Dietary Habits and Cognitive Impairment Risk Among Oldest-Old Chinese.

Objectives: This study examined the longitudinal relationship between dietary habits and cognitive impairment among the oldest-old Chinese.

Method: Cognitively intact adults aged 80 or older (N = 4,749) came from the Chinese Longitudinal Healthy Longevity Survey. Cognitive impairment was assessed by Mini-mental State Examination. Cox regressions were performed to examine the relationship between dietary habits and cognitive impairment onset during follow-up period of 1998-2012, adjusting for various time-variant and time-invariant individual characteristics.

Results: Compared with those who rarely/never consumed fruit, vegetables, meat, and soybean-derived products, participants consuming such products almost every day were 21%, 25%, 17%, and 20% less likely to develop cognitive impairment during follow-up, respectively. Compared with those who rarely/never consumed sugar, participants consuming sugar almost every day were 17% more likely to develop cognitive impairment during follow-up. Consumption of fish, egg, salt-preserved vegetable, tea, and garlic was not found to be associated with cognitive impairment.

Discussion: Dietary habits might profoundly impact cognitive functioning among the oldest-old Chinese. This work has limitations pertaining to study design and measure. Future work adopting experimental design and refined dietary measures is warranted to confirm these findings and inform public nutrition practices aiming at preventing cognitive decline among the oldest-old Chinese population.