According to Austrian researchers, a long, passionate kiss helps regulate the heartbeat, lowers cholesterol and decreases blood pressure.
Kissing relieves stress
When your mouth is slightly open as it is when you kiss it relaxes your jaw, encouraging the rest of your body to relax. Kissing also makes you breathe more deeply, another trigger for relaxation.
Kissing helps weight control
Kissing burns 100 calories an hour - not quite as much as running on a treadmill which burns 700 to 800 - but a lot more enjoyable! In fact, according to one study three passionate kisses a day will help you lose a pound in weight.
Kissing makes you look younger
Kissing stimulates more than 30 facial muscles, helping to smooth out lines and wrinkles, tone your cheek and jaw muscles and boost circulation to the face bringing a youthful glow.
Kissing helps protect against infection
Around 80 per cent of the bacteria in saliva are common to everyone and 20 per cent are unique to you. The exchange of saliva in kissing stimulates your immune system to create antibodies to the 'foreign' bacteria, a process called cross-immunotherapy which helps you fight infection.
Kissing boosts self-esteem
Kissing makes you feel happy, triggering the release of feel-good chemicals called endorphins, which then make you feel happier still.
Research shows that kissing taps into the brain's limbic system, which releases PEA, the 'love chemical' that's also found in chocolate, encouraging a feeling of euphoria which can last for an hour or two.
Kissing helps you bond
Kissing causes the brain to release oxytocin, sometimes called 'the bonding hormone'. This hormone, which is also secreted at orgasm and by breastfeeding mothers, helps you feel closer to your partner, promoting feelings of calm and contentment.
Kissing eases allergies
According to research from Japan, kissing can help reduce the symptoms of hayfever. It seems that a 30-minute kissing session deters the immune system from producing histamine, a chemical that's responsible for sneezes, runny nose and streaming eyes. Cuddling without the kissing doesn't work though.
Kissing combats tooth decay
Kissing stimulates the flow of saliva, which in turn neutralises acids, remineralises teeth and flushes away food particles.
Tooth decay happens when bacteria in plaque on the surface of teeth mix with sugars and starches in food, creating acids which can damage tooth enamel.
Dry mouth, which is more common as we get older and can be caused by prescription drugs for conditions such as high blood pressure, increases the risk of decay.
Find out about the health benefits of sex.