Abstract
OBJECTIVES: To explore associations of dietary diversity with cognitive function among Chinese elderly. DESIGN: This cross-sectional study was conducted in 2011-2012, data were analyzed using multiple linear regression and logistic regression models. SETTING: community-based setting in the 23 provinces in China. SUBJECTS: 8,571 elderly participants, including 2984 younger elderly aged 65-79 and 5587 oldest old aged 80+ participated in this study. MEASUREMENT: Intake frequencies of food groups was collected and dietary diversity (DD) was assessed based on the mean of DD score. Cognitive function was assessed using the Chinese version of Mini-Mental State Examination (MMSE), and cognitive impairment was defined using education-based cutoffs. Information about socio-demographics, lifestyles, resilience and health status was also collected. RESULTS: Poor dietary diversity was significantly associated with cognitive function, with β (95% CI) of -0.11(-0.14, -0.08) for -log (31-MMSE score) and odds ratio (95% CI) of 1.29 (1.14, 1.47) for cognitive impairment. Interaction effect of age with DD was observed on cognitive impairment (P interaction=0.018), but not on -log (31-MMSE score) (P interaction=0.08). Further separate analysis showed that poor DD was significantly associated with increased risk of cognitive impairment in the oldest old (p<0.01), with odds ratio (95% CI) of 1.34 (1.17, 1.54), while not in the younger elderly (p>0.05), with OR (95% CI) being 1.09 (0.80, 1.47) in the fully adjusted model. Similar results were obtained when DD was categorized into four groups. CONCLUSIONS: Poor dietary diversity was associated with worse global cognitive function among Chinese elderly, and particularly for the oldest old. This finding would be very meaningful for prevention of cognitive impairment.