The Salutary Influence of Forest Bathing on Elderly Patients with Chronic Heart Failure

Effect of urban environment on cardiovascular health: a feasibility pilot study using machine learning to predict heart rate variability in patients with heart failure

Aims

Urbanization is related to non-communicable diseases such as congestive heart failure (CHF). Understanding the influence of diverse living environments on physiological variables such as heart rate variability (HRV) in patients with chronic cardiac disease may contribute to more effective lifestyle advice and telerehabilitation strategies. This study explores how machine learning (ML) models can predict HRV metrics, which measure autonomic nervous system responses to environmental attributes in uncontrolled real-world settings. The goal is to validate whether this approach can ascertain and quantify the connection between environmental attributes and cardiac autonomic response in patients with CHF.

Methods and results

A total of 20 participants (10 healthy individuals and 10 patients with CHF) wore smartwatches for 3 weeks, recording activities, locations, and heart rate (HR). Environmental attributes were extracted from Google Street View images. Machine learning models were trained and tested on the data to predict HRV metrics. The models were evaluated using Spearman's correlation, root mean square error, prediction intervals, and Bland-Altman analysis. Machine learning models predicted HRV metrics related to vagal activity well (R > 0.8 for HR; 0.8 > R > 0.5 for the root mean square of successive interbeat interval differences and the Poincaré plot standard deviation perpendicular to the line of identity; 0.5 > R > 0.4 for the high frequency power and the ratio of the absolute low- and high frequency power induced by environmental attributes. However, they struggled with metrics related to overall autonomic activity, due to the complex balance between sympathetic and parasympathetic modulation.

Conclusion

This study highlights the potential of ML-based models to discern vagal dynamics influenced by living environments in healthy individuals and patients diagnosed with CHF. Ultimately, this strategy could offer rehabilitation and tailored lifestyle advice, leading to improved prognosis and enhanced overall patient well-being in CHF.

Nature-based interventions for physical health conditions: A systematic review and meta-analysis

Nature-based interventions (NBIs) are activities, strategies, or programs taking place in natural settings, such as exercising in greenspaces, to improve the health and well-being of people by integrating the benefits of nature exposure with healthy behaviours. Current reviews on NBIs do not report the effects on different groups of physical health conditions. The purpose of this systematic review and meta-analysis was to identify and synthesize the evidence of the effect of NBIs on physical health outcomes and biomarkers of physical health conditions. Overall, 20,201 studies were identified through searching MEDLINE, Embase, CINAHL, SPORTDiscus, and CENTRAL databases up to June 7, 2024. Inclusion criteria were: 1) randomized controlled intervention studies; 2) population with a physical health condition; 3) NBIs vs. different intervention or no intervention; and 4) measuring physical health outcomes and/or biomarkers. Twenty-six studies were included in the review, 15 of which contributed to the meta-analysis. Compared to control groups, NBIs groups showed significant improvements in: diastolic blood pressure (MD -3.73 mmHg [-7.46 to -0.00], I2 = 62%) and heart rate (MD -7.44 bpm [-14.81 to -0.06], I2 = 0%) for cardiovascular conditions, fatigue (SMD -0.50 [-0.82 to -0.18], I2 = 16%) for central nervous system conditions, and body fat percentage (MD -3.61% [-5.05 to -2.17], I2 = 0%) for endocrine conditions. High effect heterogeneity was found in several analyses and the included studies had moderate-to-high risk of bias (RoB). The non-significant outcomes showed a direction of effect in favour of NBI groups for cardiovascular, central nervous system, endocrine, musculoskeletal, and respiratory conditions. This review found some beneficial effects in favour of NBIs for health outcomes in at least three condition groups though RoB and inconsistent effects limited some interpretations. NBIs are promising therapies that healthcare professionals can consider integrating into clinical practice.

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.

Susceptibility to stress and nature exposure: Unveiling differential susceptibility to physical environments; a randomized controlled trial

BACKGROUND

Emerging epidemiological evidence indicates nature exposure could be associated with greater health benefits among groups in lower versus higher socioeconomic positions. One possible mechanism underpinning this evidence is described by our framework: (susceptibility) adults in low socioeconomic positions face higher exposure to persistent psychosocial stressors in early life, inducing a pro-inflammatory phenotype as a lifelong susceptibility to stress; (differential susceptibility) susceptible adults are more sensitive to the health risks of adverse (stress-promoting) environments, but also to the health benefits of protective (stress-buffering) environments.

OBJECTIVE

Experimental investigation of a pro-inflammatory phenotype as a mechanism facilitating greater stress recovery from nature exposure.

METHODS

We determined differences in stress recovery (via heart rate variability) caused by exposure to a nature or office virtual reality environment (10 min) after an acute stressor among 64 healthy college-age males with varying levels of susceptibility (socioeconomic status, early life stress, and a pro-inflammatory state [inflammatory reactivity and glucocorticoid resistance to an in vitro bacterial challenge]).

RESULTS

Findings for inflammatory reactivity and glucocorticoid resistance were modest but consistently trended towards better recovery in the nature condition. Differences in recovery were not observed for socioeconomic status or early life stress.

DISCUSSION

Among healthy college-age males, we observed expected trends according to their differential susceptibility when assessed as inflammatory reactivity and glucocorticoid resistance, suggesting these biological correlates of susceptibility could be more proximal indicators than self-reported assessments of socioeconomic status and early life stress. If future research in more diverse populations aligns with these trends, this could support an alternative conceptualization of susceptibility as increased environmental sensitivity, reflecting heightened responses to adverse, but also protective environments. With this knowledge, future investigators could examine how individual differences in environmental sensitivity could provide an opportunity for those who are the most susceptible to experience the greatest health benefits from nature exposure.

Effects of forest walking on physical and mental health in elderly populations: a systematic review

There is a growing awareness that spending time in nature is associated with improvement of well-being; nevertheless, the prescription of forest bathing is still limited. The aim of this systematic review was to explore the physiological and psychological benefits of different forest therapies on healthy and pathological elderly populations (>60 years) to identify the most-effective type, duration, and frequency of these interventions. A search for literature was carried out in December 2021 using PubMed, EMBASE, ResearchGate, Google Scholar and Web of Science. Grey literature was searched as well. After removal of the duplicates, within the 214 articles identified, ten met the inclusion criteria. The methodological quality of the selected studies was rated. Forest walking, alone and in combination with other activities is the most effective intervention. The selected studies reported a positive impact on physical components, including reduction in blood pressure and heart rate and improvements in cardiopulmonary and neurochemical parameters. Favorable modifications have also been noted in the psychological field, with improvements in depression, stress levels and in quality of life perception. In conclusion, forest walking may play an important role in promoting physical and mental health in healthy and pathological elderly populations. However, the lack of high-quality studies limits the strength of the results, calling for more trials.

Nature-Based Interventions Targeting Elderly People's Health and Well-Being: An Evidence Map

BACKGROUND

Healthy aging encompasses more than the absence of disease, emphasizing the preservation of functional abilities for enhanced well-being and quality of life. Nature-based interventions are scientifically proven contributors to healthy aging.

OBJECTIVE

To develop an evidence map showcasing nature-based interventions targeting older individuals' health and well-being.

METHODS

The evidence map was developed through critical analysis of systematic reviews and clinical trials utilizing the tools AMSTAR2 and CONSORT. A systematic search spanning the past decade was conducted across databases: Cochrane, SCOPUS, PubMed, Web of Science, Embase, and LILACS.

RESULTS

Twelve articles met the eligibility criteria. Nature-based interventions such as forest bathing, hiking, therapeutic gardens, virtual reality, and forest sounds were identified. Outcomes were categorized into physical aspects (cardiovascular and pulmonary; neuro-immuno-endocrinological) and mental/behavioral aspects. The final map integrated interventions, outcomes, and quality assessments.

