Men without foreskins have lower rates of human papillomavirus (HPV) and herpes, according to a study in the New England Journal of Medicine. A group of uncircumcised Ugandan men were enrolled in the study, and half were randomly selected to go under the knife. Two years later, the newly snipped men were 25 percent less likely to have contracted herpes and 36 percent less likely to have HPV.

The reason is probably a combination of two factors, says study author Dr Ronald Gray. “The underside of the foreskin has less of a protective layer of protein than regular skin, and there’s a moist cavity under the foreskin that might harbour the viruses longer.

Circumcision removes the vulnerable tissue as well as the moist environment.”