Summary: A new analysis of more than 5,000 adults shows that people with lower incomes and members of racial and ethnic groups historically underrepresented in research carry a greater burden of modifiable dementia risk factors. Vision loss and social isolation were especially prominent among those living below the poverty line, indicating that better access to eye care and stronger social supports could meaningfully lower dementia risk in disadvantaged communities.
The study, published November 12, 2025, in Neurology, identifies links between income, systemic inequities and the prevalence of preventable dementia risk factors. While the research describes associations rather than causation, it highlights clear targets for public health interventions that could reduce dementia risk and narrow health disparities.
Key findings
- Income effect: For each 100% increase above the federal poverty level, the likelihood of having an additional dementia risk factor in middle age dropped by about 9%.
- Primary contributors in low-income groups: Vision loss and social isolation were the largest contributors among people living below the poverty line—accounting for 21% and 20% respectively of potentially preventable dementia cases in that group.
- Persistent disparities: Even after adjusting for income, Black, Mexican American and other Hispanic participants showed higher rates of diabetes, physical inactivity, obesity and vision loss compared with white participants.
“Our findings provide new insight into how people living below the poverty line and those from historically under-resourced groups may bear a higher burden of many modifiable dementia risk factors,” said Eric L. Stulberg, MD, MPH, of Thomas Jefferson University Sidney Kimmel Medical College and a member of the American Academy of Neurology. “By identifying which risk factors are most prevalent in people who have a higher risk for dementia, we can better target prevention—whether that means improving access to vision care, strengthening social connection, or addressing chronic conditions like diabetes and high blood pressure.”
The researchers assessed 13 potentially modifiable dementia risk factors among more than 5,000 participants. These factors included low education, alcohol use, obesity, high LDL cholesterol, traumatic brain injury, untreated hearing loss, vision loss, diabetes, untreated high blood pressure, smoking, depression, physical inactivity and social isolation. Analyses accounted for age, sex and race and ethnicity; the authors emphasized that race and ethnicity are socially based categories rather than biological variables.
Participants were grouped across six income levels, from below the federal poverty level to more than five times that level. For each income band, investigators calculated the prevalence of each risk factor and estimated the proportion of dementia cases that could theoretically be delayed or prevented if those risk factors were eliminated.
Overall, higher income was linked to lower prevalence of nearly all examined dementia risk factors, with exceptions including obesity, high cholesterol and traumatic brain injury. The strongest income-related differences were seen for conditions related to access and lifestyle, such as untreated chronic disease and social isolation.
In the lowest income group, vision loss and social isolation stood out: eliminating or effectively treating these two factors could potentially affect roughly 40% of dementia cases in that group when their individual contributions are considered together. The authors note this does not prove causation, but suggests practical opportunities for prevention that could have large effects in disadvantaged populations.
Even after adjusting for income, several risk factors remained more common among historically underrepresented racial and ethnic groups. Black, Mexican American and non-Mexican Hispanic participants had higher prevalence of diabetes, physical inactivity, obesity and vision loss compared with white participants, pointing to persistent health inequities beyond income alone.
“Our results suggest there may be an immediate opportunity to help people reduce dementia risk factors now, particularly among those with lower incomes and groups that are historically underrepresented in clinical studies,” Stulberg said. “It is encouraging that some late-life risk factors appear modifiable and could be targets for interventions to lower dementia risk.”
The study has important limitations: it is cross-sectional and captures a single point in time rather than following people longitudinally, and some measures relied on participant self-report, which can introduce recall or reporting bias. Future longitudinal research and intervention trials will be needed to test whether targeting these specific risk factors—such as improving vision care access or reducing social isolation—actually reduces dementia incidence.
Key Questions Answered:
A: Lower income was associated with a higher number of modifiable dementia risk factors, including vision loss, diabetes and social isolation. Each doubling of income above the poverty level was linked with about a 9% lower chance of having an additional risk factor in middle age.
A: Vision loss and social isolation were the most prominent contributors among people living below the poverty line; together their estimated contributions were on the order of roughly 40% of potentially preventable dementia cases in that income group.
A: Expanding access to vision care, reducing social isolation, and improving chronic disease management could help lower dementia risk for low-income and historically underrepresented populations.
About this social neuroscience and dementia research news
Author: Renee Tessman
Source: AAN
Contact: Renee Tessman – AAN
Image: The image is credited to Neuroscience News
Original Research: The findings appear in Neurology