A major study found that common dementia risks may have a much stronger impact on women’s brains than previously recognized.
Women may not only experience some dementia risk factors more often than men, but those risk factors may also have a stronger effect on their cognitive health, according to new research from the University of California San Diego School of Medicine.
The study, published in Biology of Sex Differences, examined data from more than 17,000 middle-aged and older adults and found notable differences in both the prevalence and impact of several established dementia risk factors.
“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.”
Why Women Face Higher Dementia Rates
Women account for nearly two-thirds of the approximately seven million people living with Alzheimer’s disease in the United States. Although women generally live longer than men, researchers say longevity alone does not explain the difference.
Scientists have increasingly focused on understanding how biological, social, and lifestyle factors contribute to women’s elevated risk of dementia. Particular attention has been given 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 information from the Health and Retirement Study, a nationally representative group of U.S. adults in mid to late life.
The researchers evaluated 13 well-established and modifiable dementia risk factors, including educational attainment, hearing loss, smoking, alcohol consumption, obesity, depression, physical inactivity, hypertension, diabetes, and other cardiometabolic conditions.
Key Differences Between Women and Men
The analysis showed several clear differences in how frequently certain risk factors occurred among men and women.
Women were more likely to report:
- Depression (nearly twice as common in women as men — 17% vs. 9%)
- Physical inactivity (48% vs. 42%)
- 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 were more likely to experience:
- Hearing loss (64% vs. 50%)
- Diabetes (24% vs. 21%)
- Heavy alcohol use (22% vs. 12%)
High blood pressure was widespread in both groups, affecting roughly six out of ten participants. Average body mass index levels for both men and women fell within the overweight to obese range.
Some Risk Factors Affect Women More Strongly
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 and higher body mass index, showed stronger negative relationships with cognitive function in women.
The team also found that hearing loss and diabetes, 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 More Personalized Dementia 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, increasing physical activity, and improving cardiovascular health, particularly uncontrolled hypertension.
Understanding the Causes Behind the Differences
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.
“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.”
Reference: “Sex differences in modifiable risk factors of dementia and their associations with cognition” by Megan C. Fitzhugh, and Judy Pa, 20 May 2026, Biology of Sex Differences.
DOI: 10.1186/s13293-026-00908-7
The study was funded by the National Institute on Aging (RF1AG088811, PI: Pa) and the Alzheimer’s Association (SAGA23-1141238, PI: Pa).
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