Abstract Humans have enjoyed forest environments for ages b…

pxl272 ·

Abstract
Humans have enjoyed forest environments for ages because of the quiet atmosphere, beautiful scenery, mild climate, pleasant aromas, and fresh, clean air. In Japan, since 2004, serial studies have been conducted to investigate the effects of forest environments (Forest bathing/Shinrin-yoku) on human health. My research team has established a new medical science called Forest Medicine. The Forest Medicine is a new interdisciplinary science, belonging to the categories of alternative medicine, environmental medicine and preventive medicine, which studies the effects of forest environments (Forest bathing/Shinrin-yoku) on human health. It has been reported that Forest bathing/Shinrin-yoku has the following beneficial effects on human health:
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1
Shinrin-yoku increases human natural killer (NK) activity, the number of NK cells, and the intracellular levels of anti-cancer proteins, suggesting a preventive effect on cancers.
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2
Shinrin-yoku reduces blood pressure and heart rate showing preventive effect on hypertension and heart diseases.
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3
Shinrin-yoku reduces stress hormones, such as urinary adrenaline and noradrenaline and salivary/serum cortisol contributing to stress management.
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4
Shinrin-yoku increases the activity of parasympathetic nerves and reduces the activity of sympathetic nerves to stabilize the balance of autonomic nervous system.
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Shinrin-yoku improve sleep.
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Shinrin-yoku increases the levels of serum adiponectin and dehydroepiandrosterone sulfate.
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In the Profile of Mood States (POMS) test, Shinrin-yoku reduces the scores for anxiety, depression, anger, fatigue, and confusion, and increases the score for vigor, showing preventive effects on depression.
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Shinrin-yoku may apply to rehabilitation medicine
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Shinrin-yoku in city parks also has benefits on human health.
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Shinrin-yoku may have preventive effect on COVID-19 by boosting immune function and by reducing mental stress.
Taken together, these findings suggest that Shinrin-yoku may have potential preventive effects on non-communicable diseases.
Keywords: Blood pressure, Forest bathing, Forest Medicine, Immune function, NK, Nervous system, Phytoncide, POMS, Shinrin-yoku, Stress hormone
What is Shinrin-yoku/Forest bathing?
Humans have enjoyed forest environments for ages because of the quiet atmosphere, beautiful scenery, mild climate, pleasant aromas, and fresh, clean air. Researchers in Japan have tried to find preventive effects against non-communicable diseases from forests and have proposed a new concept called “Shinrin-yoku/Forest bathing” [1–3].
Shinrin-yoku is translated into Forest bathing in English. Shinrin in Japanese means ‘forest’, and yoku means ‘bath’. Therefore, Shinrin-yoku means bathing in the forest atmosphere, or taking in the forest through our senses. This is not exercise, or hiking, or jogging. It is simply being in nature, connecting with it through our sense of sight, hearing, taste, smell and touch. Shinrin-yoku is like a bridge. By opening our senses, it bridges the gap between us and the natural world [1, 2].
People can enjoy the Shinrin-yoku through all five senses [3].
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Sense of sight: green color, yellow color and red color, forest landscape, etc.
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Sense of smell: special good smell, fragrance from trees and flowers, phytoncides.
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Sense of hearing: forest sounds, listen to the birds singing and the breeze rustling in the leaves of the trees.
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Sense of touch: touching trees, put your whole body in the forest atmosphere.
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Sense of taste: eating foods and fruits from forests, taste the fresh air in forests.
Why forest bathing/shinrin-yoku is necessary?
Stress is a keyword to understand why Shinrin-yoku is necessary in Japan. In 1984, the word ‘technostress’ was coined to describe unhealthy behaviour around new technology. Technostress can arise from all manner of everyday usage, like checking your phone constantly, compulsively sharing updates and feeling that you need to be continually connected. Symptoms run from anxiety, headaches, depression, mental fatigue, eye and neck strain to insomnia, frustration, irritability and loss of temper [4]. Since the year 2000, we have officially become an urban species. The urban population worldwide grew from just 746 million in 1950 to 3.9 billion in 2014, according to the United Nations Population Division. By 2050, 75% of the world’s projected 9 billion population will live in cities [2]. In Japan, prevalence of cancers and non-communicable diseases such as heart disease, diabetes, cerebrovascular disease and hypertension are increasing [5]) and more than half of deaths are attributed to non-communicable diseases [6]. According to the Ministry of Health, Labour and Welfare of Japan, the percentage of workers with anxiety and stress was more than 50% in 1982, 62.8% in 1997, 58% in 2007, and 60.9 in 2012 [3], suggesting a major mental health problem. Stress can induce almost all non-communicable diseases, such as cancers, hype…