L-glutamine, also known as glutamine, is an amino acid. Amino acids are organic compounds often referred to as the building blocks of proteins. They play critical roles in health, such as building new proteins and making hormones and neurotransmitters (messengers between nerve cells).
Amino acids are considered essential or non-essential. Unlike non-essential amino acids, the nine essential amino acids cannot be produced by your body and you must obtain them through your diet.
L-glutamine is a special type of amino acid categorized as “conditionally essential”. Conditionally essential amino acids become essential only under certain circumstances, such as severe burns, prolonged exercise, pregnancy, trauma, or illness.
As the most abundant amino acid in your body, L-glutamine is an important fuel source for your immune cells. It also fights inflammation, protects cells from damage, and plays many other essential roles in health.
In addition to building protein, L-glutamine supports health in several ways. It regulates the body’s acid-base balance, supports muscle growth and repair, regulates protein production and use, helps produce certain antioxidants, and removes waste products, such as ammonia, from your body.
Below are a few more ways L-glutamine can benefit your health.
Supports gut health
L-glutamine is an important fuel source for intestinal cells and improves their function and growth.
This amino acid supports gut health by helping to maintain a balanced microbiome (the diverse environment of bacteria in your gastrointestinal tract), reducing inflammation in the gut and protecting intestinal cells from damage.
L-glutamine also regulates tight junctions, protein clusters that regulate how water and nutrients enter the intestine. They prevent potentially harmful compounds, such as bacteria and toxins, from entering the intestines.
Due to the protective effects of L-glutamine on the gut, studies show that people who have higher levels of glutamine in their blood may have a lower risk of diseases of the digestive system, such as colon cancer, colitis and Crohn’s disease. However, other studies have found that glutamine supplementation did not improve symptoms of Crohn’s disease.
Necessary for immune function
Immune system cells use L-glutamine at a high rate. It is essential for the growth of lymphocytes — white blood cells that produce antibodies to protect the body from disease and infection — and neutrophils, which kill disease-causing compounds such as bacteria and fungi.
L-glutamine also regulates the levels of cytokines, which are small proteins that regulate inflammation. It reduces the production of pro-inflammatory cytokines, limiting inflammation and supporting immune function.
In some cases, people who are very injured or ill experience a significant drop in glutamine levels. Additional treatment with glutamine supports recovery by strengthening the immune system and protecting against organ damage. Studies show that treatment with glutamine can reduce the risk of infection and length of hospital stay in critically ill patients.
L-glutamine administration has also been shown to reduce the risk of complications after surgery and promote recovery in surgical patients. However, more research is still needed to confirm the effects of glutamine in critically ill and post-surgical patients.
Important for heart health
L-glutamine is crucial for cardiovascular function and helps reduce risk factors for heart disease. It plays a central role in promoting the function of endothelial cells, which are the cells that line blood vessels. L-glutamine improves endothelial cell function and protects cells from oxidative damage.
The body also uses glutamine to create glutathione, a powerful antioxidant that reduces harmful free radicals and limits oxidative damage to cells.
Low glutathione levels have been linked to many chronic health conditions, including heart disease. Maintaining healthy levels of L-glutamine can support optimal levels of glutathione, which protects the heart from oxidative damage and prevents heart disease.
L-glutamine may also protect against risk factors for heart disease, such as high levels of lipids (fats) in the blood, insulin resistance, high blood pressure, and high blood sugar.
A study of 15,040 people with diabetes found that people who consumed more L-glutamine in their diet had, on average, a lower risk of heart disease, death from heart disease, and death from all causes.
L-glutamine is a conditionally essential amino acid, meaning your body usually produces enough to support its needs.
Studies show that the body produces between 40-80 grams of L-glutamine per day. Under normal circumstances, the body can maintain healthy levels of L-glutamine by producing the amino acid internally and by consuming foods rich in L-glutamine.
However, after specific situations—such as trauma, overexertion, and pregnancy—an L-glutamine supplement may be necessary to meet the body’s needs and maintain normal L-glutamine levels.
- Burns: people with burn injuries can have significant losses of amino acids, including L-glutamine. Supplemental treatment with L-glutamine and other amino acids can help heal wounds, improve immunity, and reduce the risk of death in people who have experienced burns, as well as other injuries and trauma.
- Intense exercise: Overtraining, such as during high-intensity exercise or prolonged exercise like marathon running, can also lead to low L-glutamine levels. This can suppress the immune system and increase infection rates in overtrained athletes. Research results show that the level of L-glutamine in the blood can be reduced by approximately 20% after one hour of marathon running.
- pregnancy: L-glutamine also becomes conditionally necessary during pregnancy. This is because a pregnant woman’s typical production rates are unable to support the needs of both the parents and the fetus.
In these situations, L-glutamine intake must be increased by supplementation or increased dietary intake. In critical care settings, L-glutamine is sometimes administered by IV.
Both plant and animal foods contain L-glutamine. This includes:
- Beef
- Pork
- Poultry
- A fish
- Beans
- Milk
- Yogurt
- Cheese
- Spinach
- parsley
Because L-glutamine is found in many foods and is produced naturally by the body, most people can maintain optimal glutamine levels by following a balanced, nutritious diet.
L-glutamine is available in supplement form, including as a stand-alone supplement.
It can also be found in products containing more amino acids. These products are available in several forms, such as capsules and powders.
L-glutamine supplements have been linked to several health benefits, such as improving symptoms of sickle cell disease, supporting exercise recovery, improving certain aspects of gut health, and more.
If you are purchasing an L-glutamine supplement, it is best to choose products that have undergone independent certification by independent laboratories. This can increase your chances of purchasing a safe and quality supplement.
There is no set recommended dosage for L-glutamine supplements. Talk to your healthcare provider about dosage and potential drug interactions before starting a supplement.
Your body produces L-glutamine naturally and it is found in many foods. Eating normal amounts of L-glutamine in the diet is not associated with health risks or side effects.
When taken as a dietary supplement, L-glutamine is considered safe for people without health problems, even when taken in high doses.
However, L-glutamine supplementation may worsen hepatic encephalopathy, a brain disorder that occurs when the liver is unable to remove toxins from the blood, in people with advanced liver cirrhosis.
If you have liver disease or any other medical condition, such as sickle cell disease, you should not take L-glutamine supplements without first talking to your doctor.
L-glutamine is an amino acid that plays critical roles in health, such as supporting immune and digestive health and protecting against heart disease.
The L-glutamine your body produces and you consume through your diet is usually enough to meet your body’s needs. However, some people, such as people who are critically injured, pregnant, or participating in strenuous exercise, may need additional L-glutamine to meet their daily needs.