We all know that living in a city can be stressful and intense. With already half of the world’s population living in cities (and more moving in every day), cities will only become bigger, noisier, and more crowded — which probably means a lot more stress for a lot more people. But there’s an antidote: spending time in nature can make a big difference, even if it’s just for an hour every now and then, a new study reports.
For decades, researchers have found mental health differences between those living in rural and urban environments. It’s clear that spending time in a natural environment can be psychologically beneficial, reducing stress and negative emotions. Nevertheless, the neural underpinnings of these effects of nature are still poorly understood.
The amygdala, a part of the brain involved in stress processing, has been shown in studies to be less activated during stress in people who live in rural areas compared to those living in cities. But whether nature actually caused this or if there were other factors at play wasn’t clear, Sonja Sudimac, neuroscience researcher and lead author of the study, said in a statement.
The benefits of nature
In a new study, researchers created a unique experiment to figure out whether and how spending time in nature directly reduced our stress responses. They recruited about 60 volunteers and asked them to take an MRI scan. The researchers then tracked amygdala activity during several tests in order to measure their stress levels.
After establishing baseline measurements, each person was randomly allocated to take a 60-minute walk either in the city or in a forest. The urban route was in a busy street in Berlin, while the natural one was in a nearby forest. Once they finished the walk, the participants went back to the laboratory and repeated the MIR imaging tests.
Everyone who walked around the forest saw a decline in their stress levels, while those walking on the urban route saw no change in amygdala activity. These results indicate that urban exposure doesn’t necessarily increase an individual’s stress responses but that time in nature can reduce that neural activity, the researchers said. It also suggests that it’s not the walking itself producing the improvement, but rather the time spent in nature.
“We demonstrated that amygdala activation decreased during a stress task after nature exposure, whereas it remained stable after urban exposure,” the researchers wrote in the the journal Molecular Psychiatry. “This strongly argues in favor of the salutogenic effects of nature as opposed to urban exposure causing additional stress.”
The study again confirms the importance of urban design policies to create accessible green areas in cities so as to boost people’s mental health and overall wellbeing. The researchers said they are now working on another study to understand how a 60-minute walk in nature vs urban environment affects stress in mothers and their babies.
The study is fully accessible here.