The Effects of Forest Therapy on Immune Function

Greenspaces And Cardiovascular Health

Accumulating evidence suggests that living in areas of high surrounding greenness or even brief exposures to areas of high greenery is conducive to cardiovascular health, which may be related to the environmental, social, psychological, and physiological benefits of greenspaces. Recent data from multiple cross-sectional, longitudinal, and cohort studies suggest that living in areas of high surrounding greenness is associated with a lower risk of all-cause and cardiovascular mortality. High levels of neighborhood greenery have been linked also to a decrease in the burden of cardiovascular disease risk factors as reflected by lower rates of hypertension, dyslipidemia, and diabetes. Those who live in greener environments report better mental health and more frequent social interactions, which can benefit cardiovascular health as well. In this narrative review, we discuss evidence linking greenspaces to cardiovascular health as well as the potential mechanisms underlying the beneficial effects of greenspaces, including the impact of vegetation on air, noise and light pollution, ambient temperature, physical activity, mental health, and biodiversity. We review literature on the beneficial effects of acute and chronic exposure to nature on cardiovascular disease risk factors, inflammation and immune function, and we highlight the potential cardiovascular effects of biogenic volatile organic compounds that are emitted by trees and shrubs. We identify current knowledge gaps in this area and underscore the need for additional population studies to understand more clearly and precisely the link between greenness and health. Such understanding is urgently needed to fully redeem the promise of greenspaces in preventing adverse environmental exposures, mitigating the effects of climate change, and creating healthier living environments.

Forest therapy using virtual reality in the older population: a systematic review

Introduction

As life expectancy increases, more attention needs to be paid to their mental and physical condition. Many older patients are also bedridden, which makes some treatments, like in vivo exposure to natural environments, more difficult to be applied. This study aimed to systematically review articles that include interventions combining virtual reality and forest environment, targeting a sample of older people.

Methods

Based on PRISMA guidelines, we conducted a literature search in three databases (EBSCO, PubMed, and Scopus), plus gray literature (OpenGrey). We considered only studies that used forest settings via virtual reality and included a sample with age ≥ 65.

Results

After the screening and eligibility stages, 7 articles have been included.

Discussion

The study underlines the need to implement research in this direction to standardize effective procedures that can be used to improve the mental and physical health of the older people and caregivers, while also reducing social costs.

Effects of an urban forest healing program on cancer-related fatigue in cancer survivors

PURPOSE

This study aimed to examine the effects of an eight-session structured urban forest healing program for cancer survivors with fatigue.

BACKGROUND

Cancer-related fatigue (CRF) is a complex and multifactorial common symptom among cancer survivors that limits quality of life (QoL). Although health benefits of forest healing on physiological, physical, and psychological aspect as well as on the immune system have been reported in many studies, there is limited evidence on the efficacy of specialized forest program for cancer survivors.

METHOD

A single-blinded, pre-test and post-test control group clinical trial was conducted with -75 cancer survivors assigned to either the forest healing group or the control group. The intervention was an eight-session structured urban forest program provided at two urban forests with easy accessibility. Each session consists of three or four major activities based on six forest healing elements such as landscape, phytoncides, anions, sounds, sunlight, and oxygen. Complete data of the treatment-adherent sample (≥ 6 sessions) was used to examine whether sociodemographic, clinical, physiological (respiratory function, muscle strength, balance, 6-min walking test) and psychological (distress, mood state, sleep quality, QoL) characteristics at baseline moderated the intervention effect on fatigue severity at 9 weeks.

RESULTS

Significant time-group interactions were observed muscle strength, balance, 6-min walking test, distress, fatigue, moods, and QoL. The mean difference in fatigue between pre- and post-forest healing program was 9.1 (95% CI 6.2 to 11.9), 11.9 (95% CI 7.6 to 16.1) in moods, and -93.9 (95% CI -123.9 to -64.0) in QoL, showing significant improvements in forest healing group, but no significant improvements in the control group.

CONCLUSION

This study suggests that a forest healing program positively impacts the lives of cancer survivors, by addressing both physical and psychological challenges associated with CRF.

TRIAL REGISTRATION NUMBER

KCT0008447 (Date of registration: May 19, 2023).

Cognition and Interaction: From the Perspective of Daily Therapeutic Landscape of the Coastal Zone

This study explored the relationship between mental and physical therapeutic effects through three dimensions: man-environment relationships, a sense of place, and symbolic landscapes. The study used a combination of qualitative and quantitative research methods. Local residents living in the coastal area of Xinglin Bay were the research objects. Quantitative data analysis revealed that the frequency of residents' visits was an important variable affecting their physical and treatment perceptions. For those who visit frequently, these visits can evoke memories, which can better express their sensory experience. The text analysis showed that residents picked up two major landscape elements to form the sense of place and symbolic landscape: one is the water body in the coastal zone, and the other is the cultural symbol of the peninsula. Based on untoward event experience, the residents assembled the elements into a new spatial relationship with therapeutic affordance.

