L-Glutamine or Glutamine is an amino acid that is a building block of protein that has several health benefits, particularly in relation to building muscle. L-glutamine is the most abundant amino acid in the bloodstream. Your metabolic organs, like your gut, liver, and skeletal muscles, actually control the release of glutamine in your body.

Food Sources

Found in both animal and plant proteins (including in high levels in both casein and whey protein), glutamine is also available in supplement form. Glutamine can be found in animal proteins, such as meats and dairy, along with plant-based protein sources, such as beans, raw spinach, parsley and red cabbage. It’s worth noting, though, that animal proteins tend to provide amino acids that are more digestible than plant proteins.

Benefits of L-Glutamine

Many of your immune cells can depend quite heavily on glutamine to survive, grow, and function. It’s an essential nutrient for lymphocyte proliferation (your body’s first step in terms of the immune response). In addition to cytokine production and supporting your body’s natural defences against foreign particles.  

Supporting digestive health is another benefit of glutamine. Intestinal permeability, also known as leaky gut, affects millions of people and is a component of various gastrointestinal issues. Glutamine is the major fuel source for cells of the small intestine and has been shown to support intestinal health and help address leaky gut. Some studies found that supplementing with L-glutamine decreased intestinal permeability.

L-Glutamine has also been shown to improve muscle recovery. During an intense workout, the stress on the body can increase the requirement for glutamine. The levels of cellular glutamine can drop by 50% and plasma levels by 30%. This can create a muscle-wasting state where the body uses the muscle as energy rather than carbohydrates, but glutamine can help prevent this from occurring. Adding L-glutamine can help to reduce this state from happening, supporting strength, helping repair skeletal muscles and reducing recovery time.

Issues with Deficiency

The body can synthesize L-glutamine utilizing glutamic acid or glutamate. However, if the body is unable to produce enough, it needs to be collected directly from the diet. There are millions of people that suffer from digestive conditions, and it is thought that a lack of certain nutrients in our diets contributes to this, including L-glutamine. This can be due to a number of factors including a low protein diet, excess stress, intense exercise, or undergoing illness. This is where supplementing the diet with glutamine can potentially be helpful.

Who Can Use L-Glutamine?

Generally, L-glutamine has been found to be safe for most people when consumed in moderate amounts and for short periods of time. There appears to be a low risk of side effects when taken up to 20-30 g a day, which would be considered high doses. Those who should be more cautious would be individuals with kidney or liver issues.