Evidence suggests that ejaculation frequency may be inversely related to the risk
of prostate cancer (PCa), a disease for which few modifiable risk factors have been
To incorporate an additional 10 yr of follow-up into an original analysis and to comprehensively
evaluate the association between ejaculation frequency and PCa, accounting for screening,
clinically relevant disease subgroups, and the impact of mortality from other causes.
Design, setting, and participants
A prospective cohort study of participants in the Health Professionals Follow-up Study
utilizing self-reported data on average monthly ejaculation frequency. The study includes
31 925 men who answered questions on ejaculation frequency on a 1992 questionnaire and
followed through to 2010. The average monthly ejaculation frequency was assessed at
three time points: age 20–29 yr, age 40–49 yr, and the year before questionnaire distribution.
Outcome measurements and statistical analysis
Incidence of total PCa and clinically relevant disease subgroups. Cox models were
used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).
Results and limitations
During 480 831 person-years, 3839 men were diagnosed with PCa. Ejaculation frequency at age 40–49
yr was positively associated with age-standardized body mass index, physical activity,
divorce, history of sexually transmitted infections, and consumption of total calories
and alcohol. Prostate-specific antigen (PSA) test utilization by 2008, number of PSA
tests, and frequency of prostate biopsy were similar across frequency categories.
In multivariable analyses, the hazard ratio for PCa incidence for ≥21 compared to
4–7 ejaculations per month was 0.81 (95% confidence interval [CI] 0.72–0.92; p < 0.0001 for trend) for frequency at age 20–29 yr and 0.78 (95% CI 0.69–0.89; p < 0.0001 for trend) for frequency at age 40–49 yr. Associations were driven by low-risk
disease, were similar when restricted to a PSA-screened cohort, and were unlikely
to be explained by competing causes of death.
These findings provide additional evidence of a beneficial role of more frequent ejaculation
throughout adult life in the etiology of PCa, particularly for low-risk disease.
We evaluated whether ejaculation frequency throughout adulthood is related to prostate
cancer risk in a large US-based study. We found that men reporting higher compared
to lower ejaculatory frequency in adulthood were less likely to be subsequently diagnosed
with prostate cancer.