catechins
2 interactions related to catechins
green tea + iron
Green tea polyphenols, especially the catechin EGCG, bind non-heme iron in the gut and form insoluble complexes that the intestine cannot absorb. The effect is most pronounced when green tea is consumed together with an iron supplement or an iron-rich plant meal, and it can be blunted by spacing the two apart and by pairing iron with a vitamin C source.
oolong tea + iron
Oolong tea is partially oxidised and contains the same families of iron-binding polyphenols found in green and black tea, including catechins and theaflavins. These polyphenols can bind non-heme iron in the gut and lower how much is absorbed when tea is taken with iron-rich meals or supplements. The effect is well documented for green and black tea; for oolong specifically it is a reasonable extrapolation of the same mechanism rather than a directly measured result.