Interactions of epigallocatechin gallate with other agents (micronutrients, foods):
Tea and non-heme iron
Dietary iron exists either divalent as a component of the heme molecule (Fe2+) or in trivalent form (Fe3+). Heme iron is found mainly as hemoglobin and myohematin in meat, poultry, and fish. Non-heme iron is found in plants, dairy products, and in iron-containing dietary supplements.
The polyphenols contained in tea (especially flavonoids such as epigallocatechin gallate) are able to bind the non-heme iron and thus inhibit the intestinal absorption (uptake via the intestine) of this form of iron. Absorption of non-heme iron can be reduced by up to 79% by consuming black or green tea. Important notes!Therefore, if there is a risk of iron deficiency, it is advisable to drink tea or tea extracts between rather than during meals. In the case of supplements containing iron, tea should not be drunk one hour before and two hours after taking the supplement.
Furthermore, simultaneous consumption of vitamin C and iron-containing foods or supplements increases the absorption of iron. Study results also show that low levels of polyphenols (max. 4.6 mg/L) do not inhibit intestinal iron absorption by concurrent consumption of 100 µmol/L vitamin C. At higher concentrations, this effect was abolished.
