How does ejaculation frequency affect rates of prostate cancer?

Ejaculation Frequency and Prostate Cancer Risk

Higher ejaculation frequency is associated with a reduced risk of prostate cancer, with men who ejaculate 21 or more times per month experiencing a 19-33% lower risk compared to those ejaculating 4-7 times per month, particularly for low-risk, organ-confined disease. 1

Magnitude of Protective Effect

The protective association is most robust when examining ejaculation frequency during middle age and throughout adult life:

• Men with ≥21 ejaculations per month at ages 40-49 years have a 22% reduced risk (HR 0.78,95% CI 0.69-0.89) compared to those with 4-7 ejaculations per month 2
• At ages 20-29 years, the same comparison yields a 19% risk reduction (HR 0.81,95% CI 0.72-0.92) 2
• When averaged across a lifetime, high ejaculation frequency confers a 33% risk reduction (HR 0.67,95% CI 0.51-0.89) 3

The protective effect remains consistent even after accounting for PSA screening practices, with similar rates of PSA testing and prostate biopsy across ejaculation frequency groups. 2

Disease-Specific Associations

The benefit is predominantly seen for low-risk, organ-confined prostate cancer rather than aggressive disease:

• The inverse association is driven primarily by low-risk disease 1, 2
• For organ-confined cancer specifically, the protective effect remains statistically significant 3
• Advanced prostate cancer shows no statistically significant association with ejaculation frequency 3

However, one case-control study from Spain found contradictory results, suggesting that low ejaculation frequency (0-3 times per month) in the year before diagnosis was associated with higher risk, particularly for aggressive disease (ISUP 3-5: OR 2.76) and locally advanced-metastatic tumors (OR 4.70) 4. This represents the inverse perspective of the same relationship and may reflect reverse causation, where early disease symptoms reduce ejaculation frequency.

Biological Mechanisms

The protective effect operates through androgen receptor regulation and 5α-dihydrotestosterone (DHT) concentration modulation in the prostate: 1

• Ejaculation increases androgen receptors at the ventral prostate as the first elevated response 5
• The 5α-DHT:AR complex interacts with DNA enhancer elements to regulate androgen-specific target genes and maintain prostate homeostasis 5
• Frequent ejaculation may prevent accumulation of potentially carcinogenic secretions or inflammatory mediators in prostatic ducts 2

Clinical Implications and Caveats

This association does not translate into a formal screening or prevention recommendation, as the impact on prostate cancer mortality remains unknown: 6

• The protective effect is not sufficient to modify current screening guidelines, which focus on PSA testing and digital rectal examination 6
• For PSA testing specifically, results are more reliable if the patient has abstained from ejaculation for 48 hours; if not met and PSA is marginally elevated, repeat testing after 48 hours of abstention is reasonable 6

Important methodological consideration: Most evidence comes from prospective cohort studies that rely on self-reported ejaculation frequency, which may be subject to recall bias, though prospective designs minimize this concern compared to case-control studies. 2, 3 The one case-control study showing opposite results 4 may suffer from reverse causation bias, where undiagnosed prostate cancer or urinary symptoms reduce ejaculation frequency before diagnosis.

Practical Guidance

While frequent ejaculation appears protective, this should not be promoted as a primary prevention strategy given:

• The effect size is modest (19-33% relative risk reduction) 1, 2
• No data exist on whether this translates to reduced prostate cancer mortality 6
• The association may not be causal, and confounding factors cannot be entirely excluded 7
• Risky sexual behavior must be avoided to prevent sexually transmitted infections 5

The evidence supports counseling men that frequent ejaculation in the absence of risky sexual behavior is unlikely to increase prostate cancer risk and may confer modest protection, particularly against low-risk disease. 1, 2