Phenylketonuria natural treatment with supplements by Ray Sahelian, M.D.

Phenylketonuria PKU requires a lifelong low-phenylalanine diet that provides the majority of protein from a phenylalanine-free amino acid formula.

Fish oil benefit
Effect of fish oil supplementation on fatty acid status, coordination, and fine motor skills in children with phenylketonuria.
J Pediatr. 2007 May;150(5):479-84. Division of Metabolic Diseases and Nutrition, Dr. von Haunersches Kinderspital, Ludwig-Maximilians-University, Munich, Germany.
Thirty-six patients with Phenylketonuria (1-11 years of age, good metabolic control: plasma phenylalanine < or = 360 micromol/L for > or = 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). Supplementation increased phospholipid n-3 LC-PUFA, decreased n-6 LC-PUFA. Patients tolerated fish oil well. Plasma phenylalanine remained unchanged. In patients with Phenylketonuria, fish oil supplementation enhances n-3 LC-PUFA levels and improves motor skills.

Benefit of Glycomacropeptide
Improved nutritional management of phenylketonuria by using a diet containing glycomacropeptide compared with amino acids
American Journal of Clinical Nutrition, doi:10.3945/ajcn.2008.27280
Glycomacropeptide (GMP), an intact protein formed during cheese production, contains minimal phenylalanine. The objective was to investigate the effects of substituting GMP food products for the AA formula on acceptability, safety, plasma AA concentrations, and measures of protein utilization in subjects with PKU.
Eleven subjects participated in an inpatient metabolic study with two 4-d treatments: a current AA diet (AA diet) followed by a diet that replaced the AA formula with GMP (GMP diet) supplemented with limiting AAs. Plasma concentrations of AAs, blood chemistries, and insulin were measured and compared in AA (day 4) and GMP diets (day 8). The GMP diet was preferred to the AA diet in 10 of 11 subjects with PKU, and there were no adverse reactions to GMP. There was no significant difference in phenylalanine concentration in postprandial plasma with the GMP diet compared with the AA diet. When comparing fasting with postprandial plasma, plasma phenalyalanine concentration increased significantly with the AA but not with the GMP diet. Blood urea nitrogen was significantly lower, which suggests decreased ureagenesis, and plasma insulin was higher with the GMP diet than with the AA diet. GMP, when supplemented with limiting AAs, is a safe and highly acceptable alternative to synthetic AAs as the primary protein source in the nutritional management of PKU. As an intact protein source, GMP improves protein retention and phenylalanine utilization compared with AAs.