The tonic of the wilderness was Henry David Thoreau’s
classic prescription for civilization and its discontents, offered in the 1854
essay Walden: Or, Life in the Woods. Now there’s scientific evidence supporting
eco-therapy. The Japanese practice of forest bathing is proven to lower heart
rate and blood pressure, reduce stress hormone production, boost the immune
system, and improve overall feelings of wellbeing.
Forest bathing—basically just being in the presence of
trees—became part of a national public health program in Japan in 1982 when the
forestry ministry coined the phrase shinrin-yoku and promoted topiary as
therapy. Nature appreciation—picnicking en masse under the cherry blossoms, for
example—is a national pastime in Japan, so forest bathing quickly took. The
environment’s wisdom has long been evident to the culture: Japan’s Zen masters
asked: If a tree falls in the forest and no one hears, does it make a sound?
To discover the answer, masters do nothing, and gain illumination.
Forest bathing works similarly: Just be with trees. No hiking, no counting
steps on a Fitbit. You can sit or meander, but the point is to relax rather
than accomplish anything.
“Don’t effort,” says Gregg Berman, a registered nurse,
wilderness expert, and certified forest bathing guide in California. He’s
leading a small group on the Big Trees Trail in Oakland one cool October
afternoon, barefoot among the redwoods. Berman tells the group—wearing
shoes—that the human nervous system is both of nature and attuned to it. Planes
roar overhead as the forest bathers wander slowly, quietly, under the green
cathedral of trees.
From 2004 to 2012, Japanese officials spent about $4 million
dollars studying the physiological and psychological effects of forest bathing,
designating 48 therapy trails based on the results. Qing Li, a professor at
Nippon Medical School in Tokyo, measured the activity of human natural killer
(NK) cells in the immune system before and after exposure to the woods. These
cells provide rapid responses to viral-infected cells and respond to tumor
formation, and are associated with immune system health and cancer prevention.
In a 2009 study Li’s subjects showed significant increases in NK cell activity
in the week after a forest visit, and positive effects lasted a month following
each weekend in the woods.
This is due to various essential oils, generally called
phytoncide, found in wood, plants, and some fruit and vegetables, which trees
emit to protect themselves from germs and insects. Forest air doesn’t just feel
fresher and better—inhaling phytoncide seems to actually improve immune system
function.
Experiments on forest bathing conducted by the Center for
Environment, Health and Field Sciences in Japan’s Chiba University measured its
physiological effects on 280 subjects in their early 20s. The team measured the
subjects’ salivary cortisol (which increases with stress), blood pressure,
pulse rate, and heart rate variability during a day in the city and compared
those to the same biometrics taken during a day with a 30-minute forest visit.
“Forest environments promote lower concentrations of cortisol, lower pulse
rate, lower blood pressure, greater parasympathetic nerve activity, and lower
sympathetic nerve activity than do city environments,” the study concluded.
In other words, being in nature made subjects,
physiologically, less amped. The parasympathetic nerve system controls the
body’s rest-and-digest system while the sympathetic nerve system governs
fight-or-flight responses. Subjects were more rested and less inclined to
stress after a forest bath.
Trees soothe the spirit too. A study on forest bathing’s
psychological effects surveyed 498 healthy volunteers, twice in a forest and
twice in control environments. The subjects showed significantly reduced
hostility and depression scores, coupled with increased liveliness, after
exposure to trees. “Accordingly,” the researchers wrote, “forest environments
can be viewed as therapeutic landscapes.”
Berman advised the forest bathers to pick up a rock,
put a problem in and drop it. “You can pick up your troubles again when you
leave,” he said with a straight face.
City dwellers can benefit from the effects of trees
with just a visit to the park. Brief exposure to greenery in urban environments
can relieve stress levels, and experts have recommended “doses of nature” as
part of treatment of attention disorders in children. What all of this evidence
suggests is we don’t seem to need a lot of exposure to gain from nature—but
regular contact appears to improve our immune system function and our
wellbeing.
Julia Plevin, a product designer and urban forest bather,
founded San Francisco’s 200-member Forest Bathing Club Meetup in 2014. They
gather monthly to escape technology. “It’s an immersive experience,” Plevin
explained to Quartz. “So much of our lives are spent interacting with 2D
screens. This is such a bummer because there’s a whole 3D world out there!
Forest bathing is a break from your phone and computer…from all that noise of
social media and email.”
Before we crossed the threshold into the woods in Oakland,
Berman advised the forest bathers to pick up a rock, put a problem in and drop
it. “You can pick up your troubles again when you leave,” he said with a
straight face. But after two hours of forest bathing, no one does.
Joy Chiu, a leadership and life coach on the forest bath led
by Berman, explained that this perspective on problems lasts long after a bath,
and that she returns to the peace of the forest when she’s far from here,
feeling harried. “It’s grounding and I go back to the calm feeling of being
here. It’s not like a time capsule, but something I can continually return to.”https://qz.com/804022/health-benefits-japanese-forest-bathing/?utm_source=atlfb
