NEW YORK, Jun 12 (Reuters Health) - Despite high hopes that estrogen might
slow down the mental decline of Alzheimer's disease, a new study has failed to
find any such benefits of the female sex hormone. Compared with women taking a
placebo pill that did not contain any hormones, women who took estrogen
supplements were no more likely to have their memory improved or restored,
researchers report.
Though the results are disappointing, they do not necessarily rule out a
role for estrogen in either the treatment or prevention of Alzheimer's disease,
according to the study's authors. Estrogen may turn out to be beneficial when
used in combination with other drugs, according to a team of researchers led by
Dr. P.N. Wang, of the Taipei Veterans General Hospital in Taiwan. Or it is
possible that estrogen may help stave off the development of Alzheimer's when
taken before symptoms of the memory-robbing disease begin.
In the study, 50 women with Alzheimer's were randomly assigned to a daily
dose of an estrogen/progestin supplement (Premarin, Wyeth-Ayerst) or (an
inactive) placebo. The Asian division of Wyeth-Ayerst provided the hormones and
placebo used in the study.
After 12 weeks, women taking estrogen did not perform significantly better
on tests of memory, concentration and other intellectual skills, the researchers
report in the June 13th issue of Neurology. In addition, physicians failed to
detect any differences when they examined the participants.
The findings conflict with several previous studies that found that estrogen
supplements helped improve dementia in women with Alzheimer's disease. But all
of these studies were small, and in most of them, women and their doctors knew
whether they were taking estrogen, the report indicates. In this study, neither
the doctors nor patients knew which women were taking estrogen until the study
was completed.
But the study is not the final word on estrogen and Alzheimer's, according
to the study's senior author. "Although we had more subjects than previous
studies, 50 is probably not enough," Dr. Hsiu-Chih Liu, said in a statement
issued by the journal. "Moreover, it may require a longer period, such as one
year, to produce a significant effect."
In an editorial that accompanies the study, Drs. Karen Marder and Mary Sano,
of Columbia University in New York, point out that this is the third study
published this year that has failed to show that estrogen improves mental
function in women with Alzheimer's disease.
A better understanding of estrogen's effects on the brain might be gained by
studying its effects throughout the life, rather than after symptoms begin,
according to Marder and Sano. Perhaps the decline in estrogen levels that occurs
during menopause makes the brain susceptible to the effects of Alzheimer's
disease, they suggest.
"In the meantime, the results of randomized clinical trials do not support a
role for estrogen in the treatment of Alzheimer's disease," the editorialists
state, although they point out that individual women may choose to take estrogen
based on its other benefits, which include an ability to protect against
osteoporosis.
