This is a bit unrelated, but I eat a plant-based diet. I’m also a 20-something year old woman of child bearing age who runs, so making sure I’m getting enough iron from plant sources is important to me. I’ve heard that tannins in coffee, tea, and chocolate can hinder the adsorption of iron when consumed together. Is there evidence to support this? Thank you!
ksduck / Originally posted below Dried apples versus cholesterol
Answer:
Quoting from “Green tea does not inhibit iron absorption” published 2009 in the International Journal of Cardiology, “The only reference that I could find in the literature about a negative effect of tea drinking on iron absorption came from Tunisia. But the experiment was carried out on rats. Therefore, unless you are a rat and a rat in Tunisia, you should not worry about development of iron deficiency anemia from tea drinking.”
In 2008, though, a study in India found that drinking tea with meals could cut iron absorption in half. This is a function of publication delays. The cardiology journal piece was published in 2009 but was written in 2007, before the India study surfaced. The good news, though, is that the study found that vitamin C triples iron absorption, so as long as you’re drinking tea with lemon, or eating vitamin C rich foods at your meals (like citrus, broccoli, tropical fruits, bell peppers, etc.) then this shouldn’t be an issue. If, however, you don’t like lemon (and lemon in coffee? Yuck!) and aren’t eating these kinds of foods, then menstruating women may want to lay off tea and coffee (and cocoa and peppermint tea) during meals and up to an hour before to maximize iron absorption. In men (and nonmenstruating women), the reduction of iron absorption may not necessarily be a bad thing. In fact, the effect of coffee on iron absorption has been used to explain why coffee consumption has been found to be protective against diseases tied with iron overload such as diabetes and gout.
For a related phenomenon, see my video New Mineral Absorption Enhancers Found and the accompanying blog post How to Enhance Mineral Absorption.
Image credit: Aleksey / Flickr