Effects of phytoncide on immune cells and psychological stress of gynecological cancer survivors: randomized controlled trials

This study aimed to identify neuroendocrine substances and natural killer (NK) cells, including their subsets and receptors, to determine whether phytoncides scented in an urban hospital could help improve stress in cancer survivors. Fifty-five gynecological cancer survivors were assigned to either the control group (CG, n=28) or phytoncide group (PTG, n=27). The PTG meditated by lying down in a space scented with phytoncide for 1 hr a day, 5 days a week for 8 weeks. Stress levels in both groups were high prior to the experiment and decreased by 9.31%±45.98% (P=0.003) only in the PTG after the experiment. Although the parasympathetic nerve activity of the PTG increased, the epinephrine and cortisol levels were significantly (P<0.001) decreased by 5.29%±25.5% and by 24.94%±11.62%. Moreover, the PTG showed a significant increase in the levels of NK cell subsets after 8 weeks, whereas there was no improvement in the CG. In conclusion, phytoncide fragrance reduces stress, increases the number of NK cells and their family even in a nonforest environment, and improves innate immunocytes in gynecological cancer survivors; parasympathetic nerve activity and cortisol hormones play critical roles in this process. That is, a phytoncide essential oil helps to stimulate changes in immunocytes' mobility by affecting the human nervous and endocrine systems, thereby providing relief for psychological stress among cancer survivors who previously had cancer cells.

Effects of Plant-Emitted Monoterpenes on Anxiety Symptoms: A Propensity-Matched Observational Cohort Study

Immersive experiences in green areas, particularly in forests, have long been known to produce beneficial effects for human health. However, the exact determinants and mechanisms leading to healthy outcomes remain to be elucidated. The purpose of this observational cohort study was to investigate whether inhaling plant-emitted biogenic volatile compounds, namely monoterpenes (MTs), can produce specific effects on anxiety symptoms. Data from 505 subjects participating in 39 structured forest therapy sessions at different Italian sites were collected. The air concentration of monoterpenes was measured at each site. STAI state questionnaires were administered before and after the sessions as a measure of anxiety. A propensity score matching analysis was then performed, considering an above-average exposure to inhalable air MTs as the treatment. The estimated effect was -1.28 STAI-S points (95% C.I. -2.51 to -0.06, p = 0.04), indicating that the average effect of exposure to high MT air concentrations during forest therapy sessions was to decrease anxiety symptoms.

Exurban and suburban forests have superior healthcare benefits beyond downtown forests

Forests in urban areas provide great healthcare benefits to citizens, but it is less well known whether this benefit is related to different geographical spaces. We selected exurban forest, suburban forest, downtown forest, and urban control in Guangzhou, China to analyze the change characteristics of negative air ion concentration (NAIC), air oxygen content (AOC), and human comfort index (HCI). Based on Criteria Importance Through Intercriteria Correlation (CRITIC) method, the urban forest comprehensive healthcare index (UFCHI) was established. Finally, the evaluation criteria for UFCHI were identified by cluster analysis. The results demonstrated that (1) The NAIC in exurban forest (2,713 ± 1,573 ions/cm3) and suburban forest (2,147 ± 923 ions/cm3) was evidently better than downtown forest (1,130 ± 255 ions/cm3) and urban control (531 ± 162 ions/cm3). (2) The AOC was in the order of exurban forest (21.17 ± 0.38%) &gt; suburban forest (21.13 ± 0.30%) &gt; downtown forest (21.10 ± 0.16%) &gt; urban control (20.98 ± 0.12%). (3) The HCI in urban control (5.56 ± 2.32) and downtown forest (5.15 ± 1.80) is higher than suburban forest (4.02 ± 1.53) and exurban forest (3.71 ± 1.48). (4) The UFCHI in exurban forest (1.000), suburban forest (0.790), and downtown forest (0.378) were beneficial to human health to some extent, while urban control (0.000) was at Level IV, having no healthcare benefit. Except in winter, the UFCHI in exurban forest and suburban forest were all at Level II and above; while downtown forest and urban control were all at Level III and below at all seasons. Overall, urban forests in the exurbs and suburbs have better healthcare benefits than those in the downtowns. Furthermore, it is recommended that urban residents visit exurban and suburban forests for forest therapy in spring, summer, and autumn.

Long-Term Effects of Mountain Hiking vs. Forest Therapy on Physical and Mental Health of Couples: A Randomized Controlled Trial

BACKGROUND

Lifelong physical activity is related to longer health span, which is reflected at an individual level, and is of substantial socioeconomic relevance. Sedentary lifestyles, on the other hand, pose an increasingly major public health problem. In addition, the COVID-19 pandemic had a negative impact on activity levels and well-being. Previous research indicates that contact with nature might improve exercise levels as well as well-being.

METHODS

This randomized, controlled clinical trial (ANKER-study) investigated the effects of two types of nature-based therapies (forest therapy and mountain hiking) in couples (FTG: n = 23; HG: n = 22;) with a sedentary or inactive lifestyle on health-related quality of life, relationship quality and other psychological and physiological parameters.

