n−6 Docosapentaenoic acid is not a predictor of low docosahexaenoic acid status in Canadian preschool children123

• Published in: The American journal of clinical nutrition 2004-11, Vol.80 (3), p.768-773
• Main Authors: Innis, Sheila M, Vaghri, Ziba, King, D Janette
• Format: Article
• Language: English
• Subjects: brain development; docosahexaenoic acid; docosapentaenoic acid; Essential fatty acids; linoleic acid; trans fatty acids
• ISSN: 0002-9165
• DOI: 10.1093/ajcn/80.3.768

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. We determined n−3 fatty acid status and investigated the relation between 22:6n−3 and 22:5n−6 in children. 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. 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. 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.