glutamine

Foods Richest in glutamine

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About glutamine

Description

Glutamine is an amino acid synthesized from glutamic acid (glutamate). It is classified as conditionally essential: under normal conditions the body produces sufficient quantities, but during severe physiological stress (major surgery, extensive burns, critical illness) endogenous synthesis cannot keep pace with demand. Glutamine is the most abundant free amino acid in blood and muscle tissue, participating in nitrogen transport, acid-base regulation, intestinal barrier maintenance, and immune cell proliferation. Its use among athletes is based on observations of reduced upper respiratory infections after intense exercise, though the clinical evidence for this application remains mixed.

How it functions

Enterocytes (the cells lining the small intestine) use glutamine as their primary fuel source, preferring it over glucose. This metabolic preference makes glutamine central to intestinal barrier integrity. When the intestinal lining is well-maintained, it blocks pathogenic microorganisms and limits absorption of allergenic molecules. Lymphocytes and macrophages also oxidize glutamine at high rates, making it a substrate for immune cell function during infection.

Glutamine participates in acid-base regulation. The body synthesizes glutamine from glutamate and ammonia; when blood ammonia levels rise, glutamine synthesis increases to sequester this toxic compound. Conversely, when blood pH drops too low, glutamine can be broken down to release ammonia and raise pH.

Glutamine also serves as a precursor to the antioxidant glutathione, participates in glycogen synthesis, and provides nitrogen for nucleotide biosynthesis (the building blocks of DNA and RNA).

Deficiency symptoms

Because glutamine can be synthesized by the body from the amino acid glutamate, glutamine deficiency is not very common. Nevertheless, individuals undergoing severe physical trauma due to infection or extensive burns typically have low glutamine levels. These individuals often exhibit a weakened immune system and heightened intestinal permeability (also called “leaky gut”), which suggests that an inadequate supply of glutamine is associated with reduced immune function and increased intestinal permeability.

Toxicity symptoms

Consumption of glutamine from food sources alone is not known to cause any harmful effects. Glutamine supplementation, even in doses exceeding 10 grams per day, is also believed to be safe. However, in a few research studies, patients given intravenous nutritional formulas (total parenteral nutrition) containing glutamine developed elevated liver enzymes, a sign of liver toxicity. When the glutamine was removed from the nutritional formulas, the liver enzymes of the patients returned to normal levels. Persons sensitive to monosodium glutamate (MSG) may also want to avoid glutamine supplements, since the body can convert glutamine into glutamate. For this same reason, people with epilepsy or bipolar disorder should use glutamine supplements with extreme caution. To date, Tolerable Upper Intake Levels have not been established for glutamine.

Impact of cooking, storage and processing

There is no research showing problematic effects of cooking, storage, or processing on glutamine levels in food.

Factors that affect function

Muscle and blood concentrations of glutamine are rapidly depleted when the body is confronted with any type of physical stress. For example, high-intensity exercise, injury, surgery, burns, infections, and malnutrition cause the body to use up its stores of glutamine, and during these stressful times the body is unable to synthesize glutamine fast enough to meet its needs for this amino acid. Consequently, people under physical stress may be at risk for glutamine deficiency.

Also, the principle site for glutamine synthesis is muscle tissue. As a result, people with low muscle mass, such as the elderly, or muscle wasting diseases (for example, AIDS) may be at risk for glutamine deficiency.

Nutrient interactions

The conversion of glutamic acid to glutamine requires a form of niacin (vitamin B3) as a cofactor. Glutamic acid itself is often synthesized through a transamination reaction that requires vitamin B6. Both B3 and B6 are therefore necessary cofactors for adequate glutamine production.

Health conditions

Glutamine may play a role in the prevention and/or treatment of the following health conditions:

Food sources

Food sources of glutamine include most high-protein foods including beef, chicken, fish, beans, and dairy products.

 

Food Source Analysis not Available for this Nutrient

Public health recommendations

No Dietary Reference Intakes have been established for glutamine.

Drug-nutrient interactions

Glutamine may be helpful in reducing the side effects associated with chemotherapy drugs, including mouth sores, diarrhea, and muscle and joint pain.

The body metabolizes glutamine to another amino acid called glutamate. Many anti-seizure medications including carbamazepine, phenobarbital, phenytoin (Dilantim TM), primidon (Mysoline TM), and valproic acid (Depakene TM) work by blocking glutamate stimulation in the brain. As a result, persons taking an anti-seizure medication should consult with a health care practitioner before taking a glutamine supplement.

Form in dietary supplements

As a dietary supplement, glutamine is available in protein powders and powdered drink mixes.

