Not all have regular nature contact, especially those that reside in socioeconomically disadvantaged neighborhoods that have less access to parks and wilderness. Similarly, low-income neighborhoods are less likely to have school gardens. Pediatricians are in a unique position and have the opportunity to advocate for children's contact with nature. This systematic review assesses the evidence base for the effects of nature contact on children's health that can be used by pediatricians to promote evidence-based recommendations and policies.
The authors reviewed 298 studies investigating nature exposure and health outcomes and behaviors or academic and learning outcomes in children. Nature exposure included either gardening, green space activity, residential green space, school green space, greening intervention, wilderness experience, nature walk, and “other” (i.e., mixed spaces). Health outcomes/behaviors included: physical activity; cognitive, behavioral and mental health; body mass index; cardiovascular and metabolic measures; asthma and allergy; academic and learning; and other. The studies included children who were infants through adolescents (under 19 years of age). Study quality and potential for bias was assessed.
Findings were reported with respect to strength of evidence based either on the type of nature exposure or the health outcome or behavior. The strongest evidence related to type of nature exposure was for the association between residential green space and improved health; physical health outcomes were most common followed by mental health outcomes. Moderately positive associations were reported for school green space and general green space and child health. Wilderness experience and gardening also had moderately positive associations; though findings were strong, there were fewer studies in this area and some had methodological weaknesses. Though findings were strong in some cases (e.g. nature walks), classroom intervention, greening interventions and nature walks demonstrated low strength of evidence given the small number of studies in each category. With regard to analysis by type of outcome, strong evidence was reported for physical activity, with the most common nature exposures being residential green space and general green space. Strong positive outcomes were also reported for cognitive, behavioral, and mental health, most frequently with residential green space, and particularly for attention and depressive symptoms. Wilderness exposure studies sometimes also reported positive outcomes in these domains, including wellbeing, restoration, and stress. Childhood weight status had moderately positive associations and was most frequently associated with residential green space. The strength of the evidence was attenuated because most of the studies were observational rather than experimental. Academic and learning outcomes, asthma and allergy outcomes, and cardiovascular and metabolic outcomes had low strength of evidence given the small number of studies in each category. For asthma and allergy, the authors also reported that some studies found that more nature exposure, particularly for residential green space, was associated with an increase rather than decrease in asthma and allergy symptoms. The authors noted that the variety of nature and outcome measures, the moderate to high risk for bias, and the preponderance of observational (as opposed to experimental) studies limited their ability to make conclusions about a causal relationship between nature and health outcomes.
This review found primarily positive associations between more nature exposure and more positive children's health. There was strong evidence for the relationship between nature contact and outcomes related to physical activity and cognitive, behavioral, and mental health. When looking at nature exposures, green spaces closer to the child's home and school had the strongest evidence. The findings provide an evidence-base to advocate for policies and practices that support equitable access to nature for children.
Research Partner