Ingesting iron together with white tea (Camellia Sinensis) may decrease its antioxidant capacity and phenolic content in human plasma

Abstract

It was hypothesized that ironpolyphenol chelates formed in the lumen or in the food matrix are poorly absorbed, thus tea bioactivity may be affected when iron is ingested together with tea. Ten women, aged 25 – 55 years, received white tea infusion or a mixture of white tea infusion and iron lactate in a randomized cross over design. Blood samples were drawn before the administration of and 30, 60 and 90 min after the consumption of the test drinks. White tea increased the antioxidant capacity measured with Ferric Reducing Antioxidant Power assay (FRAP) and the phenolic content of plasma measured with total catechin and High Performance Liquid Chromatography (HPLC) assays (p < 0.0001) in a time dependent way (p < 0.0001) but in the presence of iron the increase was lower (p = 0.0057). These results suggest that iron may modify the antioxidant properties of tea polyphenols and are in support of the hypothesis.