10 Foods That Contain Glutathione Core Med Science 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 15 Effective Foods to Boost Glutathione Levels Naturally Natural Ways to Increase Your Glutathione Levels Foods High in Glutathione Dr. Christina Carlyle