Q: What is glutathione, and is there any reason to take supplements of it?
A: Glutathione, a protein composed of three amino acids, is made primarily in the liver and is found in some foods. It’s also sold as a dietary supplement and is featured in many “anti-aging” programs.
An essential antioxidant, glutathione is involved in DNA synthesis, immunity, sperm formation, and many other important processes. Higher glutathione levels have been linked to better health and longevity, while lower levels are associated with conditions such as cancer, heart disease, diabetes, dementia, and Parkinson’s disease. Levels also decline with age.
But how much we need—and whether supplementation helps—is largely unknown. Like other proteins, when glutathione is consumed orally, it is broken down into its amino acids in the gastrointestinal tract. So it’s not surprising that studies using oral doses as a way to boost glutathione levels and produce antioxidant effects in the body have been disappointing overall. Other forms—intravenous, inhaled, or intramuscular—are more likely to survive intact for cells to use.
There’s preliminary evidence that inhaled or injected glutathione (but not oral) may help with conditions such as cystic fibrosis and Parkinson’s disease, but these and other proposed medical uses are still unproven.
The best way to boost glutathione in your body is to eat a balanced diet that includes nutrients such as selenium, vitamins B6 and C, riboflavin, and protein—all of which help increase glutathione production or activity. Alpha lipoic acid and N-acetylcysteine (a building block of glutathione) may raise glutathione levels as well, but there’s too little research to recommend supplements. Small studies suggest that prolonged moderate exercise may also boost glutathione. Alcohol and smoking, on the other hand, may reduce levels.
Also see Is Grape Seed Extract Worth Taking?