Association of Dietary Patterns with Cognitive Function and Cognitive Decline in Sydney Memory and Ageing Study: A Longitudinal Analysis

Abstract

BackgroundThe relationship of dietary patterns to cognitive health in older adults has attracted much research attention. However, results from existing studies are inconclusive. ObjectiveThe aim of this study was to investigate the association between dietary patterns and overall cognitive performance and cognitive change over time. DesignThis analysis was conducted as part of the longitudinal Sydney Memory and Ageing study with 6 years’ follow-up. Mediterranean diet and Dietary Approaches to Stop Hypertension diet scores were generated based on dietary intake for each individual, assessed by the Dietary Questionnaire for Epidemiological Studies Version 2. Participants/settingThis longitudinal study comprised 1037 community dwelling nondemented participants aged 70 to 90 years at baseline (September 2005 to December 2007), recruited from Sydney, Australia. Main outcome measuresNeuropsychological tests assessed global cognition and 6 cognitive domains on 4 occasions, at baseline and 2, 4, and 6 years later. Statistical analyses performedLinear mixed-model analyses were conducted to examine the relationship between dietary scores, food components, and overall cognitive function and cognitive change over 6 years. ResultsNo associations of Mediterranean or Dietary Approaches to Stop Hypertension dietary scores with overall cognition and cognitive decline over 6 years were found. Higher intake of legumes and nuts was related to better overall performance in global cognition (β = .091; 95% CI: 0.035-0.146; P = .001) and to multiple cognitive domains and to less decline in global cognition (β = −.016; 95% CI: −0.032 to −0.001; P = .032). ConclusionStudy findings suggest that greater consumption of legumes and nuts may be important to slow cognitive decline with age.