Continuing on in our “We are what we eat” series, today we have a look at one of the more noble and press-hogging elements that we absolutely cannot do without; iron. The name itself conjures images of strength and power, mass and might. Human history even has an Age named after it! By mass, iron is the most common element found on this planet, and the fourth most abundant element in the earth’s crust. It is an essential element for most life on earth, and it is in our bodies, all of us, we are all iron men and women. Of course it’s not like our skeletons are made of cast iron, clunking around. In humans, iron is present throughout our entire bodies, on a molecular level. The amount of iron in our bodies is only 3-4 grams, distributed throughout the body in hemoglobin, tissues, muscles, bone marrow, blood proteins, enzymes, and plasma transport. The greatest portion of iron is in our blood, in hemoglobin.
In humans iron is required for several complex processes necessary to sustain life, like the manufacture of red blood cells that takes place in bone marrow. Red blood cells carry oxygen from the lungs to every cell in the body, and iron is part of the haemoglobin, the pigment in red blood cells that binds to oxygen. Insufficient iron will lead to a reduction in haemoglobin and impacts it’s ability to carry oxygen, noticeable to us as fatigue, dizziness or compromised immune system. After delivering the oxygen to the needy cells, iron is not done its work; it takes away the garbage, carbon dioxide, and brings it to the lungs to get rid of through exhaling.
Iron is also used to convert blood sugars into energy, so if you are iron deficient (anemic) this conversion does not go so well. Your lack of energy may be due to a lack of iron necessary to produce energy from the sugars. It is also vital in the production of enzymes needed for the creation of new cells, amino acids, hormones and neurotransmitters, and is especially important during recovery from illness or high workloads such as an athlete might experience, and as such an iron deficiency will affect the immune system.
Even though we only have roughly 3-4 grams in us, we still lose some on a daily basis due to perspiration, loss of blood, urination and defecation and day to day loss of old, dead skin cells. So how much do we need to replenish? Growing boys and girls need about between 8 and 10 mg a day, and women from the onset of menses to menopause need 18 mg/day, and pregnant women 27mg. After menopause women need about the same amount as men, 8mg a day.
It’s easy to get enough iron in your diet; eat iron rich foods like lentils, a variety of beans, chickpeas, dark leafy greens like spinach, eggs, dried fruit, edamame (soy beans) and tofu, blackstrap molasses, and poultry, red meat and fish. And cooking with cast iron like a Dutch oven or frying pan can add as much as 80% of your RDA of iron to your food! Here is a good list of iron rich foods, and how much iron is in each serving.