Healthy people at low risk of iron deficiency should not need to limit coffee and caffeine. However, those at risk of iron deficiency are advised to avoid coffee and caffeine at mealtimes and wait at least one hour after a meal before consumption.
Is coffee bad for iron deficiency?
You may be wondering if you should drink coffee while suffering from anemia. Caffeine has no effect on iron absorption so if someone is concerned about a 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.
Does coffee lower hemoglobin?
There was no significant effect of discontinuing coffee consumption on changes in hemoglobin in either nonanemic or anemic children, or plasma ferritin in children who did not take iron supplements.
How long after taking iron can I drink coffee?
When you take ferrous sulfate (or when you eat foods that are high in iron), make sure you leave a 2-hour gap before having tea or coffee or any of the foods on this list.
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.
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 harbor 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 a 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.
Other Substances that Affect Iron Absorption:
Caffeine in coffee is not the only substance known to interfere with iron absorption.
The polyphenols found in coffee and tea are also thought to be major inhibitors of iron absorption.
These include chromogenic acid, which is found mainly in coffee, cocoa, and some herbs. Also, tannins found in black tea and coffee inhibit iron absorption. These compounds bind with iron during digestion, making them more difficult to absorb.
Their effect on iron absorption is dose-dependent, meaning that iron absorption decreases as the polyphenol content of the food or beverage increases.
One study found that consuming 5 mg of tannins inhibited iron absorption by 20%, while 25 mg of tannins reduced it by 67% and 100 mg by 88%.
The Bottom Line
Caffeinated drinks like coffee and tea have been shown to inhibit iron absorption. However, this is more likely due to their polyphenol contents, not caffeine itself.
Caffeinated foods and drinks are not associated with iron deficiency in healthy people, as iron absorption is affected by many other dietary factors.
However, those at risk of deficiency would benefit from avoiding coffee and tea at mealtimes and waiting an hour after a meal to drink coffee or tea.