You have no doubt heard or read some variation on the statement that alcohol is good for your heart. There is, in fact, a large body of scientific evidence linking moderate drinking to decreased risks of heart attack and stroke over the longterm.
But, as with most things, it’s not that simple. The amount of alcohol a person drinks is critical. It’s very clear that heavy drinking carries health hazards, including a heightened risk of death from cardiovascular causes.
What’s more, recent research has highlighted the following point: Alcohol has a range of physiological effects, some of which may be beneficial and some of which may cause harm. And even moderate drinking has a complicated connection to heart health.
A complex relationship
In general, “moderate” drinking" is defined as consuming up to one alcoholic drink per day for women, and up to two per day for men. Many studies have found that moderate drinkers typically have a lower risk of developing heart disease than both abstainers and heavier drinkers.
There may be other differences between those groups of people, of course. Moderate wine drinkers may be generally healthier or more educated or have better diets, for example. Studies have attempted to account for those differences, but they still can’t prove that a daily glass of wine will ward off a heart attack.
Other types of evidence exist as well. Lab research has shown that alcohol has direct effects on the cardiovascular system, some of which could do the heart good: Alcohol seems to influence cholesterol metabolism, and over time, moderate drinking may raise HDL (good) cholesterol. It may also help improve blood vessel function and prevent blood clots.
That said, research has also revealed short-term effects that are not heart-friendly. Soon after you drink, the body experiences a spike in blood pressure, a short-lived inflammatory response, a revved-up heart rate, and an increase in the blood’s tendency to clot. There may also be temporary shifts in heart rhythm.
So the relationship between alcohol and heart health is not simple—as research published in 2016 in the journal Circulation illustrates.
Risks versus benefits
In that review, researchers combined the results of 23 previous studies to examine how alcohol affects cardiovascular risks over the week following drinking. On average, they found moderate drinkers were more likely to have a heart attack or stroke in the hour after drinking than at other times.
That risk dissipated within 24 hours, however—and by that point, moderate drinking was linked to a slightly decreased risk of heart attack. It was also tied to a dip in the risk of ischemic stroke within the following week. (Ischemic strokes are caused by a blood clot, and account for the vast majority of all strokes.)
In contrast, heavy drinking seemed to raise the risks of heart attack and stroke not only immediately, but over the next week, as well.
The researchers were not able to determine whether the type of alcohol—red wine versus beer, for example—mattered. Questions remain about what role a person’s habitual drinking plays.
In one study the researchers reviewed, the immediate risks of moderate drinking were not seen in daily drinkers. But it’s unknown whether such regular drinking makes people immune to the acute effects of alcohol.
Another point to consider: Alcohol may not have long-term benefits when it comes to other forms of heart disease. In one study of nearly 80,000 Swedish adults, moderate drinkers were slightly more likely to develop atrial fibrillation over the next dozen years, versus people who rarely drank.
The bottom line
Because alcohol carries potential risks, you should never start drinking to protect yourself from having a heart attack or stroke.
If you already drink, do so only in moderation. And always talk to your doctor about whether alcohol is safe under your particular circumstances—it may interact with medications you are taking.
Amy Norton has been a medical journalist since 1999. She was a staff writer and editor for Physician’s Weekly and Reuters Health, and has written on health and medicine for MSNBC, The Scientist, Prevention and HealthDay. When she’s not writing, she is teaching yoga.