CONCLUSIONS

The survey highlights the positive impact of nature-based interventions on the health of the elderly. This study provides insights across various domains, fostering the development of programs and policies in management to promote healthy aging. Regarding healthcare, it encourages discourse among professionals regarding the integration of nature-based practices for equitable care in both individual and group settings. Furthermore, it underscores the need for research in the Southern Hemisphere, particularly in Brazil, where the study was conducted.

Shinrin-Yoku (Forest Bathing): A Scoping Review of the Global Research on the Effects of Spending Time in Nature

Background

This Scoping review (ScR) builds upon the 2017 review conducted by Hansen et al which contributed to evidence base shinrin-yoku (SY), also known as forest bathing (FB), has many positive health effects and is becoming a prescribed dose (specific time spent in nature) by health care providers. Practice and research regarding SY, has been historically based in Asian countries with a recent increase in Europe. The need and call for more research worldwide continues to further the evidence of SY as a health promotion modality. Through this ScR the authors identified programmatic components, health information monitored and screened, time spent in nature, geographical regions, trends, and themes in SY research worldwide.

Methods

Following PRISMA-ScR guidelines we searched across 7 electronic databases for SY or FB research articles from 2017 through 2022. PubMed, CINAHL, PsycInfo, ScienceDirect, SCOPUS, Embase, JSTOR were included due to the interdisciplinary nature of SY or FB research. Each database provided unique strengths ensuring a capture of a wide range of articles. The resulting articles were screened and extracted through Covidence.

Results

Database searches returned 241 results, with 110 references removed during the deduplication process, 131 were initially screened in the title and abstract review stage. Resulting in 82 unique results deemed relevant and screened in full text. During the final stage of the review, 63 articles met all inclusion criteria and were extracted for data.

Conclusions

The practice of SY has physiological (PHYS) and psychological (PSYCH) benefits across age groups. Research findings indicate either the natural or the virtual environment (VW) has significant health benefits. Continued research is encouraged globally for short- and long-term health outcomes for all individuals. The connection with nature benefits the mind, body and soul and is supported by Henry David Thoreau's philosophy: "Our livesneed the relief of where the pine flourishes and the jay still scream."

Effects of Linpan nature therapy on health benefits in older women with and without hypertension

Background

Nature therapy can significantly benefit the physiology and psychology of middle-aged and older people, but previous studies have focused on forest environments. The restoration potential of rural environments in urban fringe areas, which are more accessible to older people on a daily basis, has not been fully studied. This study assessed the effects of nature therapy on the physical and mental health of older women in a rural setting (locally known as Linpan) in the urban fringe area of Chengdu, China.

Methods

We recruited a total of 60 older women (65.3 ± 5.5 years old) living in cities for 3 days of nature therapy in the winter (30 subjects) and spring (30 subjects), including 20 hypertensive patients.

Results

The results showed that the overall blood pressure, pulse and sleep dysfunction rating scores of the participants were significantly lower than the pretest levels, and the finger blood oxygen saturation, mid-day salivary alpha-amylase and cortisol were increased post-treatment. Increases in these biomarker indicates and increase in stress. There were significant differences in the changes in systolic blood pressure between the hypertension group (HTN) and the normal group (normal) (HTN decreased by 8.8%, normal decreased by 5.4%), salivary alpha-amylase content (HTN decreased by 0.3%, normal increased by 16.9%), and sleep dysfunction rating scores (HTN decreased by 59.6%, normal decreased by 54%). The decreases in systolic blood pressure and pulse in the winter group were higher than those in the spring group by 1.8 and 4.4%, respectively, while the increases in salivary alpha-amylase content and salivary cortisol content were lower than those in the spring group by 11.7 and 11.2%, respectively, and the decrease in sleep dysfunction rating scores was lower than that in the spring group by 7.1%.

Conclusion

Our study concluded that nature therapy based on various health activities in the Linpan has significant health effects on older women. It can regulate blood pressure and pulse in older women, relieve cardiovascular disease, improve sleep quality. Meanwhile, older women with high blood pressure experienced a more significant effect than the healthy group.

Health effects of green prescription: A systematic review of randomized controlled trials

An increasing number of studies have examined the effects of green prescription on various health outcomes. The aim of this study was to systematically review published randomized controlled trial studies on the health benefits of green prescriptions. We searched PubMed, Scopus, and Web of Science for the relevant original articles published in English until June 30, 2023. Our search initially retrieved 26176 articles, of which 31 studies were included in our review after removing the duplicates and excluding ineligible articles based on their titles, abstracts, and full-text review. Consistent positive health benefits of green prescription were reported for psychological health and wellbeing (16 out of 24 studies), cardiometabolic health (five out of nine studies), physical activity (eight out of nine studies), and inflammation (two out of two studies). The reviewed studies did not report any significant benefits in orthopedic conditions, pain, and recovery from exhaustion disorder due to their implemented green prescriptions; however, the number of studies was too small to generalize the effect of green prescriptions on these outcomes. The quality of these studies was generally acceptable, with 28 studies having some concerns regarding their overall risk of bias and only three studies with a high risk of bias. All in all, this systematic review suggests that green prescriptions can be effective in improving various health outcomes, but further studies with larger sample sizes and objective measures are needed.

Effect of nature prescriptions on cardiometabolic and mental health, and physical activity: a systematic review

Nature prescriptions are gaining popularity as a form of social prescribing in support of sustainable health care. This systematic review and meta-analysis aims to synthesise evidence on the effectiveness of nature prescriptions and determine the factors important for their success. We searched five databases from inception up to July 25, 2021. Randomised and non-randomised controlled studies featuring a nature prescription (ie, a referral or an organised programme, by a health or social professional, to encourage spending time in nature) were included. Two reviewers independently conducted all steps of study selection; one reviewer collected summary data from published reports and conducted the risk of bias assessment. Random-effect DerSimonian-Laird meta-analyses were conducted for five key outcomes. We identified 92 unique studies (122 reports), of which 28 studies contributed data to meta-analyses. Compared with control conditions, nature prescription programmes resulted in a greater reduction in systolic blood pressure (mean difference -4·82 mm Hg [-8·92 to -0·72]) and diastolic blood pressure (mean difference -3·82 mm Hg [-6·47 to -1·16). Nature prescriptions also had a moderate to large effect on depression scores (post-intervention standardised mean difference -0·50 [-0·84 to -0·16]; change from baseline standardised mean difference -0·42 [-0·82 to -0·03]) and anxiety scores (post-intervention standardised mean difference -0·57 [-1·12 to -0·03]; change from baseline standardised mean difference -1·27 [-2·20 to -0·33]). Nature prescriptions resulted in a greater increase in daily step counts than control conditions (mean difference 900 steps [790 to 1010]) but did not improve weekly time of moderate physical activity (mean difference 25·90 min [-10·26 to 62·06]). A subgroup analysis restricted to studies featuring a referring institution showed stronger effects on depression scores, daily step counts, and weekly time of moderate physical activity than the general analysis. Beneficial effects on anxiety and depression scores were mainly provided by interventions involving social professionals whereas beneficial effects on blood pressures and daily step counts were provided mainly by interventions involving health professionals. Most studies have a moderate to high risk of bias. Nature prescription programmes showed evidence of cardiometabolic and mental health benefits and increases in walking. Effective nature prescription programmes can involve a range of natural settings and activities and can be implemented via social and community channels, in addition to health professionals.

