Study reveals exposure to sunlight likely to improve human sex life

Getting out in the sun can boost your sex drive, according to an Israeli study, because sunlight causes you to release higher levels of sexual hormones. Researchers at Tel Aviv University exposed 32 adults to different levels of ultraviolet radiation from sunlight, while quizzing them about how horny they were feeling.  They also discovered that UV exposure boosted levels of sexual hormones, and also increased testosterone levels in the men, making them more aggressive. But they warned that a lot of research is required before any treatment can be designed, and said people should be careful about too much exposure to the sun. Before experimenting on humans, the team exposed animals to sunlight, and found that the female hormone levels 'rose significantly,' and led to enlarged ovaries. They also found the attraction between males and females increased, and both were more willing to engage in sexual intercourse, even out of normal rutting season.

Study author, Professor Carmit Levy said scientists have known for years that UV radiation from sunlight increases testosterone levels in males and plays a role in both the behavioural and hormonal regulation of sexuality in mammals. However, the mechanism responsible for this regulation remained unknown, so the Israeli team created their experiments to uncover the details. They then removed a protein from the skin of the animals called p53, that identifies DNA damage and activates pigmentation changes during sunlight exposure. The removal of p53 eliminated the effect of UVB exposure on the animals' sexual behaviour, showing that exposure to radiation through the skin was the cause of the hormonal, physiological and behavioural changes. They also found that the protective system, through the protein p53, is responsible for the regulation of sexuality in response to sunlight. The last stage of the study included 32 human subjects, who filled out questionnaires on behaviours of romantic passion and aggression.  Treated with UVB phototherapy, both the men and women showed a rise in romantic passion - with a higher libido and increased interest in having sex. The male volunteers were also more aggressive than before being exposed to the UVB phototherapy - where they are exposed to UV radiation similar to sunlight. Similar results were found when the subjects were asked to avoid sunlight for two days, and then tan themselves for approximately 25 minutes.