Glutamine, or L-glutamine, is an amino acid derived from another amino acid, glutamic acid. Glutamine plays a role in the health of the immune system, digestive tract, and muscle cells, as well as other bodily functions. It appears to serve as a fuel for the cells that line the intestines. Heavy exercise, infection, surgery, and trauma can deplete the body's glutamine reserves, particularly in muscle cells.
The fact that glutamine does so many good things in the body has led people to try glutamine supplements as a treatment for various conditions, including preventing the infections that often follow endurance exercise, reducing symptoms of overtraining syndrome, improving nutrition in critical illness, alleviating allergies, and treating digestive problems.
There is no daily requirement for glutamine because the body can make its own supply. As mentioned earlier, various severe stresses may result in a temporary glutamine deficiency.
High-protein foods such as meat, fish, beans, and dairy products are excellent sources of glutamine. Typical daily intake from food ranges from approximately 1 to 6 g.
Typical therapeutic dosages of glutamine used in studies ranges from 3 to 30 g daily, divided into several separate doses.
Endurance athletes frequently catch
after completing a marathon or similar forms of exercise. Preliminary evidence, including one small
Another small double-blind, placebo-controlled trial suggests that glutamine might support standard therapy for
Because, as noted above, cells of the intestine use glutamine for fuel, the supplement has been tried as a supportive treatment for various digestive conditions, with mixed results. Tested uses include reducing diarrhea caused by the drug
Glutamine appears to help reduce leakage through the intestinal wall.
Preliminary evidence suggests glutamine combined with
Based on glutamine's role in muscle, it has been suggested that glutamine might be useful for athletes experiencing
What Is the Scientific Evidence for Glutamine?
Infections in Athletes
A double-blind, placebo-controlled study evaluated the benefits of supplemental glutamine (5 g) taken at the end of exercise in 151 endurance athletes.
For other approaches to this problem, see the article titled
Recovery From Critical Illness
One small double-blind study found that glutamine supplements might have significant nutritional benefits for seriously ill people.
One double-blind, placebo-controlled study of 25 people found that use of glutamine at 30 g daily for 7 days reduced diarrhea caused by the protease inhibitor nelfinavir.
In addition, combination supplements containing glutamine may help reverse HIV-related weight loss. For example, a double-blind, placebo-controlled study found that a combination of glutamine and
There is mixed evidence regarding whether glutamine can reduce the side effects of
Based on a review of several studies, there is some preliminary evidence that glutamine may help relieve the pain associated with nerve damage (peripheral neuropathy) caused by some chemotherapy drugs.
Researchers conducted investigations in rats and found that glutamine could protect the heart from damage caused by loss of oxygen.
Because glutamine is the major fuel source for cells of the small intestine, glutamine has been proposed as a treatment for
A double-blind, placebo-controlled trial of 31 people ranging from 18 to 24 years of age evaluated the potential benefits of glutamine as a
Similarly, negative results were seen in a small double-blind, placebo-controlled trial of weightlifters using a dose of 0.3 g per kg of total body weight.
As a naturally occurring amino acid, glutamine is thought to be a safe supplement when taken at recommended dosages. There is strong evidence that glutamine is safe at levels up to 14 g per day, although higher dosages have been tested without apparent adverse effects. 42
Nevertheless, those who are hypersensitive to monosodium glutamate (MSG) should use glutamine with caution, as the body metabolizes glutamine into glutamate. Also, because many anti-epilepsy drugs work by blocking glutamate stimulation in the brain, high dosages of glutamine might conceivably overwhelm these drugs and pose a risk to people with
Maximum safe dosages for young children, pregnant or nursing women, or those with severe liver or kidney disease have not been determined.
Interactions You Should Know About
If you are taking:
- Antiseizure medications, including carbamazepine
13. Akobeng AK, Miller V, Stanton J, et al. Double-blind randomized controlled trial of glutamine-enriched polymeric diet in the treatment of active Crohn's disease. J Pediatr Gastroenterol Nutr . 2000;30:78-84.
14. Den Hond E, Hiele M, Peeters M, et al. Effect of long-term oral glutamine supplements on small intestinal permeability in patients with Crohn's disease. JPEN J Parenter Enteral Nutr . 1999;23:7-11.
17. Shabert JK, Winslow C, Lacey JM, et al. Glutamine-antioxidant supplementation increases body cell mass in AIDS patients with weight loss: a randomized, double-blind controlled trial. Nutrition . 1999;15:860-864.
18. Clark RH, Feleke G, Din M, et al. Nutritional treatment for acquired immunodeficiency virus-associated wasting using beta-hydroxy beta-methylbutyrate, glutamine, and arginine: a randomized, double-blind, placebo-controlled study. JPEN J Parenter Enteral Nutr . 2000;24:133-139.
26. Shabert JK, Winslow C, Lacey JM, et al. Glutamine-antioxidant supplementation increases body cell mass in AIDS patients with weight loss: a randomized, double-blind controlled trial. Nutrition . 1999;15:860-864.
27. Clark RH, Feleke G, Din M, et al. Nutritional treatment for acquired immunodeficiency virus-associated wasting using beta-hydroxy beta-methylbutyrate, glutamine, and arginine: a randomized, double-blind, placebo-controlled study. JPEN J Parenter Enteral Nutr . 2000;24:133-139.
31. Den Hond ED, Hiele M, Peeters M, et al. Effect of long-term oral glutamine supplements on small intestinal permeability in patients with Crohn's disease. JPEN J Parenter Enteral Nutr. 1999;23:7-11.
32. Akobeng AK, Miller V, Stanton J, et al. Double-blind randomized controlled trial of glutamine-enriched polymeric diet in the treatment of active Crohn's disease. J Pediatr Gastroenterol Nutr. 2000;30:78-84.
38. Quan ZF, Yang C, Li N, Li JS. Effect of glutamine on change in early postoperative intestinal permeability and its relation to systemic inflammatory response. World J Gastroenterol . 2004;10:1992-1994.
Last reviewed April 2009 by EBSCO CAM Review Board
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