Glutamine

Glutamine is a classified as a conditionally essential amino acid since under certain circumstances the body is unable to produce enough to meet its needs. During these times, it becomes essential to obtain glutamine through dietary sources. Glutamine can be synthesized in the body from another amino acids, known as glutamic acid or glutamate.

Glutamine is the most abundant amino acid in the blood and the muscle tissue where it participates in many physiological functions. It plays an integral role in maintaining the health of the gastrointestinal tract as well as the immune system. Recently, it has become popular among athletes since it is believed to speed post-exercise recovery and help prevent infections following athletic events.

Physiological functions of glutamine

• Maintains gastrointestinal tract health
• Plays a role in the production of the antioxidant glutathione
• Ensures proper acid-base balance in your body
• Helps maintain muscle mass

Physiological events that may signal a need for greater glutamine intake

• Frequent colds and flus
• Intestinal dysbiosis
• Muscle wasting or low muscle mass
• Severe burns
• Regular high-intensity exercise

Functions of glutamine

Promotes gastrointestinal health

Glutamine is the preferred energy source for the cells that line the small intestines. Through nourishing these cells, glutamine helps to maintain gastrointestinal tract health and integrity, which is vital to preserving overall well-being. Since a healthy gastrointestinal tract lining acts as an important defense against disease-causing microorganisms and also minimizes the absorption of potentially allergenic molecules, glutamines benefits have far reaching effects.

Regulation of acid-base balance

Glutamine helps to maintain the body's proper acid-base balance. Glutamine is synthesized from glutamate and ammonia, with the latter being a toxic waste compound with a high pH value (an alkaline compound). When ammonia levels are elevated, the body can remove it from the blood by synthesizing glutamine. If the blood is too acidic (the pH is too low) the body can then break down glutamine into glutamate and ammonia so as to increase the pH of the blood.

Other functions of glutamine

Glutamine has a variety of other functions in the body including serving as a precursor to the antioxidant glutathione, participating in glycogen synthesis (the storage form of carbohydrate), and providing nitrogen compounds for the manufacture of nucleotides used to make DNA and RNA. In addition, it serves not only as the fuel source for small intestine cells but for muscle and immune system cells as well.

Causes and symptoms of glutamine deficiency

People under physical stress are likely to be at risk for glutamine deficiency. When the body is taxed by physical stress, blood and muscle concentrations of glutamine are rapidly depleted as the body is unable to manufacture this amino acid fast enough to meet its needs for it. Injury, surgery, burns, infections, malnutrition and high-intensity exercise are among the situations involving physical stress that engender glutamine deficiency. Additionally, as muscle tissue is the principal site for glutamine synthesis, those with reduced muscle mass such as the elderly or those experiencing muscle wasting disease (as occurs in AIDS, for example) may be at greater risk for glutamine deficiency.

Low glutamine levels typically occur in individuals who are experiencing severe physical trauma caused by infections or extensive burns. As these individuals usually have increased intestinal permeability (leaky gut) and a weakened immune system, some healthcare practitioners postulate that reduced intestinal integrity and immune function, in otherwise healthy persons, may be associated with insufficient glutamine supply.

Causes and symptoms of glutamine toxicity

Dietary consumption of glutamine has not been found to cause any toxicity effects. Oral glutamine supplementation is believed to be safe, even in doses exceeding 10 grams per day. An exception to this would be individuals who are sensitive to glutamate as they may want to avoid glutamine supplements or use them with caution. This includes persons who are sensitive to monosodium glutamate (MSG) as well as those with bipolar disorder or epilepsy.

The results of a few research studies highlight some potential concerns with certain other applications of glutamine administration. In these studies, after patients were given glutamine-containing intravenous nutritional formulas (total parenteral nutrition), they developed signs of liver toxicity manifested as elevated liver enzymes. Their liver enzymes returned to normal after the glutamine was removed from the nutritional formulas.

The Institute of Medicine at the National Academy of Sciences has yet to establish a Tolerable Upper Intake Level (UL) for glutamine.

Effects of cooking, storage and processing on glutamine

There is currently no research showing that cooking, storage or processing negatively impacts glutamine content.

Interactions between medications and glutamine

Glutamine may affect the treatment course of the following medications:

• Chemotherapeutic agents
  • Glutamine may reduce associated side effects, including diarrhea, mouth sores, and joint and muscle pain.
• Anti-seizure medications
  • The body metabolizes glutamine to glutamate, an amino acid whose stimulation in the brain is blocked by these medications. Therefore, individuals taking anti-seizure medications should consult with a healthcare practitioner before supplementing with glutamine.

   

Interactions that occur between glutamine and other nutrients

Vitamin B3 is required for the conversion of glutamine from glutamic acid, a common source of endogenous glutamine. The synthesis of glutamic acid itself requires vitamin B6 in order to occur.

Health conditions that require special emphasis on glutamine

Individuals who have the following health conditions should pay special attention to their glutamine status:

• Alcoholism
• Candida yeast overgrowth
• Chemotherapy side effects
• Food allergies
• HIV/AIDS
• Irritable bowel syndrome
• Post-exercise colds and flu
• Severe burns
• Ulcerative colitis

Forms in which glutamine is found in dietary supplements.

Glutamine is oftentimes found in protein powders as well as powdered drink mixes.

Foods that are concentrated sources of glutamine

Food sources of glutamine include most high-protein foods including beans, beef, chicken, dairy products and fish.