Non-linear relationships between age-friendly neighborhood environments and cognitive health among older adults in Guangzhou, China

Understanding the complex relationships between neighborhood environments and cognitive health is critical for developing age-friendly communities. Although numerous studies have explored the linkages between neighborhood age-friendliness and cognitive health among older adults in Western contexts, their non-linear relationships in rapidly urbanizing Chinese megacities remain inadequately understood. A holistic insight into which age-friendly neighborhood domain is more important to older adults’ cognition warrants investigation. This study examines the non-linear relationships between neighborhood age-friendliness across nine domains and cognitive function among older adults in Guangzhou, China, using data from 1383 older adults across 30 urban neighborhoods. Results from Generalized Additive Mixed Models (GAMMs) reveal that secure environment and civic participation exhibit non-linear associations with Mini-Mental State Examination (MMSE) scores, and that secure environment and distance to transit exert curvilinear effects on the risk of cognitive impairment. Higher levels of green and blue environments and civic participation are linearly associated with lower odds of cognitive impairment. Age-stratified analyses reveal that older adults aged 70+ demonstrate greater environmental sensitivity, with significant non-linear effects across multiple domains, whereas younger older adults (60-69) show primarily linear relationships. Education-stratified analyses indicate that lower-educated older adults are more dependent on physical and social environmental support, while higher-educated older adults show sensitivity to civic participation and communication and information services. These findings advance environmental gerontology theory by capturing age-education gradients in environmental docility effects and offer evidence-based public policy recommendations that prioritize vulnerable populations in enabling healthy ageing in Chinese megacities and other rapidly urbanizing and ageing contexts.