About 6 million U.S. adults aged 65 and above have Alzheimer’s disease, with nearly two-thirds being women. While genetics and longer life spans have conventionally explained this gender disparity, there’s a growing belief that menopause might significantly contribute to the elevated risk of dementia later in life.
Menopause, marking the end of fertility, triggers changes not just in the ovaries but also in the brain. Dr. Lisa Mosconi, a neuroscientist leading the Women’s Brain Initiative at Weill Cornell Medicine, suggests that women undergoing menopause experience brain change akin to those in their ovaries. While most women navigate this phase without lasting health consequences, around 20 percent may develop dementia in subsequent decades.
The female brain, rich in estrogen receptors, particularly in memory, mood, sleep, and body temperature control areas, operates optimally with high and consistent estrogen levels. Estrogen plays a vital role in the brain’s defence against aging and damage.
Menopausal changes not only affect specific brain regions but are also thought to alter the brain’s structure, evidenced by reduced volume in menopausal brains compared to age-matched males and pre-menopausal women. This decline in estrogen during menopause may contribute to structural brain changes, potentially influencing dementia risk. The research highlights the intricate relationship between hormonal shifts and brain health, revealing a previously overlooked facet of dementia risk in women.
Menopausal symptoms, such as sleep disturbances and hot flashes, have been linked to dementia. A study revealed that hot flashes correlate with increased brain lesions, indicating declining brain health. Another study found that hot flashes during sleep are associated with elevated Alzheimer’s biomarkers. Despite these findings, most women experience stabilization in brain function after menopause. Dr. Pauline Maki emphasizes that while menopausal changes may have associations with dementia-related factors, it’s crucial not to catastrophize this universal transition, considering that 80 percent of women navigating menopause will not develop dementia.
Dr. Jessica Caldwell, director of the Women’s Alzheimer’s Movement Prevention Center at the Cleveland Clinic in Las Vegas. notes that up to 40% of dementia cases could be prevented with midlife lifestyle changes. For menopausal women, three key strategies include appropriately timed hormone therapy, consistent exercise, and adopting a healthy diet, addressing both short-term symptoms and long-term dementia risk.
Hormone therapy
Recent studies challenge concerns about hormone therapy for menopause and dementia risk. A nuanced perspective emerges, suggesting that starting hormone therapy when menopausal symptoms commence is linked to a reduced risk of Alzheimer’s and dementia. While some studies found no impact on dementia risk, such therapy effectively addresses symptoms like hot flashes and night sweats, improving overall quality of life and, as Dr. Maki notes, contributing to “important determinants of brain health.”
Consistent exercise
Physical inactivity poses a higher risk of neurodegenerative diseases in women than in men, with women being twice as likely to be inactive throughout their lives. A 2018 study spanning 44 years discovered that higher fitness levels at the study’s onset correlated with a reduced risk of dementia in later life for nearly 200 middle-aged women. Brain scans of physically active middle-aged women also showed fewer Alzheimer’s biomarkers compared to their sedentary counterparts, reinforcing the significance of exercise in brain health.
A healthy diet
Recent research underscores the association between specific diets and a reduced risk of dementia for both men and women. Diets like the Mediterranean and MIND diets, emphasizing vegetables, fruits, whole grains, lean proteins, and healthy fats, show protective effects. The Mediterranean diet, especially, benefits women with a genetic risk for Alzheimer’s. Preliminary research suggests that plant-rich diets nourish gut bacteria, potentially aiding in estrogen level balance, presenting an additional benefit for women’s health.
Many of these lifestyle changes take time that many middle-aged women feel they don’t have, Dr. Caldwell said.
“We are expected by society to put ourselves after everybody else, whether that’s kids, parents or spouses, and we need to keep ourselves on the priority list,” she said. “Because if we don’t do these types of health-maintenance behaviours, we will not have the healthy brain aging we want.”
