Shinrin-Yoku: Why I Wander in the Woods
By Jennifer Swartout, M.S., M.A., CNS, LDN, LMT
Adjunct Faculty, Nutrition and Integrative Health
Birds are singing, spring is springing! Nature is constant only in its harmonious balance of Yin and Yang and the cycle of the seasons.i Shinrin-yoku or “forest bathing” is a term first used by the Japanese Ministry of Agriculture, Forestry and Fisheriesii and is really just a concise wording for “getting back to nature,” “going to the woods,” or taking some time in the wilderness. Call it what you like, shinrin-yoku gets us back to who we really are intrinsically. It gives our mind a chance to reassess our needs according to evolutionary knowledge, and to conserve vital resources for when they are absolutely necessary.iii
Traditional acupuncturists believe nature is “without and within us, each of us every moment. We are nature, a replica of the universe, passing from season to season in a natural unending cycle of life.”iv Nei Ching tells of Yin and Yang, which continually wax and wane providing balance and a natural cycle of life and death. And so a healthy person depends on Allostasis, a regulatory system that continually fluctuates within a mean, to respond to the catabolic and anabolic necessities for survival. Nature is efficient and getting back to the woods provides a sense of familiarity and pleasure which the brain equates with an allowance for energy conservation and relaxation.
Cortisol levels, which rise when we perceive ourselves as isolated or in danger, were significantly lower (p< 0.01) after subjects spent time in the forest.v Nature brings us to a place of calm oneness with other living creatures; it is a gentle reminder of the oneness and purpose of our own lives.vi Not only that, today’s environmental input becomes tomorrow’s regulatory cues; even the mere planning to go into nature starts the parasympathetic relaxation of the body and the reservation of costly resources. The average pulse of subjects was 6% lower after just sitting and watching the forest environment, and subjects who knew they were going to the forest had lower levels of cortisol (p< 0.09) even before going than did subjects going to the city.vii Remarkably, the body begins to respond to the mind’s a priori before an actual occurrence even happens. The body also benefits from forest bathing long after time spent in the woods. White blood cell activity in male office workers increased and remained elevated for thirty days after a three day stay in the forest.viii
Stress is a number one cause for sleep disturbance; lack of sleep causes functional problems and it is an important cue for health practitioners to assess imbalance in the body. Sleep actigraphs (worn on the wrist like a watch) recorded that actual sleep time increased significantly post afternoon walks in the woodsix and self-reported sleeping habits such as depth and length of sleep, were significantly elevated on evenings after nature walks. Aromatic volatile substances have a great impact on our emotional and memory centers, and hence have effects on regulation of physiology. The nose knows!
Subjects reported an immediate feeling of relaxation just from smelling cedar, and prefrontal brain activity and blood pressure both lowered upon exposure to cedar chips.x
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Modern society and its concrete blocky structures are evolutionarily abnormal and stressful; the wilderness provides a backdrop of familiarity and connectedness, calming the body, mind, and spirit. It feels brighter and better in nature; the smell of woody green, the sound of singing birds or a running stream and the scenery of a living forest ecosystem are enjoyable. Subjects reported the forest area comparable in luminescence to that of urban areas, when in fact there was less than 5% of the total amount of light than in the city. Thermal conditions in the forest were also reported more comfortable than in the city. Lower scores of depression and higher scores of friendliness and well-being were recorded on days after time in the woods. The amount of time in the forest and the length of the stroll did not have a correlation with the positive effects of shinrin-yoku. Any amount of time in the woods is good time in the woods.xi
Nature is the perfect duality; as night follows day, spring/winter, and life/decay, early scholars realized that there was no better teacher (Nei Ching). When we go to nature our physiology remembers that we are part of the cycle of life; we see first-hand how light and water turns to wood, wood decays to earth, earth to rocky metal, hot metal to burning fire, and fiery sun with water to wood. Everything is connected; again and again, the cycle continues. Much like an herbal remedy, listening ear, micronutrient, or an acupuncture needle, nature heals by opening the door to proper flow. It allows the body, mind and spirit to reset, conserve vital resources and let energy go where it is most needed.
Wordsworth (1888) so eloquently describes the anxiety of isolation and the lasting relief and pleasure that the scenic company of nature can bring. He integrates the heavens and the earth, and Western scientific knowledge with sage Eastern wisdom in a poetic package of nature as healer (from www.poetryfoundation.org):
“I wandered lonely as a cloud
That floats on high o’er vales and hills,
When all at once I saw a crowd,
A host, of golden daffodils;
Beside the lake, beneath the trees,
Fluttering and dancing in the breeze.
Continuous as the stars that shine
And twinkle on the milky way,
They stretched in never-ending line
Along the margin of a bay:
Ten thousand saw I at a glance,
Tossing their heads in sprightly dance.
The waves beside them danced; but they
Out-did the sparkling waves in glee:
A poet could not but be gay,
In such a jocund company:
I gazed–and gazed–but little thought
What wealth the show to me had brought:
For oft, when on my couch I lie
In vacant or in pensive mood,
They flash upon that inward eye
Which is the bliss of solitude;
And then my heart with pleasure fills,
And dances with the daffodils.”
NOTES i Connelly, D.M. (1994). Traditional acupuncture: The law of the five elements. (2nd ed.), Laurel, MD: Tai Sophia Institute. ii Park, B., Tsunetsugu, Y., Kasetani, K., Hirano, H., Kagawa, T., Sato, M., & Miyazaki, Y. (2007). Physiological effects of shinrin yoku (taking in the atmosphere of the forest)- using salivary cortisol and cerebral activity as indicators. Journal of Physiological Anthropology, 26, 123-128. iii Snow, J. (2012). Foundations of Health and Wellness, Isci 632 [PowerPoint slides]. Retreived from class notes. Tai Sophia, Laurel, MD. iv Ibid., Connelly., 11 v Park, B. J., Tsunetsugu, Y., Kasetani, T., Kagawa, T., & Miyazaki, Y. (2009). The physiological effects of shinrin-yoku (taking in the forest atmosphere or forest bathing): evidence from field experiments in 24 forests across Japan. Environmental Health Prev Med, 2010(15), 18-26. vi Nei Ching (1972). The yellow emperor’s classic of internal medicine. Translated by Ilza Veith. Berkley, CA: University of California Press. vii Ibid., Park et al., 2007 viii ibid., Park et al., 2009 ix Morita, E., Imai, M., Okawa, M., Miyaura, T., & Miyazaki, S. (2011). A before and after comparison of forest walking on the sleep of a community-based sample of people with sleep complaints. BioPsycoSocial Medicine, 5(13), Retrieved from http://www.bpsmedicine.com/content/5/1/13 x ibid., (Tsunetsugu et al., 2009). xi ibid., (Tsunetsugu et al., 2009 & Morita, 2011).