THE secret of a long life is abstinence from sex, scientists revealed yesterday.
A team from the University of Sheffield believes nuns and spinsters who stay away from the pleasures of the flesh outlive sexually active adults.
The "no sex" strategy for survival came from results found studying the sex lives of beetles at the university’s department of animal and plant sciences. They discovered that mealworm beetles, which mate every day, die young, while those which avoid mating live for much longer.
Dr Michael Siva-Jothey, the leader of the team, said: "Nuns tend to have a longer lifespan than women with children and most people know of someone with a maiden aunt who seems to live forever. The question is, why?
"The beetles which mate die sooner than the beetles which don’t mate. The mechanism is not the same in humans, but the principle is the same.
"In beetles, mating released hormones needed to produce sperm in a male or eggs in a female and that had a negative effect on the immune system.
"The assumption then is that if the immune system is downgraded, that leads to a loss of longevity. It is fair to assume that would be the same with other organisms including humans, because mating has a dual effect - a positive one, but then a negative one on the immune system.
"That is important to evolutionary biologists. The goal of evolution is not to live longer but to leave as many offspring as possible so if you produce a lot of offspring and die young then you have done your job in evolutionary terms.
"It makes perfect sense if you try to understand how sexually transmitted disease evolved and spread. The best time for a disease to find a host is during sexual activity when the immune system is weakened."
The findings are just one in a long line of evidence that suggest that males live longer if they abstain from sex.
In 1997, Dr David Gems, a geneticist at University College London, found that males who remain celibate are more likely to survive into a ripe old age.
He discovered that males are actually designed to live longer, but any help from nature is wiped out by the pursuit of sex.
Dr Gems reached the controversial conclusion while studying nematode worms.