A study of nearly 3,000 brain MRI exams suggests that where people live may have a measurable influence on brain health. Researchers found that people living in highly socioeconomically disadvantaged neighbourhoods showed signs of poorer brain health, including older-appearing brains and lower total brain volume. The findings were published in Radiology, a journal of the Radiological Society of North America (RSNA).
“We’ve long suspected that your living environment affects your brain, but until now it’s not been proven at scale in clinical populations,” said Dr. John-Paul J. Yu, associate professor at the University of Wisconsin School of Medicine and Public Health. He said the study identified robust, measurable differences suggesting that living environments can affect the brain at the molecular and cellular level.
For the retrospective study, researchers examined whether living in the most socioeconomically disadvantaged neighbourhoods was associated with two measures of brain health: brain age gap and total brain volume. Brain age gap refers to the difference between a person’s actual age and the estimated age of their brain based on MRI. A brain that appears older than a person’s chronological age may indicate poorer brain health.
The researchers analysed MRI exams from 2,826 patients—1,094 men and 1,732 women—ranging in age from 18 to 96. The scans were collected during inpatient and outpatient clinical examinations at the University of Wisconsin Hospitals and Clinics and community partners between January and June 2024. Patients whose scans showed evidence of disease were excluded, and the analyses accounted for age and sex.
Researchers also assigned each patient an Area Deprivation Index (ADI) score based on their residential zip code. The ADI measures neighbourhood-level socioeconomic disadvantage using 17 indicators related to income, education, employment and housing. The study used information derived from the 2023 American Community Survey to assess the socioeconomic conditions of patients’ neighbourhoods.
The results showed that people living in the most disadvantaged neighbourhoods had a higher brain age gap and lower total brain volume than those living in less disadvantaged areas. “We found that residents in the most disadvantaged neighborhoods had an accelerated brain age compared with people living in less deprived areas,” Dr. Yu said. Elevated brain age has previously been associated with cardiovascular risk factors, psychiatric illness and cognitive impairment.
MRI analysis also showed that residents of the most disadvantaged neighbourhoods had greater volumes of white matter hyperintensities—areas that appear as bright spots on brain MRI and can reflect damage to small blood vessels. Dr. Yu described them as “the footprints of cardiovascular damage in the brain.” Greater white matter hyperintensity volume has been linked with increased risks of memory loss, cognitive difficulties and dementia.
The researchers said MRI-derived measures could potentially help identify how social and environmental conditions are reflected in brain health and may eventually contribute to clinical risk assessment. The findings also highlight the importance of considering neighbourhood conditions alongside individual health factors. According to Dr. Yu, socioeconomic disadvantage can reflect accumulated structural inequities that extend beyond individual behaviours, making neighbourhood-level information potentially valuable when designing health interventions, shaping public policy and identifying communities that may benefit from improved access to care.
More information: Ethan H. Willbrand et al, Evaluating the Effect of Neighborhood-level Disadvantage on Brain Health: An Imaging Epidemiology Study, Radiology. DOI: 10.1148/radiol.260693
Journal information: Radiology Provided by Radiological Society of North America