Complément Alimentaire Glutamine

Glutamine is an essential amino acid for many bodily functions, particularly valued in sports and bodybuilding. Although naturally produced by the body, its demand can increase during intense or prolonged physical exertion.

For this reason, the glutamine supplement has become a popular ally for many people, especially athletes, to increase their intake.

What is glutamine?

Glutamine, also known as L-glutamine, is a non-essential amino acid naturally produced by the body. This production primarily occurs in skeletal muscles, which are the main sites of synthesis (1), but also partially in the liver and lungs. The body is capable of manufacturing glutamine from other amino acids.

Glutamine is widely distributed throughout the body and is found in large quantities in:

• Skeletal muscles, where it accounts for the majority of free amino acids,
• The blood, where it circulates abundantly to be transported to organs that need it,
• The liver, brain, lungs, and intestines, where it plays numerous roles.

Under normal circumstances, the body produces enough to meet its needs. However, certain specific circumstances, such as intense training, can increase the demand for glutamine beyond what the body can produce.

Foods rich in glutamine

Glutamine is a non-essential amino acid because the body normally produces enough of it to meet its needs. However, during intensive training or in situations of significant physical stress, this endogenous production may not be sufficient to meet the increased demand.

To naturally support your reserves, it is important to include foods containing glutamine in your diet, such as:

• Lean meats, such as chicken and turkey, rich in protein and glutamine.
• Fish, sources of essential amino acids, including glutamine.
• Eggs provide complete protein and glutamine.
• Dairy products, such as milk, yogurt, and cheese.
• Green leafy vegetables, such as spinach or kale, contain moderate amounts of glutamine.

However, when diet is not enough to compensate for this increased demand (especially for athletes undergoing prolonged or intense effort), l-glutamine supplementation can be useful to increase the intake of this amino acid.

What is L-glutamine?

L-glutamine is the biologically active form of glutamine, meaning it is the form naturally found in the human body and in food. The letter "L" refers to the spatial configuration of the molecule, a distinction used in chemistry.

In the case of glutamine, only the L form is used by the body. This is therefore the version found in natural proteins, synthesized in the body, and used in dietary supplements.

When "glutamine" is mentioned in the context of nutrition or sports supplements, it almost always refers to L-glutamine, even if the label sometimes doesn't specify it.

Forms of glutamine: powder or capsules?

Glutamine supplements are primarily available in two formats: powder and capsules.

L-glutamine powder is often preferred for its dosing flexibility. It allows for precise adjustment of the quantity to be ingested according to personal needs, which is particularly useful for athletes who want to fine-tune their intake down to the gram. In addition, powder is generally more economical than capsules, especially when purchased in large quantities.

Glutamine capsules, on the other hand, offer convenience of consumption and ease of transport. However, the dosage is fixed per capsule, which can limit personalization.

The choice between powder and capsules therefore mainly depends on individual preferences and ease of use, as well as how one wishes to integrate glutamine into their daily routine.

When and how to take glutamine?

The recommended dosage varies depending on exercise intensity and individual needs. Generally, a dose of 3 to 5g per day is commonly used. It is advisable to take glutamine after training.

In cases of significant physical stress, higher doses may be considered, but it is essential to consult a healthcare professional before increasing the dose.

How to choose a glutamine supplement?

When selecting a glutamine supplement, several criteria should be considered:

• Purity: Opt for products containing pure L-glutamine, without additives or contaminants.
• Form: Depending on preference, choose between powder or capsules.
• Dosage: Ensure the product offers a dosage suited to your needs.

Glutamine supplement: in summary

Glutamine is a particularly popular dietary supplement in the world of sports. Although the body can produce it naturally, needs can quickly increase in situations of physical stress.

To maximize the benefits, it is essential to choose a quality product that guarantees the purity and concentration of l-glutamine, the active form of this amino acid. The integration of the supplement must also be adapted to your personal routine and your objectives.

Finally, remember that supplementation should always complement a healthy lifestyle. This comprehensive approach will allow you to fully benefit from the advantages of glutamine, while respecting your body's specific needs.

Sources:

1. ANSES, Dietary supplements for athletes, 2016. https://www.anses.fr/fr/system/files/NUT2014SA0008Ra.pdf
2. Zhang J., Tian R., Liu J., et al. A two-front nutrient supply environment fuels small intestinal physiology through differential regulation of nutrient absorption and host defense. Cell, 2024. DOI: https://www.cell.com/cell/abstract/S0092-8674(24)00903-6?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867424009036%3Fshowall%3Dtrue