The Relationship Between Nature and Immigrants' Integration, Wellbeing and Physical Activity: A Scoping Review

Exposure to nature has been suggested to promote immigrants' health and facilitate adaptation. This review summarizes previous research focusing on the relationship between nature and immigrants' integration, wellbeing and physical activity. A search strategy was developed and adapted to seven databases. After removing duplicates, 4861 records were screened, 81 met inclusion criteria. Community gardens and urban parks were the most studied environments. In these settings, embodied experiences (the interactive processes of sensing and cognition) can foster new memories that facilitate adaptation and attachment to new natural environments. Social interaction and reconnecting with pre-migration experiences through specific use patterns can promote cultural continuation, sense of belonging and wellbeing. Other health benefits such as physical activity, disease management and improved nutrition were less frequently studied. Barriers to participation and recommendations for research and practice were also identified. Use of stronger study designs and greater inclusion of immigrant groups in research, design and evaluation of nature-based initiatives is needed.

An eye-tracking study on visual perception of vegetation permeability in virtual reality forest exposure

Previous studies have confirmed the significant effects of single forest stand attributes, such as forest type (FT), understory vegetation cover (UVC), and understory vegetation height (UVH) on visitors' visual perception. However, rarely study has yet clearly determined the relationship between vegetation permeability and visual perception, while the former is formed by the interaction of multiple forest stand attributes (i.e., FT, UVC, UVH). Based on a mixed factor matrix of FT (i.e., coniferous forests and broadleaf), UVC level (i.e., 10, 60, and 100%), and UVH level (0.1, 1, and 3 m), the study creates 18 immersive virtual forest videos with different stand attributes. Virtual reality eye-tracking technology and questionnaires are used to collect visual perception data from viewing virtual forest videos. The study finds that vegetation permeability which is formed by the interaction effect of canopy density (i.e., FT) and understory density (i.e., UVC, UVH), significantly affects participant's visual perception: in terms of visual physiology characteristics, pupil size is significantly negatively correlated with vegetation permeability when participants are viewing virtual reality forest; in terms of visual psychological characteristics, the understory density formed by the interaction of UVC and UVH has a significant impact on visual attractiveness and perceived safety and the impact in which understory density is significantly negatively correlated with perceived safety. Apart from these, the study finds a significant negative correlation between average pupil diameter and perceived safety when participants are viewing virtual reality forests. The findings may be beneficial for the maintenance and management of forest parks, as well as provide insights into similar studies to explore urban public green spaces.

Associations of forest negative air ions exposure with cardiac autonomic nervous function and the related metabolic linkages: A repeated-measure panel study

Forest environment has many health benefits, and negative air ions (NAI) is one of the major forest environmental factors. Many studies have explored the effect of forest environment on cardiac autonomic nervous function, while forest NAI in the among function and the underlying mechanism still remain unclear. To explore the associations and molecular linkages between short-term exposure to forest NAI and heart rate variability (HRV), a repeated-measure panel study was conducted among 31 healthy adults. Participants were randomly selected to stay in a forest park for 3 days and 2 nights. Individual exposures including NAI were monitored simultaneously and HRV indices were measured repeatedly at the follow-up period. Urine samples were collected for non-targeted metabolomics analysis. Mixed-effect models were adopted to evaluate associations among NAI, HRV indices and metabolites. The median of NAI concentration was 68.11 (138.20) cm^-3 during the study period. Short-term exposure to forest NAI was associated with the ameliorative HRV indices, especially the excitatory parasympathetic nerve. For instance, per interquartile range increase of 5-min moving average of NAI was associated with 9.99 % (95%CI: 8.95 %, 11.03 %) increase of power in high frequency. Eight metabolites were associated with NAI exposure. The down-regulated tyrosine metabolism was firstly observed, followed by other amino acid metabolic alterations. The NAI-related metabolic changes reflect the reduction of inflammation and oxidative stress. HRV indices were associated with 25 metabolites, mainly including arginine, proline and histidine metabolism. Short-term exposure to forest NAI is beneficial to HRV, especially to the parasympathetic nerve activity, by successively disturbing different metabolic pathways which mainly reflect the increased anti-inflammation and the reduced inflammation. The results will provide epidemiological evidences for developing forest therapy and improving cardiac autonomic nervous function.

Is altitude a determinant of the health benefits of nature exposure? A systematic review and meta-analysis

Introduction

Nature exposure is a widely accepted option for promoting public health owing to the recent surge of scientific evidence. However, the actual settings to facilitate this initiative is yet to be extensively reviewed. In this systematic review, we have aimed to provide an up-to-date summary of interventional studies investigating the psycho-physiological effects of forests and urban forests, including details on their physical settings, and investigate an effect-modifying role of altitude and summarize data on the magnitude and shape of the association.

Methods

A keyword search using five electronic academic databases (PubMed, Embase, PsycINFO, Web of Science, and Scopus) was conducted to identify relevant articles published in English from the inception year to the end of February 2022. The methodological quality was evaluated using the ROBINS-I or ROB2 tool, depending on the study design. Meta-regression and random effects model were jointly used to examine the relationship between altitude and health outcomes.

Results

We included 27 eligible studies and 31 cases extracted from 19 studies were used for the meta-analysis. In the meta-regression, we observed a non-linear association between altitude and psycho-physiological effects. Altitude had a positive quadratic association with anxiety (p < 0.000, adjusted R ² = 96.79%), depression (p < 0.000, adjusted R ² = 98.78%), and fatigue (p < 0.000, adjusted R ² = 64.74%) alleviating effects. Conversely, altitude demonstrated a negative non-linear association with the blood pressure-lowering effect (p = 0.009, adjusted R ² = 32.83%). Additionally, the thermal index (THI) and illuminance (lx) levels were significantly associated with effect sizes of psychological restoration.

Discussion

This review provides moderate-certainty evidence for an effect-modifying role of altitude. The meta-regression results suggested the optimal and minimal altitude ranges for psychological restoration and physiological relaxation, respectively. Despite some limitations, the study findings provide a significant basis for utilizing altitude, which is easily accessible and simple, to promote the health benefits of nature-based initiatives.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022310894, identifier: CRD42022310894.

The impact of greenspace or nature-based interventions on cardiovascular health or cancer-related outcomes: A systematic review of experimental studies

SIGNIFICANCE

Globally, cardiovascular disease (CVD) and cancer are leading causes of morbidity and mortality. While having different etiologies, CVD and cancer are linked by multiple shared risk factors, the presence of which exacerbate adverse outcomes for individuals with either disease. For both pathologies, factors such as poverty, lack of physical activity (PA), poor dietary intake, and climate change increase risk of adverse outcomes. Prior research has shown that greenspaces and other nature-based interventions (NBIs) contribute to improved health outcomes and climate change resilience.

OBJECTIVE

To summarize evidence on the impact of greenspaces or NBIs on cardiovascular health and/or cancer-related outcomes and identify knowledge gaps to inform future research.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 and Peer Review of Electronic Search Strategies (PRESS) guidelines, we searched five databases: Web of Science, Scopus, Medline, PsycINFO and GreenFile. Two blinded reviewers used Rayyan AI and a predefined criteria for article inclusion and exclusion. The risk of bias was assessed using a modified version of the Newcastle-Ottawa Scale (NOS). This review is registered with PROSPERO, ID # CRD42021231619.

RESULTS & DISCUSSION

Of 2565 articles retrieved, 31 articles met the inclusion criteria, and overall had a low risk of bias. 26 articles studied cardiovascular related outcomes and 5 studied cancer-related outcomes. Interventions were coded into 4 categories: forest bathing, green exercise, gardening, and nature viewing. Outcomes included blood pressure (BP), cancer-related quality of life (QoL) and (more infrequently) biomarkers of CVD risk. Descriptions of findings are presented as well as visual presentations of trends across the findings using RAW graphs. Overall studies included have a low risk of bias; and alluvial chart trends indicated that NBIs may have beneficial effects on CVD and cancer-related outcomes.

