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 Understanding Glutathione Deficiency Invigor Medical Glutathione Levels and Susceptibility to Chemically Induced Injury in Two Human Prostate Cancer Cell Lines Glutathione Landing Page Homocysteine: Genetics, High Homocysteine Levels, and Solutions