Women's Brains May Be More Vulnerable to Dementia Risk Factors, Landmark Study Reveals
核心洞察
A study of over 17,000 adults found that several modifiable dementia risk factors have a disproportionately larger impact on cognitive decline in women compared to men.
Cardiovascular and metabolic conditions, including hypertension (搜索) and higher BMI, showed stronger negative associations with cognitive function in women, despite some being more prevalent in men.
Women were nearly twice as likely to report depression (搜索) (17% vs. 9%) and had higher rates of physical inactivity and sleep problems, while men had higher rates of hearing loss (搜索) and diabetes (搜索).
Women may not only experience certain dementia risk factors more frequently than men, but those same risk factors may also exert a stronger toll on their cognitive health, according to new research from the University of California San Diego School of Medicine. The findings, drawn from a nationally representative cohort of more than 17,000 middle-aged and older U.S. adults, suggest that prevention strategies tailored by sex could prove more effective than one-size-fits-all approaches.
The study, published in Biology of Sex Differences, examined 13 well-established and modifiable dementia risk factors — including educational attainment, hearing loss (搜索), smoking, alcohol consumption, obesity (搜索), depression (搜索), physical inactivity, hypertension (搜索), diabetes (搜索), and other cardiometabolic conditions — and assessed both their prevalence and their impact on cognitive performance in women versus men.
"Looking beyond which risk factors are most common, we found that some have a disproportionately larger impact on women's cognition," said Megan Fitzhugh, PhD, assistant professor of neurosciences at UC San Diego School of Medicine and first author of the study. "This suggests that prevention efforts may be more effective if they are tailored not just to risk factor prevalence, but to how strongly each factor affects cognition in women versus men."
A Disproportionate Burden
Women account for nearly two-thirds of the approximately seven million people living with Alzheimer's disease (搜索) in the United States. While women generally live longer than men, researchers say longevity alone does not explain the disparity. Scientists have increasingly focused on understanding how biological, social, and lifestyle factors contribute to women's elevated risk, with particular attention to factors that can potentially be changed or managed over time.
To investigate these differences, Fitzhugh and Judy Pa, PhD, professor of neurosciences at UC San Diego School of Medicine and corresponding author of the study, analyzed data from the Health and Retirement Study, a nationally representative group of U.S. adults in mid to late life.
Prevalence Patterns Differ by Sex
The analysis revealed clear differences in how frequently certain risk factors occurred among men and women. Women were more likely to report depression (搜索) — nearly twice as common in women as men (17% vs. 9%) — as well as physical inactivity (48% vs. 42%) and sleep problems (45% vs. 40%). Women also had slightly lower average educational attainment, another factor linked to increased risk of cognitive decline later in life.
Men, by contrast, were more likely to experience hearing loss (搜索) (64% vs. 50%), diabetes (搜索) (24% vs. 21%), and heavy alcohol use (22% vs. 12%). High blood pressure was widespread in both groups, affecting roughly six out of ten participants, and average body mass index levels for both men and women fell within the overweight to obese range.
Impact, Not Just Prevalence
The researchers found that prevalence alone did not tell the whole story. Several risk factors were associated with larger declines in cognitive performance among women than men. Cardiovascular and metabolic conditions, including hypertension (搜索) and higher body mass index, showed stronger negative relationships with cognitive function in women.
Notably, hearing loss (搜索) and diabetes (搜索) — despite being more common among men — were linked to poorer cognitive performance in women. These findings indicate that the same health condition may not carry the same level of cognitive risk for everyone. A factor that has a moderate impact on cognition in men may have a considerably stronger effect in women, increasing its overall contribution to dementia risk.
"These differences highlight the importance of considering sex as a key variable in dementia research," said Pa. "Sex differences are profoundly overlooked among many leading causes of death like Alzheimer's, heart disease and cancer."
Toward Precision Prevention
The findings support growing interest in precision medicine — an approach that aims to tailor prevention and treatment strategies to individual characteristics, including sex. Rather than concentrating only on the most common risk factors in the population, the results suggest that prevention efforts could be more effective if they focus on the factors that have the greatest impact on cognitive health within specific groups.
Because the risk factors identified in the study are modifiable, researchers say there are practical opportunities for intervention. For women, this could include greater attention to treating depression (搜索), increasing physical activity, and improving cardiovascular health, particularly uncontrolled hypertension (搜索).
"Ultimately, a more nuanced understanding of these differences could help us design smarter, more targeted interventions," Fitzhugh said. "That's an essential step toward reducing the burden of dementia for everyone, but especially for women, who are disproportionately affected."
Unanswered Questions and Future Directions
The researchers say additional studies are needed to determine why these sex-based differences exist. Potential explanations include hormonal influences, genetic factors, and differences in access to health care, but the interactions among these factors remain unclear.
The study was funded by the National Institute on Aging (RF1AG088811, PI: Pa) and the Alzheimer's Association (SAGA23-1141238, PI: Pa).