L-glutamine – a compendium of knowledge

Glutamine, is it worth using? Perhaps for many people the answer to this question is not unambiguous, that’s why this article was created. It will dispel all doubts about the appropriateness of using glutamine in body sports – bringing her advantages and action.

  1. What is glutamine?

Glutamine is an endogenous amino acid. It is formed in the body as a result of transformation from glutamic acid. Synthesis occurs in many tissues, but only the lungs, skeletal muscles and adipose tissue can release it into the blood. It is an ingredient of most vegetable and animal proteins. In the human body it accounts for about 70% of the amino acid pool.

Glutamine can occur in three forms

– L-glutamine – a free form that has been synthetically produced. Metabolism of this form is very fast. This is due to the rapid use of it by intestinal bacteria. Consequently, it positively influences the improvement of the digestive process;

– N-acetyl-L-glutamine (NAG) – the combination of glutamine with acetic acid significantly increases the absorption of this form to muscle cells. In this case, a smaller dose is enough to achieve the same result;

– glutamine peptide – is formed by the transformation of gluten obtained from wheat, therefore it can not be used by people allergic to gluten. It is slowly absorbed and thus allows long-term use of glutamine.


  1. L-glutamine effect. What gives you glutamine?

Glutamine is an energy fuel for red blood cells of the intestinal mucosa, liver cells and lymphocytes (immune cells). It prevents the disappearance of intestinal villi, prevents the passage of bacteria. It strengthens the immune system by biosynthesis of immune bodies and macrophages. In addition, it regulates the acid-base balance. Glutamine is found in large amounts in the brain. It improves his work and improves concentration and memory. It also helps to increase the concentration of growth hormone in the blood, which participates in the synthesis processes taking place in the body. What’s more, it helps in burning fat. This is related to the regulation of the level of insulin and glucose in the blood, which is especially important for diabetics.

Among scientists, opinions about glutamine are divided. Researchers at the University of Oxford have shown that glutamine given to marathon runners immediately after the run and again 2 hours later reduces the risk of infection and regulates the activity of immune cells. Only 19% of people consuming glutamine supplements fell ill during the week of running. While in the group of people taking placebo, 51% got sick. Parry-Bollings et al. Believe that glutamine supplements can reduce the risk of infection and promote the growth of muscle mass. Other studies have not confirmed the effect of glutamine on muscle growth.

An experiment was carried out in which strength training people participated. They were divided into two groups – one consuming supplements with glutamine, the other taking placebo. After six weeks, the same muscle mass gain was observed in both groups. However, manufacturers of dietary supplements with glutamine argue that glutamine has an effect on the growth of muscle tissue. It works by saving protein in the body during intense physical exercise. It hydrates the muscles and increases the volume of muscle cells. It reduces the activity of enzymes that lead to the breakdown of muscle proteins and inhibits the activity of stress hormones, including cortisol, the concentration of which increases after intensive training. Hammarqvist et al. Conducted a study in which they examined the effect of glutamine on muscle condition in patients after abdominal surgery.Twenty-two patients took part in the study, 13 of whom received a placebo and 9 of a glutamine supplement. In patients receiving glutamine, significantly lower loss of this amino acid in skeletal muscle, better protein metabolism and increased nitrogen balance were observed.


Glutamine and burns

Glutamine is crucial when it comes to burns. Burn is tissue damage due to high temperature or chemical substances. Most of them are minor burns requiring emergency relief. The problem is burns covering a minimum of 20% of the body surface, known as heavy. In this case, comprehensive treatment is required. Glutamine stimulates the immune system, reduces the number of infectious complications, shortens treatment time and reduces the mortality rate. During burns, intestinal mucosa, kidneys, immune system and liver need significant amounts of glutamine. This demand can not be met by releasing the amino acid from skeletal muscle. Therefore, the European Association of Parenteral and Enteral Nutrition recommends supplementation of glutamine in people with burns.Garrel and Zhou in their studies showed a beneficial effect of glutamine on wound healing and shortening the duration of treatment. The positive effect of glutamine on burns has also confirmed the thorough analysis of all published data on this topic by Windle.


Glutamine and the intestines

More and more is being said about the so-called leaky intestinal syndrome. It is an autoimmune disease that contributes to the development of many other diseases, such as thyroid disease – Hashimoto, arthritis or skin problems.

