Effects of forest therapy camp on quality of life and stress in postmenopausal women

Abstract

The purpose of this study was to examine the effects of forest therapy camp on quality of life (QOL) and stress in postmenopausal women during a three-day and two-night forest camp. To observe the changes of QOL and stress, examinations of salivary cortisol were performed and a questionnaire concerning QOL was given four times: two weeks before the camp, immediately after the camp, two weeks after the camp, and four weeks after the camp. Immediately after the camp, little change was found concerning the concentration of salivary cortisol. It is supposed that this result was due to the exercise effect of being in the forest, which increased the subjects’ alertness. Two weeks and four weeks after the camp, meaningful changes appeared in the salivary cortisol levels, which confirmed that the effects of forest therapy continue after the camp. QOL results dramatically increased immediately after the camp, and while the two-week results dipped slightly from the initial post-camp results, the increase is still meaningful. The four-week post-camp results dipped slightly more, but the increase is still meaningful. The results of our analysis show that the benefits of forest therapy continue after the completion of the camp. After the camp, the positive effect on depression and QOL lasted for four weeks, and for this reason, we recommend postmenopausal women take monthly visits to forests to improve their mental and physiological stability.

Keywords:

• forest therapy
• quality of life
• salivary cortisol
• stress

Introduction

Menopause is a natural stage in a woman’s life, but the hormonal changes which occur with this event can lead to physiological and psychological problems. During menopause, the structure of the brain and the hormonal balance change. These changes are akin to when children enter puberty. This change of life usually affects women between the ages of 40 and 50, but can happen as late as 60, as estrogen and progesterone levels change and affect the temporal lobe and limbic system. These hormonal changes often lead to emotional changes and cause feelings of moodiness, nervousness, anxiety and impatience (Northrup 2010). These emotional changes often cause stress which leads to worsening hormonal imbalances. Previous research has shown that high stress hormone levels lead to low bone density (Kim and Park 2013). Furthermore, statistics show a meaningful correlation between high stress and menopausal disorders (Park and Lee 2000). Women with chronic stress not only have cortisol imbalances, but they also have imbalances in their estrogen, progesterone and testosterone levels.

For this reason, menopausal women must accept the physical changes as their bodies age and adapt to their new life situations in order to lower their stress and ultimately restore hormonal balance. Therefore, a new method is needed to positively confront the negative menopausal effects for many women.

Forest therapy offers an alternative technique that takes advantage of the inherent curative factors found in forests. First, there are sounds in the forest which make people comfortable. Second, exposure to sunlight promotes serotonin production, and from sunlight, people obtain vitamin D, which makes bones stronger and aids in cell division (Korea Forest Service 2014). Third, when enjoying waterfalls, visitors are exposed to negative ions, which have been shown to lower physiological stress reactions (Kim et al. 2008). Finally, forest air has phytoncide which stimulates the sense of smell and helps produce a state of balance and comfort.

Research has shown that such forest healing factors promote physical and mental health. Forest bathing and other forest activities have positive effects on psychological stability (Lee and Lee 2012; Shin 2010). In addition, psychological healing programs conducted in a forest environment have been shown to be effective in the treatment of depression (Woo et al. 2012). One study compared the results of holding a healing program for the elderly in a forest versus holding the same program indoors and found that the self-esteem of the participants was boosted in the forest, while depression decreased (Im et al. 2014). Due to the beneficial results found in previous studies, it is expected that the physiological changes in postmenopausal women after completing our forest therapy camp would lead to decreases in depression and increases in quality of life.

This type of research is important because the average lifespan is increasing, and the number of years a woman lives after menopause is much greater than in the past. Women will live roughly one-third of their lives after menopause, so concerns about postmenopausal health and mental stability must be addressed. This research has determined that quality of life and stress levels can be improved by the forest therapy camp.

Material and methods

Participants

The subjects of this research were 24 postmenopausal Korean women who volunteered to join this camp. They ranged from 55 to 70 years of age and were primarily from urban areas.

