The next time you plant a kiss on your sweetheart, you may be improving your health in the process. The science of smooching tells us that we benefit from puckering up.

People in most cultures kiss as a way to share affection with romantic partners, children, and other loved ones. Although kissing can be physiologically arousing, it may also reduce stress, leading to improvements in health conditions that are aggravated by stress.

For example, Japanese allergist Dr. Hajime Kimata noticed that stress can trigger allergic reactions in people with allergies. To explore whether kissing can improve allergic symptoms, he recruited romantic couples to smooch for 30 minutes while listening to romantic music. Doing so, he found, reduces the body’s production of the histamine IgE, which is responsible for many of the symptoms of allergies, such as sneezing and nasal congestion. Among patients with allergic rhinitis and atopic dermatitis, Kimata has also found that kissing reduces the swelling, burning, and itching that often appear on the skin in response to allergens.

Similarly, a study in my own lab recruited married and cohabiting couples to increase their frequency of kissing over a 6-week period. Compared to a control group of participants who did not kiss more, the kissers experienced a significant decrease in their stress, as well as a significant increase in their relationship satisfaction.

To be sure, not all effects of kissing are positive. Kissing can transfer the Epstein-Barr virus, which causes infectious mononucleosis (also known as the “kissing disease”). People with allergies to specific foods or drugs can experience allergic reactions when kissing others who have ingested those allergens. And of course, kissing while suffering a cold or flu can easily spread those illnesses to others.

Those exceptions aside, kissing does us good. It’s free, it’s fun, and it’s beneficial!