RESULTS

The results of this study displayed that healthy and highly functioning women and men with sedentary lifestyles mentally benefit from contact with nature (quality of life, satisfaction with life, mood, internal and external health-related control beliefs). The gender-specific effect on women is most visible in the physiological outcomes (hemopoietic system, aerobic capacity, skeletal muscle mass and hydration) of mountain hiking. Men and women showed small improvements in blood pressure as a result of the interventions.

CONCLUSIONS

The ANKER-study provides a method for valid comparison of forest therapy interventions for the first time. Regarding the COVID-19 pandemic, the nature-based intervention presented could offer a multimodal contribution to maintaining a more active lifestyle, further contact with nature that affects peoples physical as well as mental health, and an improvement in social interaction.

Essential Oils, Phytoncides, Aromachology, and Aromatherapy—A Review

Chemical compounds from plants have been used as a medicinal source for various diseases. Aromachology is a unique field that studies the olfactory effects after inhaling aromatic compounds. Aromatherapy is a complementary treatment methodology involving the use of essential oils containing phytoncides and other volatile organic compounds for various physical and mental illnesses. Phytoncides possess an inherent medicinal property. Their health benefits range from treating stress, immunosuppression, blood pressure, respiratory diseases, anxiety, and pain to anti-microbial, anti-larvicidal, anti-septic, anti-cancer effects, etc. Recent advancements in aromatherapy include forest bathing or forest therapy. The inhalation of phytoncide-rich forest air has been proven to reduce stress-induced immunosuppression, normalize immune function and neuroendocrine hormone levels, and, thus, restore physiological and psychological health. The intricate mechanisms related to how aroma converts into olfactory signals and how the olfactory signals relieve physical and mental illness still pose enormous questions and are the subject of ongoing research. Aromatherapy using the aroma of essential oils/phytoncides could be more innovative and attractive to patients. Moreover, with fewer side effects, this field might be recognized as a new field of complementary medicine in alleviating some forms of physical and mental distress. Essential oils are important assets in aromatherapy, cosmetics, and food preservatives. The use of essential oils as an aromatherapeutic agent is widespread. Detailed reports on the effects of EOs in aromatherapy and their pharmacological effects are required to uncover its complete biological mechanism. This review is about the evolution of research related to phytoncides containing EOs in treating various ailments and provides comprehensive details from complementary medicine.

The Influence of Virtual Forest Walk on Physiological and Psychological Responses

The authors of this paper sought to investigate the impact of virtual forest therapy based on realistic versus dreamlike environments on reducing stress levels. Today, people are facing an increase in stress levels in everyday life, which may be due to personal life, work environment, or urban area expansion. Previous studies have reported that urban environments demand more attention and mental workload than natural environments. However, evidence for the effects of natural environments as virtual forest therapy on stress levels has not yet been fully explored. In this study, a total of 20 healthy participants completed a letter-detection test to increase their stress level and were then randomly assigned to two different virtual environments representing realistic and dreamlike graphics. The participants' stress levels were assessed using two physiological methods that measured heart rate and skin conductance levels and one psychological method through the Profile of Mood States (POMS) questionnaire. These indicators were analyzed using a sample t-test and a one-way analysis of variance. The results showed that virtual forest environments could have positive stress-relieving effects. However, realistic graphics were more efficient in reducing stress. These findings contribute to growing forest therapy concepts and provide new directions for future forest therapy research.

Non-Pharmacological Measures in the Prevention and Treatment of COVID-19 Infection

BACKGROUND

Previous pandemic and catastrophic events significantly changed the life of every human being, bringing him/her into a state of stress and the need to quickly adapt to new ways of daily activity. COVID-19 has a negative impact on all elements of health: social, physical and mental. Pharmacotherapy, as well as protective measures (isolation, wearing masks and maintaining physical distance) did not give the expected results. Vaccination has not yet led to herd immunity, so it is still jeopardizing every aspect of human health (1, 2). Non-pharmacological methods, such as stress and sleep control, physical activity and contact with nature are of great importance since they can significantly contribute to staying healthy during a pandemic.

OBJECTIVES

The aim of this paper is to evaluate the impact of non-pharmacological measures such as stress and sleep control (with different measures against the negative effects of anxiety and depression on mental state) and the possible positive impact of "forest bathing" on improving the immune response to the virus and its consequences.

METHODS

Available evidence-based studies on ways to com- bat stress and the effect of the proposed measures on human mental health and the im- mune system were analyzed. From the mentioned studies, recommended measures have been registered, which refer to stress and sleep control, diet and eating habits, contact with nature ("forest bathing", gardening), virtual communication and meditation (mindfulness practice).

RESULTS AND DISCUSSION

The combined results of these studies indicate that COVID-19 has a chronic course and complications that significantly affect the physical, mental and emotional state of the patient. Proven positive effects of non-pharmacological measures can be applied in the daily practice of primary health care in the comprehensive fight against the COVID-19 pandemic.

CONCLUSION

Non-pharmacological measures such as stress and sleep control, spending time in nature, healthy diet, and physical activity may improve the immune response to COVID-19. These measures, with their positive effects on all aspects of health, can make a major contribution to controlling and improving the quality of life during the COVID-19 pandemic.