When it comes to ‘fitness chemistry’ few things are more complicated to understand , the subject of rumours, and potentially misused ,than amino acids.
Amino acids are the building blocks of proteins. The twenty amino acids required for human life fall into two categories. The eleven non-essential amino acids can be manufactured in our bodies on an as needed basis. The nine essential amino acids must be supplied in the diet because we cannot make them.
Glutamine is a ‘conditionally essential’ amino acid. While we can make it, in times of physical stress or injury our demand for it increases beyond our capacity to replace it, so taking supplemental amounts of it can be helpful. One challenge of using glutamine supplements is known as the ‘glutamine paradox’. Between 50 - 85% of ingested glutamine doesn’t make it to the muscles. It gets used up supporting the liver, intestines, and immune system first!
Glutamine plays key roles in the synthesis of other amino acids, protein synthesis, and glucose. It is the most abundant amino acid in human muscle and plasma and makes up about 60% of the free-floating amino acid pool in skeletal muscles. Additionally, it is an important building block for the very powerful antioxidant glutathione, it boosts anti-inflammatory processes, and increases glycogen stores. Some sources indicate that doses as small as 2 g per day may enhance growth hormone release. Growth hormone is necessary for the repair of damaged tissues and is responsible, in part, for the increase in muscle mass when one begins to exercise.
Physically stressful times and overtraining increase cortisol production and reduce glutamine levels, which weakens the immune response and has catabolic effects on muscle tissue. Breaking down muscle tissue, as happens in strenuous exercise, increases the amount of free nitrogen in the body. Glutamic acid, the precursor of glutamine, picks up that free nitrogen and morphs into glutamine becoming an amino acid that can be used to make other proteins and GABA. GABA is another amino acid that functions as a neurotransmitter. When properly balanced with other nutrients GABA prevents anxiety and stress impulses in the nervous system from reaching their destinations. Glutamic acid is the only tool the brain has to detoxify itself of ammonia, and the resulting glutamine has proven useful in stimulating mental alertness, correcting some equilibrium problems, calming erratic behaviour in aging people, improving learning power, and strengthening memory. Other positive effects of glutamine include stopping sugar and alcohol cravings, speeding healing of peptic ulcers, speeding healing of intestinal tract issues, reducing arthritic symptoms, strengthening connective tissues, helping maintain proper pH balance, reducing fatigue, and minimizing auto-immune disorders.
A diet containing high protein foods, including meat, fish, chicken, beans, and dairy products usually supplies enough glutamine to meet normal requirements. It may not supply enough glutamine if you work out daily or for extended lengths of time.
Winterdyk and Jensen recommend using a form of glutamine called ornithine alpha-ketoglutarate.They recommend taking this in dosages that are graduated by body weight and duration of workout three hours away from other amino acid supplements and protein-rich foods.
Specific contraindications to glutamine supplementation include: avoid using glutamic acid supplements if you are allergic to MSG; do not use glutamine if you have cirrhosis of the liver, kidney problems, Reye’s syndrome, or any condition that results in an accumulation of ammonia in the blood.
There is one known general negative side-effect to taking glutamine. Large doses, generally considered to be more than 10 g per day, can lead to diarrhoea and intestinal cramping. Most sources recommend starting with small doses and building it gradually to upwards of 20 g per day. While extensive studies have been done using glutamine with burn victims, surgery recovery, and trauma, all showing impressive results, no double-blind studies have been published showing the effects of glutamine on athletes although athletic doses of .5 – 1 g three times per day are recommended by some sources.
So, while it remains unproven for athletic purposes specifically, other testing indicates it may be useful for healing from overtraining, inflammatory processes, injury, and bowel related issues.
Sources
Complete Idiot’s Guide to Sports Nutrition. Weatherwax, Dawn and Weiss, Sonia. Alpha Publishing, New York, 2003
Prescription for Nutritional Healing. Balch, Phyllis. Avery Publishing, New York, 2006
The Complete Athlete. Winterdyk, John and Jensen, Karen. Alive Books, Burnaby, BC, 1998
The information in this website is not meant to diagnose or prescribe. It is meant as information only. For any health concerns you have, please consult with the trained health practitioner of your choice.
