Red wine, in moderation, has long been thought of as heart healthy. The alcohol and certain substances in red wine called antioxidants may help prevent heart disease by increasing levels of "good" cholesterol and protecting against artery damage.
While the news about red wine might sound great if you enjoy a glass of red wine with your evening meal, doctors are wary of encouraging anyone to start drinking alcohol. That's because too much alcohol can have many harmful effects on your body.
Still, doctors do agree that something in red wine appears to help your heart, though it's unclear just exactly what that "something" is. Researchers think antioxidants, such as flavonoids or a substance called resveratrol, have promising heart-healthy benefits.
Antioxidants aren't the only substances in red wine that look promising. The alcohol in red wine also appears to be heart healthy. Find out what's known — and not known — about red wine and its possible heart-health benefits.
Research studies on the heart-health benefits of red wine have reported mixed results. Some studies show that red wine seems to have even more heart-health benefits than other types of alcohol, while other studies show that red wine isn't any better than beer, white wine or liquor for heart health. There's still no clear evidence yet that red wine is superior to other forms of alcohol when it comes to possible heart-health benefits.
The studies supporting red wine suggest antioxidants in red wine called polyphenols help protect the lining of blood vessels in your heart. These antioxidants come in two main forms: flavonoids and nonflavonoids.
Resveratrol might be a key ingredient in red wine that helps prevent damage to blood vessels, reduces "bad" cholesterol and prevents blood clots.
Most research on resveratrol has been conducted on animals, not people. Research in mice given resveratrol has indicated that the antioxidant might also help protect them from obesity and diabetes, both of which are strong risk factors for heart disease. However, those findings were reported only in mice, not in people. In addition, to get the same dose of resveratrol used in the mice studies, a person would have to consume 100 to 1,000 bottles of red wine a day.
Some research shows that resveratrol could be linked to a reduced risk of inflammation and blood clotting, both of which can lead to heart disease. More research is needed before it's known whether resveratrol was the cause for the reduced risk.
Some companies sell supplements containing resveratrol. However, not enough is known about resveratrol's effects to endorse resveratrol supplements. Research into the potential heart-health benefits of resveratrol is continuing.
The resveratrol in red wine comes from the skin of grapes used to make wine. Because red wine is fermented with grape skins longer than is white wine, red wine contains more resveratrol. Simply eating grapes, or drinking grape juice, has been suggested as one way to get resveratrol without drinking alcohol. Some studies have suggested that red and purple grape juices have some of the same heart-healthy benefits of red wine.
Other foods that contain some resveratrol include peanuts, blueberries and cranberries. It's not yet known how beneficial eating grapes or other foods might be compared with drinking red wine when it comes to promoting heart health. The amount of resveratrol in food and red wine can vary widely.
Various studies have shown that moderate amounts of all types of alcohol benefit your heart, not just alcohol found in red wine. It's thought that alcohol:
Red wine's potential heart-health benefits look promising. Those who drink moderate amounts of alcohol, including red wine, seem to have a lower risk of heart disease. However, more research is needed before we know whether red wine is better for your heart than are other forms of alcohol, such as beer or spirits.
Neither the American Heart Association nor the National Heart, Lung, and Blood Institute recommend that you start drinking alcohol just to prevent heart disease. Alcohol can be addictive and is associated with other health issues.
Drinking too much increases your risk of high blood pressure, high triglycerides, liver damage, obesity, certain types of cancer, accidents and other problems. In addition, even small amounts of alcohol can cause cardiomyopathy — weakened heart muscle — causing symptoms of heart failure in some people. If you have heart failure or a weak heart, you should avoid alcohol completely. If you take aspirin daily, you should avoid or limit alcohol, depending on your doctor's advice. You also shouldn't drink alcohol if you're pregnant. If you have questions about the benefits and risks of alcohol, talk to your doctor about specific recommendations for you.
If you already drink red wine, do so in moderation. Moderate drinking is defined as an average of two drinks a day for men and one drink a day for women.
A drink is defined as 12 ounces (355 milliliters, or mL) of beer, 5 ounces (148 mL) of wine or 1.5 ounces (44 mL) of 80-proof distilled spirits.
The limit for men is higher because men generally weigh more and have more of an enzyme that metabolizes alcohol than women do.