Journal of Inherited Metabolic Disease

, Volume 32, Issue 1, pp 32–39

Nutritional management of PKU with glycomacropeptide from cheese whey

  • D. M. Ney
  • S. T. Gleason
  • S. C. van Calcar
  • E. L. MacLeod
  • K. L. Nelson
  • M. R. Etzel
  • G. M. Rice
  • J. A. Wolff
BH4 and PKU

DOI: 10.1007/s10545-008-0952-4

Cite this article as:
Ney, D.M., Gleason, S.T., van Calcar, S.C. et al. J Inherit Metab Dis (2009) 32: 32. doi:10.1007/s10545-008-0952-4

Summary

Individuals with phenylketonuria (PKU) must follow a lifelong low-phenylalanine (Phe) diet to prevent neurological impairment. Compliance with the low-Phe diet is often poor owing to restriction in natural foods and the requirement for consumption of a Phe-free amino acid formula or medical food. Glycomacropeptide (GMP), a natural protein produced during cheese-making, is uniquely suited to a low-Phe diet because when isolated from cheese whey it contains minimal Phe (2.5–5 mg Phe/g protein). This paper reviews progress in evaluating the safety, acceptability and efficacy of GMP in the nutritional management of PKU. A variety of foods and beverages can be made with GMP to improve the taste, variety and convenience of the PKU diet. Sensory studies in individuals with PKU demonstrate that GMP foods are acceptable alternatives to amino acid medical foods. Studies in the PKU mouse model demonstrate that GMP supplemented with limiting indispensable amino acids provides a nutritionally adequate source of protein and improves the metabolic phenotype by reducing concentrations of Phe in plasma and brain. A case report in an adult with classical PKU who followed the GMP diet for 10 weeks at home indicates safety, acceptability of GMP food products, a 13–14% reduction in blood Phe levels (p < 0.05) and improved distribution of dietary protein throughout the day compared with the amino acid diet. In summary, food products made with GMP that is supplemented with limiting indispensable amino acids provide a palatable alternative source of protein that may improve dietary compliance and metabolic control of PKU.

Abbreviations

AA

amino acid

GMP

glycomacropeptide

LNAA

large neutral amino acids

MS/MS

tandem mass spectroscopy

PAH

phenylalanine hydroxylase

Phe

phenylalanine

PKU

phenylketonuria

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • D. M. Ney
    • 1
  • S. T. Gleason
    • 1
  • S. C. van Calcar
    • 2
  • E. L. MacLeod
    • 1
  • K. L. Nelson
    • 3
  • M. R. Etzel
    • 4
  • G. M. Rice
    • 2
  • J. A. Wolff
    • 2
  1. 1.Department of Nutritional SciencesUniversity of WisconsinMadisonUSA
  2. 2.Waisman CenterUniversity of WisconsinMadisonUSA
  3. 3.Wisconsin Center for Dairy ResearchUniversity of WisconsinMadisonUSA
  4. 4.Department of Food ScienceUniversity of WisconsinMadisonUSA

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