A Quick Guide to Glutamine
In this article:
- Glutamine Protects and Heals the Gut
- Glutamine Enhances Muscle Growth and Athletic Performance
- Glutamine Supplementation Improves Immune Function
- Glutamine - Usual Dosage
- Glutamine - Side Effects
- Glutamine - Drug Interactions
Glutamine is the most abundant amino acid (the building block units of protein) in the body and is involved in more metabolic processes than any other amino acid. Glutamine is especially important in serving as a source of fuel for cells lining the intestines and for the proper functioning of white blood cells. It is important to these cells because glutamine is utilized at higher rates by these cells and other rapidly dividing cells. Without glutamine, these cells do not divide properly.
The importance of glutamine is well-appreciated in conventional medicine. It is an extremely important component of intravenous feeding mixes in hospitals because double-blind studies have shown to dramatically increase survival in critically ill subjects.
Glutamine is indicated in conditions linked to increased intestinal permeability (a “leaky gut”) including inflammatory bowel disease, celiac disease, diabetes, high sugar intake, and use of various drugs (in particular nonsteroidal anti-inflammatory drugs and prednisone). Glutamine is helpful in fighting the leaking gut by increasing energy production within the intestinal lining as well as by strengthening the tight junctions between cells.
Glutamine supplementation is a very important consideration in preventing some of the intestinal damage caused by chemotherapy and radiation. It has also been shown to prevent the mouth ulcers (stomatitis) and suppression of the immune system in cancer patients receiving chemotherapy
Glutamine supplementation has also been shown to be of value in patients undergoing abdominal surgeries such as gastrectomies, sigmoidectomies, cholecystectomy, colectomies, and rectal resections. Trauma from abdominal surgery may also compromise the intestinal lining and lead to a leaky gut. Glutamine supplementation has been shown to help reduce markers of intestinal permeability after abdominal surgeries.
Glutamine is also helpful in healing peptic ulcers. In a double-blind clinical study of 57 patients, those taking 1.6 g/day of glutamine showed better results than those patients using conventional therapy alone. Half of the glutamine patients showed complete healing within 2 weeks and more than 90 percent showed complete relief and healing within 4 weeks. It is believed that glutamine promotes the manufacture of protective mucoproteins that line the stomach and small intestine.
Glutamine is the most abundant amino acid in the blood and in the free amino acid pool of skeletal muscle. Glutamine stimulates the synthesis and inhibits the degradation of proteins and is an energy source for muscle cell division. Glutamine is also a precursor for the synthesis of amino acids, proteins, nucleotides, glutathione, and other biologically important molecules. Glutamine has an anabolic effect on skeletal muscle.
There is some evidence that over-training results in low glutamine levels and that glutamine supplementation can help prevent over-training in the first place as well as help an athlete recover from over-training. Plasma glutamine concentrations increase during exercise. However, during the post-exercise recovery period, plasma concentrations decrease significantly. Several hours of recovery are required before plasma levels are restored to pre-exercise levels. If recovery between exercise bouts is inadequate, the acute effects of exercise on plasma glutamine concentrations can be cumulative leading to very low levels of glutamine. This situation can have extremely detrimental effects on athletic performance and muscle growth. Glutamine supplementation has been shown to boost muscle levels of glutamine and promote muscle protein synthesis. However, it does not appear to enhance exercise performance in the absence of glutamine shortages in the body. The clearest benefit of glutamine supplementation in athletes is in the prevention of infections.
Glutamine supplementation has been shown to boost immune function and fight infection. These effects have been best demonstrated in endurance athletes (extreme exercise suppresses the immune system) and critically ill subjects. It is not known if glutamine supplementation enhances immune function in healthy individuals.
Glutamine is available in capsules, tablets, and powder. The typical dosage of glutamine is 3 to 5 grams daily. An alternate recommendation is 20 to 30 grams of whey protein concentrate.
No side effects have been reported at dosages as high as 21 grams per day.
No adverse drug interactions are known. Glutamine may reduce some of the side effects of drugs on the gastrointestinal tract.