What is iron?
Iron is a mineral that plays an important role in the growth and development of our bodies. It is also a necessary component for certain cellular functions as well as hormone production. There are generally two different types of iron: heme iron and non-heme iron.
What's the difference between heme and non-heme iron and why is that important?
Meats, poultry, and seafood contain heme iron as well as non-heme iron, whereas plants and iron-fortified foods contain only non-heme iron. While our bodies are able to absorb the heme iron contained in meat and fish more readily, you can also easily get the iron you need on a vegetarian or plant-based diet.
The big downside to heme iron is that it has been linked to several forms of cancer and heart disease.
The American Association for Cancer Research published a research paper in 2011 indicating that "evidence supports the hypothesis that heme iron present in meat promotes colorectal cancer".
In 2013, the American Heart Association published a study funded by the Swedish Council for Working Life and Social Research (FAS) that clearly indicates a correlation between high heme iron intake and an increased risk of stroke. These are just a few examples to show you what I'm on about.
Also, our bodies have trouble removing excess heme iron. Non-heme iron intake from plant-based sources is naturally regulated in the human body, preventing it from overloading.
How much iron do I need?
Ladies need about 18 mg per day (and an extra 27mg during pregnancy) up to the age of 50, gentlemen need about 8mg (which is the same as for 50+ ladies).
What foods contain iron and how much do I need to eat per day?
Iron is a bit harder to come by than the likes of Vitamin C. A lot of iron in our diet comes from iron-fortified foods such as breakfast cereal. That's good news for chocolate lovers though, dark chocolate (>50% cacao) contains a fair amount of Iron: 3 ounces (85 grams) can account for half your daily iron intake (7-8mg). White beans are also a good source of iron. One cup (220g) contains about 8mg. If you want something a bit more exciting, any combination of lentils, spinach, tofu, kidney beans, chickpeas, tomatoes, potatoes, and cashew nuts will help your body get the iron it needs.
Considering the scientific information given on heme iron, I wouldn't recommend meats, poultry or fish as a source of iron.
What happens if I don't get enough iron?
Iron deficiencies are very subtle. But the lack of iron has significant impacts on our bodies on a cellular level. Our red blood cells will become smaller and carry less oxygen from our lungs throughout the body. Symptoms are tiredness and a general lack of energy. Your memory and concentration will suffer and the ability of your body to fight off infections will decrease. Children could potentially develop learning difficulties.
I have to stress, though, this may also happen as a result of blood loss or through diseases that interfere with nutrient absorption.
Can an overdose of iron also be harmful?
The tolerable upper intake level for healthy adults is 45mg of iron: that's a lot of dark chocolate! So the risk of iron overload from dietary sources is fairly low. However, high iron intake levels from supplements may cause nausea, abdominal pain, vomiting, and faintness.
More than 25mg of elemental iron from supplements can reduce zinc absorption, which is another important mineral. As with many other things, severe cases of iron overdose can lead to organ failures and even death. But you're not going to get there by just eating dark chocolate and beans, don't you worry!
I hope you learned a thing or two about iron today. Thanks for reading and stay healthy!