Since I learned that my iron stores
were extremely low last year, the topic of iron absorption has been of great interest to me. I love both coffee and tea, but I was concerned when I heard that both could prevent me from absorbing as much iron from meals.
While this is not necessarily a bad thing for everyone — in contrast, high iron levels are a risk factor for some (men in particular) — but this could present a problem for those who have low iron.
For example, this study
looked at the effect of different beverages on iron absorption when consumed with a hamburger. When the meal was served with tea, there was a 62 percent reduction of iron absorbed; with coffee, a 35 percent reduction. Orange juice increased iron absorption by 85 percent, while pure alcohol and wine increased absorption just slightly (though wine with a high iron content significantly increased the amount of iron absorbed). Milk and beer had no effect, and Coca-Cola increased absorption slightly.
So yes, tea and coffee had a definite effect on iron absorption, but here is the catch — this was regarding non-heme iron. Heme iron is iron from meat sources. Non-heme iron is from plant sources. In other words, those who are depending on plant-based foods for their iron should be especially careful.
Does this mean that coffee and tea are bad for you? In my opinion, no. As someone who struggles to keep my iron levels normal, I simply make sure that I don't consume coffee and tea with my meals or near the time when I take my iron liquid supplement (since it is a non-heme iron source).
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