Human First

Moderate evidence

Is time in green space good for your health?

Does exposure to parks, trees and other green space measurably affect health?

Bottom line

A review of 143 studies found that more exposure to green space was associated with lower stress hormone levels, lower heart rate and lower blood pressure1, though many of the studies were of poor quality2.

A systematic review and meta-analysis brought together 103 observational and 40 interventional studies covering around 100 health outcomes3.

Greater exposure to green space was associated with lower salivary cortisol, a marker of stress, as well as lower heart rate and lower diastolic blood pressure1.

The authors concluded that green space is associated with numerous health benefits, but cautioned that several of the pooled results were limited by poor study quality and large differences between studies2.

They called on practitioners and policymakers to create, maintain and improve accessible green spaces in deprived areas, where people may benefit most4.

What this does not show

  • Most of the studies are observational, and people who live near green space may differ in other ways, such as income.
  • The authors themselves flag poor study quality and high heterogeneity in several of the pooled results.

Claims and sources

  1. Increased greenspace exposure was associated with decreased salivary cortisol (-0.05), heart rate (-2.57) and diastolic blood pressure (-1.97).

    Research finding Moderate evidence

    • Twohig-Bennett C, Jones A (2018). The health benefits of the great outdoors: A systematic review and meta-analysis of greenspace exposure and health outcomes. Environmental Research. doi:10.1016/j.envres.2018.06.030

  2. The authors concluded greenspace exposure is associated with numerous health benefits, but several meta-analysis results were limited by poor study quality and high levels of heterogeneity.

    Research finding Moderate evidence

    • Twohig-Bennett C, Jones A (2018). The health benefits of the great outdoors: A systematic review and meta-analysis of greenspace exposure and health outcomes. Environmental Research. doi:10.1016/j.envres.2018.06.030

  3. The review included 103 observational and 40 interventional studies investigating about 100 health outcomes.

    Research finding Moderate evidence

    • Twohig-Bennett C, Jones A (2018). The health benefits of the great outdoors: A systematic review and meta-analysis of greenspace exposure and health outcomes. Environmental Research. doi:10.1016/j.envres.2018.06.030

  4. The authors urged practitioners and policymakers to create, maintain and improve accessible greenspaces in deprived areas.

    Research finding Limited evidence

    • Twohig-Bennett C, Jones A (2018). The health benefits of the great outdoors: A systematic review and meta-analysis of greenspace exposure and health outcomes. Environmental Research. doi:10.1016/j.envres.2018.06.030

Version 1. First published , updated . Approved by The Human First editors on . Sources last verified 2026-10-24. Machine-readable version.