Esteemed scientists have found that regular ejaculation can significantly reduce the risk of developing prostate cancer. So this November, as well as growing a moustache to support Movember, it’s okay to be a big jerk. The Harvard study, tracking nearly 32,000 men over 18 years, found those who ejaculated 21 or more times a month had a 31 per cent lower risk of developing prostate cancer than those who did so less frequently.