Dear Doctor: I’ve been seeing advertisements for glutathione, saying the supplement enhances the body’s cells. The ads also say the claims haven’t been evaluated by the Food and Drug Administration. What can you tell me about it?
Dear Reader: Glutathione is an antioxidant produced in the body through enzymatic reactions, using the amino acids cysteine, L-glutamic acid and glycine. It helps repair cells damaged by pollution, stress and other harmful influences, and it is undeniably important.
Mice unable to form glutathione will die before birth. Mice that have been genetically altered to not produce glutathione in the liver will die after one month. People with mutations in the enzymes that form glutathione are more susceptible to oxidative stress. The deficiency in the production of glutathione leads to the breakdown of red blood cells, enlargement of the spleen, gall stones, and after many years can lead to mental deterioration. Also, these patients are more prone to severe anemia when exposed to certain chemicals or drugs.
Less is known about glutathione’s use as a general supplement, although it has been evaluated by the FDA for AIDS-related weight loss. People with AIDS have reduced production of glutathione in the intestine, and supplementation with glutathione could help in the ability to digest food.
Glutathione has also been studied in cystic fibrosis patients. Decreased glutathione in their intestines can lead to inflammation of the intestine, pain, decreased absorption of food, weight loss and growth failure. A 2015 study published in the Journal of Pediatric Gastroenterology and Nutrition found that supplementation with glutathione three times per day with meals has been shown to decrease intestinal inflammation and improve growth in children with cystic fibrosis.
Other research assessed glutathione’s effect on people with vascular disease of the arteries that go to the legs. Decreased blood flow can lead to calf pain when walking, but the study found that glutathione given intravenously twice a day helped ease patient symptoms.
Because you’re presumably healthy, you’re unlikely to have any deficiency in the production of glutathione. If you’re interested in improving your body’s ability to recover from exercise by enhancing your muscles’ ability to heal, that’s a different question. People who exercise vigorously create oxidative free radicals, which can lead to muscle fatigue and decrease muscle performance —suggesting that an antioxidant may be helpful.
However, people who exercise regularly naturally produce more antioxidants in the muscles to prevent damage, possibly in response to the regular formation of oxidative free radicals. Regardless, the body takes care of itself without the need of a supplement.
As of yet, there is no good study of the use of glutathione in healthy people. Some nutritionists recommend increasing the intake of the amino acids cysteine and glutamate, which make glutathione, but this hasn’t been studied either.
In short, the supplement has shown benefit among cystic fibrosis and AIDS patients who have decreased glutathione in the intestine, and it may show benefit in inflammatory conditions of the intestine, such as ulcerative colitis and Crohn’s disease, but this needs to be studied as well.
At this point, I would not recommend taking glutathione. If you’re healthy, your body should produce an adequate amount of this important antioxidant.
Robert Ashley, M.D., is an internist and assistant professor of medicine at the University of California, Los Angeles.