Research about alcohol’s effects on the body can give you whiplash—one day it’s a veritable superfood, the next day it’s something to drink with caution. You’ve probably heard a little red wine can be good for you (it’s part of the heart-healthy Mediterranean diet, after all). But that doesn’t necessarily mean your heart will thank you for splitting a bottle of Malbec with your partner during date night.
“We know that alcohol is actually—in some ways—good for the heart in moderation,” says Paul Knoepflmacher, MD, a clinical instructor in medicine at The Mount Sinai Hospital. “We know that alcohol can raise the level of HDL, or good, cholesterol.” (Here’s more info about the types of cholesterol and their effect on the body.)
Moderation is the key word, of course. But the vagueness of “moderation” makes it even tricker. Is moderation having one glass a night? One glass a week? Several glasses, once a week?
The American Heart Association defines moderation of alcohol as one or two drinks a day for men and one drink per day for women. And serving size matters: One drink means 12 ounces of beer, four or five ounces of wine, 1.5 ounces of 80-proof spirits, or one ounce of 100-proof spirits.
“A lot of people see those Olivia Pope-size wine glasses and they’re doing a 10-ounce pour,” says Frances Largeman-Roth, RDN, a nutritionist in New York City. Largeman-Roth suggests using a measuring cup if you’re drinking at home until you get a sense of what a serving size looks like. Spoiler alert: It shouldn’t be filled to the brim.
Sticking to the recommended limit can help you reap the health benefits of alcohol without as much of the risks. “When you get outside of that moderate range, it backfires,” says Largeman-Roth. Here’s how alcohol can negatively affect the heart.
Too much alcohol can raise blood pressure. High BP, also called hypertension, is a significant risk factor for heart disease. (Learn what blood pressure numbers mean here.)
Too much alcohol can weaken the heart muscle. The heart needs to work extra hard to pump blood throughout the body is blood pressure is high. The constant strain can weaken the muscle and make it less effective. This in turn can affect almost the whole body, since all your organs and cells require oxygen from the blood to function at their best.
Too much alcohol can cause abnormal heart rhythms. This is commonplace enough that doctors coined the term “holiday heart syndrome” to describe patients having fluttering heartbeats after heavy weekend or holiday season drinking. According to a 2016 study in the Journal of American College of Cardiology, an irregular heartbeat can happen to even “infrequent and nondrinkers” for up to 24 hours after binge drinking. Regular binges were also linked to an increased risk of atrial fibrillation, a condition signaled by racing, “fluttering” heartbeats. Women who drank more than 14 drinks a week increased their risk by 17 percent; men who had more than 21 drinks increased their risk by 25 percent.
Too much alcohol can also cause excess calorie intake. “It’s easy to overconsume,” says Largeman-Roth. “Especially as we get into middle-age and beyond, it becomes harder to burn off those calories.” This can lead to weight gain, which puts additional strain on the heart. Learn more here about how weight affects heart health.
“You can certainly enjoy alcohol responsibly, but you do have to stick to those serving sizes,” says Largeman-Roth. “The dose definitely makes the poison.”