There is growing evidence suggesting the health benefits of spending time in the forest, including physical exercise in the forest. With Covid-19 lockdown measures, researchers are reporting rising inactivity levels and mental health issues are mounting, especially for youth. There is a place you can visit which allow for exercise, mental restoration, and so much more- green spaces. Exciting research findings support and promote the forests' ability to strengthen the immune systems, lower blood pressure, provide anti-asthmatic properties, lower cortisol levels, improve mood levels, and lower inflammation.

Let’s go over some surprising health benefits supporting idea of the forest as medicine, which may leave you wanting to go outside for a walk or run, and find yourself supporting the need and promotion for ‘green prescriptions’. 

Antiviral plant VOC may enhance immune system response- promote antiviral response and protect respiratory health

Compelling findings support the health protective benefits of green spaces and forest exposure. Roviello & Roviello (2021) noted that some regions in Italy reported lower numbers of Covid-19 cases and it's severity, and these locations happened to be in close proximity to heavily forested regions. These findings are interesting because it suggests there are health-protecting natural volatile organic compounds (VOC) emitting from plant life offering protection in human health. 

Particular VOC in plant life and fungi have been noted as being particularly beneficial for human health. For example, Behl et al. (2020) explained that plant-derived triterpenoids which have been used medicinally for years in several Asian countries, encompass health protecting compounds and "exhibit numerous therapeutic activities such as antiviral, anti-diabetic, anti-inflammatory antispasmodic, and immuno-modulatory activities" (p.12). In addition, the bitter tasting saponin compounds can bolster immune cell activity and “have ability to inhibit the cancer cells by arresting cell cycle and apoptosis” (Behl et al., 2020, p.11). 

Well, it seems the VOC could be a potential “weapon” as the authors named it, against Covid-19. Analyzing data from persons living near heavily-forested Mediterranean regions in Italy, such as Sardinia, Calabria, and Basilicata, the researchers noticed there were fewer severe cases of Covid-19. This may be explained partially by examining the environment; these regions have higher forest densities emitting higher amounts of natural VOC from trees and various Mediterranean plants into the atmosphere, and there is less fine particulate matter (PM) in the air. It is suggested that the surrounding forests may benefit the immune systems of the surrounding inhabitants. 

The researchers also recommend that governments worldwide consider green prescriptions, and the creation of nasal sprays with plant VOC as an accessible approach to providing health-protective benefits.

Interested in the scientific methods, the phytoconstituents, and its pharmacokinetic properties of VOC and findings? Click here to dive into the chemistry and findings of the Roviello & Roviello (2021) study.

Forest bathing reduces blood pressure, improves heart rate variability, elevates reported mood, increases NK cells and much more

A literature review from researchers Yau & Loke (2020) reported that walking in forests  improved health markers such as: increased self-reported mood levels, reduced cortisol levels and blood pressure, reduced urinary adrenaline and noradrenaline (produces fight or flight response), and inhibited inflammation.  Forest bathing has also been associated with increasing heart rate variability (HRV). HRV is directed through the body's autonomic nervous system, and it is the variability of time between heartbeats. HRV is controlled by the parasympathetic system (the rest and digest response, a relaxed state where HRV is up) and the sympathetic nervous system (turns on when we are stressed or in danger, HRV goes down). It is generally believed that the more HRV, the better you can manage and respond to stress, improve performance, and can be used as a preventative health tool.

A prominent study from Li et al., (2008) found that forest bathing increased the bodies Natural Killer (NK) cells and activity, and increase anti-cancer protiens. NK cells can be imagined as immune system super-soldiers- NK cells shoot out toxins that can kill viral, abnormal, and cancer tumor cells through apoptosis. Generally speaking, current evidence suggests that spending time in forested areas supports health, and the inhalation of certain plant VOC may add more arsenal to bolster your immune response to fight infection. 

Forest bathing elevates serotonin levels-you feel happier and your mood is stabilized

A study from Park et al., (2020) reported physiological effects of forest bathing from a group of middle-aged women in South Korea. The evidence showed that the 3-day forest-bathing group had elevated serotonin levels (a good feeling neurotransmitter) compared to the urban group who underwent a similar program in university-setting.

In trying times, naturally elevating serotonin levels is a great coping mechanism. Do you know what else increases serotonin? Physical exercise. Exercising to the point of raising your heart rate will increase blood flow and nutrients to the brain, and the contraction of skeletal muscle tissue creates a wonderful cascade of anti-depressant neurotransmitters. Exercising in the forest packs a powerful double punch and boosts your mood, and this can be done through walking, going for a run, or taking your workout outdoors. 

Physical exercise is an immune system supporter, mood, and creativity booster. In regards to physical exercise-“it triggers many biological processes within the human body which in turn lead to heightened natural defenses against viral infections’’ (Roviello et al. 2021, p.1). Current evidence suggests this is especially the case especially when performed in outdoors, especially in green space.

To boost your immune system and protect your mental health: move more and spend time in the forest or green spaces. You can even bring plants into your living space, especially in your bedroom to assist in filtering air. Bringing plants into your indoor living spaces aligns with a biophilic design which purposefully connects you with nature indoors. Spread the word, advocate for green prescriptions and the protection of our forests for the health of all.

References

Behl, Tapan & Kumar, Keshav & Brisc, Ciprian & Rus, Marius & Nistor-Cseppento, Carmen & Bustea, Cristiana & Aron, Raluca & Pantis, Carmen & Zengin, Gokhan & Sehgal, Aayush & Kaur, Rajwinder & Kumar, Arun & Arora, Sandeep & Setia, Dhruv & Chandel, Deepak & Bungau, Simona. (2020). Exploring the multifocal role of phytochemicals as immunomodulators. Biomedicine & Pharmacotherapy. 133. 110959. 10.1016/j.biopha.2020.110959.

Li, Q., Morimoto, K., Kobayashi, M., Inagaki, H., Katsumata, M., Hirata, Y., Hirata, K., Suzuki, H., Li, Y. J., Wakayama, Y., Kawada, T., Park, B. J., Ohira, T., Matsui, N., Kagawa, T., Miyazaki, Y., & Krensky, A. M. (2008). Visiting a Forest, but Not a City, Increases Human Natural Killer Activity and Expression of Anti-Cancer Proteins. International Journal of Immunopathology and Pharmacology, 117–127. https://doi.org/10.1177/039463200802100113

Park, B. J., Shin, C. S., Shin, W. S., Chung, C. Y., Lee, S. H., Kim, D. J., Kim, Y. H., & Park, C. E. (2020). Effects of Forest Therapy on Health Promotion among Middle-Aged Women: Focusing on Physiological Indicators. International journal of environmental research and public health, 17(12), 4348. doi.org/10.3390/ijerph17124348https

Roviello, V., Gilhen-Baker, M., Vicidomini, C., & Roviello, G. N. (2021.). Forest-bathing and physical activity as weapons against COVID-19: a review. Environmental chemistry letters, 1–10. Advance online publication.

Roviello, V., Roviello, G.N. (2021) Lower COVID-19 mortality in Italian forested areas suggests immunoprotection by Mediterranean plants. Environ Chem Lett (19), 699–710. doi.org/10.1007/s10311-020-01063-0

Yau, K. K., & Loke, A. Y. (2020). Effects of forest bathing on pre-hypertensive and hypertensive adults: a review of the literature. Environmental health and preventive medicine, 25(1), 23. https