Post-menopausal women undergoing estrogen treatment may get the added bonus of improved memory, say researchers.
A study at the Yale University School of Medicine of 46 post-menopausal women found that estrogen increased activity in regions of the brain associated with memory.
Researchers say that estrogen might stimulate the brain to make the type of neural connections typically seen in younger people. They believe that the increased brain activity should mean an accompanying improvement in memory function.
"It suggests that the neural circuitry in memory for mature individuals...can be changed" by estrogen, said Dr. Sally E. Shaywitz, one of the study's authors. "It is a very hopeful sign."
The study appears in the latest Journal of the American Medical Association.
Production of estrogen, the primary female hormone, drops sharply after women reach menopause. Previous research has found that estrogen protects against heart disease, brittle bones, decreases the risk of colon cancer and may even help women live longer.
Studies have also suggested that estrogen may reduce the risk of Alzheimer's disease. The ability to establish new connections in the brain is what is lost with the onset of Alzheimer's.
An expert not involved in the study said the research was significant as another demonstration that estrogens have positive effects on certain aspects of mental function.
"What this study suggests is that what estrogen can do is rewire the central nervous system," said Dr. Stanley Birge, a professor of geriatrics and gerontology at the Washington University School of Medicine in St. Louis. "Perhaps even in the 70 or 80 year-old individual we have the potential" for such regeneration.
Estrogen replacement therapy, however, also carries risks. Studies show it can increase the risk of breast and endometrial cancer.
Shaywitz said estrogen "is not some magic pill," and further study is needed on its benefits and potential side effects.
The researchers used functional magnetic resonance imaging to measure brain activity as the women conducted tasks involving verbal and visual memory. The women, who ranged in age from 33 to 61, were treated with either estrogen or a placebo in a random trial from 1996 through 1998.
Researchers cautioned that while they observed increased brain activity in women given estrogen, there was no subsequent improvement in verbal and nonverbal memory tasks.
Shaywitz said the lack of quantifiable evidence pointing to improved memory function was probably because the tasks were simple and almost all were performed correctly. If a study participant was asked something she did not know, the MRI would measure her effort rather than her memory function, she said.
"This is one step...but this a good step in that it does show a physiological change in areas of the brain related to memory," said Dr. Rodrigo Kuljis, a neurologist at the University o Miami School of Medicine.
Written By Andrew Buchanan