Experiment place

The camp took place at Chungbuk University’s experimental forest at Woraksan National Park (Figure 1). This park is a mixed forest which has many pine trees and features many scenic views. The various sites were carefully evaluated and selected prior to the camp in order to offer the maximum forest effect to the participants. In particular, sites were chosen which appealed to the five senses.

Figure 1. Research area: Woraksan national park.

The contents of the forest therapy camp

Forest therapy encompasses several essential elements. Among these are viewing forest landscapes, walking in the forest, and forest bathing, and these activities were the key components of our camp (Table 1). Viewing forest landscapes has a positive physiological and psychological effect (Ikei et al. 2014). Previous research has also shown that walking in an urban park decreased negative feelings and improved mood (Song et al. 2013), and walking in a forest environment helped participants improve stress and fatigue levels (Choi et al. 2011; Horiuchi et al. 2013). Forest bathing, which essentially is being surrounded by a forest environment, is effective for increasing relaxation and decreasing stress and fatigue (Hohashi and Kobayashi 2013). In addition, a forest bathing trip with female participants significantly increased natural killer (NK) cell activity (Li 2008), while one with male participants was found to have a positive effect on the human immune system (Park et al. 2010).

Table 1. Time table of the forest therapy camp.

Day	Time	Contents
1	11:00–13:00	Lunch with natural herbal food and free time
	13:00–13:30	Orientation
	13:30–17:30	Forest bathing, forest walking, forest landscape viewing
	17:30–19:00	Dinner with natural herbal food
	19:00–20:30	Forest walking, forest meditating
2	06:00–07:30	Forest walking, forest meditating
	07:30–09:00	Breakfast with natural herbal food
	09:00–09:30	Go to the forest
	09:30–12:00	Forest bathing
	12:00–13:30	Lunch box and natural snack
	13:30–15:30	Forest walking, forest landscape viewing
	15:30–16:00	Return to the camp
	16:00–17:30	Forest bathing
	17:30–19:00	Dinner
	19:00–20:30	Forest walking, forest meditating
	20:30–	Free time and Sleep
3	06:00–07:30	Forest walking, forest meditating
	07:30–09:00	Breakfast with natural herbal food
	09:00–10:00	Forest walking
	10:00–10:30	Camp review with photos and video
	10:30–12:30	Post check-up
	12:30–13:30	Lunch with natural herbal food
	13:30–14:00	Meeting to close

Instruments

Salivary cortisol

The Center for the Studies on Human Stress (CSHS) states that checking cortisol by way of saliva is the preferred method because of its non-invasive advantage over testing blood cortisol (Centre for Studies on Human Stress 2007). Cortisol is a steroid hormone secreted from the adrenal cortex. It is found in a person's blood and saliva in the same concentrations. Because saliva collection uses no needle, it is more proper for our research because a subject's cortisol can be distorted by the additional stress of blood collection.

Because stress increases cortisol levels, it is possible to determine stress levels by checking cortisol. The body forms cortisol according to its circadian rhythm. It is at its highest in the early morning, and then lowest at night. Thus, because of the influence of the time of day, this research checked the subjects’ cortisol levels at 11 a.m. for every measurement. For each saliva collection the participants rinsed their mouths with clean water 10 min prior to the measurement. Then a cotton swab was placed under each subject's tongue and was removed after a sufficient amount of saliva was secreted. Participants expelled the cotton swabs into sterile collection kits without touching them, and the kits were then placed in a special freezer which held the samples at –20 °C. After all of the samples were collected, they were analyzed at the same time. Salivary Cortisol ELA kits were used for every sample.

Quality of life

Each woman was checked according to the Smithkline Beecham “Quality of Life” Scale, which was developed by Dunbar et al. (1992) and translated into Korean by Yoon et al. (1998). The participants answered all 23 questions in the following fields: efficacy, psychological well-being, stability, physical well-being and vitality.

