Effect of Fish Oil Supplementation on Fatty Acid Status, Coordination, and Fine Motor Skills in Children with Phenylketonuria

ObjectiveTo investigate effects of long-chain omega-3 polyunsaturated fatty acids (LC-PUFA) on motor skills in patients with phenylketonuria (PKU).Study designThirty-six patients with PKU (1-11 years of age, good metabolic control: plasma phenylalanine ≤360 μmol/L for ≥6 months). We determined plasma phospholipid fatty acids, and in patients >4 years of age (N = 24) the motometric Rostock-Oseretzky Scale (ROS), before and after supplementation with fish oil for 3 months (15 mg docosahexaenoic acid [DHA]/kg body weight daily). ROS was also assessd in 22 age-matched controls.ResultsPatients had low n-3 LC-PUFA in plasma phospholipids (DHA, 2.37 ± 0.10%; eicosapentaenoic acid [EPA], 0.4 ± 0.03%) and poorer ROS performance than controls (motor development index [MQ] 107 ± 3 vs 117 ± 3, P = .010). Supplementation increased phospholipid n-3 LC-PUFA (DHA 7.05 ± 0.24%; EPA 3.31 ± 0.19%; P < .001), decreased n-6 LC-PUFA (arachidonic acid, 9.26 ± 0.23% vs 6.76 ± 0.16%; P < .001) and improved ROS (MQ 115 ± 3.54, P = .011, paired t test). ROS was unchanged in 11 retested controls (MQ 115 ± 5.16, P = NS, paired t test multivariate analysis of variance [MANOVA] for time by group, P = .027). Patients tolerated fish oil well. Plasma phenylalanine remained unchanged.ConclusionIn patients with PKU, fish oil supplementation enhances n-3 LC-PUFA levels and improves motor skills.