In response to a new study showing that estrogen does not slow the effects of Alzheimer's disease, Yale researchers say more studies are needed to answer key questions about estrogen's possible role in preventing or delaying the disease.
Sally Shaywitz, M.D. and Bennett Shaywitz, M.D. wrote an editorial about the study, which was done by researchers at the University of California at Irvine, in the February 23 issue of Journal of the American Medical Association (JAMA). Drs. Shaywitz pointed out areas where future research can address issues that the study did not raise, such as estrogen's role in Alzheimer's disease prevention, and its effect on a younger population of mid-life women who do not have Alzheimer's disease.
"There's good evidence that estrogen improves cognition in younger women," said Bennett Shaywitz, professor of pediatrics and neurology at Yale School of Medicine. "In older women who do not have Alzheimer's disease, estrogen has also been shown to improve a variety of cognitive functions."
Whether or not estrogen given in the early postmenopausal period can prevent or delay the onset of Alzheimer's disease or diminish its severity also needs to be explored, Bennett Shaywitz said.
The UC Irvine study looked at women who were an average age of 75 to determine whether estrogen replacement therapy plays a role in improving or stabilizing the deterioration of mental function associated with Alzheimer's disease. After one year, study results showed no improvement in mood, memory, attention, language and motor skills. The study was conducted over a longer period and enrolled more women than past studies.
Using a methodology similar to the one used in the UC Irvine study, Shaywitz said, future work should focus on whether estrogen can prevent the occurrence of Alzheimer's disease, and there is also a need to determine estrogen's role, if any, in delaying or reducing the severity of the disease.
"We are optimistic that recent advances in technology, particularly functional brain imaging may now provide new opportunities to better address questions about estrogen's effects on cognitive function," Shaywitz said.