As with black tea, phenolic compounds/polyphenols (antioxidants) present in tea leaves bind to dietary iron and significantly inhibit its absorption. Absorption is inhibited by up to 28% in green tea drinkers 1. Similar effects are thought to occur when you take concentrated green tea extract too!
A study conducted in young women found that drinking tea with a meals cuts down iron absorption by half. And, ascorbic acid (vitamin C) present in citrus fruits and vegetables boosts iron absorption 2.
Vitamin C, meat and fish are all iron absorption enhancers that can help in overcoming the inhibition of iron absorption as a result of tea drinking.
Research also suggests that meals high in protein and iron interact with green tea polyphenols and decrease their antioxidant potential 3. Therefore, you may not get the full benefits out of your green tea when eating and drinking these together.
How do I get maximum health benefits?
The following are a few recommendations for green tea drinkers, which can help you maximise the health benefits of green tea without losing out on iron.
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Have green tea drinks or supplements at least 1-2 hours before or after your meals.
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Make sure you eat meat, have lots of iron rich vegetables every day, or take an iron supplement.
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Include vitamin C rich foods in your meals since it increases iron absorption from your fruit and vegetables.
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Consider a vitamin C supplement as well as a green tea extract.
References
Morck, T. A., Lynch, S. R., & Cook, J. D. (1983). Inhibition of food iron absorption by coffee. American Journal of Clinical Nutrition, 37(3), 416-420.
Thankachan, P., Walczyk, T., Muthayya, S., Kurpad, A. V., & Hurrell R. F. (2008). Iron absorption in young Indian women: The interaction of iron status with the influence of tea and ascorbic acid. American Journal of Clinical Nutrition, 87, 881-886.
Zijp, I. M., Korver, O., & Tijburg, L. B. M. 2000. Effect of tea and other dietary factors on iron absorption. Critical Reviews in Food Science and Nutrition, 40(5), 371-398.