Frequent ejaculation has been linked with a significantly lower risk of prostate cancer; but is that a link of causation or correlation? Well… science isn't yet sure.
The headline-making 2016 study was published in the medical journal European Urology. Scientists followed 32,000 American men over the course of 18 years, tracking via survey their ejaculation frequency and the rate at which they developed prostate cancer. There had been smaller previous studies and conjecture on the linkage, but this was by far the largest study done.
The results were stark: men who ejaculated an average of at least 21 times per month were diagnosed with prostate cancer at a rate of 20% lower than men who ejaculated 4-7 times per month.
But what does this mean? Well, science doesn't have that answer yet.
The question of correlation or causation is up in the air because of the prostate's role in ejaculation. The prostate and its associated seminal vesicles are responsible for the bulk of the fluid production that goes into semen (the testicles only produce sperm cells, which make up just 5-10% of semen volume). Unlike the testicles, which continually produce sperm without respect to ejaculation frequency, the prostate and seminal vesicles are more responsive to sexual activity. It takes the seminal vesicles three days to refill their fluid reservoirs, so frequent ejaculation keeps emptying them and forcing continued production.
Does that mean that frequent ejaculation keeps the prostate active and reduces the odds of developing cancer? Or is it something else like hormones driving a higher libido and thus more frequent urges to ejaculate while separately lowering the risk of prostate cancer? Is it just genetic predisposition?
It's also not known if the setting of the ejaculation matters — the study didn't differentiate between masturbation, sex, or nocturnal emissions (wet dreams). As far as the scientists were concerned, if you came then it counted.
So does frequent ejaculation actually reduce the risk of prostate cancer? Maybe. Further study on the subject is warranted. In the meantime, feel free to cum regularly; it can't hurt, and it just so happens to feel good!