Red wine, in limited amounts, has long been thought of as healthy for the heart. The alcohol and certain substances in red wine called antioxidants may help prevent coronary artery disease, the condition that leads to heart attacks.

Links between red wine and fewer heart attacks aren't well understood. But antioxidants in red wine may increase levels of high-density lipoprotein (HDL) cholesterol, also called the "good" cholesterol, and protect against cholesterol buildup.

Experts say not to start drinking alcohol to help your heart. This is especially true if you have alcohol use disorder or if alcohol use disorder is in your family. Too much alcohol can harm the body in many ways.

But if you already have a glass of red wine with your evening meal, drinking it in limited amounts may improve your heart health.

Antioxidants in red wine called polyphenols may help protect the lining of blood vessels in the heart. A polyphenol called resveratrol is one part of red wine that's gotten noticed for being healthy.

Resveratrol might help prevent damage to blood vessels, lower low-density lipoprotein (LDL) cholesterol, also called the "bad" cholesterol, and prevent blood clots.

But study results on resveratrol are mixed. Some research shows that resveratrol could be linked to a lower risk of swelling and irritation, called inflammation, and blood clotting. Both can lower the risk of heart disease.

But other studies have found that resveratrol does not protect against heart disease. More research is needed.

The resveratrol in red wine comes from the skin of grapes used to make wine. Simply eating grapes or drinking grape juice might be a way to get resveratrol without drinking alcohol. Red and purple grape juices may have some of the same heart-healthy pluses of red wine.

Peanuts, blueberries and cranberries also have some resveratrol. It's not yet known whether eating grapes or other foods promotes heart health the way drinking red wine might. And it's not known how much resveratrol is needed to protect the heart. The amount of resveratrol in food and red wine can vary widely.

There also are resveratrol supplements. However, they might cause side effects. And research suggests that the body can't absorb most of the resveratrol in supplements.

Many studies have shown that drinking regular, limited amounts of any type of alcohol helps the heart. It's not just red wine. It's thought that alcohol:

• Raises HDL cholesterol, also called the "good" cholesterol.
• Helps keep blood clots from forming.
• Helps prevent artery damage from high levels of LDL cholesterol, also called the "bad" cholesterol.
• May improve how well the layer of cells that line the blood vessels works.

Researchers keep studying whether red wine and other alcoholic drinks can help the heart. Those who drink regular, limited amounts of alcohol, including red wine, seem to have a lower risk of heart disease. Drinking regular, limited amounts is called drinking in moderation.

But there might be other reasons for the lower risk of heart disease in people who drink red wine in moderation. For instance, they might eat a healthier diet and be more active than those who don't drink red wine. And they might have higher incomes and better access to health care as well.

More research is needed about whether red wine is better for the heart than other types of alcohol, such as beer or hard liquor.

The American Heart Association and National Heart, Lung, and Blood Institute advise against starting to drink alcohol just to prevent heart disease. Some people who drink alcohol have trouble stopping, called addiction. And drinking alcohol can cause other health problems or make them worse.

Drinking too much alcohol increases the risk of:

• Accidents, violence and suicide.
• Certain types of cancer.
• Heart failure.
• Irregular heart rhythms such as atrial fibrillation, which can lead to stroke.
• High blood pressure.
• Liver and pancreas diseases.
• Stroke.
• Weight gain and obesity.

Do not drink alcohol at all if you:

• Are pregnant, think you might be pregnant or are trying to become pregnant.
• Have a personal or strong family history of alcohol use disorder.
• Have liver disease.
• Have pancreas disease linked to alcohol use.
• Have heart failure or a weak heart.
• Take medicines that don't mix well with alcohol.
• Are breastfeeding, especially within two hours of drinking alcohol.

If you have questions about the plusses and risks of alcohol, talk with your health care professional.

If you already drink alcohol, do so in moderation. For healthy adults, that means:

• Up to one drink a day for women.
• Up to two drinks a day for men. The limit for men is higher because men most often weigh more than women and have more of the substance that breaks down alcohol in the body.

A drink is defined as:

• 12 ounces (355 milliliters) of regular beer.
• 5 ounces (148 milliliters) of wine.
• 1.5 ounces (44 milliliters) of hard liquor or distilled spirits.