Abstract
BACKGROUND: Both air pollution and lifestyle are associated with cognitive function, with air pollution showing detrimental associations and healthy lifestyles showing beneficial ones. The extent to which a favorable lifestyle can mitigate the adverse association of air pollution with later-life cognitive function warrants further investigation. METHODS: A total of 7 651 individuals aged 65 years and above from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) were followed up between 2008 and 2018. Cognitive function was measured at each wave using the Mini-Mental State Examination (MMSE). Particulate matter (PM1, PM2.5, and PM10) concentrations were assessed using satellite-based spatiotemporal models. A favorable lifestyle was defined based on four lifestyle factors: (1) never drinking, (2) never smoking, (3) regular physical activity, and (4) adherence to a healthy diet. Linear mixed-effects models were used to estimate the association between PM exposure and cognitive function as well as potential effect modification by lifestyle. RESULTS: Overall, PM exposure was significantly associated with cognitive function, with MMSE scores decreasing by 0.47 points (95% confidence interval (CI), -0.62 to -0.33), 0.66 points (95% CI, -0.83 to -0.49), and 0.62 points (95% CI, -0.78 to -0.46) per interquartile range (IQR) increase in PM1, PM2.5, and PM10, respectively. A favorable lifestyle was positively associated with better cognitive function. Moreover, the adverse association between PM exposure and cognitive function was significantly attenuated among individuals with a favorable lifestyle (P for interaction = .007, .013, and .037 for PM1, PM2.5, and PM10, respectively). CONCLUSION: A favorable lifestyle may mitigate the adverse association between PM exposure and cognitive function. Lifestyle interventions could be beneficial in reducing potential neurological effects of ambient air pollution.