Household cooking fuel and cognitive function trajectories among middle-aged and older adults: evidence from a longitudinal study

OBJECTIVES: Cognitive decline among middle-aged and older adults is an increasing public health concern, and household cooking fuel use has been suggested as a potential environmental risk factor. This study examined the association between household cooking fuel and long-term cognitive function trajectories. METHODS: Data were obtained from 6306 respondents in the China Health and Retirement Longitudinal Study (CHARLS) between 2011 and 2020. Cognitive function was assessed using standardised measures of episodic memory and mental status. Group-based trajectory modelling was used to identify distinct cognitive function trajectories over time. Multinomial logistic regression was applied to examine the association between household cooking fuel type and trajectory membership. Subgroup analyses were conducted by marital status and sensitivity analyses using propensity score matching (PSM) were performed to assess the robustness of the findings. RESULTS: Four distinct cognitive function trajectories were identified. Compared with clean fuel users, individuals using solid fuels were significantly more likely to belong to lower or declining cognitive trajectories. Results from the PSM analysis were consistent with the main findings. CONCLUSION: Household solid fuel use is associated with unfavourable cognitive function trajectories among middle-aged and older adults. Expanding access to cleaner household energy and reducing exposure to cooking-related smoke may be relevant public health strategies for ageing populations.