The health benefits of the great outdoors: A systematic review and meta-analysis of greenspace exposure and health outcomes
Summary & key facts
Researchers looked at about 140 studies to see how contact with greenspace — parks, street trees, and other natural areas — relates to health. They found that more greenspace was linked with lower signs of stress, better heart and birth outcomes, lower rates of some diseases, and better self-reported health. The authors say the links are promising for public health, but they also warn that many studies were different from each other and some were low quality, so we cannot be certain greenspace alone causes these benefits.
- The review combined results from about 140 studies, including experiments and observational studies, that measured almost 100 different health outcomes.
- More greenspace was linked with lower salivary cortisol and lower heart rate, which are biological signs usually associated with less stress.
- People living near more greenspace showed lower average blood pressure and better heart-rate variability, measures that relate to heart and nervous-system health.
- Greater greenspace exposure was associated with lower risks of preterm birth, type 2 diabetes, and dying from any cause.
- Many studies reported fewer cases of stroke, high blood pressure, unhealthy blood fats, asthma, and coronary heart disease with more greenspace nearby.
- For outcomes that could not be combined into single numbers, between about two-thirds and all studies showed health-positive links with more greenspace, including some brain-related and cancer-related outcomes.
- The authors warn that some combined results come from studies with mixed quality and a lot of variability, so the exact size of the benefits and whether greenspace is the direct cause are not certain.
Abstract
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.
