Fish consumption, intake of fats and cognitive decline at middle and older age: the Doetinchem Cohort Study

Purpose To get insight in the impact of fish and fat intake in the prevention of accelerated cognitive decline with ageing, we tested associations between fish and different fat intakes and 5-year change in cognitive functions.

Methods In 2612 men and women of the Doetinchem Cohort Study, aged 43-70 years at baseline, dietary intake (including fish consumption) and cognitive function were assessed at baseline and at 5-year follow-up. Average fish consumption (frequency) and intakes (as energy percentages) of total fat, saturated, mono unsaturated, and polyunsaturated fatty acids (PUFA), linoleic, docosahexaenoic, eicosapentaenoic, and a-linolenic acid (ALA), and cholesterol were averaged over baseline and follow-up. Intakes were studied in relation to 5-year change in global cognitive function, memory, information processing speed, and cognitive flexibility, using ANCOVA and multivariate linear regression analyses.

Results No consistent association between (fatty) fish consumption and cognitive decline was observed. Higher cholesterol intake was associated with faster cognitive decline (p <0.05). Higher n-3 PUFA (especially ALA) intake was associated with slower decline in global cognitive function and memory (p <0.01). Intakes of other fatty acids were not associated with cognitive decline.

Conclusions Higher cholesterol intake was detrimental, while higher ALA intake was beneficial for maintaining cognitive function with ageing, already at middle age.