A Review of the Health Benefits of Greenness

Researchers are increasingly exploring how neigh- borhood greenness, or vegetation, may affect health behaviors and outcomes. Greenness may influence health by promoting physical activity and social contact; decreasing stress; and mitigating air pollution, noise, and heat exposure. Greenness is generally measured using satellite-based vegetation indices or land-use databases linked to participants’ addresses. In this review, we found fairly strong evidence for a positive associ- ation between greenness and physical activity and a less con- sistent negative association between greenness and body weight. Research suggests greenness is protective against ad- verse mental health outcomes, cardiovascular disease, and mortality, though most studies were limited by cross- sectional or ecological design. There is consistent evidence that greenness exposure during pregnancy is positively asso- ciated with birth weight, though findings for other birth out- comes are less conclusive. Future research should follow subjects prospectively, differentiate between greenness quantity and quality, and identify mediators and effect modifiers of greenness-health associations.