Diet and Nutrition

The Power Of Glutamine

Entering the 21st century we find research producing new and exciting discoveries in the fitness, health, nutrition and supplement fields.

As strength-trainers who pay close attention to their bodies it is of up most importance that we make sure those bodies are finely-tuned machines. While proper nutrition serves to shed unsightly body fat and build up our physiques we also need to look to supplements to add to our arsenal of equipment as we forge onward to achieve our personal goals.

With each day that passes we¹re constantly bombarded (through television, magazines, radio, and the internet) with a greater variety of consumable supplements.

If you¹re an avid strength-trainer there¹s a good chance you¹ve purchased a protein supplement of some kind. And a lot of you are probably familiar with the amino acid called Glutamine. This item has gained a reputation of sorts, and has become the choice of body-builders, weight-lifters, athletes…and even celebrities.

The benefits of Glutamine cover a number of functions. In many fitness circles it is touted as being THE versatile supplement. Because of these athletes, weight-lifters, strength-trainers and body-builders that are serious about improving their health and body should consider placing this supplement near the top of their list. As new research sheds more light, and as more studies are published, Glutamine is becoming the vogue article.

Glutamine is a component of the building blocks for proteins and nucleotides (these are the structural units of RNA and DNA). It regulates the ammonia levels in tissues and contains anti-depressive properties. Later, I will touch upon some of the other functions of Glutamine.

Of all the amino acids Glutamine is the most abundant in our body. It is stored mainly in the muscles but can be found as well in the lungs, liver, brain and blood (plasma). It comprises approximately 50-60% of the free amino acids in muscle(1). This accounts for most of the body¹s Glutamine reserves.

It has taken over 20 years to establish that exercise causes muscle tissue to release large quantities of the amino acid Glutamine(1,2). Intense exercise has been found to deplete Glutamine levels by as much as 34-50% (3). During heightened exercise periods, fasting or trauma (surgery) Glutamine, along with other amino acids, are released from the muscle–Glutamine more than any of the others (1,2). As a result, body tissue gives up more than is supplied by our natural diet as well as more than the body can synthesize (4).

Glutamine from food makes up roughly 4-8% of food protein and can be found in milk, meat and some nuts. Because of low blood levels your muscles release Glutamine into the blood stream. Here Glutamine is transferred to other tissues to be used as fuel. Unfortunately the end result of the process leaves the individual with their intracellular stores depleted. Studies show that that after such a session glutamine levels in the muscles will have been depleted within 4-6 hours and it can take more than 24 hours to recover to pre-exercise levels. As one can see, if an individual were to train in an intensely day in and day out their Glutamine stores wouldn’t have the opportunity to replenish themselves and could lead an individual to falling into a catabolic state. This can be described as overtraining.

Overtraining is a state incurred as a result of increased training volumes and intensities combined with a failure to balance the two variables out with adequate recovery periods. Furthermore the outcome of the increased training intensity and volume coupled with low Glutamine stores wreak havoc on the individual¹s immune system. Not only do the muscles use Glutamine as a means to preserve muscle but the immune system uses large amounts as well(5). This is one reason why scientists have been become aware of weakened immune systems in athletes. With low levels, both the muscle and the immune system receive inadequate supplies, and this is what leads to a loss of muscle, strength and a weakened immune system(6,7). Therein lies the problem.

On the brighter side evidence seems to indicate that Glutamine can possibly favor recovery in these ways:

  1. Glutamine spares myosin heavy chain proteins (they determine a muscle¹s contractile properties and capabilities).
  2. Glutamine promotes glycogen formation (8).
  3. Glutamine protects the immune system (9,10).
  4. Glutamine promotes protein synthesis (11).
  5. Glutamine appears to be anti-catabolic (13).
  6. Glutamine elevates growth hormone levels (12).

