Q & A: Tea and iron absorption.

Original Post on 12 May 2005

Your Question: I read this article [1] that talked about the many benefits of drinking tea. But I was told by my doctor that drinking tea can make my iron deficiency worse. Can you please clarify this?

I cannot verify all the evidence presented in the article that you have referenced to. However, I have managed to find a couple of medical papers discussing similar findings as presented in that article. I have to admit that those findings are very interesting. It is however very important to understand that not all those findings constitute the best medical evidence at present. The studies quoted have too few participants with just too many confounding factors. But nonetheless, they are very exciting inferences.

It will be worthwhile for someone to invest a bit of money and time to conduct furthur studies to see if we can get more evidence.

Anyway, that was not your question.

Tea contains an ingredient called Tannic acid. Tannic acid has a high affinity to react with dietary iron. This changes the dietary iron to a form that is not easily absorbed. Therefore it can reduce the absorption of dietary iron. If you have been diagnosed with iron deficiency anaemia (as demonstrated by blood tests that directly measure iron levels- very important in Maldives where Thalassaemia is so common) and you have been prescribed iron supplements, it maybe best for you to avoid drinking tea at the time or close to the time you are taking your iron tablets. This will help ensure that iron absorption is not hindered by Tannic acid.

I don’t think there is any need for you to stop drinking tea altogether. This however would be the advise to very small infants who are iron deficient. In their case it may be best to avoid tea altogether until their iron deficiency is corrected.

I would also like to state here that tea may have all these benefits that are very important, but it would be wise to have moderation in its consumption. As the old saying goes: too much of a good thing can be bad!

[1] http://www.kavaasaa.com/sihhath/kaanaa/sai.htm