Dietary patterns and trajectories of global- and domain-specific cognitive decline in the Lothian Birth Cohort 1936

Healthy dietary patterns may protect against age-related cognitive decline, but results of studies have been inconsistent and few have had extensive longitudinal follow-up with comprehensive cognitive testing. The aim of the present study was to determine associations of dietary patterns with trajectories of global- and domain-specific cognitive change over a 12-year period. Data from 863 community-dwelling, dementia-free participants from the Lothian Birth Cohort 1936 study of ageing completed a FFQ at baseline (aged 70 years) and underwent cognitive testing at baseline, and at the ages of 73, 76, 79 and 82 years. Composite cognitive scores were constructed for four cognitive domains (visuospatial ability, processing speed, memory and verbal ability) and global cognitive function. A Mediterranean-style pattern and a traditional pattern were derived using principal component analysis of self-reported dietary intakes. In fully adjusted latent growth curve models, higher baseline adherence to the Mediterranean-style dietary pattern (beta = 0 center dot 056, P = 0 center dot 009) and lower baseline adherence to the traditional dietary pattern (beta = -0 center dot 087, P < 0 center dot 001) were cross-sectionally associated with better verbal ability. A slightly steeper decline in verbal ability over 12 years was observed in those with higher Mediterranean-style diet scores at baseline (beta = -0 center dot 003, P = 0 center dot 008). All other associations were non-significant. Our findings in this well-characterised Scottish cohort indicate that adherence to a healthy Mediterranean-style diet is associated cross-sectionally with better verbal (crystallised) ability, with the converse being true for the traditional diet. A healthier baseline diet did not predict a reduced risk of global- or domain-specific cognitive decline.

Automated summary

The study found that adherence to a Mediterranean-style diet was associated with better verbal ability, while adherence to a traditional diet was associated with better language ability. However, long-term adherence to a healthy diet may not necessarily predict a reduced risk of global or domain-specific cognitive decline.