The effect of coffee on iron absorption is a question I frequently get asked by my female friends and I was asked a similar question this morning. I thought the question and my response might be of interest to some of you, so here is it…

“Morning Liz, it’s interesting you mentioned caffeine this morning, because I’ve just been chatting to one of the physio’s at work who has an iron deficiency. She has reduced her caffeine to help as she is aware it could affect absorption. But she was wondering if decaf would still affect the absorption. Do you know if it’s over a certain amount of caffeine that will affect it or if it’s just having any? I guess as always it’ll depend on the person and other dietary factors. Thanks x”

My response:
“Morning! It’s not actually the caffeine but the tannins, polyphenols and phytates often found in caffeinated drinks that inhibit the absorption of iron as well as other vitamins and minerals (such as zinc and vitamin A). So she should avoid drinking tea (black and green) and coffee (caffeinated or decaf) around the time she eats (give at least a 3hour window). She should also avoid grains and legumes with her meals because they are high in phytates. She may already be aware that vitamin C enhances the absorption of iron so pairing her steak (or liver for a supersonic iron boost) with broccoli, followed by strawberries for dessert will be an added bonus!”

Hi! I’m Liz I’m a Registered Nutritionist. I love food and am fascinated by the impact of what we eat and drink has on our health and wellbeing.