A new study has found quantifiable evidence that supports the common-sense idea that walking in nature could lower your risk of depression. The study, published in Proceedings of the National Academy of Science, found that people who walked for 90 minutes in a natural area, as opposed to participants who walked in a high-traffic urban setting (El Camino Real in Palo Alto, California, a noisy street with three to four lanes in both directions), showed decreased activity in the subgenual prefrontal cortex, a brain region active during rumination — repetitive thought focused on negative emotions. “These results suggest that accessible natural areas may be vital for mental health in our rapidly urbanizing world,” said co-author Gretchen Daily, the Bing Professor in Environmental Science and a senior fellow at the Stanford Woods Institute for the Environment. “Our findings can help inform the growing movement worldwide to make cities more livable, and to make nature more accessible to all who live in them.” “This finding is exciting because it demonstrates the impact of nature experience on an aspect of emotion regulation — something that may help explain how nature makes us feel better,” said lead author Gregory Bratman, a graduate student in Stanford’s Emmett Interdisciplinary Program in Environment and Resources, the Stanford Psychophysiology Lab and the Center for Conservation Biology. “These findings are important because they are consistent with, but do not yet prove, a causal link between increasing urbanization and increased rates of mental illness,” said co-author James Gross, a professor of psychology at Stanford.
Essential for urban planners to incorporate nature
It is essential for urban planners and other policymakers to understand the relationship between exposure to nature and mental health, the study’s authors write. “We want to explore what elements of nature — how much of it and what types of experiences — offer the greatest benefits,” Daily said. As noted in the paper, “Never before has such a large percentage of humanity been so far removed from nature ; more than 50% of people now live in urban areas, and by 2050, this proportion will be 70% . Although urbanization has many benefits, it is also associated with increased levels of mental illness, including anxiety disorders and depression [3-5].”