CONCLUSIONS & IMPLICATIONS

(1) Clinical implication: Healthcare providers should consider the promotion of nature-based programs to improve health outcomes. (2) Policy implication: There is a need for investment in equitable greenspaces to improve health outcomes and build climate resilient neighborhoods. (3) Research or academic implication: Research partnerships with community-based organizations for a comprehensive study of benefits associated with NBIs should be encouraged to reduce health disparities and ensure intergenerational health equity. There is a need for investigation of the mechanisms by which NBIs impact CVD and exploration of the role of CVD biological markers of inflammation among cancer survivors.

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 stays in a forest promote relaxation and reduce 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 (HSP, SV12 score > 18) 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 (CSP-14) 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). CSP-14 in part showed significant differences-total score (p = 0.054, Cohen's d = 0.319), item "integration" (p = 0.028, Cohen's d = 0.365)-favoring the effects of the forest. These effects were more pronounced in summer (August). In October, during rainfall, we detected no relevant differences. POMS only showed a significant difference in the subcategory "depression/anxiety" in favor of the field. The amount of cortisol in saliva was not different between the groups. 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.

Does Forest Therapy Have Physio-Psychological Benefits? A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Forest therapy involves visiting forests or conducting forest-based treatment activities to improve one's health. Studies have investigated the health benefits of forests, but consensus has not been reached. This study comprised a systematic review and meta-analysis to determine how forest therapy affects the physiological and psychological health of adults. The Cumulative Index to Nursing and Allied Health Literature, Embase, and Medline databases were searched on 31 August 2021. Systematic review and meta-analysis, risk evaluation, GRADE evaluation, and advertisement effect evaluation were performed for each article. The effect size was calculated by dividing blood pressure as a physiological indicator and depression as a psychological indicator. Of the 16,980 retrieved studies, 17 were selected based on the inclusion criteria. Of these, eight studies were included in the meta-analysis. The effect size of forest therapy on improving systolic and diastolic blood pressure was not significant; however, it significantly reduced depression. While the results have limited generalizability due to the inclusion of few studies, the effects of forest therapy on reducing depression have been confirmed. Since the application of forest therapy was heterogeneous in these studies, a moderator effect analysis or subgroup analysis in meta-analysis should be performed in the future.

Striving with Global Stress on a Local Level: Has the COVID-19 Pandemic Changed the Relationship between People and Nature?

The COVID-19 pandemic had harsh consequences on human health and society across the globe. In addition to health effects, the pandemic also influenced people’s values, concerns, and ethics due to lockdowns and general limitations in societal activities. In this study, we examined changes in the relationship between people and nature caused by COVID-associated stress, as well as its consequences on life quality, by comparing questionnaire-based survey data before and during the pandemic. We found that the pandemic had positive effects on individual respondents’ relationships with nature. Respondents who were more affected by the pandemic rated their life quality lower than those who were less affected. In accordance, the pandemic had a negative effect on people’s life quality, especially for people living in areas where the environment (coastal water quality) was in poor condition. Our results support the prediction that environmental quality may buffer against global stress and improve societal wellbeing.

Horticulture therapy affected the mental status, sleep quality, and salivary markers of mucosal immunity in an elderly population

Horticultural therapy (HT) has been reported to be beneficial to mental and physical health. This study investigated the effects of HT on the psychological status and mucosal immunity of elderly individuals. Twenty-four participants aged 70-93 were recruited from residential facilities and adult day-care services. Six different HT activities were designed and guided by licensed instructors who performed saliva collection and helped the participants complete the questionnaires before and after each activity. The sleep quality scores were collected during the 6 weeks of HT activities. Saliva was collected and analyzed to determine the concentrations of immunoglobulin A (IgA), lactoferrin, chromogranin A (CgA), α-amylase (AA) and total protein (TP). Comparisons of the questionnaire scores between preactivity and postactivity showed that feelings of satisfaction and happiness were significantly enhanced after each activity. In addition, sleep quality was significantly improved after the 6-week course of HT activities. Regarding mucosal immunity, the preactivity IgA and IgA/TP were significantly increased at week 3 and week 6; in addition, the ratio of lactoferrin/TP was significantly decreased at week 6 compared to week 1. The postactivity AA and CgA levels were significantly enhanced at weeks 2, 3 and 5 compared to the corresponding preactivity levels. In conclusions, HT activities significantly improved the happiness, satisfaction, well-being and sleep quality of the elderly. Moreover, mucosal immunity proteins, including IgA, lactoferrin, CgA and AA, were significantly increased.

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.

Mountain Hiking vs. Forest Therapy: A Study Protocol of Novel Types of Nature-Based Intervention

INTRODUCTION

The global rise of urbanization has much triggered scientific interest in how nature impacts on human health. Natural environments, such as alpine landscapes, forests, or urban green spaces, are potential high-impact health resources. While there is a growing body of evidence to reveal a positive influence of these natural environments on human health and well-being, further investigations guided by rigorous evidence-based medical research are very much needed.

OBJECTIVE

The present study protocol aims at testing research methodologies in the context of a prospective clinical trial on nature-based interventions. This shall improve the standards of medical research in human-nature interactions.

METHODS

The ANKER Study investigates the influence of two novel types of nature-based therapy-mountain hiking and forest therapy-on physiological, psychological, and immunological parameters of couples with a sedentary lifestyle. Two intervention groups were formed and spent a seven-day holiday in Algund, Italy. The "forest therapy group" participated in daily guided low-power nature connection activities. The "hiking group", by contrast, joined in a daily moderate hiking program. Health-related quality of life and relationship quality are defined as primary outcomes. Secondary outcomes include nature connection, balance, cardio-respiratory fitness, fractional exhaled nitric oxide, body composition and skin hydration. Furthermore, a new approach to measure health-related quality of life is validated. The so-called "intercultural quality of life" comic assesses the health-related quality of life with a digitally animated comic-based tool.

Nature-Based Interventions for Psychological Wellbeing in Long-Term Conditions: A Systematic Review

Background: With the global burden of disease increasing, particularly in relation to often preventable chronic diseases, researchers and clinicians are keen to identify interventions that can mitigate ill health and enhance the psychological wellbeing of people living with long-term conditions (LTCs). It is long established that engagement with nature can support human health and wellbeing, and in recent years, nature-based interventions (NBIs) have been advanced as of potential benefit. This review thus sought to systematically appraise published evidence of the application of NBIs to address psychological wellbeing for those living with LTCs. Methods: A systematic search of three databases, PsycINFO, MEDLINE and SCOPUS, was undertaken, and the BestBETs quality assessment checklist was used to appraise methodological quality of elicited studies. Results: Of 913 studies identified, 13 studies (12 using quantitative methods, one qualitative) were used. Included papers reported use of a variety of psychological outcomes alongside more circumscribed physiological outcomes. Quality appraisal showed modest robustness, some methodological weaknesses and a dominance of application in developed countries, yet synthesis of studies suggested that reported psychological and physiological outcomes present a strong argument for NBIs having a promising and positive impact on psychological wellbeing. Conclusions: NBIs have positive psychological and physiological impacts on people with LTCs, suggesting they may be a suitable addition to current maintenance treatment. Future research should focus on minimising study bias and increasing the potential for cross-cultural applications.

What Activities in Forests Are Beneficial for Human Health? A Systematic Review

Over the past decade, clinical trials of forest-based interventions have increased, leading to their recognition as preventive medicine. However, little is known about the differences in health effects according to the activity characteristics of interventions. This study aimed to understand the types of activities and their associated health effects to identify differences in health effects between activities. PubMed, PsycINFO, Web of Science, and Scopus databases were searched, and methodological quality was assessed using Cochrane ROB2. A total of 32 randomized controlled trials (RCTs) met the eligibility criteria. Health outcomes were collected from 6264 participants aged 6-98 years, and the sample size was 12-585. The Interventions were walking (n = 21), staying (n = 7), exercise (n = 4), indirect exposure (n = 4), and the activity time was between 10 and 240 min. Overall, walking showed consistent positive health effects, and there were differences in effects on anxiety and depression, cognitive function, stress hormone, and inflammation according to the activity. However, most of the included studies had a high risk of bias, and interventions were limited to specific activities, durations, and frequencies. Although a few limitations remain, the findings in this study are of great significance in providing the basis for the design of forest-based interventions.

