Natures Medicine in your backyard! An article by 3rd year medical student Arshvir Singh Dhari

Subtle Yet Significant: Nature’s Medicine in Your Backyard

The spring sunlight pierced through the towering firs. Below, the silence was punctuated by chirping sparrows and buzzing hummingbirds, while deer browsed away quietly and cautiously. These are the sounds and sights from my first morning on Mayne Island. The surrounding forests here offer not only a soothing sense of calm that epitomizes rural life on Mayne Island, but they also offer many subtle yet significant health benefits. Research suggests that spending a few minutes in a natural environment each day is linked to positive changes across multiple body systems, highlighting the connection between time in nature and our own wellbeing.

Mood and Mental Health. Time in nature has important implications for mental wellbeing. Studies show that people can begin to feel happy and restored within just a few minutes of exposure to natural environments. Forest bathing, a relaxation technique that involves immersing oneself within the forest environment, can reduce symptoms of anxiety and depression. Notably, research has even found that the presence of high levels of residential green space during childhood is associated with a lower risk of developing many psychiatric disorders later in life, exemplifying the long-term mental health benefits of early and sustained exposure to green spaces.

Stress and Sleep. Immersing in nature is also linked to lower stress. This is evident not only through subjective reports of stress, but also through objective biochemical changes measured in the blood. Viewing or walking around a forest environment for a few minutes is linked to a decrease in cortisol levels, a stress hormone. There is also evidence that exposure to green spaces is linked to improvements in the quality and quantity of sleep.

Heart Health. The heart benefits from exposure to nature. A reduction in blood pressure can be seen in forest environments, suggesting that such settings induce physiological relaxation. This effect can be seen in those who have normal blood pressure and especially in those who have high blood pressure (hypertension). A reduction in heart rate can also be observed in these settings. Furthermore, access to green spaces promotes physical activity which, in combination with lower stress and lower blood pressure, can lead to lower incidence of cardiovascular disease.

Immune Function. Forest bathing is associated with an increase in the body’s production of anti-cancer proteins as well as the activity of natural killer cells, a type of cell in the immune system that plays an important role in killing virus-infected cells and tumor cells. Forest bathing exposes the individual to phytoncides, airborne molecules that are released by plants and trees to protect themselves from insects and infections. These phytoncides are believed to increase the activity of natural killer cells, highlighting the significant impact that natural environments can have on the immune system at cellular and molecular levels.

Ultimately, Mayne Island’s abundant green spaces naturally lend themselves to a wide spectrum of nature-based activities, such as forest bathing, walking, hiking, and more. Spending at least 120 minutes in nature each week can improve mental and physical health. Given these benefits, some physicians are even prescribing nature time to patients. On Mayne Island, nature’s medicine is free and in your backyard. Consider giving it a try. To learn more about nature’s health benefits and what you can do, visit www.parkprescriptions.ca.

Arshvir Singh Dhari (UBC Medical Student, Class of 2027)

References

1. Jimenez MP, DeVille NV, Elliott EG, Schiff JE, Wilt GE, Hart JE, et al. Associations between

Nature Exposure and Health: A Review of the Evidence. Int J Environ Res Public Health. 2021

Apr 30;18(9):4790. doi:10.3390/ijerph18094790 PubMed PMID: 33946197; PubMed Central

PMCID: PMC8125471.

2. Ideno Y, Hayashi K, Abe Y, Ueda K, Iso H, Noda M, et al. Blood pressure-lowering effect of

Shinrin-yoku (Forest bathing): a systematic review and meta-analysis. BMC Complement Altern

Med. 2017 Aug 16;17:409. doi:10.1186/s12906-017-1912-z PubMed PMID: 28814305; PubMed

Central PMCID: PMC5559777.

3. Kondo MC, Jacoby SF, South EC. Does spending time outdoors reduce stress? A review of real-

time stress response to outdoor environments. Health & Place. 2018 May 1;51:136–50.

doi:10.1016/j.healthplace.2018.03.001

4. Li Q, Morimoto K, Nakadai A, Inagaki H, Katsumata M, Shimizu T, et al. Forest bathing

enhances human natural killer activity and expression of anti-cancer proteins. Int J

Immunopathol Pharmacol. 2007;20(2 Suppl 2):3–8. doi:10.1177/03946320070200S202 PubMed

PMID: 17903349.

5. Shin JC, Parab KV, An R, Grigsby-Toussaint DS. Greenspace exposure and sleep: A systematic

review. Environmental Research. 2020 Mar 1;182:109081. doi:10.1016/j.envres.2019.109081

6. Kondo MC, Triguero-Mas M, Donaire-Gonzalez D, Seto E, Valentín A, Hurst G, et al.

Momentary mood response to natural outdoor environments in four European cities.

Environment International. 2020 Jan 1;134:105237. doi:10.1016/j.envint.2019.105237

7. Song C, Ikei H, Miyazaki Y. Physiological Effects of Nature Therapy: A Review of the Research

in Japan. Int J Environ Res Public Health. 2016 Aug;13(8):781. doi:10.3390/ijerph13080781

PubMed PMID: 27527193; PubMed Central PMCID: PMC4997467.

8. Morita E, Fukuda S, Nagano J, Hamajima N, Yamamoto H, Iwai Y, et al. Psychological effects of

forest environments on healthy adults: Shinrin-yoku (forest-air bathing, walking) as a possible

method of stress reduction. Public Health. 2007 Jan 1;121(1):54–63.

doi:10.1016/j.puhe.2006.05.024

9. Engemann K, Pedersen CB, Arge L, Tsirogiannis C, Mortensen PB, Svenning JC. Residential

green space in childhood is associated with lower risk of psychiatric disorders from adolescence

into adulthood. Proc Natl Acad Sci U S A. 2019 Mar 12;116(11):5188–93.

doi:10.1073/pnas.1807504116 PubMed PMID: 30804178; PubMed Central PMCID:

PMC6421415.

10. Gascon M, Triguero-Mas M, Martínez D, Dadvand P, Rojas-Rueda D, Plasència A, et al.

Residential green spaces and mortality: A systematic review. Environment International. 2016 Jan

1;86:60–7. doi:10.1016/j.envint.2015.10.013

11. Twohig-Bennett C, Jones A. The health benefits of the great outdoors: A systematic review and

meta-analysis of greenspace exposure and health outcomes. Environ Res. 2018 Oct;166:628–37.

doi:10.1016/j.envres.2018.06.030 PubMed PMID: 29982151; PubMed Central PMCID:PMC6562165.