HLNYC Home > News > Fitness

Frequency of Ejaculation Unrelated to Prostate Cancer Risk

While researchers still do not know what exactly causes prostate cancer, the second-leading cause of cancer death in men, a study in this week’s issue of the Journal of the American Medical Association (JAMA) lets ejaculation off the hook. 

By: Michael Long

4-7-04

According to the Centers for Disease Control and Prevention, prostate cancer is the second leading cause of cancer death in men in the United States and is the most commonly diagnosed form of cancer in men other than skin cancer.  In 2004, the American Cancer Society estimates that over 230,000 American men will be diagnosed with prostate cancer and over 29,000 will die from the disease.  Despite its deadly toll on society, scientists are still undecided on what causes the disease and how to best prevent it in the first place. 

Until this week, mainstream scientists have assumed that increased ejaculation was associated with prostate cancer risk, supporting the widespread belief that masturbation is bad for your health  This assumption was based mainly on the theory that high levels of testosterone lead to increased sex drive and, possibly, to prostate tumor cell growth.  Other theories held that higher rates of sexual activity may lead to exposure to infectious agents, which may increase the risk of prostate cancer, although this link has not been proven.

Other scientists held that decreased ejaculation may actually lead to higher rates of prostate cancer due to the retention of chemicals and other carcinogens in the prostate fluids.  By removing these fluids often, these scientists theorized, prostate cancer may be reduced. 

A new study published this week in the Journal of the American Medical Association (JAMA), found that increased lifetime ejaculation rates (including sexual activity, masturbation and nocturnal emission) are not related to increased prostate cancer risk, and may actually reduce the risk of prostate cancer. 

In 1992, investigators for the Health Professionals Follow-up Study, a prospective study of health risks and chronic disease in 51,529 predominantly white health professionals aged 40-75, mailed questionnaires to study members asking them to report ejaculation frequency in their 20’s, 40’s and within the last year. 

Every two years, study members were asked whether they were diagnosed with prostate cancer and medical records were reviewed to determine positive diagnosis of prostate cancer, with subsets for organ-confined prostate cancer and more advanced cancer that had spread to the surrounding tissue.

The study, led by Michael F. Leitzmann, MD, of the National Cancer Institute, found surprisingly that increased rates of lifetime ejaculation were not associated with increased risk of total prostate cancer. 

To calculate a relative risk (RR) of diagnosis with prostate cancer, investigators compared prostate cancer diagnosis to a reference population.  To remove other risk-factors for prostate cancer from the analysis, the study controlled for race, family history of disease, vasectomy, body mass index at 2, height, history of smoking, history of type 2 diabetes, physical activity, and intake of total energy, calcium, fructose, vitamin E supplement, zinc supplement, red meat, tomato-based foods, fish, alpha-linolenic acid and alcohol.

In their article, the authors report, “When the entire range of ejaculation frequency was analyzed as a continuous variable in the multivariate model, each increment of 3 ejaculations per week across a lifetime was associated with a 15% (95% CI, 4%-24%) decrease in risk of total prostate cancer.”

Oddly, when advanced prostate cancer was considered the results did not support a clear relationship between increased ejaculation frequency and decreased cancer risk.  Study authors report, “In contrast to the results for total and organ-confined prostate cancer, the intermediate categories of ejaculation frequency at ages 40 to 49 years were associated with a lower risk of advanced prostate cancer.”  However, there were not enough cases of advanced prostate cancer to measure its relationship to lifetime ejaculation frequency. 

So, while there are still some questions about whether increasing ejaculation frequency can reduce your risk of prostate cancer, this study proves conclusively that lifetime ejaculation frequency is not related to an increase in prostate cancer risk. 

On behalf of the many men in this country, thank you Dr. Leitzmann and colleagues, for clearing this one up.

References:

“Ejaculation Frequency and Subsequent Risk of Prostate Cancer,” Journal of the American Medical Association.  Vol. 291 No. 13, April 7, 2004.

http://jama.ama-assn.org/cgi/content/abstract/291/13/1578

“Cancer Prevention and Control,” National Center for Chronic Disease Prevention and Health Promotion. Centers for Disease Control and Prevention.  Accessed on July 6, 2004. 

http://www.cdc.gov/cancer/prostate/index.htm

“Cancer Statistics Presentation 2004,” American Cancer Society.  Accessed on July 6, 2004. 

http://www.cancer.org/docroot/STT/stt_0.asp