Kissing may be the most primal way we express affection with other humans. We kiss babies on their adorable chubby faces, friends on the cheeks, and lovers on the lips in demonstration of our feelings and desire for closeness. Kissing may be one of the earliest evolutionary mechanisms for social bonding. While there are plenty of obvious pleasures of smooching, there are also some remarkable health benefits, backed by science. Check out these 10 benefits of lip smacking:
1. Kissing releases feel-good hormones
Kissing activates the brain’s reward system, releasing neurotransmitters like oxytocin, “the love hormone,” and vasopressin, which bonds mothers with babies and romantic partners to each other. It also releases endogenous opioids, dopamine, and other helpful neurohormones to keep our moods balanced.
2. … Which have healing abilities
A 2005 study in Neuroendocrinology Letters adds, “Thus, love, pleasure, and lust have a stress-reducing and health-promoting potential, since they carry the ability to heal or facilitate beneficial motivation and behavior.” In other words, by reducing your stress hormones, your body can better focus on healing any physiological processes that are exacerbated by stress, and help contribute to more positive mental health and behavior.
3. Makes you alert
Kissing often stimulates the release of adrenaline and noradrenaline—not only do these make you feel excited by increasing your heart rate, they make you more alert, as your body prepares for action…of any kind.
4. Reduces stress
According to affection exchange theory, as mentioned in a 2009 study in the Western Journal of Communication [PDF], physical exchanges of affection, including kissing, “buffer the individual against the physiological effects of stress.” The researchers found that expressed affection, of which kissing is a prime example, was directly related to lowering the stress hormone cortisol throughout the day.
5. Positive effect on cholesterol
The same study authors theorize that if affectionate behavior reduces stress, “then it is logical to predict that it will also effect improvements on physiological parameters that are exacerbated by stress” such as cholesterol. Cholesterol has a number of essential physiological functions, they write, “including maintaining membrane fluidity, producing bile, and contributing to the metabolism of fat-soluble vitamins.” It’s also “largely responsible” for the production of steroid hormones, such as cortisol, aldosterone, progesterone, the estrogens, and testosterone.
6. Improves allergy symptoms
Allergic responses can be aggravated by stress. Since kissing reduces stress by sending those feel-good hormones mentioned earlier to the brain, as well as alleviating cortisol, a 2003 Japanese study in Physiology and Behavior explored the relationship between the stress-lowering activity of kissing on allergic reactions. Ninety participants were evenly divided into three groups: 30 with atopic dermatitis, 30 with allergic rhinitis, and 30 in a control group. In the study, the subjects, whom the authors noted “do not kiss habitually,” kissed for 30 minutes with their partner in a private room while listening to soft music. They found that at the end of their smooch sessions, the participants experienced significant relief from skin wheals (hives) and plasma neurotrophin levels (a sign of allergic reaction) associated with Japanese cedar pollen and house dust mites. In 2015, this study won an Ig Nobel prize.
7. Boost immunity
When you kiss someone on the lips you exchange bacteria. This can either make you sick, or it can help boost your immunity by exposing you to new germs that strengthen your immune system’s ability to fight these bacteria. A 2014 study in the journal Microbiome found that couples who kissed frequently were more likely to share the same microbiota in their saliva and on the surface of the tongue. How frequently? At least nine times per day.
8. Keeps the dentist away
The act of kissing stimulates your salivary glands to produce saliva, the fluid that moistens the mouth to make swallowing easier. Saliva also helps remove cavity-causing particles that stick in your teeth after eating. So while it might be a stretch to say kissing prevents cavities, it can’t hurt.