City-wide cognitive function screening study of older adults in Beijing reveal protective association of urban green space.

Green spaces offer a passive yet impactful component of urban design, with the potential to enhance cognitive function and reduce the risk of dementia in older adults. While the cognitive benefits of green spaces are recognized, particularly in improving cognitive performance among older populations, this area remains a critical yet underexplored domain within urban health research. This study aimed to investigate the association of exposure to green spaces with cognitive function among older adults across urban Beijing. A total of 62,333 participants from 114 communities were included in a city-wide screening program, utilizing an adapted version of the Mini-Mental State Examination (MMSE) and the Episodic Memory Test (EMT) to assess cognitive function. Green space exposure was quantified at the community level through multiple metrics, including accessibility (distance to large green spaces and parks), availability (Normalized Difference Vegetation Index [NDVI] and proportion of green space), and visibility (green view ratio). Multilevel linear and logistic regression models, adjusted for demographic and environmental covariates, were applied to data from 324 community healthcare centers. The findings indicated that greater exposure to green spaces, across all measured metrics, was associated with better cognitive function scores. A significant threshold was identified at 500 m from parks, beyond which cognitive function scores declined progressively with increasing distance. These results have important implications for urban planning, suggesting the need for accessible, community-level green spaces to support cognitive health for older adults in urban China.