The study that is hyperlinked in this article takes you to a blog post on the Harvard Medical School Prostate Knowlegde blog. They didn't do the study, but they wrote a post about two studies that were conducted on the topic and gave references, which made it nice to follow. After reading the two studies, i found that this title tends to be misleading in its statement. Both studies conducted found that men who ejaculate more than either 7 times per week or more than 21 times a month have a decreased risk of prostate cancer. To me, this is not regular orgasms, that amount seems to be on the higher end for most people and hard to continue through out your life. In conclusion, yes, more ejaculations can reduce your risk of prostate cancer, but the amount needed is high and must be started at a young age to fully reap the benefits.

APA References:

Giles, G.G., Severi, G., English, D.R., McCredie, M.R.E., Borland, R., Boyle, P., & Hopper, J.L. (2003). Sexual factors and prostate cancer. BJU International, 92(3), 211-216.

Leitzmann, M.F., Platz, E.A., Stampfer, M.J., Willett, W.C., Giovannucci, E. (2004). Ejaculation frequency and subsequent risk of prostate cancer. JAMA: Journal of the American Medical Association, 291(13), 1578-1586.

Links: http://jamanetwork.com/journals/jama/fullarticle/198487?=quot;,gt;

http://onlinelibrary.wiley.com/doi/10.1046/j.1464-410X.2003.04319.x/full