Your ZIP Code could reveal your risk of dementia

The study, recently featured in Alzheimer's & Dementia: Behavior & Socioeconomics of Aging (a journal of the Alzheimer's Association), found that people residing in neighborhoods marked by greater social vulnerability, environmental inequities, and economic hardship showed measurable differences in both brain structure and activity.

"This study is consistent with other research showing that the state of the social environment in which people live can shape their brain health in profound ways," said Timothy Hughes, Ph.D., associate professor of gerontology and geriatric medicine at Wake Forest University School of Medicine and senior author.

How the Study Was Conducted

The researchers examined data from 679 adults participating in the Healthy Brain Study at the Wake Forest Alzheimer's Disease Research Center. Each volunteer received brain imaging and blood testing designed to detect early indicators of Alzheimer's disease and related forms of dementia.

Those biological results were then compared with three national tools that measure neighborhood conditions by zip code: the Area Deprivation Index, the Social Vulnerability Index, and the Environmental Justice Index. These indices assess factors such as income, housing quality, pollution exposure, and community resilience.

Clear Links Between Neighborhood Stress and Brain Changes

Participants living in areas with higher scores on these indices -- indicating more social and environmental disadvantages -- showed greater evidence of brain changes tied to dementia risk. These effects were most pronounced among Black participants, whose communities often face higher levels of environmental and socioeconomic strain.

The brain-related markers included a thinner cerebral cortex, white matter changes linked to vascular disease, and reduced or uneven blood flow. Such biological differences may contribute to memory problems and cognitive decline as people age.

Environment's Lasting Impact on the Brain

"This study is one of the first to connect a variety of place-based social factors with advanced biological markers of dementia," said Sudarshan Krishnamurthy, a sixth-year M.D.-Ph.D. candidate and the study's lead author. "It shows that the conditions and environment in which people live -- such as access to clean air, safe housing, nutritious food and economic opportunity -- may leave a lasting imprint on brain health.

The findings add to growing scientific evidence that where people live and the resources available to them are not just background influences but critical factors in understanding and addressing Alzheimer's disease and related disorders.

A Call for Broader Policy Action

Krishnamurthy noted that these results highlight the need for systemic change.

"If we truly want to improve brain health across all communities, we must look beyond individual choices and hone in on the broader systems and structures that shape health at the neighborhood level."

The study was supported by the National Institutes of Health (grants F30 AG085932 and P30 AG07294) and the American Heart Association (grant 24PRE1200264).