Many people experience fuzzy thinking during perimenopause. “So many women worry that they might be losing their minds at menopause,” says Dr. Mosconi. “But the truth is that your brain is going through a transition and needs time and support to adjust.”
Fortunately, the brain changes brought on during perimenopause appear to be temporary and do not affect cognitive performance, according to Dr. Mosconi’s research. “Women may be tired, but we are just as sharp.”
For some women, the withdrawal of estrogen in perimenopause can have a more serious effect, setting the stage for Alzheimer’s disease later in life, says Dr. Mosconi. Her research has sought to explain why women are more likely than men to develop the devastating disease. “Alzheimer’s affects close to 6 million people in the United States,” she says. “But almost two-thirds of those people are women.”
Women live longer than men overall, giving them more time to develop Alzheimer’s, says Dr. Mosconi. But the gender longevity gap doesn’t fully explain the disparity.
Her research offers clues. “Estrogen literally pushes neurons to burn glucose to make energy. If your estrogen is high, your brain energy is high,” says Dr. Mosconi. “When your estrogen declines, though, your neurons start slowing down and age faster. And studies have shown that this process can lead to the formation of amyloid plaques, which are a hallmark of Alzheimer’s disease.”
Brain scans show that while amyloid plaques are rare in men at midlife, women begin to see an increase during the transition to menopause, typically in their 40s and early 50s. “Many studies show that Alzheimer’s starts with negative changes in the brain years prior to clinical symptoms,” she says. “For women, it looks like this process starts during the menopause transition.”
Dr. Mosconi emphasizes that not all women develop the plaques, and not all women with the plaques develop dementia. Rather, perimenopause appears to activate the accumulation of plaques, at least in women who have a genetic predisposition for Alzheimer’s, such as those who have a first-degree family member with the disease or who carry a particular gene (called APOE4), she says.
Women who have both ovaries surgically removed, which causes an abrupt drop in hormones, may fare even less well than those who go through the menopause transition, Dr. Mosconi says. “Unfortunately, there is evidence that having the uterus and, more so, the ovaries removed prior to menopause correlates with a higher risk of dementia in women,” she says. But the risk drops if they start taking hormones soon after surgery and continue treatment until the natural age of menopause, she adds.