer Research Fund and the American Institute for Cancer Research, there is strong evidence that two or more drinks per day increases the risk of colon cancer, and three or more drinks per day increases the risk of stomach and liver cancer. There’s also strong evidence that drinking alcohol at all increases the risk of cancers of the mouth, throat and esophagus, as well as pre- and postmenopausal breast cancer — the evidence is even stronger for the latter.

The Global Burden of Disease Study 2016, coordinated by the University of Washington’s Institute for Health Metrics and Evaluation, used 694 sources of individual and population-level alcohol consumption, along with 592 studies on the risk of alcohol to estimate that nearly 3 million deaths globally in 2016 were attributed to alcohol use. The authors found that cancer risk rises with increasing levels of consumption, and the level of consumption that minimizes health risk is zero.

So what does this mean for you, if you happen to enjoy beer, wine, a cocktail or all of the above? It means reflecting and reconciling this against the weight of the evidence that consuming alcohol does carry risks — even if you’re careful to not drive under the influence. Use the facts to make a conscious decision about whether or how much to drink that aligns with the level of personal risk you are comfortable with.