Glutathione, what does it do?

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GlutathioneJoAnn GuestNov 08, 2003 09:48 PSTGlutathioneWhat does it do? Glutathione is a small protein composed of three amino acids: cysteine, glutamic acid, and glycine. Glutathione is involved in detoxification—it binds to toxins, such as heavy metals, solvents, and pesticides, and transforms them into a form that can be excreted in urine or bile.Glutathione is also an important antioxidant.In preliminary research, dietary glutathione intake from fruit and raw vegetables has beenassociated with protection against some forms of cancer.Glutathione has also inhibited cancer in test tube3 and animal studies.4 In preliminary research, higher glutathione levels have also been associated with good health in older adults.Glutathione supplements appear to be efficiently absorbed in rats. However, the same may not be true for glutathione supplements in humans.For example, when seven healthy subjects were given

a single application of up to 3,000 mg of glutathione, there was no increase in blood glutathione levels.The authors of the study concluded "it is not feasible to increase circulating glutathione to a clinically beneficial extent by the oral administrating of a single application of 3,000 mg ofglutathione." Absorption of glutathione may be better in rats because unlike the gastrointestinal tract of rats, the human gastrointestinal tract contains significant amounts of an enzyme (gamma-glutamyltranspeptidase) that breaks down glutathione.Very preliminary evidence has suggested that absorption of glutathione can occur in the mouth when glutathione tablets are placed between the teeth and the inner cheek.Some researchers believe that supplements other than oral glutathione may be more effective in raising blood levels of glutathione.For example, in one trial, blood glutathione levels rose nearly 50% in healthy people taking 500 mg of

vitamin C per day for only two weeks.Vitamin C raises glutathione by helping the body manufacture it. In addition to vitamin C, other nutritional compounds that may, according to preliminary research, help increase glutathione levelsinclude alpha lipoic acid, glutamine,12 methionine,13 S-adenosyl methionine (SAMe).Vitamin B6, riboflavin, and selenium are required in the manufacture of glutathione. The extent to which any of these nutrients effectively increases glutathione levels in humans remains unclear.Studies using intravenous or intramuscular glutathione have found it to be useful for preventing clot formation during operations;16 reducing the side effects and increasing the efficacy of chemotherapy drugs (particularly cisplatin in women with ovarian cancer);17 18 treating Parkinson's disease;reducing blood pressure in people with diabetes with high blood pressure;20 and increasing sperm counts in men with low sperm counts.A

glutathione nasal spray has also reduced symptoms in people with chronic rhinitis.Whether oral preparations are also effective is unknown at this time. A small study in eight patients with liver cancer using oral glutathione showed modest benefits in women, but not in men, whengiven in a daily amount of 5,000 mg.An unpublished preliminary study of eight colon cancer patients also found that oral glutathione appeared to have anticancer activity.25 Nonetheless, because questions exist about the extent to which oral glutathione can be absorbed, some doctors are concerned that oral preparations may be either less effective than other forms or not effective at all.Where is it found? Dietary glutathione is found in fresh and frozen fruits and vegetables,and fish.Asparagus, avocado, and walnuts are particularly rich dietary sources of glutathione.Who is likely to be deficient? A deficiency can be the result of diseases that increase the

need for glutathione, deficiencies of the amino acids needed for synthesis, or diseases that inhibitglutathione formation.Examples of some health conditions that are associated with glutathione deficiency include diabetes, low sperm counts, liver disease, cataracts, and HIV infection, respiratory distress syndrome,cancer, and idiopathic pulmonary fibrosis. Cigarette smoking is also associated with low glutathione levels because it increases the rate of utilization of glutathione.How much is usually taken? There is very little evidence that taking glutathione supplements provides any benefit, despite promising evidence about the effects of aerosol, intravenous, and intramuscularglutathione, for people with a wide variety of conditions.People who have a proven glutathione deficiency, which may require administration of glutathione intravenously, intramuscularly, or by aerosol, should be treated by a healthcare professional. All ovarian

cancer patients currently taking cisplatin (Platinol®) should discuss using intravenous glutathione with a healthcare professional.Are there any side effects or interactions? No side effects or interactions are known with oral administration of glutathione.Are there any drug interactions? Certain medications may interact with glutathione.--References:1. Sen CK. Nutritional biochemistry of cellular glutathione. NutrBiochem 1997;8:660–72.2. Flagg EW, Coates RJ, Jones DP, et al. Dietary glutathione intakeandthe risk of oral and pharyngeal cancer. Am J Epidemiol 1994;139:453–65.3. Donnerstag B, Ohlenschläger, Cinatl J, et al. Reduced glutathioneandS-acetylglutathione as selective apoptosis-inducing agents in cancertherapy. Cancer Lett 1996;110:63–70.4. Trickler D, Shklar G, Schwartz J. Inhibition

