NEW YORK, Jan 31 (Reuters Health) -- Could testosterone supplements help
prevent Alzheimer's disease? It is possible, according to results of a new study
in which researchers exposed nerve cells to the male hormone.
In the presence of testosterone, nerve cells collected from rats and mice
tended to produce a harmless or beneficial form of beta-amyloid protein rather
than the form that makes up plaques in the brains of Alzheimer's disease
patients.
"The testosterone directs the metabolism so that much more goes to the
good pathway and much less to the bad pathway," study co-author Dr. Paul
Greengard said in an interview with Reuters Health. "In other words, you get
much less beta-amyloid peptide and you get more of this secretory beta-amyloid
precursor protein, which is considered by most people to be beneficial for the
health of the nerve cells," he added.
Greengard, of The Rockefeller University in New York, and colleagues
published their findings in the February 1st issue of Proceedings of the
National Academy of Sciences.
While the findings do not necessarily apply to the treatment of humans --
the brain being a much more complex system than a laboratory culture dish -- the
new findings suggest that testosterone may be helpful in preventing Alzheimer's
disease, according to the report.
Some studies have indicated that women who take estrogen replacement
therapy after menopause have a lower risk of the memory-robbing disorder. And
Greengard and colleagues have also shown previously that estrogen has a similar
effect on nerve cells from humans and animals.
"In older men and in older women, there's a decrease in the level of
testosterone, so the thought is that one might do some trials of testosterone in
aging men to see whether it would reduce the incidence of Alzheimer's disease as
estrogen appears to do in women," Greengard said.
"In addition, since women need both estrogen and testosterone, instead of
just using estrogen in the treatment of postmenopausal women, the thought is to
try to combine estrogen and testosterone," he added.
However, the authors caution that testosterone treatment is not without
risks. "These possible benefits must be weighed against potential deleterious
effects of testosterone, including the development of prostate cancer in men and
endometrial cancer in women," they write.
