Food and Behaviour Research

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Oily Fish Intake and Cognitive Performance in Community-Dwelling Older Adults: The Atahualpa Project

Del Brutto OH, Mera RM, Gillman J, Zambrano M, Ha JE. (2016) J Community Health.  41(1) 82-6. doi: 10.1007/s10900-015-0070-9. 

Web URL: View this and related abstracts via PubMed here.

Abstract:

Due to their high content of omega-3 polyunsaturated fatty acids, oily fish consumption is likely associated with a better cognitive performance. However, information on this association is controversial, with some studies showing a positive effect while others showing no association.

We aimed to assess the effects of oily fish consumption on cognitive performance in a population of frequent fish consumers living in rural coastal Ecuador.

Atahualpa residents aged ≥60 years were identified during a door-to-door survey and evaluated by the use of the Montreal Cognitive Assessment (MoCA). Oily fish servings per week were calculated in all participants. We estimated whether fish intake correlated with MoCA scores in generalized multivariate linear models adjusted for demographics, cardiovascular risk factors, edentulism and symptoms of depression.

Out of 330 eligible persons, 307 (93%) were enrolled. Mean MoCA scores were 19 ± 4.8 points, and mean oily fish consumption was 8.6 ± 5.3 servings per week. In multivariate analyses, MoCA scores were related to fish servings (β 0.097, 95% CI 0.005-0.188, p = 0.038). Locally weighted scatterplot smoothing showed an inflection point in the total MoCA score curve at four fish servings per week. However, predictive margins of the MoCA score were similar across groups below and above this point, suggesting a direct linear relationship between oily fish intake and cognitive performance.

Simple preventive measures, such as modifying dietary habits might be of value to reduce the rate of cognitive decline in community-dwelling older adults living in underserved populations.

KEYWORDS:

Cognitive performance; Ecuador; Montreal Cognitive Assessment; Oily fish; Omega-3; Population-based study

FAB RESEARCH COMMENT:

These findings are of course correlational - and so cannot provide evidence of a causal link between higher fish consumption and better cognitive performance in the older adults studied.  

They are, however, consistent with other substantial evidence that increased intakes of the long-chain omega-3 found in fish and seafood (EPA and DHA) can improve cognitive performance, as shown by rigorously controlled animal studies and randomised controlled trials in humans.

It is also more than plausible that other important nutrients provided by fish and seafood (including iodine, selenium, Vitamin D and B vitamins among others) would provide benefits over and above those of omega-3 alone.  

Furthermore, nutrients are likely to be better absorbed and utilised when consumed in natural foods rather than as supplements. The authors' conclusions that simple dietary modifications might help many older adults thus seem eminently sensible, and in line with the huge body of evidence from human population studies linking fish consumption with better mental as well as physical health.

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