Pollution, a lot of noise, and large numbers of people in a ‘small’ space like a city… these elements can cause chronic stress. But how does it affect the health of our thinking organ to live in the city?
A study by scientists at the Max Planck Institute for Human Development (Germany) has investigated the relationship between the availability of nature near the people who usually reside in cities and their brain health.
Earlier studies have already shown that city dwellers have a higher risk of psychiatric illnesses such as depression, anxiety disorders and schizophrenia compared to urban dwellers.
When comparing both brains by place of residence, higher levels of activity are seen in the amygdala of people living in cities than in those living in the countryside. The brain amygdala plays a major role in stress management and reactions to danger.
So scientists wondered what factors might have a protective influence for people living in cities. A research team, led by psychologist Simone Kühn, analyzed the effect of nature near homes, such as a forest, park or even a wasteland, in brain regions that process stress, such as the amygdala.
“Research into the plasticity of the brain supports the assumption that the environment can shape the structure and function of the brain, so we are interested in environmental conditions that can have positive effects on brain development have shown that living close to nature is good for health and mental well-being, so we decided to examine the inhabitants of the city,”explains Simone Kühn, the leader of the work.
The experts found an association between the place of residence and brain health. Specifically, city dwellers living near a forest were more likely to show indicators of a physiologically healthy amygdala structure and, therefore, more able to cope with stress, than those who had no near or nature traces.
This effect remained stable when controlling for differences in educational qualifications and income levels. However, it was not possible to find a positive relationship between the brain regions examined and the presence of a park or a vacant land.
Although it is not possible to distinguish whether living near a forest actually has positive effects on the amygdala or if people with a healthier amygdala are more likely to select residential areas near a forest, researchers consider the first explanation to be the most plausible.
The volunteers, a total of 341 adults between 61 and 82 years of age, belong to the Berlin Aging Study II (BASE-II), a larger longitudinal study that examines the physical, psychological and social conditions for healthy aging. In addition to performing memory and reasoning tests, they also performed magnetic resonance imaging (MRI) scans.
“Our study investigates for the first time the connection between the characteristics of urban planning and the health of the brain,” says Ulman Lindenberger, co-author of the study.
Taking into account that by 2050, almost 70% of the world population is expected to live in cities, these conclusions could be relevant for urban planning.