Glutathione - The bodies premiere antioxidant

Glutathione - What is it? Tri-peptide molecule

Glutathione is found in virtually all plant and animal cells with highest concentrations in the liver, heart, eye lens, blood cells, and trained skeletal muscle.1,12,14


It must be synthesized within the cell because GSH cannot be transported into cells.1 GSH plays a central role in all antioxidant defense systems.
It maintains a host of other anti-oxidants like vitamins C & E in their active form.1,12,14 Low cellular GSH levels are directly linked to various forms of cancer,5,11
Alzheimer's,8 Parkinson's7,13 and many other diseases normally associated with aging.4,6 In fact, low glutathione levels are so consistent with aging and degeneration they are used as cellular markers of health .6,10

Years ago studies showed that oral supplementation with the right nutritional material increased GSH levels. 2,4,5 This reduced or eliminated various tumor/cancer growths4,5 and also dramatically improved the health of people with clinical illnesses.3 It has also been shown to increase the lifespan of healthy mice up to the equivalent of 33 human years! 4,5 And now recent research has demonstrated that increasing GSH levels via precise supplementation may be the most potent ergogenic aid of all.9

A direct relationship between increasing GSH levels and enhancing exercise performance has recently been established.1,14 An oral supplement designed to increase GSH levels not only increased these levels, it also significantly improved muscular performance in a variety of tests and the subjects grew muscle without performing any weight training! 9

The researchers concluded that the enhanced performance was due directly to the increases in GSH and that the increased GSH levels decreased the amount of oxidative free radical damage that occurs during intense exercise. 9

Antioxidants and Free Radicals - What Are They?

In resting conditions oxygen content in arterial and venous blood of skeletal muscle is 20 and 15ml per 100ml of blood, respectively.14 Physical exercise increases the skeletal muscle arterio-venous oxygen difference by 3 fold and blood flow through tissue by 30 fold.14 As a result we may have up to a 100-fold increase in oxygen flux through active skeletal muscle during exercise.14 This unfortunately is a bad thing. Oxygen consumption and utilization involves a ton of chemical reactions (the swapping /donating of electrons and molecule parts). As a result, oxygen particles "snap" or "fly off" and form highly reactive little buggers called "free radicals."

A free radical is simply an oxygen molecule with an unpaired electron that desperately needs another electron to fill its outer shell.12

An anti-oxidant is merely a molecule that easily donates its electron(s) to these free radicals neutralizing them into harmless molecules. Oxidative stress occurs when local antioxidant defenses are depleted. This depletion occurs because oxidants are being formed at a rate far greater than anti-oxidant systems can combat.12 This happens in skeletal muscle during intense exercise when oxidant/anti-oxidant balance shifts towards the pro-oxidant state.1,12 A mountain of research demonstrates intense or prolonged muscular exercise results in oxidative injury to lipids, proteins and DNA within skeletal muscle.1,12,14

The Role of GSH

GSH is the center piece of all the body’s anti-oxidant defense systems. 1,2,9,12,14 It not only directly neutralizes free radicals, it also donates its unique components to other anti-oxidant compounds like vitamins C & E1 and a host of antioxidant enzymes14 to maintain them in optimal working order. Low cellular levels of GSH mean all antioxidant defense systems will not work as well as they should.14

The damage created at the DNA level impairs effective cell replication causing cells to die easier and quicker.2,6 This is the free radical theory of accelerated aging! 6

The degenerative changes associated with aging are a result of the toxic effect of excessive free radical damage.6 Where as the data on age related changes in tissue when supplementing with vitamin E and other antioxidants are at best contradictory,6 the evidence demonstrating the importance of maintaining optimal GSH levels in your body is far more consistent.2,10

Physical Exercise and Glutathione Levels

There is a direct association between exercise intensity and levels of oxidative stress. 1,9,12,14 The harder you train the more free radical damage you produce and the more depleted your antioxidant defenses become, particularly muscle GSH levels.1,14 Studies on trained and untrained humans show the same thing - intense exercise devours our bodys’ stores of GSH. 1,12,14 Condeming invivo studies with rats demonstrate exhaustive exercise depletes not only muscle GSH levels but also total body GSH pools (liver, muscle , blood, brain).14

