The health benefits of the great outdoors: A systematic review and meta-analysis of greenspace exposure and health outcomes.

Abstract

Background The health benefits of greenspaces have demanded the attention of policymakers since the 1800s. Although much evidence suggests greenspace exposure is beneficial for health, there exists no systematic review and meta-analysis to synthesise and quantify the impact of greenspace on a wide range of health outcomes.

Objective To quantify evidence of the impact of greenspace on a wide range of health outcomes.

Methods We searched five online databases and reference lists up to January 2017. Studies satisfying a priori eligibility criteria were evaluated independently by two authors.

Results We included 103 observational and 40 interventional studies investigating ~100 health outcomes. Meta-analysis results showed increased greenspace exposure was associated with decreased salivary cortisol -0.05 (95% CI -0.07, -0.04), heart rate -2.57 (95% CI -4.30, -0.83), diastolic blood pressure -1.97 (95% CI -3.45, -0.19), HDL cholesterol -0.03 (95% CI -0.05,

Conclusions Greenspace exposure is associated with numerous health benefits in intervention and observational studies. These results are indicative of a beneficial influence of greenspace on a wide range of health outcomes. However several meta-analyses results are limited by poor study quality and high levels of heterogeneity. Green prescriptions involving greenspace use may have substantial benefits. Our findings should encourage practitioners and policymakers to give due regard to how they can create, maintain, and improve existing accessible greenspaces in deprived areas. Furthermore the development of strategies and interventions for the utilisation of such greenspaces by those who stand to benefit the most.