Chicago’s Northwestern University in fact found just such a link. Apparently men with Primary Progressive Aphasia (PPA), a fairly rare condition evidenced by steady loss of language skills, are 40% likely to have undergone a vasectomy.
The general male populace has a 16% rate of vasectomies.
Looks like a link. Caution, of course, with all these studies–small pool (104 men sampled), etc, etc. The study found no such link with regard to Alzheimer’s sufferers.
What causes the link? Sandra Weintraub, PhD, theorizes that the vasectomy may breach a protective barrier between the bloodstream and testes, exposing sperm to the bloodstream. This in turn causes the body to produce “anti-sperm antibodies,” which may damage the brain. Just speculation at this point, of course. We’ll see if those 104 men are totally unrepresentative of the entire male populace.
Of course, you ALL can just go get vasectomies (assuming, you know) and we’ll see if the dementia rates shoot up.