Effects Of Nature Therapy On Mental Health

Shinrin-yoku (forest bathing) is a healing practice in Japan, where people immerse themselves in nature, while mindfully paying attention to their senses. Often involving a walk in a forest, it aims to integrate and harmonise humans with a forest. Contents of shinrin-yoku programmes include breathing yoga, meditation, walking and other recreational activities that are often aimed at producing relaxation effects. The word ‘shinrin-yoku (“森林浴”)’ was coined in 1982, for ‘yoku (bathing)’ implies the holistic nature of our health. Shinrin-yoku then began to be introduced into Japanese clinical fields. Literature reviews reported diverse health benefits of shinrin-yoku: on immune system functioning by increasing natural killer cells, and the cardiovascular and respiratory systems. The health benefits of shinrin-yoku are not limited to physical well-being; improvements have been described in mood disorders and stress, and mental relaxation.

There are several theories that account for the health benefits of exposure to nature. Kaplan’s Attention Restoration Theory claims that spending time in nature restores our concentration through practice of effortless attention. Stress Reduction Theory asserts that being in an unthreatening natural environment reduces stress and improves relevant physiological functions such as heartrate and blood pressure. Indeed, Song, Ikei and Miyazaki noted that natural stimuli help to reduce stress and strengthen our immune system. More recent studies explored the mechanism of shinrin-yoku and found that the benefits of shinrin-yoku accord with Gilbert’s (2014) model of affect regulation. Although the benefits of nature for affect regulation are often overlooked, it is essential to health and well-being.

Forest bathing and connecting with nature can help us regulate our emotions, through soothing and calming (i.e. the parasympathetic system), instead of fear, anxiety and drive (i.e. sympathetic system). Humans are more familiar with spending time in nature than in urban environments: over seven million years of human history, we have spent 99.99% of the time in nature; this may partially explain why we feel better in nature. Women living in a green-rich area had a 12% lower rate of mortality than those living in a green-poor area. Spending time in nature is related to lower rates of depression and high blood pressure, and the frequent visits to nature was related to social cohesion. Participants who viewed a towering tree for 1 min scored high awe scores, associated with more prosocial helping behaviours, than people who viewed a building with the same height. A three-day shinrin-yoku programme increased the number and activity of natural killer cells compared with 3 days of walking in a city. Likewise, a 90-min walk in nature reduced the level of rumination (negative repetitive thoughts, linking with mental health problems) and the activities of subgenual prefrontal cortex (part of brain that is related with mental health problems). Finally, there is recent evidence that visits and time in nature may be acting as proxy measures for nature connectedness.

Information provided by the following source:
Kotera, Richardson, M., & Sheffield, D. (2020). Effects of Shinrin-Yoku (Forest
Bathing) and Nature Therapy on Mental Health: a Systematic Review and Meta-analysis. International Journal of Mental Health and Addiction, 20(1), 337–361