By the numbers
University of California - San Diego
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| Why are women more likely to develop Alzheimer's disease? - Harvard Health |
Scientists at the University of California San Diego School of Medicine analyzed data from more than 17,000 middle aged and older adults and found that certain modifiable dementia risk factors appear to have a greater impact on women's cognitive function than men's.
The findings were
published May 19, 2026, in Biology of Sex Differences.
"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."
Researchers say the findings could help explain why women
account for nearly two thirds of Alzheimer's cases in the United States.
Women Bear a Larger Alzheimer's Burden
Nearly seven million Americans are currently living with
Alzheimer's disease, and women make up the majority of those cases. Although
women generally live longer than men, scientists say longer lifespan alone does
not fully explain the gap.
Researchers are increasingly studying how biological,
social, and lifestyle related factors combine to shape dementia risk
differently in women and men. Many of these factors can potentially be changed
through medical care or lifestyle adjustments.
For the new study, Fitzhugh and senior author Judy Pa, PhD,
professor of neurosciences at UC San Diego School of Medicine, examined 13
established dementia risk factors using information from the Health and
Retirement Study, a nationally representative group of U.S. adults in mid to
late life.
The factors included education level, hearing loss, smoking,
alcohol consumption, obesity, depression, physical inactivity, hypertension,
diabetes, and other cardiometabolic conditions.
Key Dementia Risks Affect Women and Men Differently
The analysis uncovered several notable differences between
women and men.
Women were more likely to report:
- Depression
(17% compared with 9% in men)
- Physical
inactivity (48% compared with 42%)
- Sleep
problems (45% compared with 40%)
Women in the study also had slightly lower average
educational attainment, which is considered a risk factor for later cognitive
decline.
Men showed higher rates of:
- Hearing
loss (64% compared with 50% in women)
- Diabetes
(24% compared with 21%)
- Heavy
alcohol use (22% compared with 12%)
High blood pressure was widespread in both groups, affecting
roughly six out of 10 participants. Average body mass index for both sexes also
fell within the overweight to obese range.
Some Risk Factors Had a Stronger Cognitive Impact in
Women
The researchers found that several risk factors were linked
to poorer cognitive performance more strongly in women than in men.
Conditions related to heart and metabolic health, including
hypertension and elevated body mass index, showed steeper negative associations
with cognition among women. Hearing loss and diabetes, despite being more
common in men, were also tied to lower cognitive scores in women.
The findings suggest the same dementia risk factor may not
affect everyone equally. A health issue that causes only moderate cognitive
effects in men could potentially have a much stronger influence on women's
brain health.
"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 results support growing interest in precision medicine,
an approach that aims to tailor prevention and treatment strategies to
individual characteristics, including sex.
Rather than focusing only on the most common dementia risk
factors across the population, the researchers suggest it may be more effective
to prioritize those that appear to have the greatest cognitive impact within
specific groups.
The team emphasized that many of the risk factors identified
in the study are modifiable, meaning there may be opportunities to reduce risk
through targeted interventions.
For women, that could include greater attention to managing
depression, increasing physical activity, and improving cardiovascular health,
especially untreated hypertension.
Researchers Call for More Study
The researchers say more work is needed to understand why
dementia risk factors may affect women differently. Possible explanations
include hormonal influences, genetic differences, and unequal access to health
care, though the exact interactions 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."
The study, titled "Sex differences in modifiable
risk factors of dementia and their associations with cognition," was
funded by the National Institute on Aging (RF1AG088811, PI: Pa) and the
Alzheimer's Association (SAGA23-1141238, PI: Pa).
The authors reported no conflicts of interest.
Journal Reference:
- Megan
C. Fitzhugh, Judy Pa. Sex differences in modifiable risk factors
of dementia and their associations with cognition. Biology of
Sex Differences, 2026; 17 (1) DOI: 10.1186/s13293-026-00908-7
