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 International Journal of Oncology Functionalized Fe Doped Carbon Dots Exhibiting Dual Glutathione Consumption to Amplify Ferroptosis for Enhanced Cancer Therapy ACS Applied Materials & Interfaces Glutathione Dependent Pathways in Cancer Cells Glutathione mediated nanomedicines for cancer diagnosis and therapy ScienceDirect Multifaceted Roles of Glutathione and Glutathione Based Systems in Carcinogenesis and Anticancer Drug Resistance Elie Hatem, Nadine El Banna, Meng Er Huang, 2017