Dietary pattern in midlife and cognitive impairment in late life: a prospective study in Chinese adults

Abstract

Background: Prospective studies linking dietary pattern and cognitive function in the elderly are limited in Asian populations.

Objective: We examined the associations between various healthful dietary patterns and risk of cognitive impairment in Chinese adults.

Methods: We used data from the Singapore Chinese Health Study of 16,948 men and women who were aged 45-74 y at baseline (1993-1998) and reinterviewed at the third follow-up visit (2014-2016), ∼20 y later. Diet quality at baseline was assessed according to the alternate Mediterranean diet (aMED), the Dietary Approaches to Stop Hypertension (DASH) diet, the alternative Healthy Eating Index (AHEI)-2010, overall plant-based diet index (PDI), and healthful plant-based diet index (hPDI). Cognitive function was evaluated using a Singapore-modified Mini-Mental State Examination during the third follow-up visit when subjects were aged 61-96 y. Multivariable logistic regression models were used to compute ORs and 95% CIs associated with the risk of cognitive impairment defined using education-specific cut-offs.

Results: Cognitive impairment was present in 2443 (14.4%) participants. The OR (95% CI) for cognitive impairment comparing the highest with the lowest quartile of diet quality scores was 0.67 (0.59, 0.77) for aMED, 0.71 (0.62, 0.81) for DASH, 0.75 (0.66, 0.85) for AHEI-2010, 0.82 (0.71, 0.94) for PDI, and 0.78 (0.68, 0.90) for hPDI (all P values for trend <0.001). Each SD increment in different diet quality scores was associated with 7-16% lower risk of cognitive impairment.

Conclusions: These results provide evidence that adherence to healthy dietary patterns in midlife is associated with a lower risk of cognitive impairment in late life in Chinese adults.

Keywords: Chinese; Dietary Approaches to Stop Hypertension diet; Healthy Eating Index; Mediterranean diet; cognition; cohort study; diet pattern; epidemiological study; plant-based diet index.

FIGURE 1

Relations of quartiles of dietary quality scores with the SM-MMSE score. The multivariable-adjusted model was adjusted for age at cognitive status measurement, year of baseline interview, sex, dialect group, marital status, education level, smoking status, physical activity, sleep duration, BMI, total energy intake, baseline history of hypertension, diabetes, cardiovascular disease, and cancer. Analyses for the DASH, PDI, and hPDI indexes were additionally adjusted for alcohol consumption, and analyses for the aMED, DASH, and AHEI-2010 were additionally adjusted for tea and coffee intake. Tests for a linear trend were calculated by fitting median scores for quartiles as continuous variables in generalized linear models. AHEI, alternative Healthy Eating Index; aMED, alternate Mediterranean Diet score; DASH, Dietary Approaches to Stop Hypertension; hPDI, healthful plant-based diet index; PDI, plant-based diet index; Q, quartile; SM-MMSE, Singapore-modified version of Mini-Mental State Examination.