A recent international study reveals that the environment in which a person lives is no less influential than their lifestyle in determining the rate at which their brain ages.
Factors such as pollution, poverty, or poor services can accelerate brain deterioration, while social justice and healthcare can slow it down.
The researchers analyzed data from 18,701 individuals across 34 countries, studying what is known as the "exposome"—the sum of environmental, social, and political factors a person is exposed to throughout their life. The results showed that these factors do not operate in isolation but interact simultaneously, with the concurrent presence of multiple risk factors amplifying the impact on brain health.
Researchers measured 73 different factors at the country level, including air pollution, climate change, water quality, green spaces, as well as indicators of poverty, inequality, and political stability. When these factors were analyzed together, they were found to explain differences in brain aging up to 15 times greater than any single factor.
The results indicate that environmental effects on the brain are cumulative and complex, with interactions between different factors significantly accelerating or slowing down aging.
For example, physical environmental factors such as pollution, rising temperatures, and a lack of green spaces have been linked to changes in brain structure, particularly in areas responsible for memory and emotional regulation. Researchers suggest these effects are related to biological processes such as neuroinflammation and oxidative stress.
Conversely, social factors such as poverty, inequality, and lack of support have a strong impact on brain function, particularly in areas related to thinking and social behavior. It is believed that prolonged exposure to stress accelerates the decline of these brain regions over time, potentially having a greater impact than some diseases like dementia.
The researchers confirmed that these results apply to healthy individuals as well as those with neurological diseases, reinforcing the idea that the general environment plays a crucial role in brain health.
The research team believes that the current focus on individual behaviors, such as food and exercise, while important, is not enough on its own to reduce the risks of brain aging, because a large part of these risks is related to broader conditions beyond the individual's control.
Accordingly, the study calls for the adoption of comprehensive policies that improve the living environment, such as reducing air pollution, increasing green spaces, improving water quality, and promoting social justice.
It also emphasizes that protecting brain health requires cooperation between multiple sectors, including environmental and social policies, along with support for institutional stability and community engagement, to ensure a healthier environment for current and future generations.
The study was published in the journal Nature Medicine.
