DHA & Lutein and fMRI Brain Mapping in Healthy Children
Condition: Healthy Nutrition
Study type: Observational

Summary: 
      Studies suggest that lutein and n-3 fatty acids may influence the development of a child's
      brain and may be related to how well children learn. Both lutein and the n-3 fats (also known
      as omega-3 fats) are not made by the body and must be obtained in the diet. The investigators
      are interested to understand the importance of n-3 fats and lutein to child brain
      development. Functional magnetic resonance imaging (fMRI) will make it possible to look into
      the brain from the outside and see which parts of the brain are being used as children
      complete working memory tasks. The investigators will study brain function using fMRI among
      children with different intakes of n-3 fats and lutein.

      Hypothesis:

        1. Children 6 years of age consuming < 25 mg/day DHA and < 400 μg lutein/day will show
           poorer activation of brain areas on fMRI than children consuming > 150 mg/day DHA and >
           1,200 μg/day lutein.

        2. Children consuming < 400 μg lutein/day and > 150 mg/day DHA will also show differences
           in fMRI results when compared to children consuming > 150 mg/day DHA and > 1,200 μg/day
           lutein.
    

Detailed description: 
      Study Design:

      A cross-sectional observational study of 62 school-age children in Vancouver, Canada.

      Dietary intake assessment:

      Children's dietary intake over the previous four weeks was estimated by interview with a
      parent using a Food Frequency Questionnaire. Three 24h recalls were administered, using the
      five-pass review technique. The children's dietary intake of DHA was quantified using
      nutrient analysis software (ESHA Food Processor SQL, version 10.10.0.0; ESHA Research), using
      Canadian foods, and checking the fatty acid composition of all foods and beverages for
      accuracy, modifying if necessary based on labels or laboratory analysis of the product.

      Blood Markers EDTA venous blood was collected and was centrifuged to collect Red Blood Cells
      (RBC). RBC fatty acids were extracted and quantified by routine gas liquid chromatography.
      RBC-DHA to DPA (n-6) ratio was used as an indicator of DHA status.

      Cognitive Measures The Kaufman Assessment Battery for Children (KABC)-II (Kaufman, 2004) was
      administered by one of two individuals trained in child psychometric testing. The KABC
      consists of several scales: (1) the Sequential Processing Scale measures short-term memory;
      (2) the Learning Ability Scale measures long-term storage and retrieval; & (3) the
      Simultaneous Processing Scale measures visual processing. Results of these 3 scales may be
      combined to give a composite Mental Performance Index (MPI) score. The Delayed Recall subtest
      was used to evaluate long-term memory.

      Statistical Analysis DHA intake and RBC-DHA:DPA were log transformed; transformed data were
      used in the subsequent analyses. Pearson's correlation tests were conducted to test (1) the
      associations between DHA intake and RBC-DHA:DPA ratio and (2) the associations between DHA
      intake and RBC-DHA:DPA with KABC-II domain scores.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        school-age children differentiated by intake of DHA and lutein
      
Keywords: DHA; lutein; neurodevelopment; fMRI