encyclopedia

Glutamic Acid and Glutamine

Natural Sources:     

Glutamic acid is found abundantly in food, particularly high protein foods such as beans and other legumes, meat and dairy products. Glutamine is also found abundantly in food and is particularly concentrated in raw parsley and spinach.     

Forms:     

Standardized glutamic acid and glutamine powders, capsules and tablets; Multivitamin and Mineral tablets containing glutamic acid and glutamine.     

Therapeutic Uses:     

– AIDS (sometimes used)
– Aging Disorders
– Alcoholism
– Alzheimer's Disease
– Angina
– Antidepressant
– Antioxidant
– Atherosclerosis
– Athletic Performance
– Autism
– Brain Functioning
– Cancer
– Depression
– Diabetes mellitus
– Digestive Disorders
– Epilepsy
– Eye Health Maintenance
– Fatigue
– Folic Acid Deficiency
– Free Radical Related Diseases
– General Debility
– Heart Health Maintenance
– Immune System
– Impotence
– Liver Health Maintenance
– Low Stomach Acid
– Macular Degeneration
– Memory
– Mental Functioning
– Mental Retardation
– Muscle Weakness
– Muscular Dystrophy
– Myocardial Infarction
– Neurological Disorders
– Parkinson's Disease
– Physical Performance
– Protein Catabolism
– Respiratory Insufficiency
– Schizophrenia
– Senility
– Stomach Acid Deficiency
– Stress
– Ulcers     

Overview:     

Glutamic acid is one of the 20 amino acids commonly found in proteins – the body's building blocks of cells, enzymes, hormones and immune components. Glutamic acid plays a central role in amino acid metabolism, acting as a precursor of glutamine, proline and arginine. Glutamic acid is also a component of folic acid. The related compound, glutamate, is a neurotransmitter and a precursor of the inhibitory neurotransmitter aminobutyrate (GABA). Glutamic acid is primarily used by the brain. It has the ability to pick up excess ammonia, which inhibits brain functioning, and convert it into glutamine. Glutamic acid can also be synthesized from several different amino acids, including glutamine. Since glutamine produces an elevation of glutamic acid, a shortage in the diet can result in a shortage of glutamic acid in the brain. Because many people have a sensitivity to free glutamic acid, it is best to supplement the diet using glutamine, which has no known toxicity even at high dosages. Glutamine has also been shown to help in the control of alcoholism, shorten the healing time of ulcers and alleviate fatigue, depression, and impotence. It has also been used successfully in the treatment of schizophrenia and senility. Additionally, glutamine is an awesome anti-aging agent that revs up glutathione levels within the body dramatically, the body's master antioxidant. Dr. Ercole Cavalieri, a renowned researcher at the Nebraska Medical Center, describes glutathione as the most important antioxidant within cells, without which we could not survive. Taking glutamine actually boosts blood levels of glutathione much more effectively than taking glutathione directly. According to researchers at Harvard Medical School, glutamine stimulates the liver to synthesize large quantities of glutathione. The body also uses glutamic acid as a principal digestive enzyme in gastric juice, which controls the degradation of protein to peptones and hydrolyses peptide linkages.

Chemistry:     

Glutamic acid is one of the 20 amino acids commonly found in proteins. It acts as a precursor of glutamine, proline and arginine. Glutamic acid can also be synthesized from several different amino acids, including glutamine. Glutamic acid acts as amino group donor in synthesis by transamination of alanine from pyruvate and aspartic acid from oxaloacetate. Glutamine is one of the major nutrients for the small-bowel mucosa; it is metabolized into glutamate and subsequently alanine in the human enterocyte.     

Suggested Amount:     

Based on controlled clinical studies with positive results, the dosage of glutamic acid generally ranges from between 2 to 15 grams daily. Dr. Douglas Wilmore of Harvard, a glutamine researcher, recommends taking 8 grams of glutamine daily – or twice that much if suffering from an infection. Even taking as much as 40 grams daily produced no noticeable side effects according to Dr. Wilmore. However, it is recommended that if you are ill, only take glutamine under a doctor's supervision.     

Drug Interactions:     

None known.     

Contraindications:     

Persons with an allergy to MSG should avoid taking supplements with glutamic acid. It is recommended to supplement with glutamine instead, particularly in this case. It is recommended that if you are ill, only take glutamine under a doctor's supervision.    

Side Effects:     

Glutamine has no noted side effects or toxicity when taken in normal recommended dosages, even when taken in dosages as high as 40 grams daily for short periods. Toxic levels are said to possibly decrease growth hormone levels and potentially interfere with acid-base balance in the body.. Glutamic acid side effects include possible headaches and neurological problems. According to WebMed researchers, monosodium glutamate (MSG) toxicity syndrome occurs in response to free-glutamic acid, which is a breakdown product of protein after it has been processed by a food manufacturer. While all protein contains glutamic acid, it is only the glutamic acid that has been freed from protein before it is consumed that causes the reactions. Growing numbers of patients and physicians and some scientists are convinced that the ingestion of processed free-glutamic acid can cause adverse reactions in one or more organs of the body. In 1969, H. H. Schaumburg, an MSG researcher who helped educate the public and the medical industry about the dangers of MSG, concluded that up to 30 percent of the population had sensitivity reactions from MSG in an ordinary diet. Reported reactions to  MSG (and therefore glutamic acid), include migraines, hives, mouth eruptions, numbness, tingling, swelling of mucous membranes in the oral, gastrointestinal or reproductive tract, asthma, runny nose, insomnia, seizures, mood swings, panic attacks, diarrhea, and cardiac irregularities.     

References:     

Heuschen UA, Allemeyer EH, Hinz U, Langer K, Heuschen G, Decker-Baumann C, Herfarth C, Stern J. 2002. Glutamine distribution in patients with ulcerative colitis and in patients with familial adenomatous polyposis coli before and after restorative proctocolectomy. Int J Colorectal Dis 2002 Jul;17(4):245-52
 
Khogali SE, Pringle SD, Weryk BV, Rennie MJ. 2002. Is glutamine beneficial in ischemic heart disease? Nutrition 2002 Feb; 18(2): 123-6.
 
Rennie MJ, Bowtell JL, Bruce M, Khogali SE. 2001. Interaction between glutamine availability and metabolism of glycogen, tricarboxylic acid cycle intermediates and glutathione. J Nutr 2001 Sep; 131(9 Suppl): 2488S-90S; discussion 2496S-7S.
 
Roth E, Oehler R, Manhart N, Exner R, Wessner B, Strasser E, Spittler A. 2002. Regulative potential of glutamine–relation to glutathione metabolism. Nutrition 2002 Mar; 18(3): 217-21.
 
Watford M, Chellaraj V, Ismat A, Brown P, Raman P. 2002. Hepatic glutamine metabolism. Nutrition 2002 Apr; 18(4): 301-3.

Additional Information:     

None.