Glutathione

An antioxidant that may have been essential to earliestlife forms, glutathione can help rid the body of toxins.

Glutathione may improve liver detoxification and immunity, improve sperm motility and protect against cataracts, glaucoma, hepatitis, liver tumours, alcohol-induced cirrhosis, chemical-induced cancers and noise-induced hearing loss.

What is It?

Glutathione is a tripeptide a protein compound consisting of three amino acids: glutamine, glycine and cysteine. It is not considered an essential nutrient because the body can synthesize it.

Glutathione is a key antioxidant involved in detoxification processes of the liver. It is needed to help produce antibodies that fight off viruses and other microbes. The highest concentrations of glutathione are found in the liver, kidneys, stomach lining, spleen, pancreas and eyes.

Glutathione is present in the cells of virtually all living organisms. Scientists speculate that it was essential to the development of life billions of years ago when the earth's environment was gaseous, toxic and inhospitable. Primitive cells had to develop antioxidants such as glutathione for their protection.

How Does it Work?

Much of the body's ability to break down and dispose of chemical toxins is dependent on enzyme detoxification processes that occur in the liver. Excessive exposure to environmental toxins taxes these functions and may make the body more susceptible to certain diseases. For example, chemicals can do extensive damage by oxidizing fats (called lipid peroxidation) in cell membranes. Glutathione is the cofactor of important enzymes that detoxify many hazardous chemicals by binding to the intermediate chemical breakdown products and making them water-soluble for excretion.

What Evidence Supports its Use?

In one animal study, glutathione regressed aflatoxin-induced liver cancers while significantly enhancing survival. Rats given glutathione had an 81 percent survival rate. All rats exposed to aflatoxin but not given glutathione died within 24 hours. In human cancers, glutathione has been utilized in a secondary role to prevent kidney and nerve toxicity from the cancer drug cisplatin.

Glutathione is the principal antioxidant in the deep lung. Aerosol glutathione has been given to HIV patients to augment deficient levels of the lower respiratory tract to improve immune defenses. A glutathione deficiency has been associated with HIV, cancer and other immune disorders.

Glutathione levels decline in the lens of the eye with advancing age, particularly prior to cataract formation. In addition, research indicates that glutathione detoxifies the aqueous fluid of the inner eye, helping to maintain adequate fluid outflow among glaucoma patients.

Two other studies are also worth noting. In one double-blind, placebo-controlled study, injected glutathione demonstrated positive effects on sperm structure and function in infertile men. In a test tube experiment, glutathione produced significant inhibition of herpes simplex virus replication.

How Should I Take It?

Dietary glutathione from vegetables, fruit, fish, meat, whey powder and particularly avocado, asparagus and walnuts is usually less than 100 milligrams daily. Supplements are available in 50-, 100- and 500-milligram doses. Some health practitioners, however, prefer to use N-acetyl cysteine (NAC) to raise glutathione levels, since it may be absorbed better than glutathione's large molecule. The amount of cysteine in the body determines how much glutathione is produced. Selenium, magnesium, zinc and vitamins B₂, B₆ and C are also required for synthesis of either glutathione or glutathione-containing enzymes.

Caveats

Oral doses up to 600 milligrams per day seem to be well tolerated. There have been no reports of adverse reactions. However, pregnant women or nursing mothers should not take supplementary glutathione.

The Bottom Line

The studies so far on glutathione are promising. An antioxidant that may have been essential to earliest life forms is finding renewed importance in a polluted environment.