Nexus Between Exposure to Natural Outdoor Environments and Cognitive Competence among Older Adults in China

With a rapidly aging population and an increasing number of older people with cognitive impairment, a multitude of social problems could arise. The natural outdoor environments (NOEs) surrounding residential areas are important environments as they directly influence the residents’ quality of life and even physical health. A plethora of studies have suggested the definitive impact of NOE on the physical and mental health of older people. There have been very few studies, however, investigating the nexus between exposure to NOE, especially blue spaces, and cognitive competence among older populations. Our study aims to explore the effects of exposure to residential NOE on cognition by investigating the correlations between exposure to the county-level NOE (i.e., green and blue spaces) and cognitive competence of older Chinese adults. Using regression methods and stratified analysis, we demonstrate that there exists a positive relation between access to blue-green spaces and cognitive competence among older Chinese adults. The cognitive competence of older adults could benefit from increased exposure to NOEs with abundant blue-green spaces. Path analysis has been further conducted to investigate the pathways through which exposure to NOE affects cognitive ability and identify the mediating effects of population density and PM_2.5 concentration. Under the person–environment framework, the findings of this study highlight the importance of well-designed NOEs for senior citizens and provide a strong theoretical foundation to support the building of age-friendly cities that could provide a healthier environment for aging in place. Finally, the limitations of this study and a few potential directions for future research are also discussed.