Greenspace, Inflammation, Cardiovascular Health, and Cancer: A Review and Conceptual Framework for Greenspace in Cardio-Oncology Research

Cardiovascular disease (CVD) is a leading cause of global morbidity and mortality. Cancer survivors have significantly elevated risk of poor cardiovascular (CV) health outcomes due to close co-morbid linkages and shared risk factors between CVD and cancer, as well as adverse effects of cancer treatment-related cardiotoxicity. CVD and cancer-related outcomes are exacerbated by increased risk of inflammation. Results from different pharmacological interventions aimed at reducing inflammation and risk of major adverse cardiovascular events (MACEs) have been largely mixed to date. Greenspaces have been shown to reduce inflammation and have been associated with CV health benefits, including reduced CVD behavioral risk factors and overall improvement in CV outcomes. Greenspace may, thus, serve to alleviate the CVD burden among cancer survivors. To understand pathways through which greenspace can prevent or reduce adverse CV outcomes among cancer survivors, we review the state of knowledge on associations among inflammation, CVD, cancer, and existing pharmacological interventions. We then discuss greenspace benefits for CV health from ecological to multilevel studies and a few existing experimental studies. Furthermore, we review the relationship between greenspace and inflammation, and we highlight forest bathing in Asian-based studies while presenting existing research gaps in the US literature. Then, we use the socioecological model of health to present an expanded conceptual framework to help fill this US literature gap. Lastly, we present a way forward, including implications for translational science and a brief discussion on necessities for virtual nature and/or exposure to nature images due to the increasing human-nature disconnect; we also offer guidance for greenspace research in cardio-oncology to improve CV health outcomes among cancer survivors.

Analysis of Urban Forest Healing Program Expected Values, Needs, and Preferred Components in Urban Forest Visitors with Diseases: A Pilot Survey

Although the effectiveness of urban forest therapy has been studied and proven, most people are not well aware of the positive healing effects of urban forests that are easily accessible in daily life compared to the known healing effect of forests located outside urban areas. In addition, there has been a study on the analysis of urban forest healing program needs in the general population, but there is a lack of evidence on the expected values and needs of urban forest healing for people with diseases. Therefore, this pilot survey aimed to investigate the expected values, needs, and preferred components of urban forest healing programs in urban forest visitors with disease via an online user survey and see if there were any differences in the purpose of the urban forest visits and expected values of urban forest healing depending on the type of disease. The survey was conducted on 294 urban forest visitors with diseases. About 79% of respondents agreed with the healing effects of urban forest, however most respondents expected healing effects on mental health rather than on physical health ("mood change" was the highest with score of 4.43/5, followed by "reliving stress" (4.35/5) and "mental and physical stability" (4.31/5)). In addition, more than 82.0% of respondents agreed to participate in the program if a healing program for disease was developed. The results of the current pilot survey indicate that the purpose of the urban forest visits and expected values of urban forest healing were largely not different by the type of disease, and people with disease had a relatively lower awareness and lower expected values of urban forest healing effects on physical health, but high demand for the program. Urban forest therapy programs should be developed based on the specific clinical characteristics of the disease to maximize the effectiveness of the program. Additionally, policies should be implemented to promote the beneficial effects of urban forest healing not only for mental health but also for physical health.

Can Different Forest Structures Lead to Different Levels of Therapeutic Effects? A Systematic Review and Meta-Analysis

In recent decades, forests have expanded from natural resources for conservation and production to health-promoting resources. With the growing body of evidence supporting the therapeutic effects of forests, the number of investigations on the relationship between forest characteristics and therapeutic effects have increased. However, quantitative synthesis of primary studies has rarely been conducted due to a limited number of health studies including forest description and high heterogeneity of forest variables. In this study, we conducted a systematic review and meta-analysis to evaluate the relationship between the forest structure and the therapeutic effect. We systematically searched the studies examining the therapeutic effects of forests with different stand density and canopy density and synthesized the results. As a result of subgroup analysis, we found that stand density modifies the therapeutic effects. Emotional and cognitive restoration showed greatest improvement in low-density forests with a stand density of less than 500/ha and the therapeutic effects diminish as the stand density increases. The impact of canopy density was not found due to a lack of studies reporting canopy density. Although some limitations remain, the findings in this study have great significance in providing the basis for establishing management strategies of forests for therapeutic use.

Green Space and Health in Mainland China: A Systematic Review

Non-communicable diseases (NCDs) have become a major cause of premature mortality and disabilities in China due to factors concomitant with rapid economic growth and urbanisation over three decades. Promoting green space might be a valuable strategy to help improve population health in China, as well as a range of co-benefits (e.g., increasing resilience to climate change). No systematic review has so far determined the degree of association between green space and health outcomes in China. This review was conducted to address this gap. Five electronic databases were searched using search terms on green space, health, and China. The review of 83 publications that met eligibility criteria reports associations indicative of various health benefits from more green space, including mental health, general health, healthier weight status and anthropometry, and more favorable cardiometabolic and cerebrovascular outcomes. There was insufficient evidence to draw firm conclusions on mortality, birth outcomes, and cognitive function, and findings on respiratory and infectious outcomes were inconsistent and limited. Future work needs to examine the health benefits of particular types and qualities of green spaces, as well as to take advantage of (quasi-)experimental designs to test greening interventions within the context of China's rapid urbanization and economic growth.

The Effects of Forest Therapy on Immune Function

We conducted a systematic review of the effects of a forest therapy program on adults’ immune function. We used PICO-SD (participants, interventions, comparisons, outcomes, study design) to identify key items. The participants were adults over the age of 18 and the intervention was forest therapy. Our comparisons included studies that comparatively analyzed urban groups or groups that did not participate in forest therapy intervention. Cases without control groups were also included. Immunological outcome measures were included in measuring intervention outcomes. All experimental studies, such as randomized controlled trials (RCTs), non-equivalent control group designs (non-RCTs), and one-group pretest-posttest design were included in the study design. A total of 13 studies were included for comparison. Forest therapy programs were divided into lodging-type and session-type programs. The representative measures for evaluating the effects of immune function were the number of NK cells, the cytotoxic activity of NK cells, and cytotoxic effector molecules. Most studies reported improvement in these measures when comparing values after intervention with values before the forest therapy intervention. Therefore, forest therapy has been found to be effective in improving immune function. More RCT studies on the effects of forest therapy on immune function are necessary.

Psycho-Electrophysiological Benefits of Forest Therapies Focused on Qigong and Walking with Elderly Individuals

We developed two distinct forest therapy programs (FTPs) and compared their effects on dementia prevention and related health problems for older adults. One was focused on Qigong practice in the forest (QP) and the other involved active walking in the forest (WP). Both FTPs consisted of twelve 2-h sessions over six weeks and were conducted in an urban forest. We obtained data from 25, 18, and 26 participants aged 65 years or above for the QP, WP, and control groups, respectively. Neuropsychological scores via cognition (MoCA), geriatric depression (GDS) and quality of life (EQ-5D), and electrophysiological variables (electroencephalography, bioimpedance, and heart rate variability) were measured. We analyzed the intervention effects with a generalized linear model. Compared to the control group, the WP group showed benefits in terms of neurocognition (increases in the MoCA score, and alpha and beta band power values in the electroencephalogram), sympathetic nervous activity, and bioimpedance in the lower body. On the other hand, the QP group showed alleviated depression and an increased bioimpedance phase angle in the upper body. In conclusion, both active walking and Qigong in the forest were shown to have distinctive neuropsychological and electrophysiological benefits, and both had beneficial effects in terms of preventing dementia and relieving related health problems for elderly individuals.

