When we spend time outdoors, it not only helps us relax and lift our spirits — the positive effect can be seen in the brain, a small pilot study now suggests. In this study, brain scans using magnetic resonance imaging showed that gray matter in one area of the frontal lobe benefits from being outdoors. The next thing scientists want to investigate is whether walking in the countryside is better than walking in the city.
Whether in a city park, garden or forest: When we are in nature, it is good for body and soul, as many studies have shown in recent years. Staying in the country relaxes us, makes our heartbeat slower and lifts our mood. People who live in greener areas have less cardiovascular disease, diabetes, and other lifestyle diseases, and children’s ability to focus increases. But trips to the countryside also have a positive effect: In 2019, a study found that just 120 minutes in nature a week was enough to boost health.
Significant effect on the frontal lobe
Simone Kuhn of the Max Planck Institute for Human Development in Berlin and colleagues have now investigated the effect of being outdoors on the brain. To do this, they regularly scanned the brains of six healthy adults living in Berlin over a six-month period using magnetic resonance imaging (MRI) – they performed a total of 280 brain scans. In addition, they recorded the amount of time the participants spent outdoors in the 24 hours leading up to the tests and asked about other factors that could affect the brain. This included the amount of fluids and number of caffeinated drinks the test subjects consumed, the amount of free time they spent and the amount of exercise they did.
Studies have shown that staying outdoors not only raised the mood of test subjects, but also had immediate effects on the brain. The more time participants spent outside before the scan, the greater the gray matter volume in the right dorsolateral prefrontal cortex. This was an area of the cerebral cortex located on the side behind the forehead, which is involved in planning and organizing actions and in what is known as cognitive control. Many mental disorders are associated with decreased gray matter in the frontal lobe region of the brain.
The effect is independent of other influencing factors
Even for the research team, it was surprising that this positive effect of being outside persisted even if all other influencing factors such as sunlight, leisure time, physical activity and fluid intake were taken into account. “It was a real surprise to us that none of these covariates were able to explain differences in the right dorsolateral prefrontal cortex,” Cohn and colleagues said. Thus, the study proves that spending time outdoors has a positive effect on the brain, regardless of other influencing factors. This seems to apply even regardless of whether we are in the city or in the country, and even for very short periods outdoors.
“Our results show that brain structure and mood improve when we spend time outdoors,” says Cohn. “It can be assumed that this also has an effect on concentration, working memory, and psychological as a whole.” This agrees well with the results of meta-analyses, which also show positive effects of being in nature on the psyche. If you are outdoors regularly, you are not only doing something good for your well-being, but also for your brain. In another study, the research team would like to determine whether residency in the country may increase these positive effects. To do this, they provide test subjects with recording devices and GPS sensors, which they can use to record factors such as exposure to light, pollutants, and noise.
Coil: Max Planck Gesellschaft; Fachartikel: World Journal of Biological Psychiatry, doi: 10.1080/15622975.2021.1938670