Countries with higher levels of inequality—whether in terms of economics, pollution, or disease—boast older brain ages, according to research published in Nature Medicine, which included contributions from the University of Surrey.
Research has identified that countries marked by significant inequalities—be it economic disparities, pollution levels, or health issues—tend to show older brain ages, as detailed in a study featured in Nature Medicine, conducted with involvement from the University of Surrey.
The rate at which our brains age can differ considerably from one person to another, creating a disparity between an individual’s biological brain age and their chronological age (the number of years they’ve lived). This gap can be influenced by various factors, including environmental influences like pollution and social aspects such as income inequality or health disparities, particularly among the elderly and those suffering from dementia. Previously, the impact of these combined factors on brain ageing across different geographical regions had not been well understood.
A team of global researchers in this study developed techniques to assess brain ageing using advanced “brain clocks” that leverage deep learning of brain networks. The study included a broad sample of 5,306 participants from 15 different countries, encompassing both Latin American and Caribbean (LAC) and non-LAC nations. By examining data from functional magnetic resonance imaging (fMRI) and electroencephalography (EEG), the researchers were able to measure the differences in brain ages between healthy individuals and those diagnosed with neurodegenerative disorders such as mild cognitive impairment (MCI), Alzheimer’s disease, and frontotemporal lobe degeneration (FTLD).
Dr. Daniel Abasolo, a co-author of the study and Head of the Centre for Biomedical Engineering at the University of Surrey, said:
“Our findings indicate that in nations with higher inequality, people’s brains age more quickly, especially in regions that are most susceptible to the impacts of ageing. We uncovered that socioeconomic disparities, air pollution, and the prevalence of diseases significantly contribute to this accelerated ageing process, notably in low-income countries.”
Participants diagnosed with dementia, especially those with Alzheimer’s, showed the most pronounced differences in brain age. The study also pointed out gender differences in brain ageing, with women from LAC countries displaying greater age differences, particularly among those with Alzheimer’s disease. These variations were found to be connected to biological sex as well as disparities in health and social conditions. Differences in data quality, demographics, or data collection methods did not account for the findings. This emphasizes the significant role of environmental and social factors in the disparities seen in brain health.
The implications of this research are significant for neuroscience and brain health, particularly in exploring how larger-scale factors (the exposome) interact with the biological processes of brain ageing across different populations. The innovative approach of incorporating multiple diversity dimensions in brain health research presents a new perspective for personalized medicine. This could be vital in recognizing individuals at risk for neurodegenerative diseases and creating targeted approaches to alleviate these risks. Furthermore, the results of this study stress the importance of acknowledging how environmental and social factors are ingrained in public health strategies. By tackling issues like socioeconomic inequality and environmental pollution, policymakers have the potential to close brain age gaps and foster healthier ageing within various communities.
