Thursday, January 16, 2020

Having more s.e.x makes early menopause less likely, research finds

Women who have s.e.x more often are less likely to have an early menopause, according to research that raises the intriguing possibility that lifestyle factors could play a more significant role than previously thought in determining when the menopause occurs.

The study, based on data collected from nearly 3,000 women who were followed for 10 years, found that those who reported engaging in sexual activity weekly were 28% less likely to have experienced menopause at any given age than women who engaged in sexual activity less than monthly.

Megan Arnot, a PhD student at UCL and the study’s first author, said the findings suggest that if a woman is not having s.e.x – and there is no chance of pregnancy – the body might “choose” not to invest in ovulation.

“There may be a biological energetic trade-off between investing energy into ovulation and investing elsewhere, such as keeping active by looking after grandchildren,” she said.

The study, published in the journal Royal Society Open Science, found that women of any age who had s.e.x weekly were 28% less likely to experience the menopause compared with those who had sex less than monthly. Those who had s.e.x monthly were 19% less likely to experience menopause at any given age compared with those who had s.e.x less than monthly.

The researchers have yet to establish what the biological mechanism might be that would result in sexual activity actively influencing when a woman’s reproductive cycle comes to an end.

The menopause is thought to occur when the number of maturing egg follicles in the ovaries drops beneath a critical threshold.

One possibility is that sexual activity stimulates the release of oestrogen, which plays a role in the complex cascade of chemical signals that result in an egg being released each month before the menopause. But the study did not test this directly. A challenge, Arnot said, is that “the whole hormonal mechanisms surrounding the menopause is really poorly understood”, meaning the work does not slot neatly into a well-established framework.

Another possibility is that the two factors – how often a woman has sex and age at menopause – are both determined by some other hormonal or biological factor that was not measured in the study. In this case the link would not be causal.

The study looked at whether living with a male partner played a part but found no link, suggesting that exposure to male pheromones did not explain the findings.

Prof Ruth Mace, an evolutionary anthropologist at UCL and the paper’s senior author, said: “The menopause is, of course, an inevitability for women, and there is no behavioural intervention that will prevent reproductive cessation. Nonetheless, these results are an initial indication that menopause timing may be adaptive in response to the likelihood of becoming pregnant.”