Does dietary DHA improve neural function in children? Observations in phenylketonuria

Area of Science:

• Nutritional Neuroscience
• Biochemistry
• Pediatric Health

Background:

• Children with phenylketonuria (PKU) have restricted protein intake, leading to low dietary long-chain polyunsaturated fatty acids (LC-PUFA).
• Low LC-PUFA intake may contribute to subtle neurological deficits in children with PKU.
• Assessing the impact of LC-PUFA supplementation on neurological function in PKU is crucial.

Purpose of the Study:

• To investigate the effects of fish oil supplementation on plasma fatty acid profiles and neurological function in children with PKU.
• To evaluate changes in visual evoked potentials (VEP) and motor skills (Rostock-Oseretzky Scale - ROS) following docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) supplementation.
• To determine if preformed n-3 LC-PUFA are essential for neurological normalcy in PKU and potentially in the general pediatric population.

Main Methods:

• 36 children with well-controlled PKU received fish oil capsules (15 mg DHA/kg/day) for 3 months.
• Plasma phospholipid fatty acids, VEP latencies, and ROS scores were measured before and after supplementation.
• Age-matched omnivorous controls were assessed similarly without supplementation for comparison.

Main Results:

• Fish oil supplementation significantly increased plasma EPA and DHA levels in PKU children.
• Arachidonic acid (AA) levels decreased, while plasma phenylalanine remained unchanged.
• PKU children showed significant improvements in VEP latencies, fine motor skills, and coordination after supplementation, unlike controls.

Conclusions:

• Preformed n-3 LC-PUFA supplementation improves neurological function, including VEP and motor skills, in children with PKU.
• These findings suggest that preformed n-3 LC-PUFA are necessary for optimal neurological development in PKU.
• The study indicates that all children may require preformed n-3 LC-PUFA for optimal neurological function, although optimal dosage requires further study.