Introduction[edit | edit source]
Nature Therapy is defined by the use of natural environments (namely forests and parks) for its therapeutical effects on the body and mind. It has been commonly known for centuries, in different cultures around the globe, that nature has beneficial effects on our health. As it might be common knowledge, research publications aiming at quantifying these effects started to emerge only a few decades ago. A global movement towards cities, resulting in disconnection from nature, along with the climate crisis we are facing, may explain the novelty of such research. Nonetheless, spending time amongst trees has been proven to support the immune system, lower blood pressure and activate the parasympathetic nervous system.
Forest Medicine[edit | edit source]
In 2007, the research group "Forest medicine Study Group" was formally established in Japan. The group has since then led multiple research on the physiological and psychological effects of forests on human health. There is now research emerging from across the globe, including North America and Europe. Outdoor and nature guides are being trained to take the roles of nature therapy guides, therapists and doctors of medicine are using it as a tool or prescribing it to their patients to complement treatments. Nature is also being "brought indoors" or recreated virtually, to access to some of the benefits observed and studied in actual natural environments.
Shinrin-Yoku[edit | edit source]
Literally "forest bathing", the practice has been integrated to the Japanese health care system since 1982 with the aim to promote wellness and disease prevention, aiming particularly for workers' stress management. It consists of simply "taking in" the forest environment through all five senses and paying close attention to those. These videos provide further details on how it is practiced.
Physiological Effects[edit | edit source]
As of now, evidence surrounding the physiological effects of spending time in the forest is mainly connected to cardiovascular and immunological systems. Quantitative data was gathered mostly in Asian countries and with healthy populations, stroke patients and people with a diagnosis of hypertension. 
Cardiovascular[edit | edit source]
Nature and Forest Therapies have been shown to reduce overall blood pressure, and lower the heart rate, while activating the parasympathetic nervous system and reducing the sympathetic nervous system. 
Immune system[edit | edit source]
By acting on the autonomous nervous system, Nature Therapy can therefore benefit the immune system directly. As we know, the immune response is at its best when the body is relaxed and resting, which is why any practice that may reduce stress and facilitate relaxation is beneficial for the immune system. Furthermore, certain chemical compounds present in the forest air would have a direct effect on the immune system.
Phytoncides and NK cells[edit | edit source]
Phytoncides, oils that trees emit to protect themselves from pathogens and parasites, have been shown to have a direct effect on the activity of NK (natural killer) cells in the body. NK cells are responsible for identifying and destroying potentially harmful organisms that enter the bloodstream. Higher activity of those cells means increase immune defense.
Stress[edit | edit source]
Psychological Effects[edit | edit source]
Nature therapy has been shown to reduce depression and anxiety, as well as affecting on the mood.
Forest as Clinical Environment[edit | edit source]
As the benefits of carrying therapy sessions in the forest or other natural environments, the use of virtual reality or the presence of plants inside clinical spaces have proven equally effective on certain levels. Since it is not always possible to carry out therapy sessions in natural spaces, those alternatives can be useful in hospitals or for patients who are unable to access such spaces.   The use of essential oils has also shown to have direct, beneficial effects on the mood and stress response of hospital workers. These oils contain the Phytoncides molecules (as described earlier), same effects are observed on the immune system and anxiety levels. 
Resources[edit | edit source]
- Sustainability Journal. A Preferred Road to Mental Restoration in the Chinese Classical Garden
- Forest Medicine Study Group. INFOM
- Forests. Peer-reviewed, open access journal of forestry and forest ecology published monthly online by MDPI.
References[edit | edit source]
- Association of Nature and Forest Therapy. Introduction to Forest Therapy and Shinrin-Yoku. Available from: https://youtu.be/mxLbmMwlI4U[last accessed 24/4/2022]
- World Economic Forum. What is Japanese “forest bathing” and how can it improve your health. Available from: https://youtu.be/stuZaKB9j7I[last accessed 24/4/2022]
- Stier-Jarmer, M., Throner, V., Kirschneck, M., Immich, G., Frisch, D., & Schuh, A. (2021, February 2). The psychological and physical effects of forests on human health: A systematic review of systematic reviews and meta-analyses. International Journal of Environmental Research and Public Health. MDPI AG.
- Bikomeye JC, Beyer AM, Kwarteng JL, Beyer KM. Greenspace, Inflammation, Cardiovascular Health, and Cancer: A Review and Conceptual Framework for Greenspace in Cardio-Oncology Research. International Journal of Environmental Research and Public Health. 2022 Feb 19;19(4):2426.
- Chae Y, Lee S, Jo Y, Kang S, Park S, Kang H. The Effects of Forest Therapy on Immune Function. International Journal of Environmental Research and Public Health. 2021;18(16):8440.
- Andersen, L., Corazon, S., & Stigsdotter, U. (2021). Nature Exposure and Its Effects on Immune System Functioning: A Systematic Review. International journal of environmental research and public health, 18(4), 1416.
- Li, Q., Nakadai, A., Matsushima, H., Miyazaki, Y., Krensky, A. M., Kawada, T., & Morimoto, K. (2006). Phytoncides (wood essential oils) induce human natural killer cell activity. Immunopharmacology and immunotoxicology, 28(2), 319–333. https://doi.org/10.1080/08923970600809439
- Li Q, Kobayashi M, Wakayama Y, Inagaki H, Katsumata M, Hirata Y, Hirata K, Shimizu T, Kawada T, Park BJ, Ohira T. Effect of phytoncide from trees on human natural killer cell function. International journal of immunopathology and pharmacology. 2009 Oct;22(4):951-9.
- Antonelli, M., Barbieri, G., & Donelli, D. (2019, August 15). Effects of forest bathing (Shinrin-Yoku) on levels of cortisol as a stress biomarker: a systematic review and meta-analysis. International Journal of Biometeorology. Springer New York LLC.
- Kim, W., Lim, S. K., Chung, E. J., & Woo, J. M. (2009). The effect of cognitive behavior therapy-based psychotherapy applied in a forest environment on physiological changes and remission of major depressive disorder. Psychiatry investigation, 6(4), 245–254. https://doi.org/10.4306/pi.2009.6.4.245
- Syed Abdullah SS, Awang Rambli DR, Sulaiman S, Alyan E, Merienne F, Diyana N. The Impact of Virtual Nature Therapy on Stress Responses: A Systematic Qualitative Review. Forests [Internet]. 2021 Dec 15;12(12):1776. Available from: http://dx.doi.org/10.3390/f12121776
- Zamanifar, S., Bagheri-Saveh, M. I., Nezakati, A., Mohammadi, R., & Seidi, J. (2020). The Effect of Music Therapy and Aromatherapy with Chamomile-Lavender Essential Oil on the Anxiety of Clinical Nurses: A Randomized and Double-Blind Clinical Trial. Journal of medicine and life, 13(1), 87–93. https://doi.org/10.25122/jml-2019-0105