UK contributes to global study showing where people live may impact how the brain ages
A large international study published in Nature Medicine analyzed brain scans and health data from 18,701 individuals across 34 countries and found that combined environmental and social factors referred to as the exposome strongly influence whether the brain appears biologically older or younger than a person’s actual age. The research, involving contributors from the University of Kentucky Sanders-Brown Center on Aging, showed that factors such as air pollution, climate, green space access, education, and inequality together explain more variation in brain aging than any single factor or even some clinical diagnoses. Using advanced imaging and machine learning, researchers estimated “brain age,” with larger gaps between brain and chronological age linked to higher risks of cognitive decline and dementia, underscoring the significant role of broader living environments in shaping brain health.
The study found that physical environmental factors such as air pollution, extreme temperatures, and limited green space are strongly linked to structural changes in the brain, while social conditions like poverty, inequality, weaker democratic systems, and low civic participation are more associated with disruptions in brain connectivity. These combined pressures were shown to accelerate brain aging even in individuals without diagnosed neurological conditions. The findings, published in Nature Medicine, highlight the need to go beyond individual lifestyle and medical approaches, emphasizing broader strategies such as reducing pollution, improving access to green spaces, strengthening education, and addressing inequality. The research also draws on long-term brainwave data contributions from the University of Kentucky Sanders-Brown Center on Aging, reinforcing the role of environmental and social contexts in shaping cognitive health.
Yang Jiang noted that the research builds on contributions from William Markesbery, who referred Alzheimer’s patients, and Greg Jicha, whose ongoing clinical efforts have expanded the cohort, alongside numerous trainees at the University of Kentucky College of Medicine. The study leveraged a unique, long term dataset of de identified electrophysiological (EEG) data from participants in the UK Alzheimer’s Disease Research Center, providing one of the most comprehensive brain aging resources in the United States. This historical dataset strengthened the global analysis by placing current brain aging patterns into a broader biological context. Overall, the international study spanning institutions across multiple continents demonstrates how cumulative environmental and social exposures interact over time and underscores the importance of examining brain health across diverse populations.
