The Science of Forest Bathing
Shinrin-yoku (Forest Bathing) was developed in Japan during the 1980’s as a response to the health crisis caused by industrialization and mass urbanization which lead to a culture of extreme stress. Forest Bathing became a government sanctioned activity and was used as a tool to help its citizens manage and overcome a number of physical and psychological ailments.
A forest walk in Japan often involves measuring a number of parameters of the participant before and after the walk such as blood pressure, salivary cortisol level and a survey of mental well-being. During a Shinrin-Yoku experience a guide leads a group into the forest and presents activities that engage the senses as a way of grounding and decreasing stress. Many Shinrin-Yoku walks in Japan also provide a doctor or nurse to help participants with specific medical needs during the walk.
Since its inception, much research has been done into the science of Forest Bathing. One finding is that forest bathing decreases stress hormones and allows the parasympathetic nervous to be activated. Many people have heard of the “Fight or Flight” response which is an unconscious stimulation of the Sympathetic Nervous system which allows our bodies to react to stress. Hormones such as adrenaline and cortisol are released into the body which, among other things, raises blood pressure and diverts blood from the digestive tract to the brain, heart and muscles. This phenomenon is necessary and very useful. However, if an individual spends too much time with their sympathetic nervous system activated, the body doesn’t have time to repair itself. It’s during the parasympathetic phase, or “Rest and Digest” phase that our bodies and minds are able to heal.
Another important finding about spending time in nature is that humans can benefit from a chemical given off by trees called Phytoncides. Phytoncides get diffused in the air when a tree is attacked by a fungus or organism and these chemicals can fend off the attack. When humans inhale phytoncides or absorb them through our skin, our bodies produce a special white blood cell called a natural killer cell, or NK cell. NK cells roam the body looking for cancer and destroying it. The Japanese discovered that simply going into the forest can be considered a form of cancer prevention.
There is also a lot of research to show that being out in nature greatly reduces our stress levels, which in turn positively impacts our wellbeing. For people that want to learn more about the science of Forest Bathing, I have provided two links below that contain robust research articles and further information.
However, you probably know intuitively that being with the more-than-human world is good for you. Try to remember a time when you spent an extended period out in nature. Maybe a camping trip or a long hike? Do you remember how you felt during that time? Let your inner knowing and your body be your guide.
Resources regarding the Science of Forest Bathing:
Science Agrees: Nature is Good for You. Association of Nature and Forest Therapy. https://www.natureandforesttherapy.org/about/science#:~:text=Forest%20bathing%20catalyzes%20increased%20parasympathetic,system%20is%20being%20triggered%20less. (accessed March 22, 2021)
Hansen, M et al. (2017, July 28). Shinrin-Yoku (Forest Bathing) and Nature Therapy: A State of the Art Review. International Journal of Environmental Research and Public Health.
Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5580555/