1. It's good for your teeth
According to dentist Dr Heidi Hausauer, kissing increases saliva flow. This in turn keeps the mouth, teeth and gums healthy by removing food particles. The extra saliva helps to wash bacteria off the teeth and reduce plaque buildup. Some experts even claims that the mineral ions in saliva can promote repair of small lesions in tooth enamel.
2. Gives immune system a boost
Just as saliva can help oral hygiene, it can also give your immune system a boost. There are more than 700 types of bacteria inside a human mouth - with no two alike. Therefore, exchanging saliva can introduce the body to new bacteria. Studies have shown that having a diverse amount of bacteria in our bodies correlates with better health - specifically when it comes to our microbiota, or the collection of microorganisms living inside us.
3. Lowers anxiety
Kissing has been shown to decrease the stress hormone cortisol and increase serotonin - a chemical responsible for maintaining mood balance - levels in the brain. It has also been shown to have similar benefits to meditation, mainly from its ability to release oxytocin, also known as the 'love' hormone.
4. Lessens allergic reactions
Dr Hajime Kimata, who specializes in allergology at a clinic in Japan, won an Ig Nobel Prize for revealing how 30 minutes of kissing can reduce the effect of allergic reactions. In 2006, his team studied 24 patients with two types of allergies: mild atopic eczema (a skin allergy) and mild allergic rhinitis (a nasal allergy). The patients were looked at before and after kissing their partners for 30 minutes while listening to soft music.
5. Lowers blood pressure
Because our lips are made up of blood vessels, kissing can lower blood pressure by dilating them and therefore allowing blood to flow to the vital organs.
6. Delays signs of aging
Because kissing increases blood flow to the face, it stimulates the production of collagen - an abundant and important protein found in our bodies, according to Dr Neinstein. 'In order to move your lips, your whole face has to get involved, which increases elasticity,' he said.
7. Burns calories
Depending on which study you look at, kissing can burn anywhere between two and six calories per minute. However, kissing with tongue - which uses all the muscles in your face - can burn up to 26 calories per minute.
8. Increases sex drive
Kissing prompts your brain to release a happy elixir of feel-good chemicals like serotonin, dopamine, and oxytocin. Additionally, testosterone - the hormone responsible for sex drive in both women and men - is released into saliva during prolonged kissing.