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REVEALED: Counties where you are most likely to develop dementia... including area where one-third of residents have the disease READ MORE: Scientists decode early dementia warning signs in new research By CASSIDY MORRISON, US SENIOR HEALTH REPORTER Published: 16:35 GMT, 6 November 2025 | Updated: 16:38 GMT, 6 November 2025 Americans living in disadvantaged neighborhoods face a significantly higher risk of dementia, new studies suggest. Scientists from Wake Forest University in North Carolina examined health data from more than 600 people who were part of the school’s brain study and had their blood tests and brain scans analyzed. The data was linked to location codes given out using the participants' home addresses. The study found that living in disadvantaged areas, measured by a 'social vulnerability index' that scores neighborhoods on factors like poverty, unemployment and lack of community support, is linked to changes in the brain associated with dementia. This connection was especially pronounced among Black individuals. People in lower-income neighborhoods with fewer health resources showed actual physical changes in their brain structure. People in these underserved areas had thinner outer layers of their brains, changes in white matter that suggest blood vessel diseases, reduced blood flow in their brains, and uneven circulation. All these factors suggest that the brain is not receiving the consistent, high-quality blood flow it needs to survive and function properly. These issues are largely driven by the same factors that define these neighborhoods. People tend to have limited access to healthy food, fewer opportunities for safe physical activity and chronic stress from financial strain and a lack of community health resources. All of these conditions can lead to untreated high blood pressure and diabetes, which silently damage the blood vessels supplying the brain. Over time, this reduced and inconsistent blood flow can cause the brain to atrophy, contributing to the onset of dementia. New research from Wake Forest University confirms a link between socioeconomic disadvantage and higher dementia risk, following similar recent findings from Cambridge University (stock) The brain uses approximately a quarter of the body's oxygen and blood supply, despite accounting for only two percent of its weight. When this supply is compromised, brain cells are damaged and eventually die, which can result in such severe cognitive decline as to warrant a dementia diagnosis. Sudarshan Krishnamurthy, a sixth-year MD-PhD candidate at Wake Forest University and lead author of the US study, said in a statement: ‘This study is one of the first to connect a variety of place-based social factors with advanced biological markers of dementia. Map reveals America's Alzheimer's hotspots by region ‘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 study included 679 North Carolinians with an average age of 70, participating in the Wake Forest Brain Study. Most of them were white females, though men made up 34 percent of the study population. Living in the most disadvantaged, poorest neighborhoods was found to cause a literal loss of brain cells in the areas critical for memory and thinking. Furthermore, active regions of the brain were not receiving the oxygenated blood they needed, and waste products were not being cleared effectively. This directly damages brain cells, allowing toxins like amyloid to accumulate. Dr Timothy Hughes, a professor of geriatric medicine at Wake Forest University School of Medicine and senior author, said: ‘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.’ After collecting blood sample data and brain scans and cross-referencing results with location codes corresponding with North Carolina residents' addresses, researchers generated composite scores to measure neighborhood-level disadvantage, vulnerability, and environmental injustice. The indices took into account poverty, education level, employment status, the quality of housing, such as lack of plumbing and median home value. The study used three separate tools to measure neighborhood challenges, and on every one, Black participants lived in significantly more disadvantaged areas. In the first tool, a score of 50 meant the neighborhood is at the national average. A score of 80 meant the neighborhood is more disadvantaged than 80 percent of all US neighborhoods. A score of 20 meant it is more disadvantaged than only 20 percent of neighborhoods, meaning it is among the least underprivileged areas. This disparity was clearest with the Area Deprivation Index, the first tool. A higher score indicates that people have less access to healthy food, safe parks for exercise, and quality healthcare. This leads to higher rates of hypertension, diabetes and obesity, all major risk factors for dementia. Black residents, on average, lived in neighborhoods with a disadvantage score of 72.1, meaning their communities were more disadvantaged than 72 percent of neighborhoods nationwide. White participants, with an average score of 51.5, indicated that they lived in neighborhoods near the national average. Another scoring tool, the Social Vulnerability Index, researchers looked at measuring people’s social support where they live and how the lack thereof can lead to chronic stress and chronically high cortisol levels. Over time, stress causes inflammation throughout the body, a known risk factor for neurological disease. The third tool, the Environmental Justice Index, measured direct physical damage from air pollution and toxic chemicals, which are known to cause brain inflammation and accelerate the accumulation of Alzheimer's proteins, such as amyloid. While the study didn't provide specific average scores for the Social Vulnerability and Environmental Justice indices, it confirmed that Black participants faced significantly higher levels of these place-based risks, creating a cumulative burden on their brain health. The scores are powerful predictors because they encapsulate the real-world conditions that, over years and decades, physically erode the brain's structure and function, making dementia a far more likely outcome. The finding that these damaging brain changes were only seen in Black participants, even after adjusting for individual cardiometabolic health, suggests that the cumulative burden of systemic and structural racism, captured by neighborhood-by-neighborhood scores, is itself a direct and independent risk factor for dementia. While older Black Americans are twice as likely as older Whites to have Alzheimer's or another dementia, research hasn't yet identified the cause. The Wake Forest study was published in the journal Alzheimer's & Dementia. A team of scientists at Cambridge University in the UK added weight to the Wake Forest findings in a study published about two weeks later, in which they reported that in underprivileged neighborhoods, daily stressors like crime, unsafe housing and poor environmental conditions create a chronic strain. This harms key cognitive skills, including processing speed and attention, which are often the first to decline due to vascular brain issues. North Carolina Share or comment on this article: REVEALED: Counties where you are most likely to develop dementia... including area where one-third of residents have the disease Add comment
