At the Dubai conference several times I heard that drinking tea with meals does decrease the amount of iron that will be absorbed by the gut. Studies have shown this to be true. The doctors speaking did agree that it works but they weren't really sure if there is any difference between the effects of green tea and black tea, but they did seem to feel that both do reduce iron absorption from food, and it was recommended as a standard practice for thals. I would think this may have an even higher special significance to non-transfusing thals who suffer from iron overload from iron absorbed by their gut.
Iron absorption by the gut is a serious problem in thals and there is some suspicion that this happens even in minor in some thals, but the effects of dietary iron are sometimes downplayed by transfusing thals, but thals do absorb far much more iron from their guts than non thals do, as the body tries to compensate for the anemia by absorbing iron. Over a period of time, iron absorption from the gut can cause or add to serious iron overload in many patients and dietary iron intake should be considered and kept to a minimum if possible.
Vitamin C has long been recommended to be taken at the same time as desferal, as it releases more of the body's iron into the blood where it can be removed by the desferal. The dose is usually limited to 100-250 mg/day, because higher doses of Vitamin C have been shown to release too much iron into the blood, sometimes resulting in clumping in the heart which can significantly reduce heart activity, and even possibily cause heart failure.