Low GSH levels are disastrous to exercise performance.1,14 An array of studies demonstrate glutathione depleted bodies display only half the endurance of their counter parts.14 Muscles low in GSH also suffer far more oxidative damage.14 GSH deficiency weakens lipid phase and enzymatic antioxidants as well.12 Without optimal levels of GSH, free radical damage hits your muscles hard.1
Interestingly, humans and rats with high GSH levels maintain very favorable redox status in response to exercise induced oxidative stress.14

A review of the literature shows that structured exercise training does get a resounding "thumbs up" in its ability to improve tissues’ defense against oxidative stress. 12 This has also been linked to improved physical performance.14 Intelligent fitness programs that allow for optimal recuperation do produce a protective effect against free radical damage, and the more aerobically fit you are the more protection you have.12

Bounous: In a recent report he concluded that the increased demand of the skeletal muscle imposed by frequent strenuous exercise deprives the immune cells of the capacity to replenish their cellular GSH levels - a prerequisite of optimal immune function.1 This diminished capacity to replenish GSH results in an undesirable competition between muscle and the immune system for sources of GSH.1 This easily creates a state of imbalance that quickly leads to prolonged poor performance.1 More serious repercussions are infections and illnesses such as Chronic Fatigue Syndrome.1

GSH is directly involved in the immediate destruction of reactive oxygen compounds generated by illness and strenuous exercise.14 It detoxifies all foreign pollutants both dietary, such as alcohol, and environmental, such as carbon monoxide and heavy metals. 2 It is an integral component of cell RNA and DNA proliferation1 and optimal immune response.2 It even protects from UV exposure (sunburn) and all other forms of radiation.4 However, it has been established that the necessary components needed to synthesize glutathione are extremely scarce in the fundamental diet.1,4

GSH is utilized so extensively by the body yet only trace amounts of GSH precursors are found in regular food.1 Substantial GSH deficiencies are not uncommon among hard training individuals. Research has repeatedly shown that boosting GSH levels can be accomplished with the right supplementation.2,3,4,5,9,14

[size=85]References:
1. Bounous G, Molson J. Competition for glutathione precursors between the immune system and the skeletal muscle: pathogenesis of chronic fatigue syndrome. Med Hypothesis 53;(4): 347-349
2. Bounous G et al. The influence of dietary whey protein on tissue glutathione and the diseases of aging. Clin Invest Med 12:343-9. 1989
3. Bounous G et al. Whey proteins as a food supplement in HIV-seropostive individuals. Clin.Invest. Med. Vol 16:3 p204-209. 1992.
4. Bounous G et al.The biological activity of undenatured dietary whey proteins: role of glutathione.Clin.Invest.Med. Vol 14:4.p296-309. 1991
5. Bounous G, G.Batist and P.Gold. Whey proteins in cancer prevention. Cancer Lett.57p91-94.1991
6. Blumburg JB, Meydani SN. Role of dietary antioxidants in aging. In Nutrition and Aging. Hutchinson MG, Munro HN (Eds). New York Academic Press, 85-97 1986.
7. Ebadi M, Srinivasan SK, Baxi MD. Oxidative stress and antioxidant therapy in Parkinson’s disease. Prog Neurobiol 48:1-19,1996
8. Jeandel C et al. Lipid peroxidation and free radical scavengers in Alzheimer’s diseaseGerontology 35:275-82 1989
9. Lands LC, Grey VL and Smountas AA. Effect of a cysteine donor on muscular performance.J Appl Physiol. 87 (4):1381-1385 1999
10. Lang CA, Naryshkin S, Schneider DL, Mills BJ et al. Low blood glutathione levels in healthy aging adults. J Lab Clin Med 120:720-5 1992
11. McIntosh GH et al. Dairy proteins protect against dimethylhydrazine-induced intestinal cancers in rats. J Nutr 125:809-16 1995
12. Powers SK, JI LL, Leeuwenburgh C. Exercise training-induced alterations in skeletal muscle antioxidant capacity:a brief review. Med. Sci. Sports Exerc. Vol31#7:987-997 1999.
13. Riederer P et al. Transition metals, ferritin, glutathione and ascorbic acid in Parkinsonian brains.J Neurochem. 52:515-20 1989
14. Sen CK. Glutathione homeostasis in response to exercise training and nutritional supplements. Molecular & Cellular Biochemistry. 196:31-42 1999
[/size]