Dietary Supplementation with Casein Glycomacropeptide, Leucine and Tryptophan Reduces Plasma Amino Acid Levels in Men.

Abstract

BACKGROUND\nThe treatment of mania in bipolar disorders needs to be more efficient, as the manic condition creates severe problems for the patient when it comes to work, finances, relationships, and health. This proof-of-concept study examines to what extent casein glycomacropeptide (CGMP) may reduce the precursors of dopamine, phenylalanine, and tyrosine, in plasma, and therefore be a potential new intervention to treat acute manic episodes.\n\n\nMETHOD\nThe study was designed as a double-blind randomised dose-response study of CGMP (with added leucine and tryptophan) in 15 healthy men, receiving 3 different doses of CGMP with an interval of at least 14 days.\n\n\nRESULTS\nAdministration of CGMP produced a dose dependent depletion of plasma aromatic amino acids. The total area under the curve of plasma ratios of phenylalanine-tyrosine compared to the level of leucine-isoleucine-valine-tryptophan was CGMP(20g): 3.648 [SE:0.3281]; CGMP(40g): 2.368 [SE:0.1858]; CGMP(60g)1.887 [SE:0.2591]. A comparison of the groups showed a dose dependent statistical difference, with a One-Way ANOVA summary (Dunnett) F= 11.87, p= 0.0003, CGMP 20g vs CGMP 40g, p= 0.0042, CGMP 20g vs CGMP 60g, p= 0.0002. No significant side effects were observed.\n\n\nCONCLUSIONS\nThis study demonstrate CGMP is a well-tolerated and effective mixture, and that 60 g CGMP produced the highest depletion of plasma aromatic amino acids (phenylalanine and tyrosine). The effect seems to be highest after 3-4 hours. We therefore conclude that this dose should be the one considered for future studies involving CGMP in humans.