Green tea catechins greatly reduce free-iron absorption. Not heme-iron (the one contained in meat). If you are not vegetarian and if you do not have nutrient deficiencies or particural healt problems, a cup of tea is not a problem too. Especially if it is not an habitude.
There are a lot of food-food interactions that should be avoided in some healt problems and anyone should take it into account according to its healt condition by its own.
