Dietary patterns and cognitive function in older New Zealand adults: the REACH study

Abstract

Purpose: The global population is ageing. Evidence show dietary patterns may be associated with cognitive status in older adults. This cross-sectional study investigated associations between dietary patterns and cognitive function in older adults in New Zealand.

Methods: The REACH study (Researching Eating, Activity, and Cognitive Health) included 371 participants (65-74 years, 36% male) living independently in Auckland, New Zealand. Valid and reproducible dietary patterns were derived, using principal component analysis, from dietary data collected by a 109-item validated food frequency questionnaire. Six cognitive domains (global cognition, attention and vigilance, executive function, episodic memory, working memory, and spatial memory) were tested using COMPASS (Computerised Mental Performance Assessment System). Associations between dietary patterns and cognitive scores, adjusted for age, sex, education, physical activity, energy, and Apolipoprotein E-ε4 status were analysed using multiple linear regression analysis.

Results: Three dietary patterns explained 18% of dietary intake variation-'Mediterranean style' (comprising: salad vegetables, leafy cruciferous vegetables, other vegetables, avocados and olives, alliums, nuts and seeds, white fish and shellfish, oily fish, and berries); 'Western' (comprising: processed meats, sauces and condiments, cakes, biscuits and puddings, meat pies and chips, and processed fish); and 'Prudent' (comprising: dried legumes, soy-based foods, fresh and frozen legumes, whole grains, and carrots). No associations between any cognitive domain and dietary pattern scores were observed. Global cognitive function was associated with being younger and having a university education.

Conclusion: In this cohort of community-dwelling, older adults in New Zealand, current dietary patterns were not associated with cognitive function.

Keywords: Apolipoprotein E; Episodic memory; Executive function; Global cognition; Healthy ageing; Mediterranean diet; Principal component analysis; Western dietary pattern; Working memory.