New health trend: Shinrin-Yoku

9. July 2020

How healthy is “forest bathing?”

The forest makes us slow down and is good for us. A form of treatment that has long been recognised in Japan is finding more and more followers in Germany. Shinrin-yoku, forest bathing, is an international health trend that originated in Japan in the 1980s.

Despite its name, it’s not about taking a bath in a lake or river or some other wooded setting. Forest bathing means intentional walking or hiking through a forest or nature in order to get closer to the trees.

In 1982, the Japanese Ministry of Agriculture, Forestry, and Fisheries coined the term Shinrin-yoku to describe making contact with the atmosphere of the forest. In 2012, a separate department was set up at Japanese universities to conduct research in

and offer specialist degrees in “forest medicine.” Five million Japanese already make use of the trails in the Akasawa National Recreational Forest.

In several studies published together with colleagues in Japan and Korea, Qing Li, a luminary of forest medicine, has shown that a short, relaxed walk through the forest has a positive impact on our health. Qing Li is Professor of Environmental Immunology at Nippon Medical School.

The forest as comfort for the soul

Forest bathing appeals to the longings of German Romanticism. Indeed, it has long been known that the forest and nature have a calming effect on many people. The forest is good for us. It helps against depression, psychological stress, and burnout.

But it also strengthens our immune system, can protect us from serious chronic diseases and even heart attacks, writes Austrian biologist and author Clemens Arvay. British researchers have also shown that a walk in the forest has a calming effect and that exercise in the forest can raise your mood and reduce stress.

In 2015, environmental psychologist Marc Berman from the University of Chicago noted in a study: The fewer trees there are in a residential area, the higher the risk of typical civilization diseases such as cardiovascular weakness, high blood pressure, and diabetes.

The forest as a kind of medicine

One of the earliest studies on the health effects of the forest appeared in 1984 in the journal “Science.” There it says: Even just being able to see trees has a measurably positive effect on people. And further: Patients who looked out of hospital windows at trees after an operation recovered faster than those who only looked at a building wall. Patients with a tree view also needed fewer pain relievers.

Forester and bestselling author Peter Wohlleben, who is very well known in Germany, is certain that the forest is a kind of medicine because of the special climate it offers. “Your blood pressure drops, you become more relaxed, especially if it is an intact forest.”

The healing power of trees

But how did the healing power of trees come about in Japan? Japan is the only country with a term (karōshi) to express the fact that some people literally work themselves to death. The medical cause of death is often a heart attack or stroke due to stress. The mass phenomenon of burnout, which has been denigrated as a “trendy illness,” reached public awareness very early in Japan, long before we started talking about it.

That was one of the key reasons why the Japanese Ministry of Agriculture, in collaboration with doctors, developed the concept of Shinrin-yoku. The priority was to combat the stress that costs the lives of so many Japanese.

Death from overwork

The infamous Japanese work ethic had clearly shown its dark side. Japanese society had a problem: people were working themselves to death. So nature therapy became increasingly important in the 1950s as people, especially city dwellers, started retreating to national parks and nature reserves in order to recover from all their work.

In 2017, the Japanese public was shocked to learn of the causes behind the death of a young woman four years earlier:

a 31-year-old political reporter had accumulated 159 hours of overtime in just one month and had been found dead in her bed in July 2013. A year later, the Japanese authorities ruled that her death was related to overwork. She had only had two days off in the month before her death. But it wasn’t until four years after her death that her employer made it public.

In Germany, in the wake of globalization, workload and stress have also increased significantly. Forest bathing could therefore also become more important in this country, also from a medical point of view. In Japan, the medical effects of Shinrin-yoku have been closely monitored scientifically since the 1990s and are considered to be well researched. As early as 1990, Miyazaki Yoshifumi, Professor and Director of the Center for Environment, Health, and Field Research at Chiba University, published a study that shows the connection between longer periods spent in the forest and a reduced number of stress hormones.

Japan and South Korea both now have what are called “healing forests” and Shinrin-yoku is a recognised form of therapy. Doctors can even prescribe their patients to spend several days in the forest. It is believed that the atmosphere of the forest has positive effects on their physical and mental health.

Guided Shinrin-yoku excursions are also offered so patients can learn how to consciously engage with nature. In Japan, forest bathing is a good option, because 67% of Japan’s land mass is forested.

By comparison, Germany, only 32% of the country’s land mass, some 11.4 million hectares (44,000 sq. mi.) is covered by forest. This actually makes Germany the country with second-largest forested land mass in Europe (Russia is first), but the vast majority consists of logging forests that are not suitable for healing purposes. But better than nothing, we think.

Green healing soon in Germany?

Although it took a long time, studies are now also being carried out in European and German forests, taking into account that the predominant tree species in this country differ significantly from the forests of Japan and South Korea.

In Bavaria, under the leadership of the Bavarian Spa Association (BHV), a field trial is being carried out in Bad Endorf accompanied by a scientific study by the Ludwig Maximilian University in Munich to examine the medical effects of forest bathing.

The goal is to create criteria for using forests in Germany for healing and spa purposes. This gives hope that doctors may be able to prescribe forest bathing in the near future, following the lead of the Japanese.

But we don’t have to wait that long: there’s nothing stopping from taking regular walks in a nearby forest and listening to the birds and babbling brooks for quick stress relief.

“Does the air in the forest protect against cancer?” a Zeit-Online article asked. The answer comes from Japan:

During a walk in the forest, we breathe in substances with which plants exchange messages called terpenes. They strengthen our immune system. For a study at the Nippon Medical School in Tokyo, researchers put twelve test subjects in a hotel. Half of the breathing air at night was enriched with a mix of forest air. 

The next day, the blood samples from these participants showed a significantly higher number and more activity on the part of the body’s own killer cells. For Professor Qing Li, director of the study, this was a groundbreaking finding.

“My experiment showed that the terpenes stimulate immune cells like natural killer cells, and that enhances the effects of immune function,” he says. “Anyone who spends a day in the forest has more natural killer cells in their blood for seven days.” The pioneer of forest medicine hopes that the strength of the trees may even prevent cancer. ” Maybe doctors can prescribe the forest as a medical treatment in the future,” he says. According to the WHO, people in Japan already have the highest life expectancy worldwide.

Conclusion: Off to the forest and stay healthy!