Iron is a crucial dietary mineral involved in several biological mechanisms, primarily the transport of oxygen in the blood. Because the organs need oxygen to function properly, a shortfall of iron can have wide-reaching health implications. Interestingly, not all cases of iron deficiency are caused by a lack of iron in the diet. Consuming tea and coffee at the wrong time, for instance, may contribute to the condition by thwarting iron absorption.
Iron deficiency is primarily caused by chronic blood loss and vigorous exercise.
The most common cause, however, is not getting enough iron-rich foods from the diet.
Though this issue is easy to correct, studies suggest people vulnerable to a deficiency may also benefit from avoiding coffee and tea at mealtimes.
According to the Australian platform Better Health, tea and coffee are two of several dietary sources known to interfere with iron absorption.
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Patients at risk of a deficiency tend to be discouraged from eating foods and drinks, such as bran, tea, and coffee, which interfere with iron absorption and meals.
The health body explains: “Tea, coffee and wine contain tannins that reduce iron absorption by binding to the iron and carrying it out of the body.
“Phytates and fibres found in wholegrain such as bran can reduce the absorption of iron and other minerals.”
One body of research exploring the role of coffee and tea in iron absorption was published in the American Journal of Clinical Nutrition.
The researchers noted: “A cup of coffee reduced iron absorption from a hamburger meal by 39 percent as compared to 64 percent with tea, which is known to be a potent inhibitory of iron absorption.”
They found no evidence of a decrease in iron absorption when coffee was consumed an hour before the meal, but inhibition was observed when coffee was taken within an hour of the meal.
Another component of tea and coffee that may potentially interfere with iron absorption is polyphenols.
These consist mainly of chlorogenic acid, which is a key active ingredient in coffee, cocoa and some herbs.
READ MORE: Iron deficiency: Tea consumption may ‘interfere with iron absorption’
Together, the components are touted as offering most of the health benefits associated with tea and coffee.
However, they can latch on to iron when consumed at the same time as the iron-containing food.
This binding primarily affects non-heme iron that is found in plant foods.
Popular sources of non-heme iron include fortified breakfast cereals, beans, dark chocolate, lentils, spinach, potato with skin, nuts and seeds.
It should be noted, however, that caffeinated foods and drinks are not typically responsible for iron deficiency in healthy individuals, so swapping these out for decaffeinated products will have an insignificant effect.
Why does the body need iron?
Red blood cells contain a complex protein called haemoglobin, which carries oxygen from the lungs to the rest of the body.
The haemoglobin protein consists partly of iron, and accounts for two-thirds of the body’s oxygen.
Iron also plays a role in the production of the protein myoglobin and enzymes in the body, as well as the immune system.