SCOTT SIMON, HOST:
It's well known that trees help counter climate change by soaking up carbon dioxide. Now there is a growing body of research to point to many ways a dose of trees can improve our mental and physical health. Here's Martha Bebinger of member station WBUR on how and why.
MARTHA BEBINGER, BYLINE: The tiny sapling Robin Williams planted 30 years ago towers above her Boston home.
ROBIN WILLIAMS: I raised this tree when I raised my children. And look at this (laughter). Look at that.
BEBINGER: She says there's something about being near this tree.
WILLIAMS: It makes everybody a little bit happy around here. When you're looking for strength, you can't do better than looking at a tree.
BEBINGER: And there's evidence Williams may well be gleaning any number of direct or associated health benefits.
HOWARD FRUMKIN: A longer life, better birth outcomes, lower stress levels, lower risk of heart disease...
BEBINGER: Dr. Howard Frumkin is at the University of Washington School of Public Health.
FRUMKIN: ...Lower risk of diabetes, reduced symptoms of ADHD. Proximity to trees is associated with a ridiculously broad range of health benefits. I wish we had pills that were this good for health.
BEBINGER: A few countries, notably Japan and South Korea, have invested in a practice known as forest bathing, which is spending time among trees as a preventive health measure. But prescribing time in nature is still pretty far outside mainstream medicine in the U.S. Frumkin says that may be because there's a lot we don't know.
FRUMKIN: What dose is needed? Do you need to walk among trees? Is it sufficient just to look at the trees from outside your window? Do you need big trees, or do small trees do the trick?
PETER JAMES: You know, we're not able to tease the forest from the trees.
BEBINGER: Peter James at Harvard Medical School aims to answer a lot of those questions. He's merging health data captured by phones, real-time surveys about well-being and mood and street-view mapping data.
JAMES: To dig into what's exactly within view - is it trees, is it flowers? - and how those things are related to health behaviors and health outcomes.
BEBINGER: Researchers are also trying to figure out how much time among trees we need. One U.K. study says two hours a week is enough for people who get outdoors to report better health than those who don't. Study co-author Dr. Sara Warber says it didn't matter whether they were exercising or sitting still.
SARA WARBER: It's all about just getting your human self out into nature.
BEBINGER: Why getting out into nature and being around trees makes us healthier and happier is less clear. Warber describes a top theory.
WARBER: We weren't designed to be inside houses. We were designed to be in nature. And we feel best when we're there.
BEBINGER: Another theory is that a walk in the woods stimulates our immune systems. Then there's the theory of awe, seeing something...
MICHELLE SHIOTA: That literally blows your mind.
BEBINGER: Michelle Shiota, who studies awe at Arizona State University, felt it earlier this summer among the redwoods north of San Francisco.
SHIOTA: Some of those benefits may come from looking at something that is so much larger than you and so much older than you and will exist long after we're gone.
BEBINGER: Of course, that's if these trees survive the fires and drought increasing with climate change. In Boston, like many places, lower-income neighborhoods have few trees. But public parks have drawn record crowds during the pandemic. Ned Friedman runs the 280-acre Arnold Arboretum.
NED FRIEDMAN: We're part of what keeps people out of hospitals. So for me, an arboretum like the Arnold and the other - the magnificent green spaces in Boston should be thought of as essential to health and well-being of the citizenry.
BEBINGER: Especially now when there's such an urgent need to boost our health as well as that of the planet.
For NPR News, I'm Martha Bebinger in Boston.
(SOUNDBITE OF GARETH COKER'S "APHRODITE - GODDESS OF LOVE") Transcript provided by NPR, Copyright NPR.
