Can trees heal people?

The establishment of dozens of “healing forests” is part of South Korea’s surprising prescription to improve its citizens’ health and wellbeing. Journalist Florence Williams takes a walk in the woods to learn more about this intriguing approach to public health.

Park Hyun-Soo didn’t look like a man on chemotherapy. Forty-one and with a full head of black hair, he can hike the socks off anyone, but he prefers to take his time. Not exactly a forest ranger, Park is is part of a new breed of Korean Forest Agency employee known as a forest healing instructor. He’d actually gone to graduate school for this, passing rigorous entrance qualifications. Although he began his career in a competitive corporate job, he received a diagnosis of chronic myeloid leukemia at age 34. He decided to seek peace and recovery in the woods, and it worked so well he decided to orient his entire life to the cypress trees.

Park greeted my translator and me in the parking lot of Jangseong Healing Forest. Between 2,000 and 3,000 visitors come through here every month, including three to four groups per day geared to some kind of healing, from cancer patients to kids with allergies to prenatal groups and everything in between. Depending on the program, participants may do activities like guided meditation, woodcrafts and tea ceremonies. But the heart of it all is walking in the hinoki forest.

Park is at the forefront of South Korea’s ambitious National Forest Plan. Its goal is “to realize a green welfare state, where the entire nation enjoys well-being.” The scope of all this is, true to Korean form, ambitious. In the same way Samsung is trying to outmaneuver Apple and K-Pop intends to dominate Asia, Korea is on a path to outdo the world in forest therapy trails and science (TEDxNavesink Talk: Making spaces of awe and restoration). Although Jangseong is one of only three official healing forests in South Korea, 34 more are slated to appear in the next two years. In addition, the Forest Agency is building an ambitious $100 million forest healing complex, complete with addiction treatment center, “barefoot garden,” herb garden, suspension bridge, and 50 kilometers of trails.

The results of this campaign are promising: visits to the country’s forests increased from 9.4 million in 2010 to 12.7 million in 2013, or one-sixth of the country’s population (around the same time, visits to national forests in the US dropped by 25 percent). The agency now offers everything from prenatal classes in the woods to forest kindergartens to forest burial options. There is even a “Happy Train” that delivers school bullies to a national forest for two days so they can learn to be nicer. At a forest named Saneum, I came upon a forest-healing program for firefighters with PTSD, where the men were practicing partner yoga in the woods.

Korea’s Jangseong Healing Forest smells great. Walking there is like moving through a picturesque vat of VapoRub.

Like the other participants, my translator and I would capture a snapshot of our stress levels before and after our walk at Jangseong Healing Forest. Unlike them, however, our agenda would just consist of a walk among the hinoki cypress with their pleasant, slightly acrid smell and robust notes of turpentine-meets-Christmas-tree. At the visitors’ center, we took our blood pressure and then inserted our fingers for several minutes into a sensor that is supposed to measure heart-rate variability. The idea was that the Korean Forest Agency will keep these records and use them to assemble a research database. Individuals can track their data over time and across different forests and facilities, so they can tell if one walk in the woods per week is enough for them to maintain lower blood pressure or if they better add more. (I checked my blood pressure again after an hour-and-a-half of leisurely walking, and I clocked a nice little drop, from 111 over 73 to 107 over 61.)

The Jangseong forest is considered a jewel in the system. As we headed out on a trail that skirts the 2,900-foot Chukryeong Mountain, Park told me about its history. Like much of Korea after World War II, these mountain flanks were once completely denuded. First the Japanese, who occupied Korea starting in 1910, cut the forests for timber. After the war, people scavenged what was left for heating fuel. Without trees to anchor the mountain, there were mudslides, and the streams choked with silt. Replanting began in the 1960s, and the Japanese hinoki cypress was a favorite for its fast growth and ability to ward off pests. Jangseong is now 88 percent hinoki. “There are two and a half million individual trees here,” said Park.

What makes the tree so unappetizing to insects has vaulted it to the heart of the Korean Forest Agency. It smells great. Walking there is like moving through a picturesque vat of VapoRub. We passed an interpretive sign claiming the woods have more oxygenated air than a city or a building. And whether or not these woods noticeably increase our oxygen supply, it feels like they do, clearing the sinuses and infusing every cell with an essence of the forest. With its rich amber bark and soaring greenery, Jangseong felt comforting, almost congregational.

I had to wonder if some of the benefits attributed to these mystical woods are the simple result of not being in the polluted city.

At the government-funded Korea Forest Research Institute, scientists are distilling essential oils from forest trees and plants and studying them for effects on allergies and their ability to kill bacteria. I may not have been actively nursing any infections, but after a few minutes of walking in Jangseong, I felt more awake than I had all day. We stopped where a wooden boardwalk crosses a small wetland lined with dogwoods, and Park pointed out a citronella plant and a Japanese cedar, also prized for anti-infective properties. He asked us to close our eyes and take deep breaths. Then he led us in gentle stretches. We raised our arms over our heads, then down, then back up, all while breathing slowly. The birds chirped, the wind blew gently through the high branches, and the sun mixed with the cool autumn air.