Forest Bathing Always Makes Sense: Blood Pressure-Lowering and Immune System-Balancing Effects in Late Spring and Winter in Central Europe

Various formats of forest bathing have been receiving increasing attention owing to their perspectives in health promotion and the treatment of chronic lifestyle diseases. The majority of field studies are still being conducted in the Far Eastern region, and they often make psychological assessments mainly in the green season. In our pretest–posttest field experiment, twelve healthy, working-age volunteers participated in a 2-h leisurely forest walking program, first in the green season (May) and then in the winter season (January), in the Mecsek Hills, next to Pécs, Hungary. Systolic blood pressure decreased after the trips both in late spring and in the winter. Based on changes in the expressions of CD69, an early activation marker, NKG2D, a major recognition receptor, perforin, granzyme B, and TIM-3, an inhibitory immune checkpoint molecule, on CD8+ cytotoxic T, NK, NK^dim, NK^bright, and NKT cells, we detected the stimulation of NK^bright cells and activation of all examined immune cell subsets in the green season. In the winter, a slight activating and an interesting balancing effect regarding TIM-3 could be observed considering our finding that basal (pretest) TIM-3 expression by NK cells was significantly lower in the winter. Our work expands the knowledge on and potentials of forest medicine.

Nature Exposure and Its Effects on Immune System Functioning: A Systematic Review

Given the drastic changes in our lifestyles and ecosystems worldwide, the potential health effects of natural environments have grown into a highly pervasive topic. Recent scientific findings suggest beneficial effects from nature exposure on human immune responses. This review aims at providing a comprehensive overview of literature published on immunomodulatory effects of nature exposure by inhalation of natural substances. A systematic database search was performed in SCOPUS and PubMed. The quality and potential bias of included studies (n = 33) were assessed by applying the EPHPP (Effective Public Health Practice Project) tool for human studies and the ARRIVE (Animal Research: Reporting of In Vivo Experiments) and SYRCLE (Systematic Review Centre for Laboratory Animal Experimentation) tools for animal studies. The synthesis of reviewed studies points to positive effects of nature exposure on immunological health parameters; such as anti-inflammatory, anti-allergic, anti-asthmatic effects or increased NK (natural killer) cell activity. Decreased expression of pro-inflammatory molecules, infiltration of leukocytes and release of cytotoxic mediators are outcomes that may serve as a baseline for further studies. However, partially weak study designs evoked uncertainties about outcome reproducibility and key questions remain open concerning effect sizes, duration of exposure and contributions of specific vegetation or ecosystem types.

Disentangling the Diversity of Forest Care Initiatives: A Novel Research Framework Applied to the Italian Context

In the effort to advance the knowledge of and disentangle the diversity of emerging forest-based initiatives for wellbeing, we propose (1) an umbrella definition (i.e., forest care initiatives (FCIs)), (2) a custom-made repository to collect and systematize information on FCIs in Italy, and (3) discuss a categorization scheme to cluster initiatives into three main categories according to target users, substitutability of the forest ecosystem, and the specificity of the health contributions to which they are aimed. We analyzed 232 initiatives, showing a lively panorama of Italian FCIs, mainly provided by private entities and civil society. FCI developments appear to be occasions for, but are not restricted to, rural and marginal areas delivering inclusive wellbeing services to a wide target user group and business opportunities. However, due to the novelty of this area of investigation, further research is needed to account for benefits and opportunities and to increase knowledge on enabling forest environments.

An inversion model for estimating the negative air ion concentration using MODIS images of the Daxing'anling region

The negative air ion (NAI) concentration is an essential indicator of air quality and atmospheric pollution. The NAI concentration can be used to monitor air quality on a regional scale and is commonly determined using field measurements. However, obtaining these measurements is time-consuming. In this paper, the relationship between remotely sensed surface parameters (such as land surface temperature, normalized difference vegetation index (NDVI), and leaf area index) obtained from MODIS data products and the measured NAI concentration using a stepwise regression method was analyzed to estimate the spatial distribution of the NAI concentration and verify the precision. The results indicated that the NAI concentration had a negative correlation with temperature, leaf area index (LAI), and gross primary production while it exhibited a positive correlation with the NDVI. The relationship between land surface temperature and the NAI concentration in the Daxing’anling region is expressed by the regression equation of y = -35.51x₁ + 11206.813 (R² = 0.6123). Additionally, the NAI concentration in northwest regions with high forest coverage was higher than that in southeast regions with low forest coverage, suggesting that forests influence the air quality and reduce the impact of environmental pollution. The proposed inversion model is suitable for evaluating the air quality in Daxing’anling and provides a reference for air quality evaluation in other areas. In the future, we will expand the quantity and distribution range of sampling points, conduct continuous observations of NAI concentrations and environmental parameters in the research areas with different land-use types, and further improve the accuracy of inversion results to analyze the spatiotemporal dynamic changes in NAI concentration and explore the possibility of expanding the application areas of NAI monitoring.

Big smile, small self: Awe walks promote prosocial positive emotions in older adults

Aging into later life is often accompanied by social disconnection, anxiety, and sadness. Negative emotions are self-focused states with detrimental effects on aging and longevity. Awe-a positive emotion elicited when in the presence of vast things not immediately understood-reduces self-focus, promotes social connection, and fosters prosocial actions by encouraging a "small self." We investigated the emotional benefits of a novel "awe walk" intervention in healthy older adults. Sixty participants took weekly 15-min outdoor walks for 8 weeks; participants were randomly assigned to an awe walk group, which oriented them to experience awe during their walks, or to a control walk group. Participants took photographs of themselves during each walk and rated their emotional experience. Each day, they reported on their daily emotional experience outside of the walk context. Participants also completed pre- and postintervention measures of anxiety, depression, and life satisfaction. Compared with participants who took control walks, those who took awe walks experienced greater awe during their walks and exhibited an increasingly "small self" in their photographs over time. They reported greater joy and prosocial positive emotions during their walks and displayed increasing smile intensity over the study. Outside of the walk context, participants who took awe walks reported greater increases in daily prosocial positive emotions and greater decreases in daily distress over time. Postintervention anxiety, depression, and life satisfaction did not change from baseline in either group. These results suggest cultivating awe enhances positive emotions that foster social connection and diminishes negative emotions that hasten decline. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Forest and Wellbeing: Bridging Medical and Forest Research for Effective Forest-Based Initiatives

Research Highlights: This review gives an overview of existing literature on the emerging topic of human wellbeing-forest contact nexus and provides a preliminary framework linking forests to wellbeing by highlighting key variables affecting this relationship. Background and Objectives: Existing literature reveals the psychological, physiological and social wellbeing benefits of contact with forest ecosystems; however, the role of forests in this relationship remains largely unexplored. The objectives of this review are twofold: (i) to provide an overview of the contributions of forest experiences to human wellbeing and the related interplay with forest ecosystems and (ii) to identify knowledge gaps to inform future research and systematize information available for forest managers and planners to support the development of effective forest-based initiatives. Materials and Methods: A scoping review was performed with a five-phase method integrating a systematic approach on Scopus, Web of Science and PubMed databases and snowball search. Studies were analyzed using a descriptive-analytical method. Results: Overall, 93 papers were included in the review. These are mainly from health-related sciences providing limited information for forest managers, planners and practitioners. Four main underlying variables of the forest-wellbeing relationship are identified: interaction, forest features, sensorial dimension of the forest and individual traits and reactions. Conclusions: Forest-based initiatives provide good opportunities for supporting public health and time spent in contact with forests seems to have a “health-bonus”. Whether and to what extent forest management can contribute to this is still poorly investigated. There is the need to better study causal relationships between specific forest features, type of interactions, frequency and “dose” of experiences, individual reactions and needs and wellbeing effects to maximize benefits from forest-based initiatives.

