We've had half a dozen posts recently about the idea of semen retention, so I thought I would share something I wrote 4 years ago on another sub about the medical disadvantages:

I was looking for this journal article, Ejaculation Frequency and Risk of Prostate Cancer: Updated Results with an Additional Decade of Follow-up and found only an abstract. So I did a quick search and found this article about it which provides more information and is more readable:

• Study: Ejaculate More, Have Less Prostate Cancer Risk

Compared with men who ejaculated four to seven times per month, men who ejaculated eight to twelve times per month had 10% less risk of cancer, men who ejaculated thirteen to twenty times per month had 20% less risk of cancer, and men who ejaculated twenty-one times or more per month had 30% less risk of cancer.

The researchers speculate what could be at work, mechanically, and offer one explanation: the prostate might accumulate potentially carcinogenic secretions that can lead to prostate cancer. This idea, known as the prostate stagnation hypothesis, has been around for decades, Dr Rider reported.

That theory might have parallels in folk wisdom. When these results were reported last year, a Medscape reader commented that the results make common sense, and urged his fellow male readers to "keep the pipes clean boys!"

It's worth noting that the prostate doesn't store semen, most of which is produced on demand by the seminal vesicles and several other glands. What collects in the prostate is "prostatic fluid - an alkaline fluid secreted by the prostate gland" that constitutes about 30% of semen by volume.

I am not a doctor or a cancer expert, just a moderately informed one-time bio major, but my own personal theory on why ejaculation reduces cancer risk is that the important factor is not the presence of a carcinogen, but the absence of a mild anti-cancer property of prostatic fluid. Specifically, "old" prostatic fluid gradually loses pH, becoming less alkaline and slightly acidic over time. And we know that cancer cells are typically acidic and grow less well in even a mildly alkaline environment.

As Constantine Kaniklidis, a breast cancer researcher, put it:

the extracellular pH (pHe) of malignant solid tumors, including breast cancer, is acidic, in the range of 6.5 to 6.9, whereas the extracellular pH of normal tissues is significantly more alkaline, in the range of 7.2 to 7.5.

So my guess is that failing to ejaculate regularly lets the prostatic fluid get old. As it ages, it becomes less alkaline and therefore less inhospitable toward any cancer cells that appear. Ejaculating often maintains the alkalinity in the prostate and prevents that from happening.

tl;dr:

Guys, if anyone tells you you're cumming too much, or tries to shame you about masturbating when you're in a relationship, or tries to give you the old Taoist BS about ejaculation being bad for your health, you now have the perfect answer. Frequent ejaculation is good for you!