Bad combination of green tea and iron
The main active ingredient of green tea is epigallocatechin gallate (EGCG), which has the ability to inhibit the pro-inflammatory enzyme myeloperoxidase (MPO). The scientists were able to demonstrate in the mouse model that iron is binding to the EGCG substance after iron-rich foods. As a result, the tea loses its antioxidant property, which protects the cells from reactive oxygen compounds and thus from oxidative stress. The same applies to ferrous preparations.
This impairment takes place mutually: namely, the iron absorption is impaired. This is important for people with iron deficiency (eg CED). You should know that one substance influences the other. The study can be found here.