In recent years, studies have shown a strong link between our emotions and cardiovascular health.

Research shows that hostility, anger, depression, anxiety and social isolation all lead to higher rates of heart disease.

The reverse is true as well: Laughter, happiness and a sense of humor actually can help you to stay healthy. Research suggests laughter can decrease stress hormones, reduce artery inflammation and increase HDL, the “good” cholesterol, says the American Heart Association (AHA).

The positive effects of laughter last 24 hours, the AHA says.

Here are three ways in which laughter can give you a healthier heart:

1. Increased blood flow

Researchers at University of Maryland Medical Center found that laughter increases your blood flow by dilating the inner lining of blood vessels, which is called the endothelium.

Laughter causes the release of beta-endorphins in the hypothalamus, which leads to the release of nitric oxide, which dilates the vessels.

Nitric oxide is a chemical that also protects the heart by reducing inflammation and preventing formation of cholesterol plaque.

The researchers said the change in the endothelium caused by laughter appears to be similar to the benefits of aerobic exercise or the use of cholesterol-lowering drugs like statins. The difference is that laughter is spontaneous and has an immediate effect.

2. Less stress hormones

Laughter has also been shown to have beneficial effects on other aspects of our biochemistry. For example, it leads to a reduction in stress hormones, including cortisol and epinephrine. Stress causes our blood vessels to constrict.

3. Antibody boost

Laughter boosts the number of antibody-producing cells, which leads to a stronger immune system.

“The benefits of laughter cannot be understated,” says cardiologist Benico Barzilai, MD. “Laughter leads to an immediate reduction in the body’s negative response to stress and causes the blood vessels of the body — including the heart — to increase blood flow as needed.”

Researchers are just beginning to understand all that laughter can do to promote heart health. There is some thought that laughing on a regular basis can even reduce your risk for a heart attack.

Here are a few suggestions to reduce stress and laugh more:

By making humor a regular part of your life, you can have a big impact on your own heart health.