Because glutathione levels decline as you age, and glycine can help slow the glutathione slide, it's a good idea to keep your levels high by eating protein rich foods, like organic poultry, grass fed Glutathione Benefits for Gut Health Nikki Yelton RD Real Time Monitoring of Glutathione in Living Cells Reveals that High Glutathione Levels Are Required to Maintain Stem Cell Function: Stem Cell Reports Good for You Glutathione Repchage Glutathione: Master Antioxidant, Reducing Oxidative Stress, and Detoxification Increasing glutathione levels by a novel posttranslational mechanism inhibits neuronal hyperexcitability ScienceDirect