Glutamine as a source of energy for intestinal cells may have particular significance in its inflammatory diseases. It reduces inflammation and oxidative stress, which arises due to the appearance of a leak in the intestinal walls. Van der Hulst et al. In their research proved that glutamine supplementation increases the intestinal integrity in people after surgical trauma. In addition, it has a beneficial effect in the prevention of gastric ulcer. It provides cells of the mucous membrane of the stomach with energy and contributes to their better blood supply through the dilation of blood vessels. Better blood supply to the gastric mucosa positively affects the healing of inflammatory changes.


  1. Glutamine for an athlete

The interest of glutamine among athletes is due to its anabolic properties against skeletal muscles. This amino acid can be transformed into asparagine, arginine and lysine, which are necessary for the construction of collagen proteins. In addition, the administration of glutamine leads to an increase in the proline and hydroxyproline concentrations necessary for these processes.

Glutamine is involved in the synthesis of muscle proteins and supports the removal of ammonia from the body. The anabolic effect (effect on the increase of muscle mass) is associated with the secretion of growth hormone.

Glutamine is also an extremely important factor in maintaining the intra-cardinal balance, as it regulates body temperature, pH, blood pressure, oxygen concentration, carbon dioxide and the volume of body fluids.

Glutathione is formed from glutamine. It is a basic antioxidant. Physical activity is associated with an increased level of oxidative stress. Hence the necessity of including antioxidant components that fight free radicals and thus eliminate the problem.

The effect of glutamine on the level of sugar in the blood is also beneficial. Thanks to this, the energy supply to the muscles is constant. Glutamine affects the recovery of glycogen stores in the muscles. The carbohydrate reserve accumulated in this form allows you to increase endurance and prolong the possibility of physical exertion.

In addition to supporting muscle building, glutamine inhibits the breakdown of muscle fibers. Playing sports involves the formation of microdamages of muscle fibers. Glutamine limits this process and allows for faster regeneration.

Physical exercise with a low or moderate degree does not significantly reduce the level of this amino acid. However, very intense and long-lasting activity reduces the synthesis and uptake of glutamine in the body

Particularly recommended is the supplementation of this ingredient in endurance sports (marathon runners, long-distance cyclists). In this case, the process of energy production in the body and the production of neurotransmitters are disrupted.


  1. Dosage of L-glutamine

Glutamine is a relatively endogenous amino acid. It means that the body has the ability to synthesize it from glutamic acid and ammonia. However, in some physiological states, the demand for it increases significantly. In order to prevent shortages it is necessary to supply it with additional supply from the outside. During intense training, stress, injuries, burns, major operations, intensive chemotherapy and radiotherapy, its amount in the blood and in the muscles is reduced. This leads to the weakening of the immune system and increases the susceptibility to various infections. Additional supplementation of glutamine can bring beneficial effects.

Many studies have confirmed that glutamine supplementation in situations of chronic stress, certain disease states and during intense workouts is critical to improving health.

There is no specific daily dose of glutamine. The daily requirement of an active person is 0.8-1.2 g per 10 kg body weight. In the case of bodybuilders, this amount may increase to 2 g per 10 kg of body weight. The recommended dose of glutamine is 5-15 g / day. It is best to eat glutamine in the morning on an empty stomach, immediately after training or at bedtime. In patients with burns it is recommended to ingest 0.3 g of glutamine per kg of body weight per day for a minimum of 5 days from the burn. Studies have shown that a six-week dose of 30 g per day improves some cardiovascular risk factors and body composition in people with type 2 diabetes. It should be remembered that glutamine can also be included in protein supplements.


  1. Side effects

To date, no side effects associated with the use of glutamine have been reported. The administration of exogenous glutamine is safe and can be beneficial in many situations, for example chemotherapy and exposure to radiation.

In the case of diabetic patients, the use of glutamine is not recommended. During its metabolism in the liver a large part is converted to glucose. People suffering from epilepsy, allergy to monosodium glutamate, and liver disease should also not supplement this component.


  1. Summary

Glutamine has a number of positive properties on the human body. It is an energy source for lymphocytes, thanks to which it strengthens the body’s immunity. It thus improves overall health. It works great during prolonged stress and intense workouts. It is also important for the condition of the digestive tract, and as you know, health begins in the intestines.



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