Studies Much healthier amygdala near the forest

MRI study analyzes stress-processing brain areas of older city dwellers
Those living near the forest can handle stress better. This was the result of a study by the Max Planck Institute for Human Development. The researchers have for the first time investigated the connection between local resident and the brain health of city dwellers. The result is also relevant for urban planning.

Living at the edge of the forest seems to have a positive effect on the stress-processing brain areas of city dwellers. Researchers found a healthier structure in them than in those who had no free nature in their immediate environment.

Life at the edge of the forest keeps the brain healthy. (Image: ferkelraggae / fotolia.com)

Noise, air pollution and many people in confined spaces: City life can cause chronic stress. City dwellers are more likely to suffer from mental illnesses such as depression, anxiety disorders and schizophrenia than rural residents. In comparison, city dwellers show higher activity of the amygdala than rural dwellers - a small region of the brain that plays an important role in stress management and response to dangers. But what factors can be preventative??

A team of scientists around the psychologist Simone Kühn has now investigated the influence of near-residential nature such as forest, urban green or water areas and fallow land on stress-processing brain areas such as the amygdala - in professional circles also called amygdala. "Research on brain plasticity supports the assumption that the environment can shape both the brain structure and its function. We are therefore interested in the environmental conditions that have a positive effect on brain development. From studies of rural dwellers, we know that living close to nature is good for mental health and well-being. So we looked at how it behaves with city dwellers, "explains first author Simone Kühn, who led the study at the Max Planck Institute for Human Development and now works at the University Hospital Hamburg-Eppendorf (UKE).

Parks have no influence

Indeed, in their study, the scientists found a link between home and brain health: those who lived near the forest showed more evidence of a physiologically healthy structure of the amygdala and may therefore be better able to cope with stress. This effect persisted even when differences in educational attainment and in income were excluded. However, no correlation was found between urban green or water areas, as well as fallow land and the brain regions studied. Whether forest-related living actually has a positive effect on the amygdala or whether people with a healthier amygdala visit forest-related residential areas can not be decided with the available data. However, against the background of previous findings, the scientists consider the first explanation more likely. In order to be able to prove this, further follow-up studies are required.

The participants of the study were from the Berlin Age Study II (BASE-II) - a follow-up study that examines the physical, mental and social conditions for a healthy aging. In total, 341 older adults between the ages of 61 and 82 years were recruited for the study. In addition to thinking and memory tasks, magnetic resonance imaging (MRI) was used to measure the structure of stress-processing brain regions - in particular the amygdala. In order to investigate the impact that near-residential nature has on these brain regions, the researchers assembled the MRI data with geo-information about the place of residence of the volunteers. This information came from the European Urban Atlas of the European Environment Agency, which gives an overview of urban land use in Europe.

Consequences for urban planning

"Our study is the first to examine the relationship between urban development features and brain health," says co-author Ulman Lindenberger, director of the Department of Developmental Psychology at the Max Planck Institute for Human Development. It is expected that by 2050, almost 70 percent of the world's population will live in cities. Therefore, the results could be important for urban planning. First, however, it is important to review the observed relationship between the brain and the forest in further studies and other cities, says Ulm Lindenberger.