Greener Surroundings, Calmer Bodies

Where the longevity meta-analysis in this library shows that green surroundings track with living longer, this earlier and broader review helps explain why, by gathering the physiological signals that sit underneath. Across twelve studies spanning populations from a few thousand people to more than forty million, greater exposure to residential green space was associated with a striking spread of stress-related and cardiovascular benefits: lower levels of the stress hormone cortisol, lower heart rate and diastolic blood pressure, healthier heart-rate variability, a lower risk of type 2 diabetes and preterm birth, better self-reported health, and reduced cardiovascular and all-cause mortality. Read together, these point to a coherent physiological story in which everyday exposure to greenery nudges the body out of a chronically stressed state. Where the evidence stops: the studies were highly heterogeneous in how they measured green space and in the populations they covered, and being observational they cannot rule out that greener neighbourhoods differ in other health-relevant ways. Its value here is mechanistic breadth. It shows that the mortality benefit is not a statistical curiosity but sits on a wide base of measurable changes in stress physiology and cardiovascular function.