Dietary Sources of Glutathione
DIETARY SOURCES OF GLUTATHIONE: Glutathione (GSH) is an antioxidant and detoxifying agent whose protective role has been demonstrated in numerous clinical studies. GSH is synthesized rapidly in the liver, kidneys, and other tissues of the body, including the gastrointestinal tract. This process is effected by aging and disease, as both of these conditions result in reduced tissue and blood levels of glutathione. Dietary forms of glutathione are efficiently absorbed into the blood, however the same is not true for glutathione supplements in humans.
When healthy subjects were given a single dose of up to 3,000 mg of glutathione researchers found there was no increase in blood glutathione levels. (Witschi A, Reddy S, Stofer B, Lauterburg BH. The systemic availability of oral glutathione. Eur J Clin Pharmacol 1992;43(6):667-9.) The authors of this study concluded "it is not feasible to increase circulating glutathione to a clinically beneficial extent by the oral administrating of a single dose of 3 g of glutathione." Johnson and coworkers (Johnston CJ, Meyer CG, Srilakshmi JC. Vitamin C elevates red blood cell glutathione in healthy adults. Am J Clin Nutr 58:103-5, 1993) found that blood glutathione levels rose nearly 50% in healthy individuals taking 500 mg of vitamin C daily. Vitamin C facilitates an increase in blood glutathione levels by supplying the body with a nutrient that is critical to the manufacture of it.
In addition, to vitamin C, dietary sources of glutathione and several other nutritional compounds can help increase glutathione levels including N-acetylcysteine (NAC), alpha-lipoic acid, glutamine, methionine, and undenatured whey protein (Bounous, G., and Gold, P., The biological activity of undenatured dietary whey proteins [Immunocal]: role of glutathione, Clin. Invest. Med. (1991) 14(4):296-309.). N-acetylcysteine has been used in combination with glutamic acid (or glutamine) and glycine (Clark, J. at www. cfsn. com) and in addition, NAC has been studied in combination with dietary proteins (Quig, D., Cysteine metabolism and metal toxicity, Alternative Medicine Review (1998) 3(4):262-270.).
Glutathione in the liver is essential to the liver's ability to detoxify. The higher the liver glutathione content, the greater the liver's capacity to detoxify harmful chemicals. Chemicals which can damage the liver, (including alcohol and acetominophen), cause the concentration of glutathione in the liver is substantially reduced, making the hepatocytes (liver cells) susceptible to damage. Silymarin not only prevents the depletion of glutathione induced by alcohol and other toxins (Chrungoo VJ et al. Indian J Exp Biol. 1997 Jun;35(6):611-7.), but can increase the level of glutathione in the cells of the liver (hepatocytes) (Valenzuela A et al. Planta Med. 1989 Oct;55(5):420-2.), and possibly by up to 35%.
Curcumin may also be useful as an agent to increase tissue glutathione levels (Dickinson, D. A., Iles, K. E., Zhang, H., Blank, V., and Forman, H. J., Curcumin alters EpRE and AP-1 binding complexes and elevates glutamate-cysteine ligase gene expression, FASEB J. (2003) 17(3):473-475.)
Alpha Lipoic Acid has also demonstrated it's ability to increase glutathione levels and act as a potent antioxidant in numerous scientific studies.
VITAMINS & MINERALS: vitamin B6, riboflavin, and selenium are required in the manufacture of glutathione, and adequate dietary consumption of foods rich in (or supplementation with) these vitamins and minerals can help the body to optimize glutathione production.(in milligrams per 3 1/2 oz (100 g) serving)
Food Glutathione Content
Apples Uncooked: 21.0 mg Cooked: 0.0 mg
Carrots Uncooked: 74.6 mg Cooked: 0.0 mg
Grapefruit Uncooked: 70.6 mg Cooked: 0.0 mg
Spinach Uncooked: 166 mg Cooked: 27.1 mg
Spinach (4) Uncooked: 9.65 mg Cooked: N/A mg
Tomatoes Uncooked: 169 mg Cooked: 0.0 mg
Asparagus (4) Uncooked: 28.3 mg Cooked: N/A mg
Avocado (4) Uncooked: 27.7 mg Cooked: N/A mg
Purslane (4) Uncooked: 14.81 mg Cooked: N/A mg
(1). JONES DP, COATES RJ, FLAGG EW, et al. (1992) Glutathione in Foods listed in the National Cancer Institute's Health Habits and History Food Frequency Questionnaire. Nutr Cancer 17: 57-75
(2). BLOCK G, DRESSER CM, HARTMAN AM, CARROLL MD (1985) Nutrient sources in the American diet: Quantitative data from the NHANES II Survey. I. Vitamins and Minerals. Am J Epidemiol 122: 13-26
(3). BLOCK G, DRESSER CM, HARTMAN AM, CARROLL MD (1985) Nutrient sources in the American diet: Quantitative data from the NHANES II Survey. Macronutrients and Fats. Am J Epidemiol 122: 27-40
(4) SIMOPOULOS AP, NORMAN HA, GILLASPY JE (1995) Purslane in human nutrition and its potential for world agriculture. World Rev Nutr Diet 77: 47-74
Dr. Petrosino received his Baccalaureate degree from Penn State University in 1975, pursued his Masters degree with honors at Penn State in 1978, and graduated Summa Cum Laude with a Doctorate in Nutrition from Lasalle University (Mandeville) in 1995. His doctoral dissertation examined the effects of race and poverty on cardiovascular health. He was an Adjunct Professor of Nutrition at LaSalle University (1995-1999); a member of the National Institutes of Health (NIH) Consensus Development Committee on Cardiovascular Disease; a Professional Member and Charter Member of the American Heart Association Scientific Council on Epidemiology and Prevention of Cardiovascular Disease; a Professional Member and Charter Member of the American Heart Association Scientific Council on Nutrition, Physical Activity and Metabolism; a Professional Member of the American Heart Association Interdisciplinary Working Group on Functional Genomics and Translational Biology; an Allied Health Care Practitioner member of the American Preventive.....