n-6 Docosapentaenoic acid is not a predictor of low docosahexaenoic acid status in Canadian preschool children

• Published in: The American journal of clinical nutrition 2004-09, Vol.80 (3), p.768-773
• Main Authors: Innis, S.M, Vaghri, Z, King, D.J
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biomarkers - blood; Brain; British Columbia; Child development; Child, Preschool; Cross-Sectional Studies; Docosahexaenoic Acids - administration & dosage; Docosahexaenoic Acids - blood; Erythrocytes - chemistry; Erythrocytes - metabolism; Fatty acids; Fatty Acids, Omega-3 - administration & dosage; Fatty Acids, Omega-3 - blood; Fatty Acids, Omega-6 - administration & dosage; Fatty Acids, Omega-6 - blood; Fatty Acids, Unsaturated - administration & dosage; Fatty Acids, Unsaturated - blood; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; Humans; Infant; Male; Nutrition Policy; Nutritional Status; Oils & fats; Predictive Value of Tests; Preschool children; Surveys and Questionnaires; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/80.3.768

Background: The n-3 fatty acid docosahexaenoic acid (DHA; 22:6n-3) is important for neural and visual functional development. In animals, 22:6n-3 deficiency is accompanied by increased docosapentaenoic acid (DPA; 22:5n-6), which suggests that the ratio of 22:6n-3 to 22:5n-6 could be a useful biochemical marker of low n-3 fatty acid status. The n-3 fatty acid status of preschool children has not been described, and data are lacking on whether low 22:6n-3 is accompanied by high 22:5n-6 in humans. Objective: We determined n-3 fatty acid status and investigated the relation between 22:6n-3 and 22:5n-6 in children. Design: In Canadian children aged 18-60 mo (n = 84), the n-3 and n-6 fatty acid status of erythrocyte phosphatidylethanolamine was measured, and dietary fat intake was estimated by using a food-frequency questionnaire. Results: The mean (± SEM) 22:6n-3 concentration in erythrocyte phosphatidylethanolamine among children was 3.06 ± 0.13 g/100 g fatty acids (5th-95th percentiles: 1.43-5.79 g/100 g fatty acids). Concentrations of 22:5n-6 increased with increasing 22:6n-3 concentrations in erythrocyte phosphatidylethanolamine (P < 0.01). Mean intakes of linoleic acid (18:2n-6), linolenic acid (18:3n-3), and trans fatty acids were 3.6 ± 0.2%, 0.7 ± 0.5%, and 2.0 ± 1.3%, respectively. Phosphatidylethanolamine 22:6n-3 and 22:5n-3 concentrations were inversely related to the intakes of 18:2n-6 and trans fatty acids, but not to those of total fat or n-3 fatty acids. Conclusions: The concentration of 22:5n-6 is not a useful biochemical marker of low n-3 fatty acid intake or status in the membrane phosphatidylethanolamine of preschool children. High intakes of 18:2n-6 and trans fatty acids could compromise the incorporation of 22:6n-3 into membrane phospholipids.