Study Suggests Vasectomy-Dementia Link
Ties to Rare Form of Dementia Seen in Early Research Must Be Confirmed
Feb. 22, 2007 -- Having a vasectomy may increase a man’s risk of developing
a rare form of dementia, early research suggests, although more study is needed
to confirm the finding.
Researchers at Chicago’s Northwestern University found that men with a
neurological condition known as primary progressive aphasia, or PPA, were more
likely to have had the sterilization surgery than men without the disorder.
PPA is a rare condition characterized by a steady loss of language
It primarily occurs after age 50. Those with the disorder have
increasing difficulty expressing themselves and understanding speech.
“We definitely aren’t saying that having a vasectomy causes this condition
or that men should not have vasectomies,” researcher Sandra Weintraub, PhD,
tells WebMD. “It is way too early for that. We need to do more research to
Vasectomy and PPA
Weintraub, a professor of neurology and psychiatry at the Northwestern
Feinberg School of Medicine, says she began investigating a possible link
between PPA and vasectomies after a 43-year-old patient asked her if his
sterilization surgery might be linked to his PPA.
He discussed the issue at a support group meeting of men with dementia, and
it turned out that eight of the nine men in the room with PPA had had
“That is when we decided to do a systematic investigation, but it took some
time because this is not a common disease,” Weintraub says.
The researchers surveyed 47 men with PPA undergoing treatment at
Northwestern’s Cognitive Neurology and Alzheimer’s Disease Center and 57 men
without dementia who were volunteers from the community. All the men were aged
55 to 80.
The researchers concluded that more than twice as many men with PPA had
undergone vasectomies as men without the dementia -- 40% vs. 16%.
In other preliminary research, Weintraub and colleagues found no difference
in vasectomy rates between patients with Alzheimer’s disease and men without
Why Vasectomy May Increase Dementia Risk
Weintraub theorized that vasectomy may raise the risk of the rare dementias
by breaching the protective barrier between the bloodstream and the testes.
When that barrier is broken, as occurs with vasectomy, sperm become exposed
to the bloodstream. In response, many men who have had the surgery produce
These antibodies may affect the brain, causing damage which can lead to
But this is only speculation, and Weintraub says she hopes to conduct much
larger studies to better understand the issue.
American Urological Association spokesman Ira Sharlip, MD, agrees that few
conclusions can be drawn without such studies.
He points to earlier concerns about vasectomies, including research in the
1980s suggesting an increased risk of atherosclerosis in men who had undergone
the procedure, and research in the 1990s suggesting a link between vasectomy
and prostate cancer.
None of those concerns turned out to be valid, Sharlip says.
Sharlip is a clinical professor of urology at the University of California,
“There have been many large, epidemiological studies comparing vasectomized
and nonvasectomized men, and none of them have shown any health risks
associated with vasectomy,” he says.
“Vasectomy is the single most reliable form of birth control that exists. I
would hope that men would not be frightened by this study, which is very
preliminary,” says Sharlip.