Both L-glutamic acid and L-glutamine are amino acids. And while their names sound similar, and they both come from the same family of amino acids known as the glutamates, they are different. Glutamic acid is best known as a component of monosodium glutamate, while L-glutamine may be known as a supplement used by athletes to help improve immune health and recovery.
L-glutamic acid is found either as a free amino acid or as part of a protein in food. While you get some of your L-glutamic acid from animal protein, plant proteins contain it in higher amounts. It's also the primary component in the flavor enhancer monosodium glutamate, or MSG, so it's found in certain processed foods as well.
Like L-glutamic acid, L-glutamine is found in a variety of different foods, including both plant and animal proteins. Some notable sources of the amino acid include chicken, milk, yogurt, raw spinach, raw parsley and cabbage.
Functions in Body
L-glutamic acid is an important brain neurotransmitter. According to the authors of a 2002 review published in Biomedicine and Pharmacotherapy, L-glutamic acid plays a critical role in the function and maintenance of synaptic nerves in the brain and is a component of learning and memory.
L-glutamine is essential for immune health and aids in eliminating toxic ammonia from your body. It also play an important role in digestion by helping to maintain acid-base balance.
Essential vs. Nonessential
L-glutamic acid is considered a nonessential amino acid, which means your body is able to produce it on its own, and you don't need to get it from the food you eat.
While your body can make L-glutamine, it is considered a conditionally essential amino acid. That means it's essential in your diet under certain conditions, including times of major illness such as trauma, surgery, bone marrow transplant or intense chemotherapy. During these times you may need to supplement with L-glutamine, according to the University of Maryland Medical Center. As with any dietary supplement, consult your doctor to discuss need.
Amount in Body
Even though there are times when it's necessary to supplement with L-glutamine, it is the most prevalent amino acid in the body, according to UMMC. L-glutamic acid is the third most prevalent amino acid and is found in levels 25 percent lower than L-glutamine, according to the Institute for Traditional Medicine. However, your body is able to convert either amino acid into the other depending on need.