Procedure and analysis

The purpose of this research was to examine the effects of forest therapy camp on the stress levels and quality of life of postmenopausal women. We checked the women a total of four times: two weeks prior to the camp, immediately after the camp, two weeks after the camp, and four weeks after the camp (Table 2). This was done in order to identify the effects of the therapy and determine the sustainability of such effects. Originally, 24 women were included, but 4 women were not able to complete the program, so the results of 20 participants were statistically analyzed using SPSS 21.0. We calculated the mean and the standard deviation of the variables. In order to verify our research results, we used paired t-test.

Table 2. Schedule of checkup.

	Date	Checkup time
Pre-checkup	28, 29 May	10:30-12:30
Post-checkup	Camp: 11–13 June
	checkup: 13 June	10:30-12:30
Post-checkup (2 week)	26, 27 June	10:30-12:30
Post-checkup (4 week)	10, 11 July	10:30-12:30

Results and discussion

Demographics of the participants

The following general characteristics were examined: age, marital status, education, religion, social activity, general personal expenditures, and presence of physical disorders.

All of the participants were postmenopausal women in the following age groups: in their fifties (7 women), in their sixties (12 women), in their seventies (1 woman) (Table 3). Eighty percent were married, 20% were unmarried. The women had varying levels of education. Forty percent of the women had completed high school, while 25% had completed middle school, and 25% had completed elementary school. Forty-five percent of the participants had some type of job (paid or voluntary). In terms of self-expenditures, the great majority (75%) spent less than 200,000 won (approximately US$170) on their own personal needs each month.

Table 3. Demographics of participants.

Characteristics	Categories	N	%
Age (years)	50-59	7	35
	60-69	12	60
	70-79	1	5
Marriage	Married	16	80.0
	Single	1	5.0
	Separation by death	3	15.0
Education	Elementary school	5	25.0
	Middle school	5	25.0
	High school	8	40.0
	College	1	5.0
Religion	None	9	45.0
	Christian	5	25.0
	Buddhism	5	25.0
	et cetera	1	5.0
Social activity	No	11	55.0
	Yes	9	45.0
Monthly expense for self (won)	≤ 200,000	14	70.0
	200,000-300,000	2	10.0
	300,000-400,000	2	10.0
	≥ 400,000	2	10.0
Chronic illness	No	8	40.0
	Yes	12	60.0

Result of salivary cortisol

Tables 4 and 5 show how the cortisol levels changed based on our research. Before the camp, the mean of the cortisol levels was 5.995; immediately after the camp, it was 5.941; two weeks later, 5.301; and four weeks later, 5.409. The decrease immediately post-camp was not statistically significant. However, the cortisol levels from the pre-camp testing and the two-week post-camp testing significantly decreased (t = 2.295, p < .05). The cortisol levels from the pre-camp and four-week post-camp tests were also significantly lower (t = 2.450, p < .05).

Table 4. Descriptive statistics of salivary cortisol (ng/ml).

Time	Mean (SD)
Pre-test	5.995 (0.983)
Post-test	5.941 (1.124)
2-week test	5.301 (0.836)
4-week test	5.409 (1.136)

Table 5. Paired t-test of salivary cortisol.

Pair	t	p
Pre-test–post-test	0.199	.850
Pre-test–2-week test	2.295	.038*
Pre-test–4-week test	2.450	.027*
Post-test–2-week test	2.137	.047*
Post-test–4-week test	2.096	.049*
2-week test–4-week test	0.247	.800

Note: *indicates significance at 5% level.

