A Cross Sectional Study to Examine the Association Between Dietary Patterns and Cognitive Impairment in Older Chinese People in Hong Kong

Background: Dietary patterns can be identified using a priori and a posterior approaches. Few studies have related dietary patterns with cognitive impairment in Chinese population. This study examined the risk of cognitive impairment associated with dietary patterns identified by both approaches.

Methods: Baseline data on 1,926 Chinese men and 1,744 Chinese women aged > 65 years participating in a cohort study examining the risk factors for osteoporosis in Hong Kong were analyzed. Dietary data were collected using a validated food frequency questionnaire. Adherence to a priori dietary patterns, namely the Mediterranean Diet Score (MDS) was assessed. Factor analysis (FA) identified three a posterior dietary patterns: "vegetables-fruits" pattern which was rich in vegetables, fruits, soy products and legumes, "snacks-drinks-milk products" pattern which was a mixture of healthy and unhealthy food groups including fast food, sweets and desserts, nuts, milk products and whole grains, and "meat-fish" pattern which included frequent intake of meat, fish and seafood. Cognitive function was assessed by the Community Screening Instrument for Dementia (CSI-D). Multivariate logistic regression examined the risk of cognitive impairment with adjustment for potential confounders.

Results: A total of 221 men and 656 women was classified as cognitive impaired. Neither the MDS nor the dietary patterns identified by FA were associated with risk of cognitive impairment in men. In women, higher "vegetables-fruits" pattern score was associated with reduced risk of cognitive impairment [Adjusted OR=0.73 (95% CI: 0.54-1.00) of the highest quartile of "vegetables-fruits" pattern score compared with the lowest quartile, ptrend=0.018]. Similar inverse trend was observed for "snacks-drinks-milk products" pattern score [Adjusted OR=0.65 (95% CI: 0.47-0.90) of the highest quartile of "snacks-drinks-milk products" pattern score compared with the lowest quartile, ptrend=0.003]. There was no association of "meat-fish" pattern or the MDS with risk of cognitive impairment in women.

Conclusion: Higher "vegetables-fruits" and "snacks-drinks-milk products" pattern scores were associated with reduced risk of cognitive impairment in Chinese older women in Hong Kong.