Glicomacrop?ptido

Related Terms

Acetyl galactosamine, branched-chain amino acids (BCAAs), carbohydrate, casein glycomacropeptide (cGMP), casein glycopeptide (CGP), casein macropeptide (CMP), casein-derived peptide (CDP), caseinglycopeptide, caseinmacropeptide, caseinoglycomacropeptide, cheese, cholecystokinin (CCK), galactosamine, galactose, glucosamine, isoleucine, kappa-casein, milk, phosphorus, sialic acid (N-acetylneuraminic acid), sweet whey, valine, whey.

Background

Purified glycomacropeptide (GMP) has been used in dietary supplements and in functional foods and beverages, which are products that claim to provide some health benefit beyond basic nutrition. GMP is produced in cheese making when an enzyme called chymosin (also known as rennin) is added to milk. Chymosin breaks down the milk protein kappa-casein into para-kappa-casein and glycomacropeptide (GMP). Para-kappa-casein is a component of the cheese curd, while the GMP peptide is part of the whey. GMP is also formed in the stomach as a product of digestion by the enzyme pepsin.
GMP differs from other whey proteins, because it contains low levels of certain amino acids, namely phenylalanine, tryptophan, and tyrosine. Because GMP is the only known naturally occurring protein that does not contain phenylalanine, it may be beneficial to incorporate it into the diet of phenylketonuria (PKU) patients, who cannot metabolize phenylalanine. Research is ongoing in this area.
GMP also has relatively high amounts of branched-chain amino acids (BCAAs). BCAAs are believed to stimulate the production of cholecystokinin (CCK), a peptide released after eating that may act as a satiety-providing appetite suppressant. The effects of GMP supplementation on satiety have not been consistent in clinical trials. Other clinical studies have tested the effects of GMP in infant formulas and weight loss.
Well-designed clinical trials are needed before firm conclusions can be made regarding the use of GMP for any health condition.

Evidence Table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *


GMP is present in infant formulas that contain whey. Results from clinical trials testing the benefits of supplementing infant formula with GMP are conflicting. Additional research is needed before firm conclusions can be made.

 C


GMP is present in infant formulas that contain whey. Results from clinical trials testing the benefits of supplementing infant formula with GMP are conflicting. Additional research is needed before firm conclusions can be made.

 C


Whey protein, which contains GMP, has been found to be more filling than other types of protein. The effects of supplementary GMP on weight loss have been inconsistent in clinical trials. Additional research is needed.

 C


Whey protein, which contains GMP, has been found to be more filling than other types of protein. The effects of supplementary GMP on weight loss have been inconsistent in clinical trials. Additional research is needed.

 C


Individuals with PKU cannot metabolize the amino acid phenylalanine and must strictly follow a diet in which most dietary protein is provided by a phenylalanine-free amino acid (AA) formula. In clinical trials, purified GMP was found to be a safe and acceptable alternative to synthetic amino acids as the primary protein source in the nutritional management of PKU. Additional research is needed to confirm these results.

 C


Individuals with PKU cannot metabolize the amino acid phenylalanine and must strictly follow a diet in which most dietary protein is provided by a phenylalanine-free amino acid (AA) formula. In clinical trials, purified GMP was found to be a safe and acceptable alternative to synthetic amino acids as the primary protein source in the nutritional management of PKU. Additional research is needed to confirm these results.

 C


Hyperthreoninemia (high threonine levels) has been documented in infants fed a whey protein-predominant formula. This condition is associated with a risk of neurotoxicity during early development. Research has shown that an experimental formula based on acid whey without GMP lacked these toxic effects.

 D


Hyperthreoninemia (high threonine levels) has been documented in infants fed a whey protein-predominant formula. This condition is associated with a risk of neurotoxicity during early development. Research has shown that an experimental formula based on acid whey without GMP lacked these toxic effects.

 D
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)

Tradition / Theory

The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

Dosing

Adults (18 years and older)
For obesity or weight loss, one 50-gram dose of bovine cheese whey product (containing GMP) has been taken by mouth. Meal replacements containing 15 grams of protein from GMP-enriched whey protein isolate diluted with 200 milliliters of water have been taken by mouth twice daily for 12 months. A beverage containing whey protein isolate plus added GMP has been taken by mouth. Breakfasts containing whey (with GMP) with 10, 55, and 35% or 25, 55, and 20% of protein, carbohydrate, and fat, respectively, have been taken by mouth.
For phenylketonuria (PKU), GMP food products have been taken by mouth for four days.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Interactions

Interactions with Drugs
GMP may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants (blood thinners) such as warfarin (Coumadin?) or heparin, antiplatelet drugs such as clopidogrel (Plavix?), and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin?, Advil?) or naproxen (Naprosyn?, Aleve?).
GMP may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. Patients taking insulin or drugs for diabetes by mouth should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
GMP may lower blood pressure. Caution is advised in patients with low blood pressure and in those taking drugs that affect blood pressure.
GMP may also interact with antibiotics, anti-inflammatory agents, antiobesity agents, antiviral agents, cholesterol- and lipid-lowering drugs, dental and periodontal agents, drugs that weaken the immune system, gastrointestinal agents, laxatives, and neurologic agents.

Attribution

This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

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Bruck WM, Redgrave M, Tuohy KM, et al. Effects of bovine alpha-lactalbumin and casein glycomacropeptide-enriched infant formulae on faecal microbiota in healthy term infants. J Pediatr Gastroenterol Nutr 2006;43(5):673-679.
Burton-Freeman BM. Glycomacropeptide (GMP) is not critical to whey-induced satiety, but may have a unique role in energy intake regulation through cholecystokinin (CCK). Physiol Behav 2008;93(1-2):379-387.
Gunther G, Boehm G, Georgi G, et al. Glycomacropeptide in premature babies' nutrition is a main cause of hyperthreoninamia in premature babies fed on a formula diet. The Cochrane Library 2010;(1)
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Rigo J, Boehm G, Georgi G, et al. An infant formula free of glycomacropeptide prevents hyperthreoninemia in formula-fed preterm infants. J Pediatr Gastroenterol Nutr 2001;32(2):127-130.
Sandstrom O, Lonnerdal B, Graverholt G, et al. Effects of alpha-lactalbumin-enriched formula containing different concentrations of glycomacropeptide on infant nutrition. Am J Clin Nutr 2008;87(4):921-928.
van Calcar SC, MacLeod EL, Gleason ST, et al. Improved nutritional management of phenylketonuria by using a diet containing glycomacropeptide compared with amino acids. Am J Clin Nutr 2009;89(4):1068-1077.
Veldhorst MA, Nieuwenhuizen AG, Hochstenbach-Waelen A, et al. A breakfast with alpha-lactalbumin, gelatin, or gelatin + TRP lowers energy intake at lunch compared with a breakfast with casein, soy, whey, or whey-GMP. Clin Nutr 2009;28(2):147-155.
Veldhorst MA, Nieuwenhuizen AG, Hochstenbach-Waelen A, et al. Effects of complete whey-protein breakfasts versus whey without GMP-breakfasts on energy intake and satiety. Appetite 2009;52(2):388-395.
Veldhorst MAB, Nieuwenhuizen AG, Hochstenbach-Waelen A, et al. Effects of high or normal casein-, soy-, or whey with or without GMP- protein breakfasts on satiety, 'satiety' hormones, and plasma amino acid responses. Appetite 2007;49(1):336.