Have you ever noticed how simply walking in nature (especially when barefoot) or stopping to smell a beautiful flower subtly changes your mood? If your answer to this is yes then take a moment to consider the why as well as how intensely you felt this mood change within yourself. If this experience does not resonate with you then perhaps give it a try. To strengthen the experience after your nature-walk or flower sniff take a moment to consider how you felt before versus afterwards. This will gradually build your ability to perceive subtle shifts within your emotional and spiritual body. The experience we are beginning to describe here is an introduction to the Japanese practice of forest bathing or shinrin-yoku. Forest bathing is the practice of fully immersing yourself within nature. The key is to be mindful throughout the entire experience by focusing on the forest noises, the way the breeze flows through the trees, the dappled sun the canopy creates as well as the calming energy emitted by the forest itself. The concept of Shinrin-yoku is fairly new, officially introduced by the Japanese Forest Agency in 1982. Since 2004 the agency has been studying the physiological benefits of the practice. In general terms, they have found that low levels of the volatile oils emitted within the forest induce relaxation while stronger, more condensed phytoncide odors are stimulating and more stress-inducing (6).
There is a growing body of research into the benefits of forest bathing, specifically in regards to the volatile oil called phytoncides produced by pine trees. These oils have been found to be anti-inflammatory, antimicrobial and analgesic (meaning they help to combat pain). This research has also found that phytoncides may have sleep-enhancing, blood pressure reducing and stress hormone reducing effects. In fact, phytoncides have been found to have a similar mechanism of action to prescription sleep-aids such as diazepam and zolpidem. Results have shown that inhaling phytoncides helps to increase sleep quantity without effecting sleep quality. Making them comparable to synthetic sleep-aids without the negative side effects such as cognitive impairment, tolerance, rebound insomnia upon discontinuation, abuse, and dependence (7). This is a very promising body of research considering how the American Sleep Association has found that roughly 30% of the American population experiences insomnia (1). One of the big factors contributing to forests bathing’s ability to improve insomnia comes from its stress relief qualities. A study conducted by Lee et al. (2019) found that forest bathing significantly increases parasympathetic (the rest-digest portion of the nervous system) activity while simultaneously suppressing stimulation of the sympathetic nervous system (fight or flight portion). They also found reduced levels of salivary cortisol (a major stress hormone, 2,3,4,6), decreased pulse rate (3,4), increased positive feeling scores and reduced scores of negative feelings on psychological reflection questions (4). In addition to reductions in pulse and heart rate, studies have found significant reductions in systolic and diastolic blood pressure and urinary outputs of the stress hormones adrenaline and noradrenaline following a forest bathing session (3). The benefits don’t seem to stop with relaxation either. A study was conducted to confirm the potential immune benefits of forest bathing. To keep the study as controlled as possible they diffused phytoncides inside a hotel room and the effects seen in participants mirrored the benefits they found in a previous forest-based study; reduction in stress hormone levels, increased natural killer cell activity and number, decreased urine output of adrenaline and noradrenaline and increased intracellular concentrations of anti-cancer proteins in lymphocytes. In addition to these excellent effects, participants also reported reduced fatigue, confusion and longer sleep hours. All of these benefits persisted for up to 7 days in their participants (5). Ultimately the take-away message is do yourself a favor and spend more time outside appreciating the natural world we call home 😊
References
1. American Sleep Association. (n.d). Sleep and Sleep Disorder Statistics. American Sleep Association.
2. Antonelli, M. Barbiere, G. Donelli, D. (2019). Effects of forest bathing (Shinrin-Yoku) on levels of cortisol as a stress biomarker: a systematic review and meta-analysis. International Journal of Biometerology, 63. 1117-1134. https://doi.org/10.1007/s00484-019-01717-x
3. Ideno, Y. Hayashi, K. Abe, Y. Ueda, K. Iso, H. Noda, M. Lee, J. Suzuki, S. (2017). Blood pressure-lowering effect of Shinrin-yoku (Forest bathing): a systemic review and meta-analysis. BMC Complement Alternative Medicine, 17. https://doi.org/10.1186/s12906-017-1912-z
4. Lee, J. Park, B. Tsunetsugu, Y. Ohira, T. Kagawa, T. Miyazaki, Y. (2019). Effect of forest bathing on physiological and psychological responses in young Japanese male subjects. Public Health, 125(2), 93-100. https://doi.org/10.1016/j.puhe.2010.09.005
5. Li, Q. Kobayashi, M. Wakayama, Y. Inagaki, H. Katsumata, M. Hirata, Y. Hirata, K. Shimizu, T. Kawada, T. Park, B.J. Ohira, T. Kagawa, T. Miyazaki, Y. (2009). Effect of Phytoncide from trees on human natural killer cell function. International Journal of Immunopathology and Pharmacology, 22(4), 951-959.
6. Tsunetsugu, Y. Park, B-J. Miyazaki, Y. (2010). Trends in research related to “Shinrin-yoku” (taking in the forest atmosphere or forest bathing) in Japan. Environmental Health and Preventive Medicine, 15. https://doi.org/10.1007/s12199-009-0091-z
7. Woo, J. Lee, J. (2020). Sleep-enhancing Effects of phytoncide Via Behavioral, Electrophysiological, and Molecular Modeling Approaches. Experimental Neurobiology, 29(2), 120-129. Doi: 10.5607/en20013
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