Glutamine does not have the same level of popularity as supplements like protein powder, creatine, or nitrogen boosters. However, with marketing slogans emphasizing its immune system-enhancing properties, it has carved out a unique place in many people's minds. This article addresses some common questions related to glutamine, but due to limited research, it should be considered a temporary reference.
What is Glutamine?
Glutamine is a non-essential amino acid, meaning our bodies can produce it on their own without the need for dietary supplementation. However, in certain conditions of severe stress or catabolic metabolism, such as sepsis, serious illness, injury, or medical emergencies, glutamine is sometimes considered a "conditionally essential amino acid."
In these situations, muscles may deplete glutamine, prioritizing the needs of the intestines and immune function over muscle protein synthesis. When this occurs, the body cannot keep up with the rate of glutamine synthesis, necessitating additional supplementation.
It's important to note that not all scientists agree that glutamine is a conditionally essential amino acid. Some argue that it is a "commercially essential amino acid" and should not be used for therapeutic purposes regardless of medical conditions.
Synthesis and Functions of Glutamine
With the assistance of an enzyme called glutamine synthetase, the body can synthesize glutamine. Glutamine synthetase acts as a catalyst, utilizing the energy of adenosine triphosphate (ATP) to condense glutamate and ammonia into glutamine.
While glutamine is primarily synthesized in muscles, it is transferred to other tissues that require it. The lungs, brain, and liver can also synthesize glutamine, but to a much lesser extent.
Glutamine is perhaps the most versatile of all amino acids, playing many crucial roles essential for maintaining the body's normal functioning. It is a so-called proteinogenic amino acid, meaning it is part of protein turnover, contributing to the synthesis of new tissues.
Additionally, glutamine regulates the body's pH, serves as an energy source for various cells, provides nitrogen for many processes, and maintains the function and integrity of the intestinal mucosa.
Glutamine is particularly crucial for the immune system. While glucose may be the primary fuel for most cells in the body, it is not the main fuel for immune system cells, such as macrophages, lymphocytes, and neutrophils. In stressful situations, these cells predominantly use glutamine as fuel over glucose.
Low levels of glutamine in the blood can negatively impact the immune system. In extreme situations like sepsis, burns, or extensive surgery, this can lead to higher complications and even an increased risk of death.
Can Glutamine Supplements Enhance Athletic Performance?
If the aforementioned effects seem inconclusive, let's examine whether glutamine can make you run faster, farther, or lift more weight. In terms of aerobic training, glutamine seems to have no significant impact.
A meta-analysis found no evidence to suggest that supplementing with glutamine can improve the oxygen consumption, oxygen consumption rate, or energy expenditure of endurance athletes. Additionally, glutamine does not increase heart rate, meaning it cannot enhance blood flow to your working muscles.
However, in anaerobic training, such as strength training, there is not enough research to provide a definitive answer. Due to a lack of data, the same meta-analysis cannot draw any conclusions. Yet, some individual studies suggest that glutamine can enhance strength and explosive power.
In one study, supplementing with glutamine partially prevented the loss of strength after muscle-damaging exercises, including 100 deep jumps. Moreover, participants who supplemented with glutamine experienced less soreness in the days following exercise.
Another study indicated that the recovery of strength after eccentric leg extensions improved when participants supplemented with glutamine. In a multiple Wingate test involving 12 male participants, recovery indices significantly improved when glutamine was consumed compared to a placebo.
What is the Safe Dosage of Glutamine?
Currently, there is no established upper limit for supplementing with glutamine. A typical mixed diet provides us with 3 to 6 grams of glutamine per day, based on a daily protein intake of 1.6 grams per kilogram of body weight. Meanwhile, many athletes and bodybuilders consume 40 grams or more of glutamine daily in supplement form.
Short-term studies have not indicated any adverse effects when healthy individuals consume 20 to 30 grams of glutamine per day. However, the challenge lies in the absence of long-term studies confirming the safety of such intake over an extended period. In a clinical setting, supplementing with 0.65 grams of glutamine per kilogram of body weight per day has not shown any negative effects.
In theory, the glutamine turnover mechanism might increase the risk of adverse health effects, but current research has not confirmed the absolute safety of long-term and high-dose glutamine intake. Nevertheless, for most physically healthy individuals, a daily intake of 14 grams seems quite safe.
Optimize Your Glutamine Intake with SRS Nutrition Express
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Reference:
[1] Is Glutamine a Conditionally Essential Amino Acid? Nutrition Reviews, Volume 48, Issue 8, August 1990, Pages 297–309.
[2] Glutamine supplementation. Annals of Intensive Care volume 1, Article number: 25 (2011).
[3] The American Journal of Clinical Nutrition, Volume 74, Issue 1, July 2001, Pages 25–32. Glutamine: commercially essential or conditionally essential? A critical appraisal of the human data.
[4] The Journal of Nutrition, Volume 131, Issue 9, September 2001, Pages 2515S–2522S. Why Is L-Glutamine Metabolism Important to Cells of the Immune System in Health, Postinjury, Surgery or Infection?
[5] The Journal of Nutrition, Volume 138, Issue 10, October 2008, Pages 2040S–2044S. Clinical Use of Glutamine Supplementation.
Post time: Dec-02-2023
