2004: Long term study on links between ejaculation frequency and risk of prostate cancer:
Leitzmann MF, Platz EA, Stampfer MJ, Willett WC, Giovannucci E. Ejaculation Frequency and Subsequent Risk of Prostate Cancer. JAMA. 2004;291(13):1578-1586. doi:10.1001/jama.291.13.1578.
Results: *”Most categories of ejaculation frequency were unrelated to risk of prostate cancer. However, high ejaculation frequency was related to decreased risk of total prostate cancer… Similar associations were observed for organ-confined prostate cancer. Ejaculation frequency was not statistically significantly associated with risk of advanced prostate cancer.”*
2016: Follow up on the 2004 study:
Rider, Jennifer et al. Ejaculation Frequency and Risk of Prostate Cancer: UpdatedResults with an Additional Decade of Follow-up
Published in final edited form in European Urology, Dec 2016, Volume 70, Issue 6, Pages 974–982.
Conclusion: *”This large prospective study provides the strongest evidence to date of a beneficial role of ejaculation in prevention of PCa… More frequent ejaculation in the absence of risky sexual behaviors could represent an important means of reducing the profound medical costs and physical and psychological side effects of unnecessary diagnosis and treatment of low-risk tumors, even though it appears to be less strongly associated with aggressive disease.”*