Monograph

L-Glutamine is the most abundant amino acid in the body and plays an important role in many metabolic processes. The health of the immune system, digestive tract, and muscle cells depend on the production of L-Glutamine. As it detoxifies ammonia from the body, L-Glutamine offers necessary protection for the body and brain. L-Glutamine is a resource for extra energy, as it converts glutamine into glucose.
 

Description

As a semi-essential amino acid, L-Glutamine is formed and stored in the skeletal muscle and lungs. During physiological stress, this amino acid can become depleted and may need to be restored through proper supplementation.

Research

Digestive Health

L-glutamine has several primary roles in the intestine, including the regulation of protein metabolism and intestinal inflammation.[1] L-glutamine is also essential to the growth and health of epithelial cells in the intestine. By supplementing with L-glutamine, epithelial cells can be restored after ischemic intestinal injuries (intestinal blockage).[2] One study found L-Glutamine reduced toxic ammonia levels in the stomach protecting epithelial cells from premature death.[3]

The amelioration of oxidative stress can lead to several health ailments. L-glutamine aids antioxidant activity to reduce the development of oxidative stress in the body.[4] The reduction of oxidative stress and the function of detoxification in the liver can be supported by L-glutamine. One study observed that L-glutamine protects against liver injuries caused by free radical damage, as supplementation aids antioxidant activity in the liver.[5]

L-glutamine can repair the colon wall after the colon comes in contact with radiation therapy. A study compared L-glutamine with L-glycine by administering supplementation to rats for seven days after radiation exposure. Results indicated L-glutamine had a greater impact on restoring the health of the colon wall.[6]

Muscle Health

L-glutamine is beneficial in inhibiting the breakdown of muscle tissue. Individuals with chronic immune infections often lose crucial body cell mass, which is actively functioning tissue in the body. This often leads to shortened life expectancy. A study recruited 26 patients with significant weight loss to take 40 g/d of L-glutamine or a placebo for three months. The study concluded that L-glutamine increased body weight by 3.2%, while the placebo group only gained 0.4%. Researchers suggest L-glutamine is a beneficial therapy for increasing weight in patients with chronic immune infections.[7]

Preliminary research suggests L-glutamine is effective in counteracting progressive muscle weakness by reducing oxidized glutathione levels. L-glutamine's antioxidant activity protected the muscles from progressive weakness.[8]

Fight Infections/Improve Healing

L-glutamine can be significantly decreased in the body during severe health problems. A review of L-glutamine research found this amino acid can be safely restored through supplementation during serious health ailments or injuries. In addition, L-glutamine supplementation has been shown to improve immune cell function and increase life expectancy that is diminished with certain illnesses.[9]

Preliminary findings suggest L-glutamine can accelerate the healing process of fractured bones by restoring a positive nitrogen balance.[10]

There is evidence that L-glutamine's benefits may extend to respiratory health. One study indicated L-glutamine suppressed pulmonary inflammation associated with breathing difficulties.[11]

Additional Information – Dosage & Interactions

Suggested Use

As a dietary supplement, take one to three capsules daily, or as directed by a physician.

Dosage

Up to 21 g per day is well-tolerated

Precautions

The maximum safe dosage of this supplement has not been determined for children, pregnant or nursing women, or those with severe liver or kidney disease. As with all supplement regimens, please consult your physician prior to use.

Individuals with Reye's syndrome, severe kidney or liver damage, or other illnesses that cause ammonia to build up in the blood should not take L-Glutamine.

Drug Interactions

Consult your physician before supplementing with L-Glutamine if you are taking the following medications.

Human Growth Hormone, Indomethacin, Methotrexate, Paclitaxel

*Statements made herein have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.

References

[1] Hubert-Buron, A, Leblond, J, Jacquot, A, et al. Glutamine pretreatment reduces IL-8 production in human intestinal epithelial cells by limiting IkappaBalpha ubiquitination. J Nutr. 2006 Jun; 136(6):1461-1465.

[2] Huang, Q, Li, H, et al. Glutamine transporter ASCT2 was down-regulated in ischemic injured human intestinal epithelial cells and reversed by epidermal growth factor. J Parenter Enteral Nutr. 2007; 31(2):86-93.

[3] Nakamura, E, Hagen, SJ. Role of glutamine and arginase in protection against ammonia-induced cell death in gastric epithelial cells. Am J Pyshiol Gastrointest Liver Physiol. 2002 Dec; 283(6):G1264-1275.

[4] Das, S, Kar Mahapatra, S, et al. Oxidative stress in lymphocytes, neutrophils, and serum of oral cavity cancer patients: modulatory array of L-glutamine. Support Care Cancer. 2007 Dec; 15(12):1399-1405.

[5] Ortiz de Urbina, JJ, Jorguera, F, et al. Effects of glutamine on antioxidants systems and hepatic detoxification in rats: influence of formulation. Nutr Hosp. 2004; 19(2):73-82.

[6] Diestel, CF, Marques, RG, Lopes-Paulo, F, et al. Role of L-glutamine and glycine supplementation on irradiated colonic wall. Int J Colorectal Dis. 2007 Dec; 22(12):1523-1529.

[7] Shabert, JK, Winslow, C, et al. Glutamine-antioxidant supplementation increases body cell mass in AIDS patients with weight loss: a randomized, double-blind controlled trial. Nutrition. 1999;15(11-12): 860-864.

[8] Mok, E, Constantin, B, et al. L-Glutamine administration reduces oxidized glutathione and MAP kinase signaling in dystrophic muscle of mdx mice. Pediatr Res. 2008 Mar; 63(3):268-273.

[9] Wischmeyer, PE. Clinical applications of L-glutamine: past, present, and future. Nutr Clin Pract. 2003 Oct; 18(5):377-385.

[10] Polat, O, Kilicoglu, SS, Erdemli, E. A controlled trial of glutamine effects on bone healing. Adv Ther. 2007; 24(1):154-160.

[11] Ko, HM, Kang, NI, et al. Glutamine preferentially inhibits T-helper type 2 cell-mediated airway inflammation and late airway hyperresponsiveness through the inhibition of cytosolic phospholipase A(2) activity in a murine asthma model. Clin Exp Allergy. 2008 Feb; 38(2):357-364.