Did you know that iron deficiency is the biggest cause of anemia worldwide? Anemia, for those unfamiliar, is when your blood isn't able to carry enough oxygen to your body, either due to a lack of red blood cells or lack of iron. How does iron figure in? Let's take a little journey inside your red blood cells to find out.
Google a picture of a red blood cell. What you'll see is a bi-concave disc (meaning it's a frisbee with a dimple on either side) that is, as the name implies, red. While you might think the shape is just for kicks, it actually serves a very important function. It's hard to imagine but your tiniest blood vessels are only wide enough for a single red blood cell (let's call them RBCs) to fit through, and it's often a very tight fit! What being bi-concave means is that your RBC is able to bend and flex around tight corners and through tiny blood vessel tubes. There are some folks who have certain blood diseases where their RBCs aren't this fabulous shape, they are spheres (hereditary spherocytosis) or shaped like crescent moons (sickle cell anemia), and those folks can have all sorts of problems, just from the shape! With spherocytosis the cells are very fragile and prone to burst open when put under pressure. In sickle cell anemia the funky shape means that the RBCs tend to get stuck and pile up in those narrowest of blood vessels. So be thankful if you are in that lucky majority who have normal shaped RBCs.
Now let's go inside the RBC. Really, in comparison to most of your cells, there's not a whole lot. There's no nucleus, which is the middle "yolk" of the cell that has all that important stuff like DNA. RBC are one a few types of cells in your body that don't have a nucleus, mainly because when they die, new cells get made from scratch rather than divide and have children cells, so they don't need DNA. What RBCs are packed full of is a molecule called hemoglobin. Hemoglobin is this fancy little protein that is made of two pairs of identical globs of protein (picture four snowballs in a square). In the center of each of these globs is a molecule that kind of resembles a trampoline, called heme, and in the middle of the trampoline is one single molecule of iron suspended. Since there are four snowballs in each hemoglobin that means that there are four iron molecules too, which doesn't seem like much, until you consider that every single RBC has an average of 280 million molecules of hemoglobin! That means there are four times that amount (I'll let you do that calculation) of iron in every RBC! Then, when you consider that the average adult has 20-30 trillion red blood cells, that gets to be a lot of iron!
So why iron? Iron has this nifty ability to bind easily to certain types of molecules, which includes oxygen (think about that old piece of rusty metal- that's iron binding oxygen too!). When a red blood cell gets into the blood vessels in your lungs it comes in contact with oxygen and the oxygen sticks to the iron molecule like a magnet. Then when that same RBC gets out to your foot which needs oxygen the iron kicks the oxygen off, then returns to the lungs to do it all over again. Unfortunately, other things can also bind to the iron. Things like carbon monoxide which binds even tighter than oxygen. Hence why carbon monoxide is so deadly toxic to you. It binds to your iron and doesn't let go easily, thus depriving your tissues of the oxygen they need to function. You will also get symptoms of this lack of oxygen if you don't have enough iron to carry the oxygen, this is called iron deficiency anemia. You can get anemia from a lot of different reasons, but this is by far the most common cause. It is most common in children and elderly folks, who are less likely to eat iron rich foods like meat. In many developing countries iron deficiency anemia is very common, especially in urban areas where poor families have little access to affordable meat. In India the rate among children is currently estimated to be around 80%. Some of the consequences are stunted growth, poor immune function, and general weakness and fatigue, among others.
There are also many interfering factors which can contribute to iron deficiency. For example calcium interferes with your body's ability to absorb iron. One recent study suggested that the ideal amount of milk for children to consume was no more than two cups a day. Any more than that could put them at risk of becoming iron deficient due to the amount of calcium in the milk. Another major interfering factor are molecules called phytates. These are found in grains and can also prevent your body from absorbing iron from the meal. An easy way to remedy this is to soak the grains overnight before using them, as this breaks down the phytates. For example, my little man loves oatmeal in the morning so I set out the bowel of oats in water with a little yogurt and let it sit overnight before cooking in the morning. This breaks down the phytates as well as starts a slow fermentation (from the yogurt) which makes the grains much easier to digest. Most traditional societies who eat grain would often do some sort of fermentation before consuming them, inherently recognizing that this made the nutrition in the grains much more accessible. Lead poisoning can also mimic iron deficiency anemia, but research suggests that it's due to the lead getting in to your bones and messing up the production of red blood cells as well as the lead interfering with iron being attached to the hemoglobin. Lead has largely been removed from modern homes, but in older homes it can still be found in paint and pipes. I know in Portland you can request a free lead water test if you live in an older home and have a child under 6 or a pregnant woman living in the home. If you are concerned about your water or paint it doesn't hurt to look into testing as even tiny amounts of lead can have pretty significant effects.
Then there's the issue of vegetarian supplied iron vs. iron from meat. You have probably heard that spinach and other dark leafy greens are just teeming with iron along with all sorts of other good vitamins. Well, it's true, but unfortunately your body has a much harder time absorbing iron from non-meat sources (this is considered "non-heme" iron vs "heme" iron that comes from meat). The iron must go through a series of reactions in your gut before it can be absorbed through the intestines whereas iron that is coming from meat is already in the proper form to be able to be sucked right up in your gut. There are a few things you can do to increase the amount of iron you absorb from food. The main thing is vitamin C. Having a big glass of orange juice or including other vitamin C rich foods with the meal can really help your body absorb more iron. Oh, and in case you're wondering, cooking in cast iron pans has also been shown to be a small source of iron for those who are just slightly deficient as trace amounts of the iron get into the food as it cooks.
So, how much iron do you need? Well this answer is different for everyone (of course- in naturopathic medicine we always approach every person as an individual), but there are some general guidelines that can help. When in doubt, it never hurts to get your iron levels checked by a medical professional, especially if you are experiencing any of the signs of anemia. Your body is actually incredibly efficient at recycling iron. When your RBCs gets broken down very little of the iron is actually lost. This means that for healthy men and non-menstruating/non-prego/non-lactating women the daily iron requirement is much lower compared to menstruating women or anyone suffering from blood loss. Children have their own requirements as they are (obviously) growing and increasing their blood supply daily. The National Institute of Health has put together several tables of daily requirements as well as recommendations on good sources of food iron: http://ods.od.nih.gov/factsheets/Iron-HealthProfessional/ I hope you feel much more informed about iron, but truly this just scratches the surface. The link above has a lot more information and resources if you want to learn even more!