Forest bathing, or being in the presence of trees, is a Japanese practice scientifically proven to boost the immune system, decrease stress, lower blood pressure and improve one’s sense of wellness.
The activity, known in Japan as “shinrin-yoku”, belongs to a broader group of natural treatment practices called eco-therapy. The collective includes adventure therapy, animal-assisted interventions, green gyms, social and therapeutic horticulture and wilderness therapy, among others.
Japan made forest bathing part of a national public health program in 1982, according to the World Economic Forum. At the time, the country’s Ministry of Agriculture, Forestry, and Fisheries was promoting topiary — the art of clipping trees and shrubs into ornamental shapes — as therapy.
The term “shinrin-yoku”, which first began as a marketing ploy, was coined by Mr. Tomohide Akiyama, Mother Earth News wrote.
Forest bathing is really just being among trees for the sake of relaxing. While simple as it sounds, Japan spent around $4 million between 2004 and 2012 to study its physiological and psychological effects, leading to the designation of 48 locations as therapy trails.
In a 2009 study, researchers found that forest visits increased the activity of human natural killer (NK) cells, which contribute to the immune system and cancer prevention. This is made possible by their inhalation of antimicrobial organic compounds called phytoncides, which are emitted by trees to primarily protect themselves from insects and harmful microorganisms.
Another study compared levels of salivary cortisol (a stress hormone), pulse rate, blood pressure and nerve activity of subjects who spent a day in the city versus subjects who spent 30 minutes forest bathing. Researchers found that “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.”
Forest bathing also appears to have a positive impact on thought processes. According to a study that surveyed healthy individuals in both control and forest environments, exposure to the latter led to decreased depression and hostility scores. They also became more energetic.
“Forest environments are advantageous with respect to acute emotions, especially among those experiencing chronic stress,” the study concluded.
These findings suggest that the Japanese, who have a historical affinity for nature, had been reaping life-saving health benefits from trees for decades.