Frequent sex may ward off prostate cancerThat’s the good news, but not any kind of frequent sex. According to a Montreal study made public Tuesday, sleeping with several women — more than 20, to be exact — has a protective factor.
It is associated with a 28-per-cent lower risk of one day being diagnosed with prostate cancer, according epidemiologist Marie-Élise Parent and her team of researchers at the Université de Montréal and INRS — Institut Armand-Frappier.
There are only “highly speculative” hypotheses at this point, said Parent, the lead researcher. One theory, supported by previous studies, suggests that men who ejaculate frequently are less likely to develop prostate cancer.
“A new partner over time keeps one active over the years,” Parent said. “So the presumption is that men with several partners were exposed to more ejaculations. That’s one explanation for our findings.
However, the Romeo, Lothario and Don Juans seeking a public health recommendation to have more sex to improve their health can forget that kind of seduction line right now. “We’re not there yet,” said Parent, a specialist in the field who is affectionately called Madam Prostate.
“And I would like to clarify that ‘sleeping with many women’ does not mean all at the same time. People must understand that it’s more than 20 women over a lifetime.”
The Montreal study PROTEUS (Prostate Cancer & Environment Study) questioned 3,208 men on various lifestyle factors, work and their sex lives. Of these men, 1,590 were found to have prostate cancer between September 2005 and August 2009, while the rest served as the control group.
The study published in Cancer Epidemiology, the International Journal of Cancer Epidemiology, Detection, and Prevention found that men who had slept with more than 20 women reduced their risk of developing all types of prostate cancer by 28 per cent.
They were also 19 per cent less likely to develop an aggressive form of the disease.
But that protection did not hold true for men who slept with men. Parent’s team found that having more than 20 male partners doubled the risk of prostate cancer compared to those who have never slept with a man. And their risk of getting a non-aggressive cancer was five times more likely. Sleeping with one man did not affect the risk.
On the other hand, virgins who had never experienced sex were almost twice as likely to have prostate cancer as those who did.
Researchers suggest that this is the first study to show that having many female sex partners, over a lifetime, provided significant protection against the disease, perhaps because frequent ejaculations reduce the concentration of cancer-causing substances in prostatic fluid and other structures associated with cancer.
But Parent could not explain why that does not apply to gay encounters. Perhaps because men who sleep with men engage in more risky sexual behaviour, or that anal intercourse may result in trauma to the prostate, but that’s only speculation, Parent said. More studies are needed.
The age of the first sexual encounter or the number of sexually transmitted infections had no bearing on the results.
Parent said her team was grateful to have participants who were willing to openly discuss their sex lives and preferences and, thanks to such frank discussions, it’s now possible to see that the frequency of partners affects disease development.
Parent’s study now has 4,000 men recruited and further analysis will look at the association between prostate cancer and such factors as stress, or night work and circumcision. Preliminary data suggests circumcision does offer some protection against the disease.
http://montrealgazette.com/news/local-news/sex-with-21-women-lowers-risk-for-prostate-cancer-study