For three years, Park had walked mindfully in these woods every single day. “I’m 100 percent sure it is helping me,” said the ranger, who is in remission. “When I was first diagnosed, I had all kinds of fear and anxiety. I am happy now. I have zero percent anxiety. People learn from nature that they can heal. Now it is my duty to be a bridge between nature and people.”

It’s hard to say, though, what’s really helping Park and the many who flock to these places. Is it the exercise? Park takes 15,000 steps a day, about 6 miles. He also believes the forest heals him, and the power of that belief is hard to overestimate.

Walking around sniffing the fresh hinoki forest, I had to wonder if some of the benefits attributed to these mystical woods are the simple result of not being in the polluted city. Regardless of whether people know exactly how polluted their neighborhoods are, their psyches seem to know. In one survey of 400 Londoners, “life satisfaction” fell significantly — half a point on an 11-point scale — for each additional 10 milligrams per square meter of nitrogen dioxide pollution.

It’s not easy to compete with multi-player gaming, but the forest healing instructor had the boys’ full attention.

If less pollution can make us feel better, the same could be said of a reduction of noise, crowds, unwelcome distractions and technology. Like Park, Kim Jooyoun is also a newly trained forest healing instructor. On Saturdays, she teaches a digital detox program for preteens in one of Seoul’s big parks, Bukhansan. A mother, she understands the pressures on young Koreans and their striving families. Some years back, when her daughter was fourteen, Kim found her child literally pulling her hair out from stress.

I visited Kim’s program on a glorious fall day. At the park, seven boys were lying like lizards on turquoise yoga mats in a relatively secluded grove. Kim was having them listen to the sounds of nature. “If you want to play games better, you need to let your eyes rest,” she told them. The boys’ mothers hung about. This was week two of a free ten-week program, and they’d signed them up through the city of Seoul, having attested to their sons’ obsessive playing video games or texting on their smartphones.

Kim arranged everyone in a circle, each person holding a twig at shoulder height. When she gave a command, each person lunged to the spot of the person next to him in time to catch their neighbor’s twig before it fell. Then they switched direction. They made the circle bigger and the lunges faster. The boys, who looked bored when it began, were soon laughing with their moms. Next, Kim asked the mothers to put on blindfolds. “I’m going to give you a chance to care for your mother since she’s always caring for you,” she explained to the boys. “The course where you will take her is not safe. There are lots of rocks and sticks.” They walked carefully for a while and then they switched places, the blinded sons alongside or just in front of their mothers. After that, Kim and her assistant led the boys on a slippery hike up a riverbed. It’s not easy to compete with multi-player gaming, but she had the boys’ full attention.

Time in the forest led 11- and 12-year-olds to report feeling happier, less anxious and more optimistic about their futures.

Kim wants to help families find a respectful balance of power between parent and child, an equilibrium between technology and human interaction, and healthier outlets for preteen anxiety, energy and aggression. She believes time outside can offer this, and the science backs her up. Two South Korean studies looked at eleven- and twelve-year-olds who qualified as borderline technology addicts. After trips to the forest of two days each, researchers found both lowered cortisol levels and significant improvements in measures of self-esteem, and the benefits lasted for two weeks. Time in the forest also led them to report feeling happier, less anxious and more optimistic about their futures, according to the lead author, Park Bum-Jin, a professor at Chungnam National University.

Professor Park recommends that preteens get out in nature for a half day or so every two weeks. For these kids, he explained, “time spent in forest is not more interesting than video games, like fruit is not more delicious than junk food. As we get older, we have a tipping point in judgment that we need more fruits than junk food. As long as playing in forest is just fun itself, it can make that tipping point come earlier.”

Park applauds South Korea’s plan for shepherding citizens into the forests through work and school programs. Koreans have been so intensively urban for long enough that they don’t know what to do with themselves in the woods. “Children and the younger generation don’t really have experience in nature; so many of them think of the forest as dirty or scary. If we don’t change their mind-set now, there will be no chance.”

Park, who lives in Seoul, takes his two kids hiking regularly because of what he’s learned. It’s their fruit, and they dutifully consume it. Nature, for Park, is the anti-city, even when it’s within a city. “We cannot give up those systems, [cities] and schools,” he said. “The forest is the only exit we have for those humans who live in the human zoo.”

Excerpted with permission from the new book The Nature Fix: Why Nature Makes Us Happier Healthier, and More Creative by Florence Williams, published by W.W. Norton & Company, Inc. Copyright © 2017 Florence Williams.