Keenan: Harvard study will appeal to men wanting to lower prostate cancer risk

Modern medicine is full of well-intentioned prohibitions. Don’t eat this food, it’s bad for your heart. Don’t have that second glass of wine, it runs afoul of new national guidelines. So, it’s both noteworthy and delightful when something that is pretty universally regarded as pleasurable pops up on the good things list. Gentlemen, this is for you.

Several studies have shown that having frequent ejaculations, especially in young adulthood, is correlated with a reduced risk of prostate cancer later in life. Researchers in the Harvard-based Health Professionals Follow-up Study have tracked over 50,000 American men since 1986. The group is mainly white and includes dentists, pharmacists, veterinarians, optometrists, ophthalmologists, and podiatrists.

One of the tantalizing questions these men were asked is how many ejaculations they have per month. Over 30,000 answered that question, and the results showed that, as expected, ejaculation frequency decreased with age. The proportion of men reporting 13 or more ejaculations per month was 57 per cent for the 20–29-year-old respondents and “dropped to 32 per cent at age 40–49.”

Writing in the journal European Urology, Harvard researchers led by Jennifer R. Rider “found that men reporting higher compared to lower ejaculatory frequency in adulthood were less likely to be subsequently diagnosed with prostate cancer.” As explained in the Harvard Health Letter, “Compared to men who reported four to seven ejaculations per month across their lifetimes, men who ejaculated 21 or more times a month enjoyed a 31 per cent lower risk of prostate cancer.”

An Australian study found similar results and, like the Harvard study, noted that high ejaculatory frequency in young adulthood was especially beneficial in preventing prostate cancer later in life. In both studies, all ejaculations were counted, regardless of how they happened. Yes, even wet dreams were included.

It’s important to note that these studies show a correlation, not a causal mechanism. Other factors may well be at play. However, the Harvard researchers did their best to control for factors like body mass index, diet, smoking, and having had a vasectomy. They even asked the men about their intake of processed meat, tomato sauce, and alcohol.

Interestingly, the men with the highest ejaculation frequency at age 40-49 were also the biggest eaters, smokers, and drinkers. The authors considered that these guys were dying prematurely from causes like heart disease and lung cancer. However, after crunching the numbers, they concluded that “the reduction (of prostate cancer) among men reporting high ejaculation frequency seemingly cannot be explained by this effect alone.”

Aside from the future risk of prostate cancer, there are some other consequences of ejaculatory frequency. A study published in Andrology tackled the question of ejaculatory abstinence (EA) on sperm quality. As might be expected, “Increasing ejaculatory abstinence length was positively correlated with semen volume, sperm concentration, total sperm count, (and) total motile sperm count.” However, holding it in too long was also correlated with an increased DNA fragmentation rate, which can impair fertility.

This study was done at a Brazilian in vitro fertilization clinic, where the goal is a healthy pregnancy. The authors concluded that “one day of EA significantly improves implantation rate and tends to increase pregnancy rate, compared to 2, 3, and 4 days of EA.”

There may be other factors to consider in ejaculation frequency. A 2003 study found that EA is related to testosterone levels. Ming Jiang and colleagues from the Hangzhou Normal College found that there is a sweet spot in raising those levels. “Fluctuations of testosterone levels from the 2nd to 5th day of abstinence were minimal,” they write. “On the 7th day of abstinence, however, a clear peak of serum testosterone appeared, reaching 145.7 per cent of the baseline.”

Advertisers of pricey supplements have done a great job of pitching the advantages of boosting testosterone levels to men around the world, though experts I have consulted say most men don’t need them. Still, if there is a safe and natural way to boost your energy levels, sex drive, and even hair follicles, this could be worth a try.

It’s also worth knowing that there is a whole body of Eastern knowledge concerning ejaculation frequency and control called Tantric Sex. Perhaps the most entertaining essay on this was by New York-based writer Peter von Ziegesar, published on aeon.com under the heading “Anti-climax.”

This guy and his wife travelled to Thailand for an “Eastern secrets of love” conference in 2014. I won’t spoil the whole story except to say that the experience included a young guy disrobing and demonstrating ejaculation control. The organizer of the conference claims that “tantric arousal reaches a scale of 10, while normal intercourse seldom rises above a six.”

Clearly, men do not open a spreadsheet at the start of the month to plot out their ejaculation schedule, nor should they. Still, it’s good to know that something that’s fun is also likely to be good for our health.

Dr. Tom Keenan is an award-winning journalist, public speaker, professor in the School of Architecture, Planning and Landscape at the University of Calgary, and author of the best-selling book Technocreep: The Surrender of Privacy and the Capitalization of Intimacy.