Effects of oily fish intake on cognitive and socioemotional function in healthy 8-9-year-old children: the FiSK Junior randomized trial

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Background: Long-chain n-3 PUFAs (n-3 LCPUFAs) accrete in the brain during childhood and affect brain development. Randomized trials in children show inconsistent effects of n-3 LCPUFAs on cognitive and socioemotional function, and few have investigated effects of fish per se.

Objectives: We aimed to investigate the effects of oily fish consumption on overall and domain-specific cognitive and socioemotional scores and explore sex differences.

Methods: Healthy 8-9-y-old children (n = 199) were randomly allocated to receive ∼300 g/wk oily fish or poultry (control) for 12 ± 2 wk. At baseline and endpoint, we assessed attention, processing speed, executive functions, memory, emotions, and behavior with a large battery of tests and questionnaires and analyzed erythrocyte fatty acid composition.

Results: One hundred and ninety-seven (99%) children completed the trial. Children in the fish group consumed 375 (25th-75th percentile: 325-426) g/wk oily fish resulting in 2.3 (95% CI: 1.9, 2.6) fatty acid percentage points higher erythrocyte n-3 LCPUFA than in the poultry group. The overall cognitive performance score tended to improve by 0.17 (95% CI: -0.01, 0.35) points in children who received fish compared with poultry, supported by n-3 LCPUFA dose dependency. This was driven mainly by fewer errors [-1.9 (95% CI: -3.4, -0.3)] in an attention task and improved cognitive flexibility measured as faster reaction time [-51 ms (95% CI: -94, -7 ms)] in a complex relative to a simple task ("mixing cost"). The fish intervention furthermore reduced parent-rated Strength and Difficulties Questionnaire total difficulties by -0.89 (95% CI: -1.60, -0.18) points mainly due to a -0.63 (95% CI: -1.11, -0.16) points reduction in internalizing problems that was reflected in tendency to a decrease in the overall socioemotional problems score of -0.13 (95% CI: -0.26, 0.01) points. The overall effects were similar in boys and girls.

Conclusions: Oily fish dose-dependently improved cognitive function, especially attention and cognitive flexibility, and reduced socioemotional problems. The results support the importance of n-3 LCPUFAs for optimal brain function and fish intake recommendations in children.

The trial was registered at www.clinicaltrials.gov as NCT02809508.

Original languageEnglish
JournalAmerican Journal of Clinical Nutrition
Issue number1
Pages (from-to)74-83
Number of pages10
Publication statusPublished - 2020

Bibliographical note

Copyright © The Author(s) on behalf of the American Society for Nutrition 2020.

    Research areas

  • Faculty of Science - Omega-3, Docosahexaenoic acid (22:6n-3, DHA), Eicosapentaenoic acid (20:5n-3, EPA), Cognitive performance, Externalizing problems, Internalizing problems, Prosocial behavior, Boys, Girls

ID: 243014702