Physiological and Psychological Effects of Walking in Urban Parks and Its Imagery in Different Seasons in Middle-Aged and Older Adults: Evidence from Matsudo City, Japan

The benefits of park therapy have been investigated in young adults, but rarely for middle-aged and older adults. This study evaluates the physiological and psychological effects of walking in urban parks and park therapy images in winter, spring, and early summer. The experiments were implemented in two walking courses in the urban park in Japan and involved 12 middle-aged and older adults. Participants walked on walking courses in an urban park and city street for 11–15 min. Their heart rate and blood pressure were evaluated to determine physiological responses. The Profile of Mood States (POMS), State-Trait Anxiety Inventory (STAI), and Landscape Image Sketching Technique (LIST) were used to determine psychological responses and spatial conditions. Walking in an urban park exhibited lower heart rates and blood pressure as compared to walking in the city. It was congruent with lowered negative moods, total mood disturbance (TMD) scores, and state anxiety, while the higher positive mood was observed in the urban parks as compared to the city. Images in winter displayed trees, relaxation, and comfort; in spring, water, activity, people, surrounding place, and recreational space; and in early summer, greenery, lawn, and broadness. In conclusion, walking in urban parks leads to physiological, psychological relaxation, and varied landscape appreciation.

How Should Forests Be Characterized in Regard to Human Health? Evidence from Existing Literature

The potential of forests as a source of health has been addressed by the scientific community and is now being considered in national forest strategies, management plans and policies. Studies identifying the mechanisms by which forest characteristics may induce these effects on human health are nevertheless scarce. This systematic review of literature on forests and human health with real-life human exposure was conducted to assess the extent to which forests have been studied and described in detail and the extent to which relationships between forest variables and health effects have been reported. The analysis underlines the lack of forest descriptions in 19.35% of the 62 studies selected for review as well as the high heterogeneity of forest variables’ description. Patterns among the articles could not be identified correlating the broader forest variable (forest type) and the most studied health variables identified (blood pressure, pulse rate or/and cortisol levels). These findings, together with previous ex situ researches, suggest the need to ameliorate and incorporate more accurate descriptions of forest variables within human health studies to provide data for forest management and the potential use of these habitats for preventive medicine and clinical practice guidelines.

Couplet medicines of leech and centipede granules improve erectile dysfunction via inactivation of the CaSR/PLC/PKC signaling in streptozotocin-induced diabetic rats

Erectile dysfunction (ED) is one of the significant complications of diabetes mellitus (DM), and CASR plays an important role in cellular antiapoptosis and NO production in the vascular endothelium by activating PKC. The present study was aimed to investigate the efficacy of Leech and Centipede Granules (LCG) through the CaSR/PLC/PKC signaling. Fifty male Sprague-Dawley rats were treated with streptozotocin to induce the DM model. After 10 weeks, an apomorphine test was used to confirm DMED. Rats with DMED were administrated with LCG and U73122 for 4 weeks. Fasting blood glucose, body weight, insulin and glucagon levels were measured. Erectile function in rats was assessed by apomorphine. Serums were measured using enzyme-linked immunosorbent assay and flow cytometry, and penile tissues were harvested for histologic and the expression of related targets analyses. After treatment, fasting blood glucose, body weight, insulin, glucagon levels, and erectile function were significantly ameliorated in the LCG groups. The LOX-1, NOX, and EMPs concentrations were significantly decreased with LCG treatment. LCG also continuously increased NO and decreased ET-1 content in penile tissues. LCG and U73122 administration also improved penile fibrosis by significantly decreasing VCAM-1, ICAM-1, and CD62P. The data also showed that LCG reduced the apoptosis level in the penis. Furthermore, the inhibited activation of the CaSR/PLC/PKC pathway was observed in DMED rats with LCG treatment. Collectively, LCG significantly ameliorated erectile function of DMED rats via increased NO generation, inhibiting endothelial cells apoptosis and penile fibrosis, which might benefit from the suppression of CaSR/PLC/PKC pathway in DMED rats.

Much More Than a Pleasant Scent: A Review on Essential Oils Supporting the Immune System

The augmenting acceptance and application of herbal medicine in prevention and treatment of diseases also involve the use of plant essential oils (EOs) through different routes of administration (aromatherapy). Scientific data supporting the efficacy of certain herbal products are continuously growing; however, the cumulative evidence is not always sufficient. The anti-inflammatory properties of EOs have been investigated more extensively and also reviewed in different settings, but so far, our review is the first to summarize the immune-supporting properties of EOs. Our aim here is to synthesize the currently available data on the immune function enhancing effects of EOs. An online search was conducted in the PubMed database, which was terminated at the end of July 2019. Other articles were found in the reference lists of the preselected papers. Studies that applied whole EOs with known components, or single EO constituents under in vitro or in vivo laboratory conditions, or in human studies, and de facto measured parameters related to immune function as outcome measures were included. Two specific fields, EO dietary supplementation for livestock and fish, and forest bathing are also explored. Some EOs, particularly eucalyptus and ginger, seem to have immune function enhancing properties in multiple studies.

Medical empirical research on forest bathing (Shinrin-yoku): a systematic review

Aims

This study focused on the newest evidence of the relationship between forest environmental exposure and human health and assessed the health efficacy of forest bathing on the human body as well as the methodological quality of a single study, aiming to provide scientific guidance for interdisciplinary integration of forestry and medicine.

Method

Through PubMed, Embase, and Cochrane Library, 210 papers from January 1, 2015, to April 1, 2019, were retrieved, and the final 28 papers meeting the inclusion criteria were included in the study.

Result

The methodological quality of papers included in the study was assessed quantitatively with the Downs and Black checklist. The methodological quality of papers using randomized controlled trials is significantly higher than that of papers using non-randomized controlled trials (p < 0.05). Papers included in the study were analyzed qualitatively. The results demonstrated that forest bathing activities might have the following merits: remarkably improving cardiovascular function, hemodynamic indexes, neuroendocrine indexes, metabolic indexes, immunity and inflammatory indexes, antioxidant indexes, and electrophysiological indexes; significantly enhancing people’s emotional state, attitude, and feelings towards things, physical and psychological recovery, and adaptive behaviors; and obvious alleviation of anxiety and depression.

Conclusion

Forest bathing activities may significantly improve people’s physical and psychological health. In the future, medical empirical studies of forest bathing should reinforce basic studies and interdisciplinary exchange to enhance the methodological quality of papers while decreasing the risk of bias, thereby raising the grade of paper evidence.

Traditional Korean Medicine-Based Forest Therapy Programs Providing Electrophysiological Benefits for Elderly Individuals

We aimed to develop forest therapy programs (FTPs) to prevent dementia and related health problems in the elderly population, with the assumption that health benefits are FTP-type specific and depend on the participant's psychophysiological traits. For this purpose, we developed two distinct FTPs, namely, a guided-breathing meditation program (BP) and a walking program (WP); we adopted the approach of Sasang constitutional (SC) medicine, which categorizes individuals into one of three SC types (SC1, SC2, or SC3) for medical care. The FTPs ran 11 sessions over 11 weeks. We recruited 29/31/28 participants who were 65 years of age or older for the BP/WP/control groups, respectively; obtained electrophysiological measurements via electroencephalogram (EEG), heart rate variability (HRV), and bioimpedance; and analyzed the intervention effects with analysis of covariance. Compared with the control, the BP and WP resulted in benefits for neural activity and parasympathetic nervous activity (PNA), respectively, and both FTPs yielded distinct beneficial effects on bioimpedance. Constitution-specific effects were also present. The SC1- and SC2-type participants gained positive effects in neural activity from the BP and WP, respectively. The SC3-type participants showed improvements in PNA from the WP. In conclusion, for older individuals, both programs conferred health benefits that would help prevent dementia, and the benefits were program-specific and constitution-specific.

