Neighbourhood green space and loneliness in middle-aged and older adults: Evidence from WHO Study on Global Ageing and Adult Health in China

Loneliness may contribute to chronic diseases, while neighbourhood green space is increasingly understood to benefit health. However, whether green space is associated with loneliness is less understood, especially for an ageing population. This study aims to explore the relationship between different measures of green space and loneliness among middle-aged and older adults (N = 8,383) based on a national cohort. Loneliness was measured with a yes or no (binary) self-reported question, while the availability of residential green space was assessed with the normalised difference vegetation index (NDVI) and proportion of neighbourhood public parks. Multilevel logistic regression models, stratified and mediation analysis were used to test whether green space availability was associated with loneliness. The results showed that both forms of residential green space were negatively associated with the risk of loneliness, even after adjustments for covariates. These associations were partially mediated by social cohesion and modified by socioeconomic status and age; residents who were males, at least 60 years old, had lower incomes, or had no high school degree showed protective associations of residential green space on loneliness in some stratified models. These findings indicate that residential green space may play an important role in loneliness risk in middle-aged and older adults, so policymakers may consider urban greening as part of their comprehensive plans to support the mental health of ageing adults.