Glutamine: role, benefits & dangers

What is glutamine?

Glutamine is an amino acid naturally synthesised by our bodies.

It is found in high concentrations in the blood, muscles and certain organs, particularly the intestine.

It is involved in many biological functions, including cell metabolism.

In addition to its physiological synthesis, the body also obtains it from a variety of foods:

• meat and fish;
• eggs;
• dairy products;
• pulses (lentils, chickpeas, beans, tofu, etc.);
• green vegetables (spinach, broccoli, Brussels sprouts, etc.);
• certain wholegrain cereals (wheat, brown rice, rye, oats, etc.);
• nuts and seeds.

Glutamine is also valued as a dietary supplement in sports nutrition and natural health.

The benefits of glutamine for the body

The benefits of glutamine for bodybuilding and sports enthusiasts

Glutamine is involved in the synthesis of proteins by our bodies (1).

By supplying them with nitrogen, it enables the cells to produce the proteins needed for muscle recovery and repair after intense effort.

This amino acid is therefore well known to sportspeople, who can take it as a supplement when they fear overtraining, for example.

Glutamine also serves as a source of energy for various cells in the body.

This is why glutamine requirements increase during periods of stress or significant physical exertion (intense effort, convalescence, illness, etc.).

Having optimal levels of glutamine helps to support the body's proper functioning, preserve muscle mass and prevent intense fatigue.

The benefits of glutamine for the proper functioning of the immune system

Among the cells for which glutamine serves as a source of energy are certain immune system cells (lymphocytes and macrophages) (2).

It enables them to multiply more efficiently and fulfil their defensive functions.

The benefits of glutamine for the intestines and digestive health

Glutamine is an important source of energy for enterocytes, the cells that make up the intestinal wall.

It promotes their healthy renewal and proper functioning.

By helping to preserve the integrity of the intestinal barrier (3), it helps to maintain a healthy intestinal environment and a balanced microbiota.

In doing so, it helps to limit intestinal permeability and thus the passage of pathogens, toxins and undesirable substances into the rest of the body.

The benefits of glutamine for the skin and hair

Because of its role in cell regeneration, glutamine is thought to contribute to healthy skin and hair.

As an essential precursor in protein synthesis, it supports the renewal of skin cells and the keratin that makes up hair.

By providing the nitrogen needed to manufacture other amino acids, it is thought to contribute to the formation of healthy hair strands(4).

What's more, thanks to its support for immunity, it helps to limit inflammation and plays a role in the natural protection of the skin and scalp against external stressors.

What happens when we don't produce enough glutamine?

Although the body produces glutamine itself and also obtains it from a balanced diet, it can be insufficient in certain situations:

• during periods of physical or psychological stress;
• during prolonged or intense physical effort;
• during convalescence (after injury, surgery, long-term illness, cancer, etc.);
• in the event of infection, chronic inflammation or digestive problems.

In these situations, it may be advisable to increase your intake of foods containing glutamine, or even to take a glutamine supplement from time to time.

When doing so, it's advisable to opt for a quality-controlled supplement that provides an adequate supply of glutamine (such as L-Glutamine, which provides 3g of glutamine a day).

To maximise the effects of glutamine in athletes, it can be combined with creatine (5) (found in our 3-Creatine formula, which combines 3 active forms) and branched-chain amino acids (6) (like those in our BCAA's supplement). These molecules are renowned for supporting sports performance and muscle recovery.

In the case of digestive problems, it may also be useful to combine glutamine with probiotics to help balance the intestinal microbiota (our Probio Forte complex combines 5 carefully selected strains).

What are the dangers and side effects of glutamine supplementation?

Glutamine supplementation is generally well tolerated.

However, at high doses, it can cause digestive problems (bloating, nausea, temporary abdominal pain).

These effects are rare and most often linked to inappropriate dosage.

Furthermore, it is generally advised not to take glutamine supplements to enhance sporting performance if you have serious liver disease, kidney disease or psychiatric disorders (7).

If in doubt, it is strongly advised to seek the advice of a health professional before considering supplementation.

Apart from these specific factors, the risk of undesirable effects is considerably lowered as long as the dosage recommended by the food supplement manufacturer is respected.