A protocol for a randomised controlled trial investigating the effect of increasing Omega-3 index with krill oil supplementation on learning, cognition, behaviour and visual processing in typically developing adolescents

BMJ Open. 2016 Jul 8;6(7):e011790. doi: 10.1136/bmjopen-2016-011790.


Introduction: The influence of n-3 long-chain polyunsaturated fatty acids (LCPUFA) supplementation on brain functioning is debated. Some studies have found positive effects on cognition in children with learning difficulties, elderly people with cognitive impairment and depression scores in depressed individuals. Other studies have found null or negative effects. Observational studies in adolescents have found positive associations between fish consumption (containing n-3 LCPUFAs) and academic achievement. However, intervention studies in typically developing adolescents are missing.

Objective: The goal of this study is to determine the influence of increasing Omega-3 Index on cognitive functioning, academic achievement and mental well-being of typically developing adolescents.

Methods and data analysis: Double-blind, randomised, placebo controlled intervention; 264 adolescents (age 13-15 years) attending lower general secondary education started daily supplementation of 400 mg eicosapentaenoic acid and docosahexaenoic acid (EPA+DHA) in cohort I (n=130) and 800 mg EPA+DHA in cohort II (n=134) or a placebo for 52 weeks. Recruitment took place according to a low Omega-3 Index (<5%). The Omega-3 Index was monitored via a finger prick at baseline and after 3, 6 and 12 months. The supplement dose was adjusted after 3 months (placebo analogously) to reach an Omega-3 Index of 8-11%. At baseline, 6 and 12 months, a neuropsychological test battery, a number of questionnaires and a standardised math test (baseline and 12 months) were administered. School grades were collected. In a subsample, sleep quality and quantity data (n=64) and/or eye-tracking data (n=33) were collected.

Ethics and dissemination: Food2Learn is performed according to Good Clinical Practice. All data collected are linked to participant number only. The results will be disseminated on group level to participants and schools. The results will be presented at conferences and published in peer-reviewed journals. The study is approved by the Medical Ethical Committee of Atrium-Orbis-Zuyd Hospital and is registered at the Netherlands Trial Register (NTR4082).

Trial registration numbers: NTR4082 and NCT02240264; Pre-results.


Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absenteeism
  • Academic Performance*
  • Adolescent
  • Adolescent Behavior / drug effects*
  • Affect / drug effects
  • Animals
  • Cognition / drug effects*
  • Dietary Supplements
  • Docosahexaenoic Acids / blood
  • Docosahexaenoic Acids / pharmacology*
  • Double-Blind Method
  • Eicosapentaenoic Acid / blood
  • Eicosapentaenoic Acid / pharmacology*
  • Euphausiacea
  • Fatty Acids, Omega-3 / blood
  • Fatty Acids, Omega-3 / pharmacology
  • Female
  • Fish Oils
  • Humans
  • Learning / drug effects*
  • Male
  • Motivation / drug effects
  • Netherlands
  • Neuropsychological Tests
  • Self Concept
  • Visual Perception / drug effects*


  • Fatty Acids, Omega-3
  • Fish Oils
  • Docosahexaenoic Acids
  • Eicosapentaenoic Acid

Associated data

  • ClinicalTrials.gov/NCT02240264
  • NTR/NTR4082