Association between Nutrition and Cognition in a Multi-Ethnic Cohort from Singapore

Abstract

Introduction: Nutrition, a modifiable risk factor, presents a low-cost prevention strategy to reduce the burden of cognitive impairment and dementia. However, studies examining the effects of dietary patterns on cognition are lacking in multi-ethnic Asian populations. We investigate the association between diet quality, measured with the Alternative Healthy Eating Index (AHEI)-2010, and cognitive impairment in middle-and old-aged adults of different ethnicities (Chinese, Malay, Indian) in Singapore. Methods: This cross-sectional study (n=3138) was based on data from the Singapore Multi-Ethnic Cohort. Dietary intake collected with a validated semi-quantitative Food Frequency Questionnaire were converted into AHEI-2010 scores, where trans-fat and sodium consumption were not considered and a score range of 0-90 was allowed. Higher AHEI-2010 score indicates better compliance to recommended dietary pattern. Cognition, assessed with the Mini-Mental State Examination (MMSE), was analysed as a continuous or binary outcome (cognitively impaired is defined using education-based cut-offs of <23, 25 or 27 for participants with no education, primary school education and secondary school education and above). Multivariable linear and logistic regression models were used to examine associations between AHEI-2010 and cognition, adjusting for covariates. Results: Participants have a mean age of 56.6 (SD = 9.3) years, and 41.6% were male. Participants have a mean AHEI-2010 score of 52.4 (SD = 9.8) and 988 (31.5%) participants had cognitive impairment. Ethnic Chinese (mean = 51.3, SD = 9.6) and Indians (mean = 51.3, SD = 9.7) had higher AHEI-2010 score than Malays (mean = 47.6, SD = 9.9). Higher AHEI-2010 scores were significantly associated with higher MMSE score (p trend < 0.001) and lower odds of cognitive impairment (p trend = 0.01). Compared with lowest quartile, participants from highest quartile had 0.44 (95%CI 0.22, 0.67) higher MMSE score and 31% less cognitive impairment odds (OR = 0.69, 95%CI 0.54, 0.88) after adjusting for all the covariates. However, no significant associations were observed for individual dietary components of the AHEI-2010 with MMSE or cognitive impairment. Discussion: Healthier dietary patterns were associated with better cognitive function in middle- aged and older Singaporeans. These findings could inform better support to promote healthier dietary patterns in Asian populations.