Kissing Compendium for the Modern Human
Background
Mouth-to-mouth contact has been observed across multiple species in the animal kingdom, including fish, birds, and primates; its functions can range from exchange of food, to assessment of physical abilities.
However, intimate kissing involving deliberate, prolonged tongue contact and saliva exchange, appears to be an adaptive courtship behaviour unique to humans. The fact that it is common in 90% of cultures¹ is perhaps less interesting than the fact that it is not common in the remaining 10%.
Emotional benefits
It has been proposed that the first kiss serves as a useful mechanism for mate-assessment and facilitating sexual arousal. However, subsequent kisses in longer-term relationships tend to help mediate feelings of attachment, and also enhance emotional bonds through sampling of chemical taste cues in saliva.²
It was been widely shown that kissing your partner releases dopamine, serotonin and oxytocin; this concoction of neurotransmitters allows us to experience feelings of euphoria, which is vital to stress-reduction and a general feeling of well-being.
Oral health benefits
There are over 700 species of bacteria and organisms in your mouth, and a single 10 second kiss can result in a mouth-to-mouth transfer of 80 million bacteria.
Similar to the gut, the oral microbiome can benefit from this exchange of bacteria, conferring an immunising effect against various diseases.³ [Disclaimer: We accept no responsibility if this fails as a pick-up line.]
Risks of saliva swapping
There exist some obvious risks of transmission of certain illnesses, such as colds and herpes simplex. There is also evidence to show the exchange of particular pathological bacteria (streptococcus mutans) can lead to cavities. However, it is likely that this transmission of bacteria is transient, and your flora should normalise between each pash sesh (depending on frequency).
How to maintain kissing health
Do not kiss anyone with obvious sores around the mouth or lips
Avoid kissing babies on the lips to prevent putting them at risk of tooth decay
Foods high in fibre, such as celery, beetroot, rocket, fennel and leafy greens can help to nourish the oral microbiome
Drink plenty of water – hydration, and its resultant increased salivary flow, is the best buffer against bad oral bacteria
Avoid excessive use of anti-microbial mouthwashes and alcohol, which can harm the microbiome
Brush teeth twice daily, floss once a day (yeah, we know it’s hard), use a salt water rinse, and visit your dentist every 6 months
In the end, life is short. So be sensible most of the time, but kiss hard, love hard and Embrace the You.
¹Wlodarski R, Dunbar RI: Examining the possible functions of kissing in romantic relationships. Arch Sex Behav. 2013, 42 (8): 1415-1423. 10.1007/s10508-013-0190-1.
² Nicholson B: Does kissing aid human bonding by semiochemical addiction?. Br J Dermatol. 1984, 111 (5): 623-627. 10.1111/j.1365-2133.1984.tb06635.x.
³Hendrie CA, Brewer G: Kissing as an evolutionary adaptation to protect against human cytomegalovirus-like teratogenesis. Med Hypotheses. 2010, 74 (2): 222-224. 10.1016/j.mehy.2009.09.033.