[Psychological relaxation effect of forest therapy: results of field experiments in 19 forests in Japan involving 228 participants].
Nihon Eiseigaku Zasshi. 2011 Sep;66(4):670-6
Authors: Tsunetsugu Y, Park BJ, Lee J, Kagawa T, Miyazaki Y
OBJECTIVES: In the present study, we aimed to clarify the psychological effects of shinrin-yoku (taking in the atmosphere of the forest) by conducting field experiments.
METHODS: The experiments were conducted in 19 forested and urban areas in Japan during the 2007-2010 period. Twelve male students participated at each of the 19 areas (a total of 228 persons). Subjective ratings of "comfortable-uncomfortable", "soothing-stimulating", and "natural-artificial" feelings were conducted after each of the participants had viewed the scenery for 15 min in the forested and urban areas. A postviewing questionnaire on "stressed-refreshed" feelings was also administered and the Profile of Mood State (POMS) questionnaire was employed to assess six aspects of mood before and after viewing the sceneries.
RESULTS: The forest environments were perceived as significantly more "comfortable", "soothing", and "natural" than the urban environments after viewing the sceneries. The score for "refreshed feeling" was also significantly higher in the forested areas. The score for the "vigor" subscale of POMS was significantly higher after viewing the scenery in the forested areas, whereas the scores for negative feelings such as "tension-anxiety", "depression-dejection", "anger-hostility", "fatigue", and "confusion" significantly decreased.
CONCLUSION: Collectively, these results suggest that the forest environments have significant beneficial and relaxing effects on human's moods compared with the urban environments.
PMID: 21996766 [PubMed - indexed for MEDLINE]
Trends in research related to "Shinrin-yoku" (taking in the forest atmosphere or forest bathing) in Japan.
Environ Health Prev Med. 2010 Jan;15(1):27-37
Authors: Tsunetsugu Y, Park BJ, Miyazaki Y
"Shinrin-yoku", which can be defined as "taking in the forest atmosphere or forest bathing", has been receiving increasing attention in Japan in recent years for its capacity to provide relaxation and reduce stress. Since 2004, the authors of this paper have been involved in an investigation designed to ascertain the physiological effects of "Shinrin-yoku" within the framework of the "Therapeutic Effects of Forests" project. We have conducted physiological experiments, both in actual forests and in the laboratory, to elucidate the physiological effects on individuals of exposure to the total environment of forests or to only certain elements of this environment, such as the odor of wood, the sound of running stream water, and the scenery of the forest. We have obtained physiological measurements of central nervous activity, autonomic nervous activity, and biomarkers reflecting stress response that can be applied in this line of approach. Using these measurements, we have summarized the separate elements of forests in terms of the five senses. We have also reviewed a selection of field studies and introduced a number of results from ongoing projects as well as those from early studies. Future perspectives are also discussed.
PMID: 19585091 [PubMed]
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
Authors: Park BJ, Tsunetsugu Y, Kasetani T, Kagawa T, Miyazaki Y
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.
PMID: 19568835 [PubMed]
Physiological effects of Shinrin-yoku (taking in the atmosphere of the forest) in an old-growth broadleaf forest in Yamagata Prefecture, Japan.
J Physiol Anthropol. 2007 Mar;26(2):135-42
Authors: Tsunetsugu Y, Park BJ, Ishii H, Hirano H, Kagawa T, Miyazaki Y
The physiological effects of "Shinrin-yoku" (taking in the atmosphere of the forest) were examined by investigating blood pressure, pulse rate, heart rate variability (HRV), salivary cortisol concentration, and immunoglobulin A concentration in saliva. Subjective feelings of being "comfortable", "calm", and "refreshed" were also assessed by questionnaire. The subjects were 12 male university students aged from 21 to 23 (mean+/-SD: 22.0+/-1.0). The physiological measurements were conducted six times, i.e., in the morning and evening before meals at the place of accommodation, before and after the subjects walked a predetermined course in the forest and city areas for 15 minutes, and before and after they sat still on a chair watching the scenery in the respective areas for 15 minutes. The findings were as follows. In the forest area compared to the city area, 1) blood pressure and pulse rate were significantly lower, and 2) the power of the HF component of the HRV tended to be higher and LF/(LF+HF) tended to be lower. Also, 3) salivary cortisol concentration was significantly lower in the forest area. These physiological responses suggest that sympathetic nervous activity was suppressed and parasympathetic nervous activity was enhanced in the forest area, and that "Shinrin-yoku" reduced stress levels. In the subjective evaluation, 4) "comfortable", "calm", and "refreshed" feelings were significantly higher in the forest area. The present study has, by conducting physiological investigations with subjective evaluations as supporting evidence, demonstrated the relaxing and stress-relieving effects of "Shinrin-yoku".
PMID: 17435356 [PubMed - indexed for MEDLINE]
Physiological effects of Shinrin-yoku (taking in the atmosphere of the forest)--using salivary cortisol and cerebral activity as indicators.
J Physiol Anthropol. 2007 Mar;26(2):123-8
Authors: Park BJ, Tsunetsugu Y, Kasetani T, Hirano H, Kagawa T, Sato M, Miyazaki Y
The purpose of this study is to examine the physiological effects of Shinrin-yoku (taking in the atmosphere of the forest). The subjects were 12 male students (22.8+/-1.4 yr). On the first day of the experiments, one group of 6 subjects was sent to a forest area, and the other group of 6 subjects was sent to a city area. On the second day, each group was sent to the opposite area for a cross check. In the forenoon, the subjects were asked to walk around their given area for 20 minutes. In the afternoon, they were asked to sit on chairs and watch the landscapes of their given area for 20 minutes. Cerebral activity in the prefrontal area and salivary cortisol were measured as physiological indices in the morning at the place of accommodation, before and after walking in the forest or city areas during the forenoon, and before and after watching the landscapes in the afternoon in the forest and city areas, and in the evening at the place of accommodation. The results indicated that cerebral activity in the prefrontal area of the forest area group was significantly lower than that of the group in the city area after walking; the concentration of salivary cortisol in the forest area group was significantly lower than that of the group in the city area before and after watching each landscape. The results of the physiological measurements show that Shinrin-yoku can effectively relax both people's body and spirit.
PMID: 17435354 [PubMed - indexed for MEDLINE]