National Geographic : 2016 Jan
58 national geographic • january 2016 pressure, and a 4 percent drop in heart rate. Miyazaki believes our bodies relax in pleasant, natural surroundings because they evolved there. Our senses are adapted to interpret in- formation about plants and streams, he says, not traffic and high-rises. All this evidence for the benefits of nature is pouring in at a time when disconnection from it is pervasive, says Lisa Nisbet, a psychology professor at Canada’s Trent University. We love our state and national parks, but per capita vis- its have been declining since the dawn of email. So have visits to the backyard. One recent Na- ture Conservancy poll found that only about 10 percent of American teens spend time outside every day. According to research by the Har- vard School of Public Health, American adults spend less time outdoors than they do inside vehicles—less than 5 percent of their day. “People underestimate the happiness ef- fect” of being outdoors, Nisbet says. “ We don’t think of it as a way to increase happiness. We think other things will, like shopping or TV. We evolved in nature. It’s strange we’d be so disconnected.” But some people are starting to do something about it. Nooshin Razani at UCSF Benioff Children’s Hospital in Oakland, California, is one of several doctors who have noticed the emerging data on nature and health. As part of a pilot project, she’s training pediatricians in the outpatient clinic to write prescriptions for young patients and their families to visit nearby parks. It’s not as simple as taking a pill. To guide the physicians and patients into a new mind-set, she says, “we have transformed the clinical space so nature is everywhere. There are maps on the wall, so it’s easy to talk about where to go, and pictures of local wilderness, which are healing to look at for both the doctor and patient.” The hospital is partnering with the East Bay Regional Parks District to provide transportation to parks and programs there for entire families. In some countries governments are promot- ing nature experiences as a public health policy. In Finland, a country that struggles with high experimental studies of the central nervous system. Measurements of stress hormones, respiration, heart rate, and sweating suggest that short doses of nature—or even pictures of the natural world—can calm people down and sharpen their performance. In Sweden physician Matilda van den Bosch found that after a stressful math task, subjects’ heart rate variability—which decreases with stress—returned to normal more quickly when they sat through 15 minutes of nature scenes and birdsong in a 3-D virtual reality room than when they sat in a plain room. A real-life experiment is under way at the Snake River Correctional Institution in eastern Oregon. Officers there report calmer behavior in soli- tary confinement prisoners who exercise for 40 minutes several days a week in a “blue room” where nature videos are playing, compared with those who exercise in a gym without videos. “I thought it was crazy at first,” says corrections officer Michael Lea. But he has experienced the difference. “There’s a lot of yelling really loud— it echoes horribly,” in the plain gym, he says. “In the blue room they tend not to yell. They say, ‘Hold on, I got to watch my video.’ ” A 15-minute walk in the woods causes mea- surable changes in physiology. Japanese re- searchers led by Yoshifumi Miyazaki at Chiba University sent 84 subjects to stroll in seven different forests, while the same number of volunteers walked around city centers. The forest walkers hit a relaxation jackpot: Overall they showed a 16 percent decrease in the stress hormone cortisol, a 2 percent drop in blood Visits to parks are down. So are visits to the backyard. One survey found only 10 percent of American teens spend time outside every day.