January 17, 2018
The hormone changes that occur in a woman’s body during menopause may affect the brain in ways that increase the risk of developing Alzheimer’s disease, a new study reports. The findings could help explain in part why women tend to get Alzheimer’s more often than men do.
Eventually, the findings could lead to new screening tests that detect brain changes that may signal women at high risk of developing Alzheimer’s, the authors say. Determining who is at risk early is important, because scientists believe that measures to curb or prevent the progression to Alzheimer’s may be most effective when given early, before damage to the brain becomes extensive.
“This study suggests there may be a critical window of opportunity, when women are in their 40s and 50s, to detect metabolic signs of higher Alzheimer’s risk and apply strategies to reduce that risk,” said the study’s lead author, Dr. Lisa Mosconi, of Weill Cornell Medicine in New York. The findings were published in the journal PLOS One.
For the study, researchers from Weill Cornell Medicine and the University of Arizona Health Sciences studied 43 healthy women who ranged in age from 40 to 60. Of them, 15 hadn’t yet shown signs of menopause, 14 were becoming menopausal and 14 were in menopause.
All got PET scans of the brain to measure the uptake of glucose, the fuel that powers activity in the brain. The tests revealed that women who were entering or who had undergone menopause had markedly lower levels of glucose metabolism in several critical brain regions than those who were premenopausal. Earlier studies have shown that people in the early stages of Alzheimer’s show a similar pattern of low glucose uptake in these brain regions.
In addition, those in the early or later stages of menopause had other changes in specific brain proteins critical for brain function. They also tended to score lower on standard memory tests, above and beyond what might be accounted for by age.
“Our findings show that the loss of estrogen in menopause doesn’t just diminish fertility,” said Dr. Mosconi. “It also means a higher vulnerability to brain aging and Alzheimer’s disease.”
The findings add to a large body of evidence linking menopause with Alzheimer’s. Other studies have shown, for example, that menopause is tied to an increase in brain levels of beta-amyloid, a toxic protein that is a hallmark of Alzheimer’s. Menopause is also tied to shrinkage of brain areas affected by Alzheimer’s. Menopause has also long been known to cause “brain fog,” or loss of mental sharpness, along with symptoms of depression, anxiety and insomnia, all of which could further aggravate existing or developing cognitive problems.
More research needs to be done to better understand how the changes of menopause, including loss of the sex hormone estrogen, may impact the brain and possibly make it more susceptible to Alzheimer’s disease.
“Our work indicates that women may need antioxidants to protect their brain in combination with strategies to maintain estrogen levels,” Dr. Mosconi said. She noted that exercise and foods that are rich in antioxidants, such as flaxseeds, also may help boost estrogen production. “We really need to follow larger groups of women over long periods to see how this menopausal change in metabolism relates to Alzheimer’s.”
By www.ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Lisa Mosconi, Valentina Berti, Crystal Guyara-Quinn, et al: “Perimenopause and emergence of an Alzheimer’s bioenergetic phenotype in brain and periphery.” PLOS ONE, 2017; 12 (10): October 2017