The benefits of nature exposure: The need for research that better informs implementation

Connecting place and nature-based traditional and spiritual practices among American Indian and First Nation youth

Understanding the role of place in connection to Indigenous youth participation in nature-based traditional and spiritual activities (NBTSA) is of primary concern as exposure to both nature and culture collectively contribute to overall health and wellbeing. From oppressive historical Indian policies to contemporary barriers by way of climate change and increased use of technology, Indigenous youth continue to face risk of detaching from nature and losing pieces of their cultural identity. Qualitative and quantitative features of place in predicting NBTSA participation among Indigenous youth are not well understood and may offer key insights that connect youth to land, water and their cultures. Moreover, application of the Indigenous Traditional Ecological Knowledge (ITEK) theoretical model to inform the social sciences has largely been absent. In this study, we sought to investigate the role of place measured by residing in a sovereign Tribal or First Nation (qualitative) and increased presence of greenspace (quantitative) exposure on participation in NBTSAs among Indigenous youth. Our findings demonstrate that although increasing residential exposure to greenspace had a positive association, residing in a Tribal Nation was a stronger predictor for NBTSA participation. Applying an Indigenous methodology to research with Indigenous populations and communities allows us to move beyond general notions of what (e.g., greenspace) promotes human-nature interaction and, instead, identify place-based determinants. Namely, the ITEK framework guided our rationale to include Tribal Nations in our study. Sovereign Nations connect youth to traditional knowledge holders that share Indigenous knowledges and practices of the land and water through story and experiential learning. Significance. This study is one of the first to measure both qualitative and quantitative features of place that influence human-nature interaction among youth that collectively identify as Indigenous. Our research found that residing in a sovereign Tribal Nation is a stronger predictor than increasing exposure to greenspace for participating in land- and water-based traditional and spiritual practices providing evidence and public health implications for Indigenous determinants to health and wellbeing.

Effect of nature on the mental health and well-being of children and adolescents: meta-review

BACKGROUND

Urbanisation is taking place worldwide and rates of mental illness are rising. There has been increasing interest in 'nature' and how it may benefit mental health and well-being.

AIMS

To understand how the literature defines nature; what the characteristics of the nature intervention are; what mental health and well-being outcomes are being measured; and what the evidence shows, in regard to how nature affects the mental health and well-being of children and adolescents.

METHOD

A meta-review was conducted, searching three databases for relevant primary and secondary studies, using key search terms including 'nature' and 'mental health' and 'mental well-being'. Inclusion criteria included published English-language studies on the child and adolescent population. Authors identified the highest quality evidence from studies meeting the inclusion criteria. Data were extracted and analysed using descriptive content analysis.

RESULTS

Sixteen systematic reviews, two scoping reviews and five good quality cohort studies were included. 'Nature' was conceptualised along a continuum (the 'nature research framework') into three categories: a human-designed environment with natural elements; a human-designed natural environment; and a natural environment. The nature 'intervention' falls into three areas (the 'nature intervention framework'): access, exposure and engagement with nature, with quantity and quality of nature relevant to all areas. Mental health and well-being outcomes fit along a continuum, with 'disorder' at one end and 'well-being' at the other. Nature appears to have a beneficial effect, but we cannot be certain of this.

CONCLUSIONS

Nature appears to have a beneficial effect on mental health and well-being of children and adolescents. Evidence is lacking on clinical populations, ethnically diverse populations and populations in low- and middle-income countries. Our results should be interpreted considering the limitations of the included studies and confidence in findings.

Impact of green space and built environment on metabolic syndrome: A systematic review with meta-analysis

