We need iron to be able to manufacture blood. A deficiency in iron causes anaemia. Anaemia is much more common these days than it was further back in human history.
Popeye the Sailor may have eaten his spinach - which is packed with iron – but it is actually very difficult for our bodies to absorb the iron in spinach, as well as in many other types of food that contain iron.
Iron can be either heme iron – found in red meat, poultry, fish and shellfish – or non-heme iron – mostly found in grains, legumes and plant foods but also in milk and eggs.
Heme iron is more easily absorbed by our bodies than non-heme iron is.
Certain substances inhibit iron absorption – making it even harder for us to get enough iron from our food. Tea, coffee, cocoa, peppermint, chamomile, egg protein and phytic acid – found in grains, legumes and most plant foods – are all iron absorption inhibitors.
It gets worse. Some minerals – calcium, zinc, magnesium and copper - compete with iron for absorption.
Riding to the rescue is vitamin C. If you eat iron-rich food in combination with food that is rich in Vitamin C – such as sweet red peppers (bell peppers), broccoli, peas, berries, citrus fruit, peaches and papayas – it will help your body absorb the iron in whatever food you are eating.
But it is still a good idea to not drink coffee, tea, peppermint or chamomile tea or milk with or directly after an iron-rich meal – and even more so if you do not eat either meat or fish (heme iron).
Those most at risk of having iron deficiency are children and women – especially women before the menopause.
Men who eat meat and fish are rarely affected by anaemia and too much iron may actually increase the risk of cardiovascular disease.
“Menstruating women, who lose iron each month, have a lesser risk of cardiovascular disease than men until after the menopause.” (Patrick Holford – The Optimum Nutrition Bible)
Vegetarians and vegans need to be extra careful about getting enough iron. Many legumes and plant foods, although less readily absorbed by our bodies, can be good sources of iron if eaten together with food which is rich in vitamin C.