title: Effects of iron and n-3 fatty acid supplementation, alone and in combination, on cognition in school children: a randomized, double-blind, placebo-controlled intervention in South Africa.
abstract: BACKGROUND
  Little is known about the combined effects of iron and n-3 (omega-3) fatty acid (FA) supplementation on cognitive performance. The provision of either DHA/EPA or iron alone in rats with combined iron and n-3 FA deficiency has been reported to exacerbate cognitive deficits associated with deficiency.
  
  
  OBJECTIVE
  We investigated the effects of iron and DHA/EPA supplementation, alone and in combination, in children with poor iron and n-3 FA status.
  
  
  METHODS
  In a 2-by-2 factorial trial, children with iron deficiency (ID) (n = 321; aged 6-11 y) were allocated to receive 1) iron (50 mg) plus DHA/EPA (420/80 mg), 2) iron plus placebo, 3) placebo plus a mixture of DHA and EPA (DHA/EPA), or 4) placebo plus placebo as oral supplements (4/wk) for 8.5 mo. Cognition was assessed at baseline and endpoint by using the Hopkins Verbal Learning Test (HVLT) and subscales of the Kaufman Assessment Battery for Children.
  
  
  RESULTS
  Both iron and DHA/EPA significantly increased weight-for-age z scores. Iron increased the number of words recalled at HVLT recall 2 (intervention effect: 0.90; 95% CI: 0.18, 1.62), and in anemic children, iron increased scores in the Atlantis Delayed test (1.51; 95% CI: 0.03, 2.99) and HVLT recall 2 (2.02; 95% CI: 0.55, 3.49). DHA/EPA showed no benefit in any of the cognitive tests but decreased Atlantis test scores (-2.48; 95% CI: -3.99, -0.96) in children who were anemic at baseline and decreased Atlantis delayed scores (-0.9; 95% CI: -1.45, -0.36) in girls with ID, whereas boys tended to perform better.
  
  
  CONCLUSIONS
  In children with poor iron and n-3 FA status, iron supplementation improved verbal and nonverbal learning and memory, particularly in children with anemia. In contrast, DHA/EPA supplementation had no benefits on cognition and impaired working memory in anemic children and long-term memory and retrieval in girls with ID.
authors.affiliation: Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, Swiss Federal Institute of Technology Zürich, Switzerland. jeannine.baumgartner@gmail.com
authors.forename: Jeannine
authors.initials: J
authors.lastname: Baumgartner
authors.forename: Cornelius M
authors.initials: CM
authors.lastname: Smuts
authors.forename: Linda
authors.initials: L
authors.lastname: Malan
authors.forename: Jane
authors.initials: J
authors.lastname: Kvalsvig
authors.forename: Martha E
authors.initials: ME
authors.lastname: van Stuijvenberg
authors.forename: Richard F
authors.initials: RF
authors.lastname: Hurrell
authors.forename: Michael B
authors.initials: MB
authors.lastname: Zimmermann
mesh_terms: D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000178:diet therapy* / Q000503:physiopathology; D002648:Child; D002657:Child Development; D003072:Cognition Disorders / Q000209:etiology / Q000517:prevention & control*; D019587:Dietary Supplements; D004311:Double-Blind Method; D015525:Fatty Acids, Omega-3 / Q000097:blood / Q000627:therapeutic use*; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D019266:Iron, Dietary / Q000627:therapeutic use*; D007859:Learning Disabilities / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008569:Memory Disorders / Q000209:etiology / Q000517:prevention & control; D008570:Memory, Short-Term; D011204:Poverty Areas; D012423:Rural Health; D012727:Sex Characteristics; D013019:South Africa; D015430:Weight Gain
chemical_list: D015525:Fatty Acids, Omega-3; D006454:Hemoglobins; D019266:Iron, Dietary