Metabolic Syndrome presents a significant public health challenge associated with an increased risk of noncommunicable diseases such as cardiovascular conditions. Evidence shows that green spaces and the built environment may influence metabolic syndrome. We conducted a systematic review and meta-analysis of observational studies published through August 30, 2023, examining the association of green space and built environment with metabolic syndrome. A quality assessment of the included studies was conducted using the Office of Health Assessment and Translation (OHAT) tool. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) assessment was used to evaluate the overall quality of evidence. Our search retrieved 18 studies that met the inclusion criteria and were included in our review. Most were from China (n = 5) and the USA (n = 5), and most used a cross-sectional study design (n = 8). Nine studies (50 %) reported only green space exposures, seven (39 %) reported only built environment exposures, and two (11 %) reported both built environment and green space exposures. Studies reported diverse definitions of green space and the built environment, such as availability, accessibility, and quality, particularly around participants' homes. The outcomes focused on metabolic syndrome; however, studies applied different definitions of metabolic syndrome. Meta-analysis results showed that an increase in normalized difference vegetation index (NDVI) within a 500-m buffer was associated with a lower risk of metabolic syndrome (odds ratio [OR] = 0.90, 95%CI = 0.87-0.93, I2 = 22.3 %, n = 4). A substantial number of studies detected bias for exposure classification and residual confounding. Overall, the extant literature shows a 'limited' strength of evidence for green space protecting against metabolic syndrome and an 'inadequate' strength of evidence for the built environment associated with metabolic syndrome. Studies with more robust study designs, better controlled confounding factors, and stronger exposure measures are needed to understand better what types of green spaces and built environment features influence metabolic syndrome.

Green and blue space exposure and non-communicable disease related hospitalizations: A systematic review

The global increase in non-communicable diseases (NCDs) presents a critical public health concern. Emerging evidence suggests that exposure to natural environments may reduce the risk of developing NCDs through multiple pathways. The present systematic review aims to synthesize and evaluate the observational evidence regarding associations between exposure to green and blue spaces and hospital admissions related to NCDs. A comprehensive literature search strategy was conducted in Embase (Ovid), PubMed, and Web of Science. The risk of bias and quality of the evidence were assessed using The Navigation Guide methodology, an approach specifically designed for environmental health research. Of 3060 search results, 17 articles were included. Notably, the majority of the studies (n = 14; 82.4%) were published from 2020 onwards. Most studies were conducted in the United States (n = 6; 35.3%) and China (n = 4; 23.5%). Exposure to green spaces was assessed through all studies, while only three included blue spaces. In terms of study design, cohort design was employed in nearly half of the studies (n = 8; 47.1%), followed by case-crossover design (n = 3, 17.6%). Over 75% of the included studies (n = 13) had a high or probably high rating in the risk of bias assessment. The studies encompassed diverse NCD outcome domains; cardiovascular diseases (CVDs) (n = 10), respiratory diseases (RSDs) (n = 2), heat-related diseases (n = 1), metabolic diseases (n = 2), cancer (n = 1), neurodegenerative diseases (NDDs) (n = 2), and mental health disorders (n = 2). The present review suggests that a clear link between blue space exposure and NCD hospital admissions is not evident. However, exposure to green spaces appears to predominantly have a protective effect, although the direction of the association varies across different outcome domains. The heterogeneity among the outcome domains together with the limited number of studies, emphasizes the need for more robust evidence.

The economics of nature's healing touch: A systematic review and conceptual framework of green space, pharmaceutical prescriptions, and healthcare expenditure associations

Green spaces play a crucial role in promoting sustainable and healthy lives. Recent evidence shows that green space also may reduce the need for healthcare, prescription medications, and associated costs. This systematic review provides the first comprehensive assessment of the available literature examining green space exposure and its associations with healthcare prescriptions and expenditures. We applied Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to search MEDLINE, Scopus, and Web of Science for observational studies published in English through May 6, 2023. A quality assessment of the included studies was conducted using the Office of Health Assessment and Translation (OHAT) tool, and the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) assessment was used to evaluate the overall quality of evidence. Our search retrieved 26 studies that met the inclusion criteria and were included in our review. Among these, 20 studies (77 % of the total) showed beneficial associations of green space exposure with healthcare prescriptions or expenditures. However, most studies had risks of bias, and the overall strength of evidence for both outcomes was limited. Based on our findings and related bodies of literature, we present a conceptual framework to explain the possible associations and complex mechanisms underlying green space and healthcare outcomes. The framework differs from existing green space and health models by including upstream factors related to healthcare access (i.e., rurality and socioeconomic status), which may flip the direction of associations. Additional research with lower risks of bias is necessary to validate this framework and better understand the potential for green space to reduce healthcare prescriptions and expenditures.