Xin-Ji-Er-Kang Alleviates Myocardial Infarction-Induced Cardiovascular Remodeling in Rats by Inhibiting Endothelial Dysfunction

The present study was designed to elucidate the beneficial effects of XJEK on myocardial infarction (MI) in rats, especially through the amelioration of endothelial dysfunction (ED). 136 Sprague-Dawley rats were randomized into 13 groups: control group for 0wk (n = 8); sham groups for 2, 4, and 6 weeks (wk); MI groups for 2, 4, and 6 wk; MI+XJEK groups for 2, 4, and 6w k; MI+Fosinopril groups for 2, 4, and 6 wk (n = 8~10). In addition, 8 rats were treated for Evans blue staining and Tetrazolium chloride (TTC) staining to determine the infarct size. Cardiac function, ECG, and cardiac morphological changes were examined. Colorimetric analysis was employed to detect nitric oxide (NO), and enzyme-linked immunosorbent assay (ELISA) was applied to determine N-terminal probrain natriuretic peptide (NT-ProBNP), endothelin-1 (ET-1), angiotensin II (Ang II), asymmetric dimethylarginine (ADMA), tetrahydrobiopterin (BH₄), and endothelial NO synthase (eNOS) content. The total eNOS and eNOS dimer/(dimer+monomer) ratios in cardiac tissues were detected by Western blot. We found that administration of XJEK markedly ameliorated cardiovascular remodeling (CR), which was manifested by decreased HW/BW ratio, CSA, and less collagen deposition after MI. XJEK administration also improved cardiac function by significant inhibition of the increased hemodynamic parameters in the early stage and by suppression of the decreased hemodynamic parameters later on. XJEK also continuously suppressed the increased NT-ProBNP content in the serum of MI rats. XJEK improved ED with stimulated eNOS activities, as well as upregulated NO levels, BH₄ content, and eNOS dimer/(dimer+monomer) ratio in the cardiac tissues. XJEK downregulated ET-1, Ang II, and ADMA content obviously compared to sham group. In conclusion, XJEK may exert the protective effects on MI rats and could continuously ameliorate ED and reverse CR with the progression of MI over time.

[Reviewing the psychological and physical health effects of forests]

Civilization illnesses today impact, and will impact in the future, everyday life of people, particularly in high-income countries. Consequences are loss in life expectancy, reduction of quality of life as well as rising economic loads. The positive effects of stays and visits in natural environments on human well-being are known for a long time. Particularly, there are many indications that forest stays have health-promoting effects. This narrative review of the literature presents the current state of the research on health-promoting effects of forest exposure. Forest exposure has positive health effects on the cardiovascular system, the immune system and on mood. Especially in the context of stress reduction, forest exposure seems to have positive influences. However, little can be concluded about the extent of these positive effects, as most studies work without control environment or control groups. Moreover forest exposure is often associated with physical activity which is also known to have health benefits. Against the background of the positive health promoting trend further research should be carried out.

Therapeutic gardens as a design approach for optimising the healing environment of patients with Alzheimer's disease and other dementias: A narrative review

PURPOSE

The first half of this paper documents the role of nature in healthcare environments and its impact on wellness, with a particular focus on gardens. The second half presents a scientific evaluation of the role of gardens as a therapeutic intervention to optimise the clinical outcomes in patients with Alzheimer's disease (AD) and dementia, including a review of the innovative application of technologies alongside nature to promote cognitive rehabilitation in this particular patient population.

METHODS

Using search engines such as the Institute for Scientific Information (ISI) Web of Science, PubMed, ProQuest Central, MEDLINE, Scopus and Google Scholar, a relevant literature search on the positive health implications of therapeutic gardens (TG) on AD and dementia patients in the healthcare milieu was conducted.

RESULTS

The health implications of TG for AD and dementia patients span physical, social, psychological and cognitive effects. Virtual reality (VR) technologies that display natural environments also offer positive cognitive outcomes for AD and dementia patients.

CONCLUSION

TG should be used to improve the health and wellbeing of AD and dementia patients, and its application should be extended to other patient populations to promote quicker recovery. Future directions in the design of TG, with a focus on patients with AD and other dementias, is also discussed.

Harnessing the Four Elements for Mental Health

Humans are intimately connected to nature, and our physical and mental health is influenced strongly by our environment. The "elements," classically described in humoral theory as Fire, Water, Earth, and Air, all may impact our mental health. In a contemporary sense, these elements reflect a range of modifiable factors: UV light or heat therapy (Fire); sauna, hydrotherapy, and balneotherapy (Water); nature-based exposure therapy and horticulture (Earth); oxygen-rich/clean air exposure; and breathing techniques (Air). This theoretical scoping review paper details the emerging evidence for a range of these elements, covering epidemiological and interventional data, and provides information on how we can engage in "biophilic" activities to harness their potential benefits. Interventional examples with emerging evidentiary support include "forest-bathing," heat therapy, sauna, light therapy, "greenspace" and "bluespace" exercise, horticulture, clay art therapy activities, and pranayamic yoga breathing exercises. Further robust research is however required to firmly validate many of these interventions, and to establish their therapeutic applications for the benefit of specific mental health disorders.

Effects of Horticultural Therapy on Asian Older Adults: A Randomized Controlled Trial

The effect of horticultural therapy (HT) on immune and endocrine biomarkers remains largely unknown. We designed a waitlist-control randomized controlled trial to investigate the effectiveness of HT in improving mental well-being and modulating biomarker levels. A total of 59 older adults was recruited, with 29 randomly assigned to the HT intervention and 30 to the waitlist control group. The participants attended weekly intervention sessions for the first 3 months and monthly sessions for the subsequent 3 months. Biological and psychosocial data were collected. Biomarkers included IL-1β, IL-6, sgp-130, CXCL12/SDF-1α, CCL-5/RANTES, BDNF (brain-derived neurotrophic factor), hs-CRP, cortisol and DHEA (dehydroepiandrosterone). Psychosocial measures examined cognitive functions, depression, anxiety, psychological well-being, social connectedness and satisfaction with life. A significant reduction in plasma IL-6 level (p = 0.02) was observed in the HT intervention group. For the waitlist control group, significant reductions in plasma CXCL12 (SDF-1α) (p = 0.003), CXCL5 (RANTES) (p = 0.05) and BDNF (p = 0.003) were observed. A significant improvement in social connectedness was also observed in the HT group (p = 0.01). Conclusion: HT, in reducing plasma IL-6, may prevent inflammatory disorders and through maintaining plasma CXCL12 (SDF-1α), may maintain hematopoietic support to the brain. HT may be applied in communal gardening to enhance the well-being of older adults.

Nature Contact and Human Health: A Research Agenda

BACKGROUND

At a time of increasing disconnectedness from nature, scientific interest in the potential health benefits of nature contact has grown. Research in recent decades has yielded substantial evidence, but large gaps remain in our understanding.

OBJECTIVES

We propose a research agenda on nature contact and health, identifying principal domains of research and key questions that, if answered, would provide the basis for evidence-based public health interventions.

DISCUSSION

We identify research questions in seven domains: a) mechanistic biomedical studies; b) exposure science; c) epidemiology of health benefits; d) diversity and equity considerations; e) technological nature; f) economic and policy studies; and g) implementation science.

CONCLUSIONS

Nature contact may offer a range of human health benefits. Although much evidence is already available, much remains unknown. A robust research effort, guided by a focus on key unanswered questions, has the potential to yield high-impact, consequential public health insights. https://doi.org/10.1289/EHP1663.