Do ecosystem improvements enhance the cognitive function of older adults: quasi-Experimental evidence from China

Although growing evidence indicates that ecosystems shape human health, their effects on older adults-a group highly sensitive to environmental stressors-remain underexplored. This study examines the effect of China's National Key Ecological Function Zones (NKEFZs), a large-scale ecosystem improvement program, on the cognitive function of older adults and explores the underlying mechanisms.

Using five waves (2011-2020) of data from the China Health and Retirement Longitudinal study (CHARLS; n = 16,003), this study employes a staggered difference-in-differences design to estimate the effects of policy on cognitive health.

NKEFZs significantly enhanced cognitive function and episodic memory by 0.467 and 0.372 points, respectively. Mechanism analysis identifies reductions in industrial smoke and dust emissions and a higher likelihood of using clean fuels for cooking or heating as possible channels through which NKEFZs contribute to improved cognitive health. Heterogeneity analyses indicate that the beneficial effects varied by gender, education, marital status, household size, health status, and smoking or drinking behaviors.

These findings highlight the role of ecosystem improvements in maintaining cognitive health and reveal disparities in the effects of such population-level interventions across individual characteristics. These insights inform other countries in developing upstream environmental strategies for dementia prevention and risk reduction.