It appears that men who have a higher number of female sex partners throughout their lifetime are at a decreased risk for prostate cancer. More specifically, having sex with more than 20 women is linked to a 28 percent lower prostate cancer risk.
The finding comes from new research out of the University of Montreal. For the study, over 3,000 men in the Montreal area answered a questionnaire that was partially focused on sexual activity. Another interesting twist researchers found was that when compared to men who had never slept with another man, men who had more than 20 male partners in a lifetime were twice as likely to be diagnosed with prostate cancer at some point in their lives.
“This is the first study, to the best of my knowledge, that has looked at the differential between having had female partners versus male partners,” said Marie-Elise Parent, a professor at the university’s School of Public Health. “In the past, there have been a few studies that have looked at the number of partners, but they were not looking at the gender.”
It appears that having several female partners over a lifetime might be protective against prostate cancer, while having several male partners could be harmful. Parent says these findings were both surprising and puzzling. But she clarified that the study only included a small population of men in the Montreal area who’d reported having sex with men, which makes the statistics weaker.
The reasons behind the findings remain elusive at this point.
“It’s totally speculative, but I think what we’re seeing here might be in line with another observation from a group in the U.S. that has observed that having a high frequency of ejaculation is protective,” said Parent. “So it could mean that having had several female partners over a lifetime is sort of an indicator of high sexual activity over a prolonged period.”
The only other drawback of the study, according to Parent, was that it did not account for masturbation.