Does Sexual Activity Affect My Risk
What does sex have to do with prostate
cancer? Could a man’s sexual activity have any repercussions—one way or
the other—on his risk of getting prostate cancer?
In the past, scientists considering
this question have come up with good but conflicting theories, says epidemiologist
Elizabeth A. Platz, Sc.D. Some researchers speculate that men who have
sex more often “may be more likely to acquire a sexually transmitted disease,
which may infect the prostate, cause inflammation and other damage, and
increase the risk of prostate cancer.” (For more on the growing link between
inflammation and prostate cancer, read
story ) Another thought is that men who have sex more often have a
higher sex drive, because of a higher level of male hormones—which, in
turn, may increase the risk of prostate cancer.
But other researchers believe that sexual
activity may actually decrease the risk of prostate cancer—that regular
ejaculation, if you will, “cleans house” in the prostate, making it a
less welcome harbor for cancer-causing agents, infection, and stagnant
materials that could lead to inflammation.
Previous studies have been inconclusive,
notes Platz, but “taken together, they hint that men who have more sex,
or who have had a sexually transmitted disease, are more likely to have
Platz and her colleagues at Harvard
and the National Cancer Institute were unconvinced. As part of a massive
study, led by epidemiologist Michael Leitzmann at Harvard, they recently
studied nearly 30,000 men participating in the Health Professionals Follow-up
Study. Most of these men were white and middle-aged, and very few had
ever had a sexually transmitted disease. “In 1992, we asked the men who
did not have prostate cancer to report their typical number of ejaculations
per month in their twenties, forties, and during the past year,” says
| Could a man’s sexual
activity have any repercussions—one way or the other—on his risk of
getting prostate cancer?
Over the next eight years, nearly 1,500
of these men went on to develop prostate cancer.
The scientists found that men who reported
more ejaculations—more than 21 a month, on average across their adult
life—had twothirds the lifetime risk of prostate cancer of men who reported
fewer (4 to 7) ejaculations a month. Notes Platz: “Compared with men reporting
fewer ejaculations per month at all ages, men who reported 21 or ejaculations
per month had one-fourth the risk of prostate cancer.”
Certain important features of this study
make these observations more credible, she adds. One is the sheer number
of men involved; another is “the fact that the men reported their ejaculation
frequency well before they were diagnosed with prostate cancer.” Also,
the scientists were able to rule out such factors as a man’s history of
sexually transmitted diseases, which could have clouded the results.
Another recent study of many men, with
and without prostate cancer, has produced similar findings, says Platz.
“Based on these two large, well-conducted studies, men should not be worried
that frequent ejaculation will cause prostate cancer.” The next step,
she adds, is to figure out why frequent ejaculation seems to have this
protective effect, and the role inflammation plays here.