Dimitropoulou, P. et al. Sexual activity and prostate cancer risk in men diagnosed at a younger age. BJU Int. 103, 178–185 (2009).

A new study has found a positive correlation between increased sexual activity in men in their 20s and 30s and risk of prostate cancer. Dimitropoulou and colleagues, who investigated both intercourse and masturbation, also found that sexual activity seemed to protect against prostate cancer in men in their 50s.

“...men with a high sex drive have increased levels of male hormones ... which has been linked to ... prostate cancer”

Sexual activity has been associated with risk factors for prostate cancer in a number of studies, but the mechanisms involved are unknown. Some research has suggested that men with a high sex drive have increased levels of male hormones, such as androgens, which has been linked to an increased risk of prostate cancer.

Dimitropoulou et al. carried out a case–control study to examine the association between frequency of sexual activity and prostate cancer risk. The researchers obtained information on intercourse and masturbation and assessed these factors individually and in combination (overall sexual activity), in 431 men diagnosed with prostate cancer before the age of 60 years, and in 409 men selected as controls. Information on lifestyle and sexual activity throughout adult life was collected by means of a postal questionnaire. Data collected included age at which the men first became sexually active, number of sexual partners, any sexually transmitted infections, and how often the men masturbated and had intercourse in their 20s, 30s, 40s and 50s.

Frequency of sexual activity decreased with increasing age in both cases and controls; however, more men with prostate cancer fell into the highest frequency of sexual activity groups in each decade. The authors report that 40% of the men with prostate cancer were categorized as being very sexually active (20 or more times a month) in their 20s, compared with 32% of men in the control group. Similar patterns were seen for men in their 30s and 40s, but the differences had evened out between the two groups (reduced frequency of overall sexual activity) for men in their 50s.

Frequency of masturbation was notably higher in men with prostate cancer than in the controls. The greatest differences were observed for men in their 20s and 30s, with 34% versus 24% and 41% versus 31% (cases versus controls), respectively, falling into the highest frequency range. The researchers observed that for men in their 50s, there was evidence of an inverse association between prostate cancer and masturbation and overall sexual activity. Dimitropoulou and colleagues hypothesize that, for men in this age group, the release of accumulated toxins during sexual activity reduces the risk of developing cancer in the prostate area. However, the possibility that prostate cancer is a causal factor of reduced sexual activity in this age group could not be ruled out.