The drop in estrogen that occurs after menopause is not associated with any changes in women’s mood or cognitive abilities, including memory, according to a study published last week by a team of researchers from Stanford University and the University of Southern California, Los Angeles.
The finding suggests, say the study’s authors, that taking hormone therapy (HT) to boost estrogen levels — even in the years immediately before and after menopause — is unnecessary for maintaining mental acuity.
This is good news for women, of course, but not for the pharmaceutical industry, which has been trying to resuscitate menopausal HT ever since a large, well-designed randomized trial revealed, starting in 2002, that giving middle-aged and older women such drugs increased their risk of developing many serious illnesses, including blood clots, stroke, heart disease, breast cancer, colon cancer and dementia (among women aged 65 and older).
The current study was published online Nov. 25 in the Proceedings of the National Academy of Sciences.
No effect among two age groups
For the study, researchers assessed the mood, memory and overall cognitive skills of 643 healthy postmenopausal women who were not using HT. They also measured the women’s blood levels of the hormones estradiol, estrone, progesterone and testosterone.
The women ranged in age from 41 to 84 years. Roughly half had gone through menopause within the previous six years; the others were at least 10 years post-menopause. (The average age of menopause in the United States is 51.)
In both the younger and the older groups, higher estradiol levels had no apparent effect, positive or negative, on cognition or mood. The data did reveal a possible association between levels of progesterone and cognition among the younger group of postmenopausal women. But that link could just be a chance finding and requires further investigation, the researchers stress in their paper.
A blow to the ‘critical window’ theory
This was the first study to investigate the possible associations between sex hormones and cognition in both younger and older postmenopausal women.
That distinction gives the study’s findings particular weight. As part of their attempt to resuscitate menopausal HT, drug companies and others have been proposing something dubbed the “critical window” theory — the idea that using HT for a few years close to the time of menopause offers women more benefits than risks.
And one of those benefits (according to HT’s supporters) is improved cognitive skills, particularly verbal memory.
The scientific evidence in support of that idea, however, has been weak at best — and sometimes rife with conflicts of interest. For example, a study that claimed earlier this year to show a significant decline in verbal memory during the transition through menopause was conducted by researchers with financial ties to various drug companies.
The findings from this new study offer some of the strongest evidence to date that menopause-related changes in estrogen levels are not associated with cognitive decline. The women in this study were all participants in the Early Versus Late Intervention Trial with Estradiol (ELITE), a large clinical trial that was designed to test the “critical window” theory about menopausal HT. Other findings from the trial, which ended earlier this year, are expected to be published in 2014.
Stay tuned. In the meantime, keep in mind that maintaining a healthy weight, staying physically active and not smoking have been repeatedly found to be among the best preventers of cognitive decline.