Although iron is found in many foods, iron deficiency is common in humans. One of the factors affecting this situation is the absorption of iron in the body. That’s why I wanted to deal with this issue separately from the functions of the iron mineral. Before looking at the factors affecting iron absorption, let’s look at what form iron is found in foods.
Iron is found in foods in 2 forms: heme and non-heme iron.
- What is heme iron, and in which foods is it found?
Heme iron is a structural compound of myoglobin, hemoglobin, and some enzymes. Red meat and white meat are among the most common foods.
- What is non-heme iron, and in which foods is it found?
Non-heme iron is found in foods with Fe+2 and Fe+3. It is also most found in plant foods—legumes, grains, fiber foods, raisins, prunes, almonds, pumpkin seeds, etc.
What Factors Affect Iron Absorption?
After examining how iron is found in foods, we can discuss its absorption. First, heme iron is more absorbed than non-heme iron. Heme iron absorption in the body is approximately 20-30%, while the absorption of non-heme iron is between 0.1-35%. In addition, the absorption of non-heme iron is increased when taken with heme iron. For this reason, it is recommended to consume non-heme iron with fish, red meat, and white meat.
Second, phytic acid in grains, seeds, and phenolic acids in fruits and vegetables reduce the absorption of non-heme iron (iron in plant foods).
Third, some proteins and peptides in calcium, whey, and legumes reduce the absorption of non-heme iron.
So how can we increase the absorption of iron minerals?
- Vegetables containing iron can be fermented and consumed.
- Ascorbic acid increases the absorption of iron minerals. In other words, instead of eating spinach and yogurt, it should be consumed by squeezing the lemon. Or, instead of drinking tea while consuming eggs for breakfast, we should consume foods containing vitamin C. Because tannins in tea reduce iron absorption.
- We can reduce phytic acid by soaking legumes in water. See: How to Sprout Grains and Legumes?
As a result, an iron mineral is a mineral that is necessary for our body. It is one of the most common minerals in the world. Therefore, consuming it by paying attention to its absorption is beneficial.
Resources:
Applegate L., Basic Principles of Nutrition and Diet, Trans. Haydar Özpınar, Istanbul Medical Bookstore, Istanbul, 2011.
Güneşer O., Yüceer Y., Minerals and Their Functional Effects, (Ed. Zeynep Banu Güzel Seydim) Functional Nutrition, Sidas Medya, İzmir, 2016, p.203-223.