We expected the immediately post-camp stress levels would be significantly lower than the pre-camp levels and for this reason expected the post-camp cortisol level to be markedly lower. According to results of paired t-test, however, the slight decrease was not significant. It is supposed that this result was due to the effects of increased exercise on the participants. Previous research supports the view that moderate- to high-intensity exercise stimulates cortisol levels (Hill et al. 2008). Another study indicated that morning and afternoon exercise for lean and obese women resulted in increased salivary cortisol levels (Azarbayjani et al. 2011). While research has consistently shown that exercise over certain intensities induces a release of cortisol (Budde et al. 2015), it should be noted that other studies have shown decreases in cortisol after exercise. One such study dealt with elderly males and females who had exercised for short durations indoors (Heaney et al. 2013). Attention should also be given to research that has shown that simple exposure to green spaces, living in close proximity (Roe et al. 2013) and viewing (Lee et al. 2008), has lowered cortisol levels. Our participants, postmenopausal women, did not exercise strenuously, but they walked in the forest and participated in forest bathing exercises for extended periods of time. The mean of the salivary cortisol levels before camp was 5.995, while immediately after the camp it was 5.941. This shows a slight decrease, but we believe that the cortisol levels were affected by a double effect: the stimulation of the physical exertion from the camp and the cortisol-depressing effect of being in a forest environment.

Furthermore, the difference between the post-two week and post-four week results was not significant (t = 0.247, p > .05), which shows the effect of the camp was continuous. These results showed that the camp had an effect on stress for at least one month.

Result of quality of life

Tables 6 and 7 show how the quality of life levels changed based on our research. Before the camp, the quality of life mean was 138.000; immediately after the camp, it increased to 152.750; two weeks later, 150.650; and four weeks later, 146.350. Pre-camp and immediately post-camp increases were statistically significantly (t = –2.390, p < .05). Pre-camp and two-week post-camp results showed significant increases (t = –2.488, p < .05). The four-week results also increased, but not significantly.

Table 6. Descriptive statistics of quality of life.

Time	Mean (SD)
Pre-test	138.000 (27.500)
Post-test	152.750 (27.580)
2-week test	150.650 (23.920)
4-week test	146.350 (27.460)

Table 7. Paired t-test of quality of life.

Pair	t	p
Pre-test–post-test	–2.390	.027*
Pre-test–2-week test	–2.488	.022*
Pre-test–4-week test	–1.434	.168
Post-test–2-week test	0.352	.729
Post-test–4-week test	1.052	.318
2-week test–4-week test	0.844	.409

Note: *indicates significance at 5% level.

The quality of life for the participants increased the most immediately after the camp, whereas the cortisol levels immediately post-camp were not decreased significantly. These results show that the psychological change from forest therapy camp would come earlier but not last as long as the physiological change, which would appear more slowly but last longer.

Conclusion

This research concerns postmenopausal women's stress and quality of life and examined how a three-day and two-night forest therapy camp affects these important components of a woman's life. We also evaluated the participants over a period of time to determine if the effects continued even after the camp had finished.

First, our research looked at how postmenopausal women's stress changes after a forest therapy camp. We used salivary cortisol to measure the changes in stress. The cortisol levels were not lower immediately, but two weeks and four weeks after the camp, the test results showed that cortisol levels had significantly decreased from pre-camp levels. We believe that the immediate post-camp cortisol levels did not change due to a temporary exercise effect. For this reason we can say that stress decreased after the forest therapy camp, and this effect lasted at least one month.

In addition, our results showed that quality of life increased from pre-camp to post-camp results. The greatest increase was from pre-camp to immediately post-camp, but the two and four week post-camp results also showed increases, though the gains slightly decreased over time. The testing showed that the camp's positive impact on quality of life lasted at least one month.

These results offer a valuable, low-cost treatment option for women who are suffering from a range of postmenopausal symptoms. Therefore, monthly forest bathing, walking, viewing, and meditating can help women who suffer from stress and low quality of life.

This research is limited in several ways. First, several types of therapy were used (forest bathing, walking, meditating, viewing, etc.). For this reason, it is not clear which components contributed the most to our results. Further research is needed to clarify and compare the various forest therapy treatment options. Also, our study used a three-day, two-night camp, and our participants achieved positive results. In real-life situations, however, such camps may not be available, so the real-world applications must be further explored to determine if shorter excursions that take place more often (for example, bi-weekly two-hour visits) to forests are also effective. Ultimately, research is needed to discover whether short excursions or lengthy camps are more beneficial.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Korea Green Promotion Agency and Rainbow Forest Foundation in 2014.