General Wellbeing

Effects of forest environment (Shinrin-yoku/Forest bathing) on health promotion and disease prevention -the Establishment of “Forest Medicine”.

Dr QIng Li’s 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:

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.
2. Shinrin-yoku reduces blood pressure and heart rate showing preventive effect on hypertension and heart diseases.
3. Shinrin-yoku reduces stress hormones, such as urinary adrenaline and noradrenaline and salivary/serum cortisol contributing to
   stress management.
4. Shinrin-yoku increases the activity of parasympathetic nerves and reduces the activity of sympathetic nerves to stabilize the
   balance of autonomic nervous system.
5. Shinrin-yoku improve sleep.
6. Shinrin-yoku increases the levels of serum adiponectin and dehydroepiandrosterone sulfate.
7. 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.
8. Shinrin-yoku may apply to rehabilitation medicine
9. Shinrin-yoku in city parks also has benefits on human health.
10. Shinrin-yoku may have a 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.

Li Q. Effects of forest environment (Shinrin-yoku/Forest bathing) on health promotion and disease prevention -the Establishment of “Forest Medicine”. Environ Health Prev Med. 2022;27:43. doi: 10.1265/ehpm.22-00160. PMID: 36328581; PMCID: PMC9665958.

Spending Time in the Forest or the Field: Investigations on Stress Perception and Psychological Well-Being-A Randomized Cross-Over Trial in Highly Sensitive Persons

Research suggests that staying in a forest promotes relaxation and reduces stress compared to spending time in a city. The aim of this study was to compare stays in a forest with another natural environment, a cultivated field. Healthy, highly sensitive persons aged between 18 and 70 years spent one hour in the forest and in the field at intervals of one week. The primary outcome was measured using the Change in Subjective Self-Perception questionnaire. Secondary outcomes were measured using the Profile Of Mood States (POMS) questionnaire and by analyzing salivary cortisol. We randomized 43 participants. Thirty-nine were allocated and included in the intention-to-treat analysis (90% female, mean age 45 years).A short-term stay in a forest in summer caused a greater improvement in mood and well-being in HSP than in a field. This effect was not detectable during bad weather in the fall.

Oomen-Welke K, Schlachter E, Hilbich T, Naumann J, Müller A, Hinterberger T, Huber R. Spending Time in the Forest or the Field: Investigations on Stress Perception and Psychological Well-Being-A Randomized Cross-Over Trial in Highly Sensitive Persons. Int J Environ Res Public Health. 2022 Nov 19;19(22):15322. doi: 10.3390/ijerph192215322. PMID: 36430041; PMCID: PMC9690301.

The physiological effects of Shinrin-yoku (taking in the forest atmosphere or forest bathing): evidence from field experiments in 24 forests across Japan.

This paper reviews previous research on the physiological effects of Shinrin-yoku (taking in the forest atmosphere or forest bathing), and presents new results from field experiments conducted in 24 forests across Japan. The term Shinrin-yoku was coined by the Japanese Ministry of Agriculture, Forestry, and Fisheries in 1982, and can be defined as making contact with and taking in the atmosphere of the forest. In order to clarify the physiological effects of Shinrin-yoku, we conducted field experiments in 24 forests across Japan. In each experiment, 12 subjects (280 total; ages 21.7 ± 1.5 year) walked in and viewed a forest or city area.

On the first day, six subjects were sent to a forest area, and the others to a city area. On the second day, each group was sent to the other area as a cross-check. Salivary cortisol, blood pressure, pulse rate, and heart rate variability were used as indices. These indices were measured in the morning at the accommodation facility before breakfast and also both before and after the walking (for 16 ± 5 min) and viewing (for 14 ± 2 min). The R–R interval was also measured during the walking and viewing periods. The results show that forest environments promote lower concentrations of cortisol, lower pulse rate, lower blood pressure, greater parasympathetic nerve activity, and lower sympathetic nerve activity than do city environments. These results will contribute to the development of a research field dedicated to forest medicine, which may be used as a strategy for preventive medicine.

Park BJ, Tsunetsugu Y, Kasetani T, Kagawa T, Miyazaki Y. The physiological effects of Shinrin-yoku (taking in the forest atmosphere or forest bathing): evidence from field experiments in 24 forests across Japan. Environ Health Prev Med. 2010 Jan;15(1):18-26. doi: 10.1007/s12199-009-0086-9. PMID: 19568835; PMCID: PMC2793346