Green tea is made from unfermented leaves and reportedly contains the highest concentration of powerful antioxidants called polyphenols. Black tea is also useful as an iron inhibitor and a mild chelator, but green tea has a higher antioxidant content, and this is very important for thals, as oxidation caused by iron is a great danger to the organs and the general health, so thals should take a diet high in antioxidant foods. Green tea extract is a concentrated form of green tea and has an even higher level of antioxidants. You can take 500-1000 mg of the extract daily. Drinking green or black tea with meals also has some value in preventing iron absorption from food.