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


METHODS
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.
Innis
Sheila M
SM
Nutrition Research Program, British Columbia Research Institute for Children's and Women's Health, University of British Columbia, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada. sinnis@interchange.ubc.ca
Vaghri
Ziba
Z
King
D Janette
DJ
D015415:Biomarkers / Q000097:blood; D001955:British Columbia; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000097:blood*; D004912:Erythrocytes / Q000737:chemistry / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000097:blood; D043371:Fatty Acids, Omega-6 / Q000008:administration & dosage / Q000097:blood; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage / Q000097:blood*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D018673:Nutrition Policy; D009752:Nutritional Status; D011237:Predictive Value of Tests; D011795:Surveys and Questionnaires
D015415:Biomarkers; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D004281:Docosahexaenoic Acids; C026219:docosapentaenoic acid