Constant exposure to environmental toxins, pollutants and radiation may damage your tissues within your body. Even normal metabolic activities generate substances called reactive oxygen species, or ROS, which have the potential to cause further injury to your cells. L-glutathione and vitamin C help to ameliorate the effects of external hazards and neutralize internally generated substances that could adversely affect your health.
Glutathione, an important antioxidant and detoxifying agent in your tissues, is manufactured from three amino acids: glutamic acid, cysteine and glycine. Glutathione works with 2 enzymes to perform its functions: glutathione peroxidase converts ROS into water molecules, and glutathione-S-transferase binds glutathione to toxic substances so the latter can be excreted from your body. According to nutritionist Elson Haas, M.D., cysteine is primarily responsible for glutathione's antioxidant properties. Thus, when your glutathione levels are low, a lack of cysteine is often the culprit. Cysteine is less common in foods than many amino acids, but you can find cysteine in high protein foods such as meats, cheeses and wheat germ, according to the University of Maryland Medical Center.
Ascorbic acid, or vitamin C, is found in a variety of foods, including citrus fruits, rose hips and acerola cherries. Vitamin C is a water-soluble nutrient with many functions, but one of its vital roles is to protect other molecules from oxidative damage. It is also involved in maintaining your body's supply of other antioxidants, such as vitamin E and glutathione, according to Haas. When vitamin C neutralizes ROS in your tissues, it is itself oxidized to a compound called dehydroascorbate. Recycling of dehydroascorbate to vitamin C helps to sustain its antioxidant function.
Recycling and Sparing
An April 1994 review in "The Journal of Biological Chemistry" describes interactions between vitamin C and glutathione that help to maintain your body's supplies of these important antioxidants. Both vitamin C and glutathione can neutralize toxic hydrogen peroxide and oxygen free radicals, but each of these compounds performs tasks that cannot be duplicated by the other. However, in an elegant example of biological cooperation, vitamin C "spares" glutathione in your tissues, and glutathione converts oxidized dehydroascorbate back into the active form of vitamin C. Take note that this review highlights studies that were done on animals and not humans.
Considerations and Recommendations
Glutathione is not an essential nutrient, as it can be manufactured in your tissues. However, increased oxidative stress can eventually deplete your body's stores of glutathione, as can insufficient dietary intake of cysteine. Supplementing with cysteine daily could help support your need for glutathione. Alternatively, you could take a supplement of reduced L-glutathione daily. However, the New York University Langone Medical Center reports that taking a glutathione supplement is pointless, and that the way to increase your amounts is by taking cysteine supplements or antioxidants or vitamin C. Ask your doctor if vitamin C, cysteine or L-glutathione supplementation could be useful for you.