Effect of a 2-y dietary and physical activity intervention on plasma fatty acid composition and estimated desaturase and elongase activities in children: the Physical Activity and Nutrition in Children Study1

Background: Evidence on the effects of lifestyle interventions on plasma fatty acid composition in children is limited. Objective: We investigated the effects of a dietary and physical activity intervention on plasma fatty acid composition of cholesteryl esters (CEs) and phospholipids and estimated desaturase and elongase activities in children. Design:We conducted a 2-y controlled dietary and physical activity intervention based on Finnish nutrition and physical activity recommendations in a population sample of 506 children aged 6–8 y. We assessed plasma fatty acid composition by gas chromatography and estimated desaturase and elongase activities as the ratio of product fatty acids to precursor fatty acids. We analyzed data by using linear mixed models adjusted for age and sex. Results: The proportion of total polyunsaturated fatty acids (PUFAs) in CEs tended to increase in the intervention group compared with the control group (P = 0.007 for group 3 time interaction). The proportion of total PUFAs in phospholipids (P = 0.019 for group 3 time interaction) and the proportion of linoleic acid in CEs (P = 0.038 for group 3 time interaction) decreased in the control group. The proportion of a-linolenic acid in CEs (P , 0.001 for group 3 time interaction) increased and in phospholipids (P = 0.015 for group 3 time interaction) tended to increase in the intervention group. The proportion of stearic acid in CEs decreased in the intervention group (P = 0.001 for group 3 time interaction). The proportion of oleic acid in CEs (P = 0.002 for group 3 time interaction) increased and in phospholipids (P = 0.023 for group 3 time interaction) tended to increase in the control group. Estimated elongase activity in CEs decreased in the control group (P = 0.050 for group 3 time interaction). Intervention had no effect on estimated desaturase activities. Conclusions: Dietary and physical activity intervention had a beneficial effect on plasma fatty acid composition in children by preventing the decrease in the proportion of total PUFAs and linoleic acid and by increasing the proportion of a-linolenic acid. This study was registered at clinicaltrials.gov as NCT01803776. Am J Clin Nutr doi: 10.3945/ajcn.116.136580.