We know that varying levels of estrogen during menopause affect the brain. A big drop in estrogen, according to experts, could lead to cognitive problems, and scientists are investigating whether menopause itself might be a risk factor for dementia. Two recent studies have shed light on the effects of menopause on memory and how taking hormone replacement drugs after menopause starts could actually help the brain.
Researchers are still trying to figure out the exact relationship between hormone levels and cognitive health but a study published this week suggests that when it comes to verbal memory, the later you hit menopause the better. The study, published in Neurology®, followed 1,315 women from the Medical Research Council National Survey of Health and Development in U.K. throughout their lives, testing their verbal memory skills and cognitive processing speed five times between the ages of 43 and 69. The study found that among 846 women who experienced menopause naturally, women who had later menopause had higher verbal memory scores but on the test of how fast the women could process information, researchers found no relationship between the age at menopause and test scores.
“It’s possible that this benefit could translate to a reduced risk of dementia years later,” said study author Diana Kuh, PhD, of the University College London. “More research and follow-up are needed to determine whether that is the case.”
Regardless of when menopause occurs, new evidence suggests that hormone replacement therapy might help to preserve the parts of the brain responsible for memory and thinking skills, and reduce the build up of beta-amyloid plaques, the sticky protein that researchers believe causes cell death in Alzheimer’s disease.
In the study, researchers observed 75 healthy women who were an average age of 53. All were between five months and three years post-menopause. They split the women into three groups: 20 took equine estrogen, a type of estrogen made from horse hormones, via pills, 22 took estradiol estrogen via a patch on the skin, and 33 received a placebo of either pills or patches. The women taking estrogen were also given progesterone, another female hormone, for the first twelve days of each month.
Researchers tested the women’s thinking and memory at the beginning of the study, at a year and a half, at three years and at four years when the study concluded, and then again three years later. They also gave them MRIs to measure brain volume and brain lesions. Sixty-eight of the 75 women were given PET scans in order to measure the amount of amyloid plaques in their brains.
They found that women who used the skin patches maintained their brain volume in the area of the brain that controls memory, thinking, planning and reasoning, for all seven years that they were measured. Those women also had less amyloid build-up in the brain.
Women who took the pill had more of an increase in brain volume than those who took the placebo, but that effect stopped once they went off the pill after four years. The difference between the pill and patch indicates that estradiol via the patch may have long-term effects for brain health.
Thinking and memory tests did not vary much between women on the placebos and women taking hormones, though.
“More research is needed to determine the biological reasons behind brain changes during menopausal hormone therapy,” said study author Kejal Kantarci, M.D., of the Mayo Clinic in the U.S. “Future research is also needed to better define just how the different hormonal products, pills versus skin patches, affect the brain,” Kantarci said.
This study was published in the journal Neurology.