Shinrin-yoku: Japanese Forest Bathing

The Japanese call it shinrin-yoku, which translates into English as forest bathing. It is a method of healing the mind and body by immersing one’s self in nature. The word bathing entails more than simply sitting or strolling through the forest. It means becoming one with it—seeing, hearing, smelling, and breathing it in. 

The term, shinrin-yoku, is relatively new. It was coined in 1982 by Tomohide Akiyama, who was then director of the Japanese Ministry of Agriculture, Forestry and Fisheries. However, the practice of gaining strength, peace, and healing from nature and the forest is neither new nor strictly Japanese.

The ancient Greek physician, Hippocrates, believed in the healing power of nature and often recommended sunbathing. The ancient Roman naturalist and philosopher, Pliny the Elder, wrote, “the smell of the forest where peach and resin are collected is extremely salutary to the depleted and to those who, after a long illness, have difficulty recovering.” Traditional Chinese Medicine was deeply influenced by Taoist philosophy that embraced Lao Tzu’s ideals of “harmony between man and nature.” Cyrus the Great, ruler of ancient Persia, built lush green gardens in his crowded urban capital to have a place of calmness and healing for the people.

More modern Europeans have also pursued improvements in health and well-being through being in nature. In 19th century Germany, the Lebensreform movement encouraged nudism, walks in the forest, and sleeping on the ground. Finland had similar “back to nature” movements.  Outward Bound is an organization founded in Great Britain in 1941. Its original purpose was to train sailors and soldiers for war time sea and mountain rescue. Over time it became a program of personal growth and self-discovery through exploring forests, mountains, rivers, and oceans, and meeting the challenges nature has to offer. It directs programs throughout the world. There are now many formalized forms of healing through experiencing nature such as ecotherapy, wilderness therapy, horticultural therapy, animal-assisted therapy, green exercise, and others.

Though the Japanese did not invent forest therapy, they have strongly embraced shinrin-yoku. The  Japanese government  has designated certain forests as therapeutic landscapes, and there are official forest therapy trails where individuals can engage in guided forest bathing experiences. The Japanese healthcare system has formally acknowledged the health benefits of shinrin-yoku, and has   integrated it into public health initiatives. Perhaps most importantly, they have supported scientific research into what benefits it offers and by what mechanisms it can improve mental and physical health.

A recent review of studies of shinrin-yoku, published by a Japanese research group led by Dr.  Yoshifumi Miyazaki, showed a variety of benefits of both physical and psychological significance.  In one such study, it was found that simply sitting in a forest for 20 minutes produced significant reductions in cortisol levels, an indication of stress reduction; sympathetic nervous activity; systolic blood pressure; and heart rate in comparison to a control group sitting in an urban environment. Activity in the parasympathetic nervous activity, taken to be a sign of relaxation, was enhanced by as much 55%. Similar results were seen in individuals after walking, rather than simply sitting, in the forest. Moreover, in those subjects natural killer cell activity, an indicator of immune function, was enhanced by 56% on the following day. A brief walk of 15 minutes in a Japanese forest was sufficient to produce beneficial changes in heart rate, heart rate variability, and blood pressure. Two standard tests, the Profile of Mood States and State–Trait Anxiety Inventory, confirmed that subjects enjoyed decreases in tension and anxiety, and increased feelings of vigor, and uplifts in mood. Even simulations of the forest environment in a laboratory, accomplished by olfactory stimulation using wood smells, tactile stimulation, and auditory stimulation using forest sounds, resulted in decreased blood pressure and pulse rate, and other physiological measures indicative of relaxation. Indeed, in a European study it was found that subjects merely shown slides or videotapes of nature had lower blood pressure; higher alpha brain wave amplitudes, an indicator of calmness; and reduced muscle tension than did subjects shown urban scenes. As an aside, one can’t help but recall the scene in the 1973 movie, Soylent Green, in which the beleaguered man in a barren, dying, over-populated world was coaxed into an “ethical suicide parlor” with the promise of spending his final moments bathing in glorious videos of the natural environment that had been destroyed.

There is compelling evidence that shinrin-yoku can be a helpful means to ease anxiety and lift mood. It appears to be helpful on its own, but there is no reason why it can’t be added to standard treatments, such as psychotherapy or medication. Still, it remains to be determined if shinrin-yoku is just one more method to slow, relax, and ease the mind, or if it offers something unique.  Dr. Miyazaki has argued the latter. He notes that humans have walked the Earth for several million years, but have lived in urban environments and with the ramifications of the Industrial Revolution for only a very small percentage of that time.  He goes on to state that all human physiological functions have evolved in and adapted to the natural, and not the urban, environment. He concludes that the physiological functions of the human are made for the forest, and thus that the forest has unique power to restore normal function.