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Is coffee having an effect on my iron absorption?

For healthy people, there is no issue with iron absorption. But for those who are iron deficient, probably best to skip having coffee or tea with a meal.

Iron is an essential dietary nutrient needed for the formation of hemoglobin, the complex protein that transports oxygen through the bloodstream and delivers it to cells where the oxygen is needed for the production of energy. It is a positively charged ion of iron (ferrous iron) embedded in hemoglobin ("heme iron") that actually binds oxygen. Iron is found in a variety of foods, especially meat since animals also rely on hemoglobin for oxygen transport. Legumes, whole grain cereals and leafy vegetables also contain iron however the iron from these is not as readily absorbed as heme iron because plant products also contain substances that can bind iron and prevent it from being absorbed.

Both coffee and tea harbour various polyphenols that have an affinity for iron. These are the same polyphenols that are touted as offering health benefits on account of their antioxidant properties. However, polyphenols only latch on to iron if they are consumed at the same time as the iron-containing food, so this would only be an issue if coffee or tea were consumed with a meal. Furthermore, the binding only affects “non-heme” iron, which is the type found in plant foods. There is no effect on “heme” iron. Caffeine has no effect on iron absorption so if someone is concerned about lack of iron there is no point in switching to decaf coffee.

For healthy people, there is no issue with iron absorption. But for those who are iron deficient, probably best to skip having coffee or tea with a meal.


@JoeSchwarcz

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