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Study Links Memory Loss, Estrogen Level
Healthy Young Women Score Lower on Tests When Hormone Suppressed, Montrealers Find
By Charlie Fidelman, The Gazette
Canada
July 26, 2006
Declining levels of estrogen can lead to memory problems and mood swings, a Montreal study suggests - bolstering the belief that hormonal changes during menopause severely affect brain function.
"We wanted to see whether estrogen could protect against the decline in working memory," McGill University psychologist, Barbara Sherwin, who conducted the study, said of age-related memory changes.
The study investigated the link between estrogen and memory by measuring cognitive behaviour before and after inducing menopause in healthy young women where the aging brain is not a confounding issue.
The results suggest estrogen is crucial to maintaining different kinds of memory in women, said Sherwin, a pioneer in the field of sex-hormone research.
"We found a significant decrease on their scores that we were able to attribute to estrogen levels," Sherwin said. "It's not that these women had to quit their jobs. But it was noticeable and documentable."
Sherwin and post-doctorate student Miglena Grigorova recruited 25 women, average age 36, who were already slated for treatment of benign uterine tumours with drugs that suppress ovarian function. The drugs lead to menopausal symptoms.
The researchers ran several memory tests - initially, when the women's ovaries were still functioning normally, and then weeks later, after hormone levels, as measured by blood tests, had decreased to post-menopausal levels.
But while performance scores of the control group (matched for age and education) had improved on the second batch of tests, those of the newly menopausal women had declined.
"That tells us working memory is a function that decreases with normal aging, and women who take estrogen around the time of menopause will be somewhat protected," Sherwin said.
The women also reported feeling moody and sad.
The study is limited by its lack of a random, double-blind control group, as it is unethical to randomly assign women needing medical attention a placebo, researchers noted.
"It's an interesting observation, but I'm not convinced that it's all about estrogen," said Christine Hitchcock, researcher in the faculty of medicine at the University of British Columbia.
Sudden onset of chemical menopause and its consequences - stress, lack of sleep, hot flashes, mood swings - can cause deficits in working memory, Hitchcock said from the university's Centre for Menstrual Cycle and Ovulation Research.
"But it could be that both (the menopause and the memory problems) are caused by the same thing" - the drug that suppresses ovarian function, she said.
Women have long complained of memory problems at the time of menopause, said Vyta Senikas, vice-president of the Society of Obstetricians and Gynecologists of Canada.
In creating artificial menopause, Sherwin's study on memory dissects two factors - the aging brain and falling levels of estrogen, Senikas said.
"The two always go hand in hand. Is it because of estrogen or because you're 65?" Senikas wondered.
"Here, the aging brain is no longer a variable. This is the first step in evidence-gathering."
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