Study: Men should ejaculate at least 21 times a month to reduce prostate cancer risk The key to good prostate health might be in your own hands: Ejaculating frequently may reduce your risk of prostate cancer, finds new research from the Boston University of Public Health in the United States. The study looked at how ejaculation frequency affected prostate cancer risk over the course of 18 years. It found that men ages 20 to 29 who ejaculated 21 times or more each month were 19 per cent less likely to be diagnosed with prostate cancer than those who ejaculated less often, between four and seven times per month. BENEFITS And it wasn't just young guys who saw the benefit: Men 40 to 49 who ejaculated at least 21 times per month reduced their risk of developing prostate cancer by 22 per cent. More research is needed to determine what's responsible for the link, but it might be that more frequent clearing of the prostate through ejaculation could cut the chances that tumour-triggering infections may develop there, noted study author Jennifer R. Rider, ScD, MPH The study showed a dose-dependent relationship with ejaculation and prostate cancer risk, meaning that the more you do it, the more your risk decreases, she stated. So even ejaculating just a few more times each month can likely bring some benefits to your prostate. And it doesn't matter whether you orgasm with your partner or on your own the advantages of ejaculation are seen regardless of whether you're having intercourse or just masturbating. .