Glutamine has now been labeled an essential amino acid for the serious strength-trainer, weight-lifter and athlete, though it can still be rated as a non-essential amino acid for other individuals. Common daily dosages range from 2-20 grams, divided up and taken at certain times throughout the day. Even though these are generally accepted recommendations don’t let this prevent you from experimenting with higher dosages (be aware at higher dosages that the body may respond differently). Effective times to ingest Glutamine would be preferably after rising from a night¹s sleep, before an exercise session, after a workout and just before bedtime. Cycling Glutamine is not necessary as the body can only produce so much depending on how hard you exercise. Instead it is advisable to keep supplementing your diet with Glutamine to ensure your Glutamine stores are always topped off. Glutamine can be purchased in a powdered as well as a pill form.

As we continue to learn more about the human body and how it reacts to certain compounds we will continue to see new and exciting discoveries which will pave the way for individuals to live longer, build stronger bodies and improve their quality of life. Glutamine is one of the most important amino acids in the body because of its versatility. Therefore it should be not be overlooked as a supplement.

What Glutamine Is Not

  • Glutamine is not Glutamic Acid
  • Glutamine is not Glutamate
  • Glutamine is not Monosodium Glutamate
  • Glutamine is not Gluten
  • Glutamine is not Glutathione

Glutamic Acid is closely related to Glutamine (see Glutamate). Glutamate is an amino acid similar to Glutamine but lacks the extra nitrogen group. Monosodium Glutamate, is also known as MSG. Gluten is a mixture of proteins not readily soluble in water, which occurs in wheat and most other cereal products. Glutathione, a compound composed of glutamate, cysteine and glycine, acts as an antioxidant in the body and prevents tissue damage.

Written by Maki Riddington

Discuss, comment or ask a question

If you have a comment, question or would like to discuss anything raised in this article, please do so in the following discussion thread on the Wannabebig Forums – The Power Of Glutamine discussion thread.

References

1. Roth E, et al. Glutamine: Anabolic effector? J Parent Ent Nutr
1990;14:1305-1365.

2. Felig P, Wahren J. Amino acid metabolism in exercising man. J Clin Invest 1971;50:2703.

3. Roth, E et al. ” Metabolic Disorders in Severe Abdominal Sepsis,
Glutamine Deficiency in Skeletal Muscle.” Clin Nutr 1 (1982):25-41.

4. Miller, A. L. 1999. Therapeutic considerations of l-glutamine: a
review of the literature. Alternative Medicine Review 4:239-248;
Antonio, J, et al. 1999. Glutamine: a potentially useful supplement for athletes. Canadian Journal of Applied Physiology 24: 1-14.

5. Griffiths M, Keast D. The effect of glutamine on murine splenic
leucocyte responses to T- and B- cell mitogens. Cell Biology
1990;68:405-408.

6. Newsholme EA. Psychoimmunology and cellular nutrition: an
alternative hypothesis. Biol Psychiat 1990;27:1-3.

7. Parry-Billings M, et al. A communicational link between skeletal
muscle, brain, and cells of the immune system. Int J Sports Med
1990;11:Suppl, 1-7.

8. Varnier, M, et al. 1995. Stimulatory effect of glutamine on glycogen accumulation in human skeletal muscle. American Journal of Phsiology 269; E309-E315.

9. Tuttle, D. 1997. Glutamine: athletic benefits times three. Let’s
Live, September, 71-73.

10. Effect of glutamine supplementation on exercise-induced changes in lymphocyte function. Am J Physiol Cell Physiol. 2001
Oct;281(4):C1259-65.

11. Dorup I, Clausen T. Effects of potassium deficiency on growth and protein synthesis in skeletal muscle and the heart. Brit J Nutr
1970;24:205-212.

12. Welbourne,T. 1995. Increased plasma bicarbonate and growth hormone after an oral glutamine load. American Journal of Clinical Nutrition 61: 1058-1061.

13. MacLennan PA, Smith K, Weryk B, Watt PW Rennie MJ. Inhibition of protien breakdown by glutamine in perfused rat skeletal muscle. FEBS Lett. 1988 Sep 12;237 (1-2) :133-6.