Which foods are highest in glutathione ? Food rich in glutathione: broccoli, cauliflower, banana, spinach, carrot, orange, avocado, onion, nuts. Glutathione is an antioxidant; helps make proteins in the body; has a variety of health benefits Stock Photo Mark Below are my top tips for boosting glutathione levels. Eat sulfur rich foods. Glutathione contains a sulfur chemical group, which is kind of like its secret weapon. Sulfur is a sticky, Natural Ways to Increase Your Glutathione Levels