Living in the city is a well-known risk factor for developing a mental disorder, while living close to nature is widely beneficial for mental health and the brain. A central region of the brain involved in processing stress, the amygdala, was found to be less activated during stress in people who live in rural areas, compared to those who live in cities, hinting at the potential benefits of nature. “But so far, the chicken and egg problem has not been able to be disentangled as to whether nature actually caused the effects in the brain or whether particular individuals chose to live in specific regions. rural or urban,” says Sonja Sudimac, predoctoral fellow at the Lise Meitner Group for Environmental Neuroscience and lead author of the study.
To obtain causal evidence, researchers from the Lise Meitner Group for Environmental Neurosciences examined brain activity in regions involved in stress processing in 63 healthy volunteers before and after an hour-long walk in the Grunewald Forest or in a shopping street with traffic in Berlin using functional magnetics. resonance imaging (fMRI). Study results revealed that amygdala activity decreased after walking in nature, suggesting that nature elicits beneficial effects on stress-related brain regions.
“The results support the previously assumed positive relationship between nature and brain health, but this is the first study to prove causation. Interestingly, brain activity after urban walking in these regions remained stable and did not show an increase, which argues against a common view that urban exposure causes additional stress,” says Simone Kühn, head of the Lise Meitner group for environmental neurosciences.
The authors show that nature has a positive impact on the brain regions involved in stress processing and this can already be observed after a one-hour walk. This contributes to the understanding of how our physical living environment affects brain and mental health. Even brief exposure to nature decreases amygdala activity, suggesting that a walk in nature could serve as a preventative measure against the development of mental health problems and buffer the potentially detrimental impact of the city on the brain. .
The results support a previous study (2017, Scientific Reports) which showed that city dwellers who lived close to the forest had a physiologically healthier amygdala structure and were therefore likely better able to cope with stress. This new study confirms once again the importance for urban planning policies of creating more accessible green spaces in cities in order to improve the mental health and well-being of citizens.
To investigate the beneficial effects of nature in different populations and age groups, researchers are currently working on a study examining how a one-hour walk in natural versus urban environments affects stress in mothers. and their babies.