Are you always tired, and do you feel like you barely make it through the work day without falling asleep at your computer? If that is the case you may be deficient in iron. Keep reading to find out how to fix this problem and how to avoid those foods that hinder iron absorption.
Introduction to Iron
We all may try to eat a meal that contains every single nutrient under the sun in one sitting, however, is that really the best way of going about it? Nutrients can be fickle sometimes, some nutrients love to be with each other, whereas others don’t get along very well, such as iron and calcium.
Iron is an important mineral because it is needed in order to make a heme molecule (see right), and four heme molecules are need to make hemoglobin. Hemoglobin is really important because red blood cells traveling through your blood require hemoglobin to transport oxygen all over your body including your brain, fingers, toes, stomach, etc. Without the iron we would not be able to use the oxygen we breath in and therefore would not exist. Which is why when people are low in iron they are usually tired and out of breath because their bodies are not able to transport the oxygen around their bodies effectively. After the red blood cells release the oxygen to their target location in the body they then pick up carbon dioxide which, is a waste product we then breathe out.
Types of Iron
One thing we need to clarify is that there are two types of iron:
- Heme iron, which is found exclusively from meat sources.
- Non-heme iron, which you can get from plant sources. However, non-heme iron is not as easily absorbed as heme iron.
It is steak night at the local restaurant and you order your steak with fries. You finish your meal and the waiter comes and carefully sneaks that dessert menu down and you notice that your favourite ice cream is back on the menu, you order it and you enjoy every bite of that ice cream. As you walk out of the restaurant you may be patting yourself on the back for having a good source of iron (the steak).
Unfortunately, you just wasted your money. The calcium in the ice cream will compete with the iron in the steak, and therefore prevent the iron from being absorbed. Both calcium and iron are absorbed in the beginning part of the small intestines called the duodenum. So, what ends up happening is that the iron will just travel right through your intestines and straight out the other side… tut tut, what a waste of good steak!
In the future, how can we prevent our perfectly good steak from being wasted? Well, try to avoid having dairy products (like the ice cream) when you are having a good source of iron (like the steak), and try to opt for a fruit based dessert such as fruit salad. If you really want to be able to give yourself a hearty pat on the back try to eat the steak with a glass of orange juice. This is a because the vitamin C in the orange juice (and in most fruits) helps promote the absorption of iron from the gut. Below is a table that highlights some of the foods to avoid or seek when consuming iron rich foods.
Drinks That Inhibit Iron Absorption
Another common food item that is often consumed after a meal is tea (typically in Britain) and coffee. Tea and coffee contain compounds that inhibit the absorption of iron from the duodenum in the small intestine by 50%. Red wine was also found to inhibit the absorption of iron from the gut. However, red wine does not contain as much iron inhibiting compound as tea and coffee. However in a balanced diet it did not significantly reduce the body’s ability to absorb iron, so having your glass of red wine with dinner may be something you want to reconsider, especially if you have an already low iron status.
Fiber comes in two types; insoluble and soluble. Soluble fiber as found in apples, lentils and beans produces a gel like substance that helps the movement of feces through the bowel. Soluble fiber does not effect iron absorption. Whereas, insoluble fiber has a unique ability to absorb toxins in the bowel and form the bulk of feces. Unfortunately, insoluble fiber also manages to hide iron, and therefore decreases iron absorption. Bran fiber is the main type of insoluble fiber that causes this inhibition. Bran fiber is the outermost layer of cereal grain. If you find that you have a low iron status, you should avoid insoluble bran fiber while consuming iron rich foods. Popcorn, brown rice and couscous are all sources of insoluble bran fiber.
Recommendations for Iron Intake
Below are the estimated average requirements (EAR) for iron intake. The estimated average requirement concept is very confusing at best, even for those in the health field. These estimated average requirements for iron intake per day, shown below, will be adequate for around 50% of the population, meaning that these numbers below may be too low a recommendation for around half of you reading thi. Confusing isn’t it? Our recommendation is to consume these amounts of iron shown below and get your iron levels tested, if you find that you are still low in iron you may be one of those people who has a greater iron requirement and you should consume more.
Brune, M., Hulten, L., Hallberg, L., Gleerup, A. and Sandburg, A. (1992). Iron Absorption from Bread in Humans: Inhibiting Effects of Cereal Fiber, Phytate and Inositol Phosphates with Different Numbers of Phosphate Groups. Human and Clinical Nutrition, 122(3), pp.442-449.
Feltrin, C., Batista de Morais, M., de Cássia Freitas, K., Beninga de Morais, T., Fagundes Neto, U. and Silvério Amancio, O. (2009). Effect of Soluble Fiber Pectin on Growth and Intestinal Iron Absorption in Rats During Recovery from Iron Deficiency Anemia. Biological Trace Element Research, 129(1-3), pp.221-228.
Fidler, M., Davidsson, L., Zeder, C. and Hurrell, R. (2004). Erythorbic acid is a potent enhancer of nonheme-iron absorption. American Journal of Clinical Nutrition, 79(1), pp.99-102.
Hurrell, R., Reddy, M. and Cook, J. (1999). Inhibition of Non-Haem Iron Absorption in Man by Polyphenolic Containing Beverages. British Journal of Nutrition, 81, pp.289-295.
Lynch, S. (2000). The effect of calcium on iron absorption. Nutrition Research Reviews, 13(02), p.141.
Malone, H., Kevany, J., Scott, J., O’Broin, S. and O’Connor, G. (1986). Ascorbic acid supplementation : Its effects on body iron stores and white blood cells. Irish Journal of Medical Science, 155(3), pp.74-79.
Defra, (2014). Nutrient Intakes. [online] Available at: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/384775/familyfood-method-rni-11dec14.pdf [Accessed 13 Feb. 2016].