Related Articles

References

  1. Choi SH, Lee S and Lee MD. Glutamine on the luminal microbial environment after massive small bowel resection. J Korean Med Sci 2002 Dec;17(6):778-83. 2002. https://doi.org/10.3346/jkms.2002.17.6.778
  2. Darmaun D. Role of glutamine depletion in severe illness. Diabetes Nutr Metab 2000 Feb;13(1):25-30. 2000. PMID:15480.
  3. DiPasquale M. Amino Acids and Proteins for the Athlete: The Anabolic Edge. CRC Press: Boca Raton, FL, 1997. 1997. https://doi.org/10.1201/9781420043815
  4. Goodman MJ, Skinner JM, Truelove SC. Abnormalities in the apparently normal bowel mucosa in Crohn's disease. Lancet 1976 Feb 7;1(7954):275-8. 1976. PMID:9640. https://doi.org/10.1073/pnas.73.9.3035
  5. Groff JL, Gropper SS, Hunt SM. Advanced Nutrition and Human Metabolism. West Publishing Company, New York, 1995. 1995.
  6. Institute of Medicine. The Role of Protein and Amino Acids in Sustaining and Enhancing Performance. National Academy Press: Washington DC, 1999. 1999.
  7. Labow BI, Souba WW. Glutamine. World J Surg 2000 Dec;24(12):1503-13. 2000. PMID:15440.
  8. Lininger SW, et al. A-Z guide to drug-herb-vitamin interactions. Prima Health, Rocklin, CA, 2000. 2000.
  9. Mahan K, Escott-Stump S. Krause's Food, Nutrition, and Diet Therapy. WB Saunders Company; Philadelphia, 1996. 1996.
  10. Medina MA. Glutamine and cancer. J Nutr 2001 Sep;131(9 Suppl):2539S-42S; discussion 2550S-1S. 2001. PMID:15400.
  11. Mithieux G. New data and concepts on glutamine and glucose metabolism in the gut. Curr Opin Clin Nutr Metab Care 2001 Jul;4(4):267-71. 2001. PMID:15430. https://doi.org/10.1186/BF03548474
  12. Reeds PJ, Burrin DG. Glutamine and the bowel. J Nutr 2001 Sep;131(9 Suppl):2505S-8S; discussion 2523S-4S. 2001. PMID:15420.
  13. Scarpignato C, Pelosini I. Management of irritable bowel syndrome: novel approaches to the pharmacology of gut motility. Can J Gastroenterol 1999 Mar;13 Suppl A:50A-65A. 1999. PMID:9590.
  14. Vardimon L. Neuroprotection by glutamine synthetase. Isr Med Assoc J 2000 Jul;2 Suppl:46-51. 2000. PMID:15470. https://doi.org/10.1016/0003-2697(77)90101-4
  15. Ziegler TR, Bazargan N, Leader LM, Martindale RG. Glutamine and the gastrointestinal tract. Curr Opin Clin Nutr Metab Care 2000 Sep;3(5):355-62. 2000. PMID:15450. https://doi.org/10.1001/archpedi.1977.02120170073015
  16. Choi SH, Lee S and Lee MD. Glutamine on the luminal microbial environment after massive small bowel resection. J Korean Med Sci 2002 Dec;17(6):778-83 2002. https://doi.org/10.3346/jkms.2002.17.6.778
  17. Darmaun D. Role of glutamine depletion in severe illness. Diabetes Nutr Metab 2000 Feb;13(1):25-30 2000. PMID:15480.
  18. DiPasquale M. Amino Acids and Proteins for the Athlete: The Anabolic Edge. CRC Press: Boca Raton, FL, 1997 1997. https://doi.org/10.1201/9781420043815
  19. Goodman MJ, Skinner JM, Truelove SC. Abnormalities in the apparently normal bowel mucosa in Crohn's disease. Lancet 1976 Feb 7;1(7954):275-8 1976. PMID:9640. https://doi.org/10.1073/pnas.73.9.3035
  20. Groff JL, Gropper SS, Hunt SM. Advanced Nutrition and Human Metabolism. West Publishing Company, New York, 1995 1995.
  21. Institute of Medicine. The Role of Protein and Amino Acids in Sustaining and Enhancing Performance. National Academy Press: Washington DC, 1999 1999.
  22. Labow BI, Souba WW. Glutamine. World J Surg 2000 Dec;24(12):1503-13 2000. PMID:15440.
  23. Lininger SW, et al. A-Z guide to drug-herb-vitamin interactions. Prima Health, Rocklin, CA, 2000 2000.
  24. Mahan K, Escott-Stump S. Krause's Food, Nutrition, and Diet Therapy. WB Saunders Company; Philadelphia, 1996 1996.
  25. Medina MA. Glutamine and cancer. J Nutr 2001 Sep;131(9 Suppl):2539S-42S; discussion 2550S-1S 2001. PMID:15400.
  26. Mithieux G. New data and concepts on glutamine and glucose metabolism in the gut. Curr Opin Clin Nutr Metab Care 2001 Jul;4(4):267-71 2001. PMID:15430. https://doi.org/10.1186/BF03548474
  27. Reeds PJ, Burrin DG. Glutamine and the bowel. J Nutr 2001 Sep;131(9 Suppl):2505S-8S; discussion 2523S-4S 2001. PMID:15420.
  28. Scarpignato C, Pelosini I. Management of irritable bowel syndrome: novel approaches to the pharmacology of gut motility. Can J Gastroenterol 1999 Mar;13 Suppl A:50A-65A 1999. PMID:9590.
  29. Vardimon L. Neuroprotection by glutamine synthetase. Isr Med Assoc J 2000 Jul;2 Suppl:46-51 2000. PMID:15470. https://doi.org/10.1016/0003-2697(77)90101-4
  30. Ziegler TR, Bazargan N, Leader LM, Martindale RG. Glutamine and the gastrointestinal tract. Curr Opin Clin Nutr Metab Care 2000 Sep;3(5):355-62 2000. PMID:15450. https://doi.org/10.1001/archpedi.1977.02120170073015