Glutamine is the most abundant amino acid (part of our protein) in the body. We can typically make enough glutamine from our protein intake or by breaking down muscle except in times of extreme stress: extreme exercise, injury, or infections. Much of our glutamine in made in the lungs, and stored in our muscles. In addition to being an important building block for protein, glutamine is known to be important for:
- Removing ammonia from the body.
- Proper immune function, being important for lymphocyte and macrophage function, and may be helpful with HIV, and for extreme athletes.
- Normal brain function.
- Proper digestion, and may be helpful in inflammatory bowel disease (IBD).
- Proper wound healing, especially with burns and extensive wounds.
SYMPTOMS OF DEFICIENCY
It appears that glutamine is an essential amino acid for intestinal growth and integrity. Deficiency has been shown to affect the levels of many other amino acids, and deficiency can impair the mTOR and MAPK/ERK signaling pathways which inhibits protein synthesis and cell proliferation. You would not suspect a glutamine deficiency, unless you were an extreme athlete, were suffering from a severe burn, in the ICU, or had HIV or some other severe chronic infection, or intestinal issues.
Glutamine is an amino acid abundant in sources of protein such as beef, pork, poultry, dairy, soy and present in wheat and greens like spinach, raw parsley, and cabbage. Typical food proteins will give you 1-6 grams of glutamine.
Most will find L-glutamine as a supplement. This is usually as an amino acid powder or part of a protein supplement. When taking a supplement, it should be taken cold or with cold liquids, as heat can destroy glutamine. Adults can tolerate supplements of up to 14 grams a day, although there are some conditions that warrant caution.
SAFETY AND TOXICITY
Glutamine can be converted to glutamate (which has an extra charged oxygen molecule). High glutamate (glutamic acid) levels have been associated with neurological problems. Glutamate in the brain and spinal cord acts as a neurotransmitter, and high concentrations have been associated with inflammatory brain disorders (eg autism), autoimmune brain disorders (MS and ALS), and can alter the blood brain barrier (especially a concern during pregnancy and the first 6 months of life. Too much glutamate at the neuron level acts like a poison and nerves can be permanently damaged at very high levels of glutamate.
Since a single dose of 5 grams of glutamine does not increase the blood level of glutamine, it is felt that this dose would be safe for most adults, and most tolerate doses up to 14 grams a day. Those with neurological disease, seizures, cancer, and bipolar may do well to avoid this supplement completely, getting their glutamine form natural foods only .
Monosodium glutamate (MSG) is a controversial source of glutamate. In some cultures such as Southeast Asia, a typical diet might include 4-5 grams of MSG daily. While most seem to tolerate this, there are also many who do not tolerate MSG, which for some triggers migraines, headaches, irritability, facial pressure, a tingling or burning sensation, and in some cases, rashes. MSG is now often hidden in foods as “natural flavors” and hydrolyzed vegetable proteins.
TOLERABLE UPPER LIMITS
There is not safe level of glutamine supplementation for pregnant women or children under age 10. For adults 18 and older doses of 500 mg 1-3 times a day are generally well tolerated and adequate. For those conditions of extreme stress doses of 5-15 grams a day are occasionally recommended by some health care providers.
You should not take glutamine supplements if you have kidney disease, liver disease, are a child or have any side effects from taking glutamine as a supplement. It is always best to get your glutamine from real food.
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