Oestrogen therapy after
menopause may help reduce the memory problems associated with stress in some
older women, a small new study suggests.
"Those higher levels
of oestrogen are related to less release of stress hormone after a stressful
event," said study researcher Alexandra Ycaza, a doctoral candidate in
psychology at the University of Southern California.
Ycaza is scheduled to
present the findings at the annual meeting of the Society for
Neuroscience, in San Diego.
The use of
hormone-replacement therapy after menopause declined sharply in the United
States after a clinical trial looking at oestrogen and progestin therapy was
halted in 2002. The researchers found that the benefits (reductions in colon
cancer, hot flashes and hip fractures) were outweighed by the risks (heart
attack, stroke and blood clots).
Many experts recommend that
women in menopause take the lowest dose of hormone therapy possible for the
briefest time only if they are having bothersome symptoms.
Stressful situation
For the study, Ycaza
evaluated women who were part of a larger study that looked at the differences
between taking hormone-replacement therapy soon after menopause versus later,
as well as the therapy's effect on the cardiovascular system.
That study assigned women
to one of two groups that taking hormone replacement and those not and then
followed them for nearly five years. For her research, Ycaza focused on 42 of
these women.
In random order, she
exposed them either to a stressful situation putting their hand in ice water
for three minutes or a non-stressful situation. During each of the sessions,
she measured levels of oestrogen and the stress hormone cortisol.
After each situation, the
women took tests to gauge their working memory, such as remembering lists of
words while reading sentences and making decisions on whether sentences were
grammatically correct.
Ycaza looked at the
performance and then looked to see if oestrogen and cortisol levels were a
factor. "Our women in the bottom level [of oestrogen] showed a decrease in
the number of words they could remember after the stressful [situation]," she
said.
They remembered about 50%
of the words after being stressed. "If they are not being stressed, they
remember about 60%."
The higher-oestrogen women
remembered 55% of the words each time, whether stressed or not before the test.
The cortisol levels of the
lower-oestrogen women doubled from before the stressful exposure to after. The
cortisol levels in the higher-oestrogen women increased very little after the
stressful exposure.
Other approaches
It wasn't known in the new
study which women were taking hormone-replacement therapy. The research did not
prove a cause-and-effect relationship between a woman having higher hormone
levels and not having a reduction in memory.
Older women can turn to
other approaches besides hormone therapy to protect memory, said Dr James
Burke, director of the Memory Disorders Clinic at Duke University Medical Centre,
in Durham, NC Burke was not part of the study.
"Research generally
supports daily exercise, intellectual stimulation, social engagement and a
Mediterranean diet," Burke said.
"The results are
intriguing, but the study was small," he said. The ice-water plunge, he
added, "is not the same as real-life stressors."
Another expert said hormone
treatment would only be viable for certain women.
"The established risks
of hormone-replacement therapy for the average post-menopausal woman are not
worth the potential benefits," said Dr Gary Kennedy, director of geriatric
psychiatry at the Montefiore Medical Centre in New York City, who reviewed the
study findings. "However, for that minority of women who are experiencing
severe symptoms, it is worth the risk to maintain function."
Exercise would help women
withstand the effects of stress, he said.
The study received funding
from the US National Institute on Ageing. Because it was presented at a medical
meeting, the conclusions should be viewed as preliminary until published in a
peer-reviewed journal.
More information
To learn more about hormone
therapy studies, try the US National Institutes of Health.
