Another Win for Estrogen Therapy: May Help Prevent Alzheimer's Disease
WebMD News Archive
Researcher Robert Greene, MD, tells WebMD that he believes the blood flow
decreases are a "triggering event" for Alzheimer?s -- meaning that they
may contribute to onset of the disease. When the brain doesn?t receive enough
blood, minor injuries occur that can lead to death of the brain cells and aging
of certain nerves in the affected area.
Greene is a reproductive endocrinologist at The North State Women's Center
in Redding, Calif.
Greene and his colleagues conducted a study involving 12 healthy menopausal
women who were experiencing daily hot flashes. Blood flow was measured when the
women were feeling "normal" -- not experiencing hot flashes -- and when
hot flashes were occurring. The measurements were taken again after the women
had received 6 weeks of treatment with either estrogen or a non-active pill
The researchers found that blood flow declined substantially during hot
flashes -- a time when all the women in the study showed blood-flow patterns
similar to those found in patients with Alzheimer?s. The women who took the
estrogen had an average 22% increase in cerebral blood flow compared with the
placebo group. The largest increase was in the left temporal region, which is
typically affected by Alzheimer?s disease.
Brain function also improved for the women who took estrogen, but the
increase was not considered significant. In an interview with WebMD, Greene
says, "The suggestion of this data is that ERT might help diminish" the
cell death and nerve aging that lead to Alzheimer?s disease. He hopes to obtain
further, more solid results when he repeats the study with 100 women who will
be studied for 3 months.
In the meantime, Greene says that physicians and researchers should keep the
study?s findings in mind when treating postmenopausal patients, since women are
three times more likely than men to develop late-onset Alzheimer?s. At the very
least, Greene says that physicians need to consider the possibility that hot
flashes are clinically important and not just a nuisance. The risks of brain
harm would be especially great in women who experience hot flashes for many
years, he notes.
Jennifer Larsen, MD, chief of endocrinology at the University of Nebraska
Medical Center, Omaha, tells WebMD that Greene is among a growing number of
researchers "who have suggested that vascular changes contribute to
Alzheimer's." But she cautions that Greene?s study does not contain enough
data to draw major conclusions.
It will not be easy to show that estrogen has an effect on brain function in
postmenopausal women, according to Larsen, because some changes may be due to
other factors. For example, Larsen days, "these women may appear to have
better cognitive function because they sleep better at night once they stop
having hot flashes."