Environment/Climate Change
Residential Greenness and Cognitive Decline in a Community-Based Cohort Anna M. Staddon* Anna Staddon Tara E. Jenson Francine Grodstein Lisa L. Barnes Melissa Lamar Gregory A. Wellenius Jennifer Weuve Marcia Pescador Jimenez
Objective: Greenness may promote cognitive health by reducing stress and air pollution exposure, and/or supporting exercise and social connection. However, research on the association between greenness and cognitive decline in diverse populations is limited.
Methods: We studied 2761 participants from the Rush Alzheimer’s Disease Research Center Memory and Aging Project, Minority and Aging Research Study, and Latino Core (enrollment began in 1997, 2004, and 2016, respectively, with ongoing follow-up). We estimated residential greenness using the Normalized Difference Vegetation Index (NDVI) at 30m resolution, a satellite-based greenness indicator at baseline and follow-up. At each wave, we assessed global cognitive function as a composite z-score combining five cognitive domains (visuospatial ability, semantic memory, working memory, perceptual speed, and episodic memory). We used mixed models to examine the association of cumulative average greenness with cognitive function and rate of cognitive decline over each year, adjusted for age, sex, race/ethnicity, education, and personal income at baseline and age 40.
Results: Mean baseline age was 77.7 (SD 7.8). In fully adjusted models, higher NDVI interquartile range (IQR) was associated with higher baseline global cognitive score (0.08; 95% CI: 0.05, 0.11; p-value: <0.0001) and slower cognitive decline (mean difference: -0.01 per year; 95% CI: -0.01, 0.00; p-value: <0.0001). Associations between NDVI and cognitive function differed for White and Black participants (0.04; 95% CI: 0.00, 0.09; p-value: 0.05, and 0.05; 95% CI: -0.02, 0.11; p-value: 0.14, respectively), while cognitive decline results were similar across White and Black participants (0.00; 95% CI: 0.00, 0.01; p-value: 0.08).
Conclusion. Residential greenness may be positively associated with baseline global cognitive function and a slower rate of cognitive decline among older adults.