This amino acid, naturally present in food, is an asset for promoting muscle mass gain and improving endurance. Virtues which have allowed citrulline to quickly gain a reputation among athletes. How does she act? How to use it best? What are the side effects of this amino acid? We take stock with Raphaël Gruman, dietician-nutritionist.
Naturally produced by the body, citrulline is a substance first identified more than 70 years ago from watermelon. Citrullus Vulgaris from which it takes its name. It is a “non-essential” amino acid (because the body is capable of making it on its own), which the body synthesizes from another amino acid, arginine. However, even if the body is capable of producing it itself, the quantity is sometimes insufficient to benefit from all the benefits that citrulline offers on our fitness and our health. This is why it is interesting to enrich your diet with foods that contain it and, if necessary, to turn to taking food supplements.
Where can you find citrulline?
If this amino acid is produced by the body, it is also present in food. “Citrulline is naturally present in foods from the cucurbit family such as watermelon (it is also the fruit which contains the most, between 0.7 to 3.6 g kg of pulp depending on its degree of maturity) , pumpkin, squash, cucumber and melon”, specifies Raphaël Gruman. But it is also added to certain food supplements. It exists in two forms: L-Citrulline, that is to say the natural form of citrulline and citrulline malate, a combination of citrulline and malic acid, and which is more quickly assimilated by the body. ‘body.
What are the benefits of citrulline?
This amino acid has many health and fitness benefits.
Citrulline eliminates toxins from the body
This is its primary role in the body! “Citrulline is part of a combination of three amino acids, along with arginine and ornithine.explains Raphaël Gruman. Citrulline participates in a cycle of chemical reactions that results in the elimination of excess intestinal ammonia, a harmful substance resulting from the breakdown of proteins present in food. It transforms this substance into urea, which will then be eliminated through urine.“.
In the liver, citrulline also promotes the elimination of nitrogen. “A buildup of nitrogen in the liver causes an increase in ammonia in the blood and can lead to serious health problems.adds the dietitian.
Citrulline improves heart function
To maintain a good cardiovascular system and balanced blood pressure, citrulline would be an asset. “This amino acid promotes the increase in levels of nitric oxide, also called nitrogen monoxide, a molecule produced by the endothelium (the inner layer of blood vessels)says our expert. However, high levels of nitric oxide promote lower blood pressure and, in turn, reduced risks of cardiac events. While low levels of nitric oxide increase the risk of high blood pressure and heart attacks.. These benefits were highlighted by an analysis carried out in 2017 which concluded that “Chronic supplementation with L-citrulline increases nitric oxide synthesis, decreases blood pressure, and may increase peripheral blood flow.”1.
Citrulline fights erectile dysfunction
Citrulline-induced vasodilation is also involved in improving erectile functions. Therefore, in the event of erectile dysfunction, taking this amino acid has the effect of treating the problem of erectile dysfunction.
Citrulline is the ally of athletes
If there is an amino acid favored by athletes, it is citrulline. Its advantages ? It would be very effective in improving energy and sports performance. By increasing muscular resistance, it improves strength, an asset very popular with bodybuilding enthusiasts. Endurance athletes will also find something to suit them.
The reason ? “As we have seen, increasing nitric oxide levels allows blood vessels to dilate, which has the advantage of providing more oxygen to the muscles and, by improving blood circulation, more nutrients to your muscles. , indicates Raphaël Gruman. Better oxygenated and better nourished, the muscles (including the heart muscle) develop more endurance capacity and the athlete benefits from increased energy during training..
Scientific studies have reported improved oxygen production, consumption and training performance with just a dose of 2.4g of citrulline per day over a period of 8 days. Finally, whatever the sport practiced, by promoting the elimination of ammonia, this amino acid reduces physical fatigue, allowing longer training.
Citrulline promotes muscle recovery
Even once training is over, this amino acid continues to help athletes because it promotes muscle recovery after exercise by more than 40% and provides increased energy. How does she act? Citrulline intervenes in the urea cycle, participating in the elimination of uric acid. In excess, this organic compound causes muscle fatigue, joint pain and increases the risk of injury (mainly tendinitis). By promoting its disappearance, L-citrulline gives athletes a boost, allowing them to minimize aches and pains and promoting faster physical recovery.
Citrulline plays a role in protein synthesis
Although citrulline is not a proteinogenic amino acid like arginine, it is a precursor of arginine: as such, it indirectly promotes protein synthesis, by almost 20%. This action contributes to the maintenance and gain of muscle mass. If it is an asset for the athlete, thus helping him in his mass gain, sick people and seniors also find it of their interest because citrulline allows them to maintain good muscle mass or even to fight against sarcopenia, it that is, the progressive and high wasting of muscle mass, strength and function during aging.
Citrulline promotes weight loss
Even if this is not its primary role, it seems that taking food supplements based on citrulline helps reduce abdominal fat and would have a beneficial effect on weight loss.
How to take citrulline?
The effects of citrulline would be better in the long term and on the condition that the intake of food supplements is regular: on average, it would take a minimum of 7 consecutive days of intake to feel the benefits. The dose then varies depending on the objective of your training sessions:
- For mass gainit is recommended to take between 3 to 5 g of citrulline, 30 to 60 minutes before training;
- To strengthen your enduranceyou can add 6 g of citrulline to your drink approximately 1 hour to 1 hour 30 minutes before the start of your training;
- To improve muscle recovery, a dose of 2 g after training is recommended. “And why not include citrulline in your recovery shake?suggests the dietician. For example, you can mix citrulline powder with 250 ml of vegetable drink, a banana, some red fruits and honey..
Finally, to improve heart function, fight against high blood pressure and erectile dysfunction, the dose is 3 to 6 g of citrulline per day. As for the duration of taking, refer to the manufacturer’s instructions or seek advice from your doctor.
Is taking citrulline supplements dangerous?
The consumption of food supplements containing citrulline by healthy adults is safe for their health, up to a dose of 15 mg per day. These are the findings of a study conducted by The Norwegian Scientific Committee for Food Safety in 20162. Likewise, taking these products is well tolerated by the body and does not cause side effects.
On the condition of respecting the recommended doses because in excess (beyond 10 g per day), citrulline can have the effect of causing digestive disorders as well as nausea.
What are the contraindications to taking citrulline?
Taking this amino acid in the form of dietary supplements is not recommended for everyone. “It is particularly not recommended in cases of poor intestinal absorption, in cases of urea disorder (also called “citrullinemia”) and for people suffering from chronic kidney failure.specifies Raphaël Gruman. In addition, in the event of antihypertensive treatment, the green light from your attending physician is recommended before undertaking a course of treatment based on citrulline: this amino acid acts on vasodilation, taking it combined with medications against high blood pressure could have has the effect of significantly lowering your blood pressure.. Finally, it is also not recommended for pregnant and breastfeeding women, as well as young children.