Sexually predatory women were, like their male counterparts, responsible for forcing men to perform a range of sexual acts that left many of them traumatised and at risk of developing emotional problems.
Professor Michael King, of the Royal Free Hospital School of Medicine, London, who led the study, said the men were victims of "sexual crimes" and there were signs that assaults were increasing. However, shame meant that most remained silent.
The survey of 2,500 men aged over 18 found that 70 (3 per cent) said they had had "non- consensual sex". This was defined as "where a person uses force or other means so that they can do sexual things to you that you did not want them to do" or "to make you do sexual things you did not want to do".
Only seven of the cases involved male rape. The remainder included acts such as masturbation, fellatio, cunnilingus and touching of genitals. In 14 cases men were forced to have intercourse with their female assailants.
Overall, 40 of the 70 men were assaulted by a man and 32 by a woman (in two cases a man and a woman were involved).
Professor King, whose findings are published in the British Medical Journal, said that although women were 10 times more likely to be victims of sexual assault than men, they could also be sexually predatory. He said many women found the findings unpalatable, because they "took the focus off" women as "the real victims". But doctors needed to be aware that men could be victims too and the figure of 3 per cent was almost certainly an underestimate.
Although most men who report sexual molestation are heterosexual, young gay men are six times more likely to be victims of assault.
The study also looked at the childhood sexual experience of the victims with a partner who was at least five years older. Among those with consent, women were perpetrators in more than nine out of ten cases, while men were perpetrators in over eight out of ten cases without consent.
Professor King said that, contrary to the common view, boys who were child victims of sexual abuse were more likely to become adult victims rather than adult perpetrators.
Boys who had sex with older women were likely to report it as consensual and to be viewed as lucky by their peers. "But there is a lot of evidence from around the world that it is abusive because it happens too early... and they suffer emotional problems later on," he said.Reuse content