The Outside RX
The Nature Cure
“Well,” he mused, “in our culture, nature is part of our minds and bodies and philosophy. In our tradition, all things are relative to something else. In Western thought, all things are absolute.”
Maybe it was the sake, but he was starting to lose me.
“The difference is in language,” he continued. “If I ask you, ‘A human is not a dog, is it?’ you say, ‘No, a human is not a dog.’ In Japan, we say, ‘Yes, a human is not a dog.’” The great sensei of nature studies peered at me over his chopsticks. I was reminded of the story of the Zen student who asks his teacher, “How do you see so much?” and the teacher responds, “I close my eyes.”
Miyazaki, I understood, was like a koan, impenetrable. But you had to trust that the guy was onto something.
ON THE MORNING OF the forest experiment, the college kids and I took turns sitting in the mobile lab at the trailhead. The boys were skinny, sleepy-eyed, and unfailingly polite. As if we were receiving sacrament, we placed hard cotton cylinders under our tongues for two minutes, then spit them out into test tubes. Once analyzed in a lab, these samples would reveal our levels of salivary cortisol, a stress hormone made in the adrenal cortex and sent to the brain. Lee, exuding calm and efficiency, hooked us up to other electrodes and devices that would track changes in blood pressure, pulse rate, and heart rate, gauging our physiological responses to the forest and the city.
These are standard measurements the team has used for years. But today they also pulled out the new battery powered spectrometer, which, when deployed, gave me a sensation of leeches sticking to my forehead. It’s designed to measure hemoglobin levels (a proxy for blood and oxygen) in the prefrontal cortex. This is the brain geography that deals with cognitive and executive functions, such as planning, problem solving, and decision making. When aggregated, these metrics paint a picture of our bifurcated nervous system.
The researchers want to know if being in nature gives these frontal lobes a much needed rest. When we are relaxed and at ease in our environment, our parasympathetic system—sometimes called the rest-and-digest branch—kicks in, stimulating appetite. This is why food tastes better in the outdoors, explained Miyazaki. But the constant stimulus of modern life triggers our sympathetic nervous system, which governs fight-or-flight behaviors. And triggers it, and triggers it. A long trail of research dating back to the 1930s shows that people with chronically high cortisol levels and blood pressure are more prone to heart disease and depression.
When it was my turn to wander through the forest for 15 minutes, I was happy to break free from the wires. The loud pulse of cicadas echoed through the woods. Light filtered gently through the beeches and Japanese horse chestnuts, and the earth smelled like, well, earth. An elderly couple ambled by, assisted by walking sticks and a bear bell. I was briefly mesmerized by a yellow butterfly. I could see why Juniko is a candidate for the country’s next forest-therapy station. Local and park officials are seeking the designation because, where there’s forest therapy, there are tourists and their yen. Miyazaki may have a mystical side, but what drives him is the data he gets from these parks. It’s a convenient arrangement.