Brain-Mental Health Benefits
To date, there is quite a bit of research exploring the impacts of exposure to nature on the brain. For example, data have shown that adolescents raised exclusively in rural environments have a larger hippocampus and better spatial processing than children exclusively raised in cities. Other research demonstrated that spending just an hour in the forest led to a decline in amygdala activity in adults, whereas it remained stable after walking in an urban setting, underscoring the salutogenic effects on brain regions related to stress. There is also evidence from a 10-year longitudinal study of more than 2 million Welsh adults that highlights the value of proximity to green or blue (eg, lakes and rivers) spaces and common mental health conditions, with every additional 360 meters to the nearest green or blue space associated with 10% greater odds of anxiety and depression.
Dr. Bird said there has been a massive sea change in attitudes among general practitioners, who have come around to embracing the concept of nature as medicine. This shift among peers, who teased him in the 1990s about his green walking and conservation prescriptions, portends a bandwagon of epic proportions that could benefit patients. He said that he was especially hopeful that green prescriptions will become mainstream in certain conditions, especially those like depression and anxiety that are resistant to medication.
But Dr. Bird cautions that primary care professionals need to be mindful. “Patients need to know that it’s real science, otherwise they’ll think that they’re being pawned off or dismissed,” he said. “I try to put real evidence behind it and explain that there’s no contraindication. The main thing is to start where patients are, what they’re feeling, and what they need. Some people just don’t like nature,” he said.
A version of this article appeared on Medscape.com.