of oralcarcinogenesisby glutathione. Nutr Cancer 1993;20:139–44.5. Julius M, Lang C, Gleiberman L, et al. Glutathione and morbidityin acommunity-based sample of elderly. J Clin Epidemiol 1994;47:1021–6.6. Hagen TM, Wierzbicka GT, Sillau AH, et al. Fate of dietaryglutathione: disposition in the gastrointestinal tract. Am J Physiol1990;259(4Pt1):G530–5.7. Favilli F, Marraccini P, Iantomasis T, Vincenzini MT. Effect oforally administered glutathione on glutathione levels in some organsofrats: role of specific transporters. Br J Nutr 1997;78:293–300.8. Witschi A, Reddy S, Stofer B, Lauterburg BH. The systemicavailability of oral glutathione. Eur J Clin Pharmacol 1992;43:667–9.9. Hunjan MK, Evered DF. Absorption of glutathione from thegastro-intestinal tract. Biochim Biophys Acta 1985;815:184–8.10. Johnston CS, Meyer CG, Srilakshmi JC. Vitamin C elevates redbloodcell

glutathione in healthy adults. Am J Clin Nutr 1993;58:103–5.11. Bunin AIa, Filina AA, Erchev VP. A glutathione deficiency inopen-angle glaucoma and the approaches to its correction. VestnOftalmol1992;108:13–5 [in Russian].12. Amores-Sanchez MI, Medina MA. Glutamine, as a precursor ofglutathione, and oxidative stress. Mol Genet Metab 1999;67:100–5.13. Wang ST, Chen HW, Sheen LY, Lii CK. Methionine and cysteineaffectglutathione level, glutathione-related enzyme activities and theexpression of glutathione S-transferase isozymes in rat hepatocytes.JNutr 1997;127:2135–41.14. Vendemiale G, Altomare E, Trizio T, et al. Effects of oralS-adenosyl-L-methionine on hepatic glutathione in patients withliverdisease. Scand J Gastroenterol 1989;24:407–15.15. Bounous G, Gervais F, Amer V, et al. The influence of dietarywheyprotein on tissue glutathione and the diseases of aging. Clin

InvestMed1989;12:343–9.16. Molloy J, Martin JF, Baskerville PA, et al. S-nitrosoglutathionereduces the rate of embolization in humans. Circulation 1998;98:1372–5.17. Smyth JF, Bowman A, Perren T, et al. Glutathione reduces thetoxicity and improves quality of life of women diagnosed withovariancancer treated with cisplatin: results of a double-blind, randomisedtrial. Ann Oncol 1997;8:569–73.18. Cascinu S, Cordella L, Del Ferro E, et al. Neuroprotectiveeffect ofreduced glutathione on cisplatin-based chemotherapy in advancedgastriccancer: a randomized double-blind placebo-controlled trial. J ClinOncol1995;13:26–32.19. Sechi G, Deledda MG, Bua G, et al. Reduced intravenousglutathionein the treatment of early Parkinson's disease. ProgNeuropsychopharmacolBiol Psychiatry 1996;20:1159–70.20. Ceriello A, Giugliano D, Quatraro A, Lefebvre PJ.

Anti-oxidantsshowan anti-hypertensive effect in diabetic and hypertensive subjects.ClinSci 1991;81:739–42.21. Lenzi A, Picardo M, Gandini L, et al. Glutathione treatment ofdyspermia: effect on the lipoperoxidation process. Hum Reprod1994;9:2044–50.22. Lenzi A, Culasso F, Gandini L, et al. Placebo-controlled,double-blind, cross-over trial of glutathione therapy in maleinfertility. Hum Reprod 1993;8:1657–62.23. Testa B, Mesolella M, Testa D. Glutathione in the upperrespiratorytract. Ann Otol Rhinol Laryngol 1995;104:117–9.24. Dalhoff K, Ranek L, Mantoni M, Poulsen HE. Glutathione treatmentofhepatocellular carcinoma. Liver 1992;12:341–3.25. Garcia-Giralt E, Perdereau B, Brixy F, et al. Preliminary studyofglutathione, L-cysteine and anthocyans (Recancostat Compositum™) inmetastatic colorectal carcinoma with malnutrition. SeventhInternationalCongress on

Anti-Cancer Treatment, February 3–6, 1996, Paris, France.26. Jones DP, Coates RJ, Flagg EW, et al. Glutathione in foodslisted inthe National Cancer Institutes Health Habits and History FoodFrequencyQuestionnaire. Nutr Cancer 1995;17:57–75.27. White AC, Thannickal VJ, Fanburg BL. Glutathione deficiency inhumandisease. J Nutr Biochem 1994;5:218–26.-- 2002 Healthnotes, Inc. All rights reserved.www.healthnotes.comLearn more about Healthnotes, the company.Learn more about the authors of Healthnotes.The information presented in Healthnotes is for informationalpurposesonly. It is based on scientific studies (human, animal, or invitro),clinical experience, or traditional usage as cited in each article.Theresults reported may not necessarily occur in all

individuals. Formanyof the conditions discussed, treatment with prescription orover-the-counter medication is also available. Consult your doctor,practitioner, and/or pharmacist for any health problem and beforeusingany supplements or before making any changes in prescribedmedications.Information expires December 2003.http://www.mothernature.com/Library/Ency/index.cfm?id=2857007

 

 

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