non-heme iron
6 interactions related to non-heme iron
black tea + iron
Black tea is rich in polyphenols (tannins) that bind iron in the digestive tract. When the two are taken together, less of the iron your body needs gets absorbed.
iron + vitamin a
Vitamin A and beta-carotene appear to improve absorption of non-heme iron from plant foods by forming soluble complexes with iron that keep it from binding to phytates and polyphenols in the gut. In controlled human absorption studies, adding vitamin A to a grain-based meal increased the amount of iron absorbed.
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.
peppermint tea + iron
Peppermint tea is rich in plant polyphenols and tannins (including rosmarinic acid) that bind non-heme iron in the gut, forming insoluble complexes the body cannot absorb. Human studies show peppermint tea substantially reduces non-heme iron absorption from a meal, placing it among the stronger natural inhibitors. Heme iron from meat, poultry, and fish is not affected.
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.
coffee + iron
Coffee contains chlorogenic acid and other polyphenols with galloyl groups that bind non-heme iron in the gut, forming poorly soluble complexes the intestine cannot absorb. Drinking coffee with or shortly after an iron-rich meal or supplement meaningfully reduces how much non-heme iron you take up.