Facts and Food Sources of Glutamine


Glutamine is an abundant amino acid in tissues and blood. It is required as a source of energy and as a precursor to glutathione. It is used by brain and converted to gamma-aminobutyric which is an inhibitory neurotransmitter. It is a dispensable amino acid and a popular supplement for strength athletes. Supplementation of glutamine promotes immune function during exercise. It is a byproduct of various metabolic reactions and synthesized in the body easily. It is a precursor for synthesis of pyrimidines and purines. It is a precursor for gluconeogenesis and acts as a main source of energy for leucocytes and enterocytes.

Glutamine has a chemical formula C5H10N2O3 and is one of twenty naturally occurring amino acids in dietary protein. L-glutamine is an ample amino acid in bloodstream and makes 30 to 35 percent of amino acid nitrogen in blood. It is called conditionally essential amino acid as body requires it in enormous amounts.

Recommended Daily Intakes

There are general protein requirements. The RDA for men and women is 0.8 g of good-quality protein a day/kg. In certain situations, glutamine may be necessary in the diet, but there is no general dietary requirement. Children ages 2 to 12 should take in 23 mg/kg/day of protein or 10 mg/pound. Adults should take 12 mg/kg/day. A normal diet contains approximately 5 to 10 g of glutamine a day. The body makes 60 to 100 g a day of glutamine. When more glutamine is necessary, the body can usually synthesize it. When there is great metabolic stress, this may not be enough. Levels of glutamine inside cells can drop 50 percent or more, and the concentration in blood plasma can drop 30 percent. This is when glutamine supplements are necessary. Glutamine can be taken by mouth, injected intravenously, or put into the intestinal tract by tube. A dipeptide is added to glutamine to make it stable in solution.  For athletes in training, 1,000 mg/day are recommended as supplements. For very sick adults, such as those with cancer or AIDS, as much as 10 to 40 g a day may be taken in divided doses.

Dietary Sources

Health Benefits of Glutamine

Some health benefits discovered about Glutamine:

  1. Cytoprotective Effects

Studies have exhibited that exogenous supplementation of glutamine has effects that could be considered cytoprotective and incorporate protein anabolic effects and promote nitrogen balance after major surgery. Glutamine vitalizes cell proliferation and inhibits apoptosis in intestinal epithelial cells, promotes endogenous immune function, inhibits oxidative stress, upregulate GSH synthesis, improve redox control and lower proinflammatory cytokine responses.

  1. Helpful for HIV/AIDS patients

In HIV/AIDS there is usually glutamine deficiency. This may be because of rapid cell turnover. During later phases of AIDS, muscle wasting further depletes glutamine. At this stage there are often infections as well as poor absorption of nutrients. In a double-blind, placebo-controlled study of AIDS patients who had lost weight, half received standard treatment, the other half also took 40 g of glutamine a day as well as antioxidants. After three months, the patients taking glutamine gained significantly more lean body mass. Studies have shown improvements in immune function as well as maintenance of lean body mass in patients with HIV/AIDS.

  1. Intestinal health

Intestinal cells do not make glutamine but must get it from elsewhere; usually skeletal muscle makes glutamine that is taken up by cells in the small intestine. In catabolic states like those above, there is often damage to the small intestine, as there is with many types of chemotherapy for cancer. Glutamine can protect the intestinal cells from this type of damage. There is evidence that glutamine can protect the bowel during critical illness. Most of the successful trials have used intravenous glutamine in TPN. There has been some limited success with oral glutamine.

A number of studies using oral glutamine for patients with Crohn’s disease, an inflammatory bowel disease, did not have positive results, however. Intestinal per- meability was not decreased, and no markers of disease improved. In developing countries, lack of growth is not just caused by malnutrition, but also by inflammation in the intestinal tract that limits digestion of nutrients. However, oral glutamine supplements do not necessarily improve weight gain along with increased nutrients. A study of Gambian infants failed to show any benefit for glutamine.

In a pilot study, glutamine given to cancer patients receiving oxaliplatin reduced the incidence and severity of peripheral neuropathy (damage to nerves going to the arms and legs) without reducing the effectiveness of cancer treatment. The dose was 30 g a day. There were no side effects. It is believed that cancer uses so much glutamine that it depletes body stores. Nerve tissue is sensitive to a lack of glutamine. Replenishing glutamine protects the nerve cells.

In a double-blind, placebo-controlled trial of oral glutamine given to patients getting chemotherapy for colorectal cancer, there were less changes in intestinal absorption and permeability in the patients given glucosamine. There were also fewer diarrheas.

  1. Glucose levels

It has been suggested that glutamine might help prediabetic and diabetic patients from getting worse or gaining weight. This was confirmed in at least one trial. Patients undergoing surgery who are on TPN or very sick often develop high blood sugars. Intravenous glutamine improves glucose metabolism in this situation.

  1. Helpful for ulcers

Millions of people are struggling with leaky gut syndrome being the main cause of autoimmune disease. Leaky gut causes thyroid problems such as Hashimoto’s disease and contributes skin conditions such as psoriasis and arthritis. Glutamine is a considerable fuel source for cells of small intestine, it helps to heal leaky gut in clinical studies. Study shows that L-glutamine supplement lowers intestinal permeability. Animal study shows that L-glutamine is beneficial for inflammatory bowel disease and ulcerative colitis.

  1. Brain activity

Glutamine is crucial to enhance brain health. Disruption of glutamine-glutamate cycle results various brain problems such as epilepsy, Reye’s Syndome, bipolar disorder, epilepsy, anxiety, schizophrenia, alcohol addiction and depression. Mitochondrial dysfunction causes an abnormal increase in neurotransmitter glutamate and cause brain at risk causing other problems.

  1. Diabetes treatment

Research shows that HGH levels are 400 percent after glutamine supplementation. The hormonal response results to increase in metabolic rate and promotes after burn effect. Afterburn effect is crucial to burn fat, build lean muscle mass and weight loss. It burns fat and build lean muscle mass by assisting to suppress insulin levels and stabilize blood glucose.  This promotes body to use less muscle mass for maintaining blood sugar and insulin sensitivity in cells.

  1. Muscle health

Glutamine is a key component in protein biosynthesis. It is essential for forming additional cells and tissues that follows strenuous weightlifting. Bodybuilders use this supplement for this reason.

  1. Enhance endurance

People who work out regularly then supply of glutamine are drained from the body. So its supplementation is crucial for maintaining endurance and get best results from exercise. Study shows that this supplement promotes muscle hydration and prevents injury.

  1. Increase metabolism

Glutamine is crucial for metabolic activities. Since it is widely available in bloodstream, glutamine is used constantly for essential daily processes.


People who are allergic to L-glutamine may experience nausea, vomiting, joint pain and hives.






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