Dietary Patterns and Cognitive Health in Older Adults: Findings from the Sydney Memory and Ageing Study

Systematic reviews report dietary patterns may be associated with cognitive health in older adults. However, inconsistent findings have been reported and relevant research lacks large scale studies. This study aims to examine the associations of dietary patterns and cognitive function among older adults in an Australian ageing cohort.

A population-based, cross-sectional analysis of the baseline phase of the Sydney Memory and Ageing Study, a well-characterised Australian ageing study.

The Sydney Memory and Ageing Study was initiated in 2005 to examine the clinical characteristics and prevalence of mild cognitive impairment (MCI).

Non-demented community-dwelling individuals from English-speaking background (N = 819) aged 70-90 recruited from two areas of Sydney, following a random approach to 8914 individuals on the electoral roll in the Sydney Memory and Ageing study.

The Cancer Council of Victoria Food Frequency Questionnaire was used to assess dietary intake. Scores for Mediterranean diet, Dietary Approaches to Stop Hypertension (DASH) diet and the Dietary Guidelines Index (DGI 2013) were generated. Two patterns - a Prudent healthy and a Western dietary pattern - were derived using principal components analysis (PCA). Neuropsychological tests were used to assess global cognition and six cognitive domains. Multivariate linear modelling assessed the relationship between dietary patterns and cognitive domain scores.

Mediterranean diet and DASH diet were both positively linked to visuospatial cognition (P=0.002 and P=0.001 respectively). Higher intake of legumes and nuts was related to better performance in global cognition (β=0.117; 95% CI:0.052, 0.181; P<0.001) and language and visuospatial cognitive domains. The Prudent healthy diet was associated with better global cognition (β=0.307; 95% CI: 0.053, 0.562; P=0.019) in women and a Western diet was related to poorer global function (β=-0.242; 95% CI: -0.451,-0.034; P=0.023) and executive function (β=-0.325; 95% CI: -0.552,-0.099; P=0.005) in men.

In this analysis, higher adherence to the Mediterranean diet, DASH diet, Prudent healthy diet and greater consumption of legumes and nuts were associated with better cognition among older adults.