Researchers at the University of California San Diego School of Medicine report that women carry a heavier burden of certain modifiable dementia risk factors and also appear more susceptible to the damage those factors do to thinking and memory. The analysis drew on data from more than 17,000 middle-aged and older adults and was published May 19, 2026 in Biology of Sex Differences.
The distinction the team draws is subtle but consequential. Most prevention research asks which risk factors are most common in a population. This study asked a different question: how strongly does each factor actually move the needle on cognition, and does that differ by sex? "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 the study's first author, who suggested prevention efforts may work better if they are calibrated to that difference rather than to prevalence alone.
The context matters because the sex gap in dementia is large and not fully explained. Of the seven million adults in the United States living with Alzheimer's disease, close to two-thirds are women. Women do live longer on average, but longevity by itself does not account for the disparity, which has pushed researchers toward the interplay of biological, social and lifestyle influences.
What makes modifiable factors a particular focus is that, unlike age or genetics, they can change over the course of a life. If the effect of a given factor on cognition is stronger in women, then broad, one-size-fits-all prevention messaging may be leaving benefit on the table. Translating that insight into sex-specific prevention strategies is the work still ahead.