Why Doctors Are Prescribing Nature Walks

Jillian Mock · TIME · APRIL 27, 2022

Featuring Gregory Bratman, Center co-director and researcher

When it comes to how nature exposure helps our stressed-out brains, researchers have two main theories, says Gregory Bratman, director of the environment and well-being lab at the University of Washington. The first, known in scientific circles as the Stress Reduction Theory, is that exposure to many forms of nature engages the parasympathetic nervous system, which is responsible for rest and digestion and encourages stress recovery. (It’s nicknamed the “rest and digest” system.) The other, the Attention Restoration Theory, suggests that nature engages people’s “soft fascination,” says Bratman. This gives our directed attention, which we use to focus, time to replenish, he says.

Much of the research has focused just on the visual aspects of nature—seeing the green of trees or grass, or the blue of a river or ocean. But “nature experiences are multi-sensory,” notes Bratman. Practitioners of shinrin-yoku (or “forest bathing”) in Japan theorize that the scent and experience of breathing in the compounds that trees exude into the air could impact immune function, says Bratman. Sound is another key sense that may indicate safety or danger, allowing relaxation or exacerbating stress—and soothing nature sounds fit firmly in the first camp, says Rachel Buxton, a conservation scientist at Carleton University in Canada, who studies soundscapes, seabird ecology, and ecological restoration.