Interaction between the animal-based dietary pattern and green space on cognitive function among Chinese older adults: A prospective cohort study

Green space is associated with better cognition, while the animal-based dietary pattern can be a risk factor. We aimed to verify the associations and explore their interaction among the elderly. The China Longitudinal Healthy Longevity Survey (CLHLS) cohort including 17,827 participants was used. The average green space coverage rate was used to measure green space exposure. The animal-based diet index (ADI) was scored based on the non-quantitative frequency questionnaire of ten types of food intake (three types of animal foods and seven types of plant foods). We used the Mini-Mental State Examination (MMSE) to assess cognitive function. The Cox proportional hazard regression was applied to explore the correlations and interactions. In the models, we gradually adjusted for the potential risk factors. Compared with participants living in the area with the lowest green space, those living with the highest were associated with a 20% decrease in the risk of cognitive impairment (hazard ratio (HR): 0.80, 95% CI: 0.73, 0.89). As for ADI, the highest group was related to a 64% increase in the risk of cognitive impairment (HR: 1.64, 95% CI: 1.38, 1.95). The protective effect of the highest green space group on cognitive impairment was more evident among participants with low ADI (HR = 0.72, 95% CI: 0.62, 0.83), compared to those with high ADI. Green space was positively associated with cognition, while the animal-based dietary pattern was a cognitive disadvantage. The animal-based dietary pattern may mitigate the beneficial effects of green space on cognition.