Haem vs Non-haem Iron: Which Form Is Better Absorbed by the Human Body?

Iron is an essential mineral that plays a vital role in numerous physiological functions, including oxygen transport, energy production, and cellular metabolism. There are two main forms of iron found in our diet: haem iron and non-haem iron. Each form has its unique characteristics and affects the absorption of iron differently. This article aims to explore the differences between haem and non-haem iron and determine which form is more readily absorbed by the human body.

Hem Iron (Haem Iron)

Hem iron, also known as haem iron, is found primarily in animal sources such as meat, poultry, and fish. Unlike non-haem iron, it is part of the heme molecule, which is tightly bound to the protein in animal tissues. This binding makes hem iron more readily absorbable by the human body. The absorption rate of haem iron is typically around 15-35%, making it a highly efficient form of iron.

Advantages of Haem Iron:
1. Higher Absorption Rate: Haem iron is more easily absorbed due to its chemical structure, which allows it to bypass some of the digestive processes that inhibit non-haem iron absorption. This makes it a preferred form of iron for individuals at risk of iron deficiency anemia.

2. No Need for Vitamin C: Unlike non-haem iron, haem iron does not require the presence of Vitamin C to be absorbed. This means that you don't need to consume Vitamin C-rich foods alongside meals containing haem iron to enhance absorption.

Non-haem Iron (Non-haem Iron)

Non-haem iron, also known as non-heme iron, is found in plant-based and animal sources that are not part of the heme structure. This form of iron is not as efficiently absorbed by the body, with an absorption rate typically ranging from 2-20%. However, this form is still widely found in a variety of foods, making it the primary source of dietary iron for many people.

Factors Affecting Non-haem Iron Absorption: 1. Phytates: Phytates, found in foods like grains and legumes, can inhibit the absorption of non-haem iron. To counteract this, it is recommended to soak grains before consumption, as this process can reduce phytate content.

2. Caffeine and Tannins: Beverages containing caffeine, such as tea and coffee, as well as tannin-rich foods like red wine, can also inhibit the absorption of non-haem iron. It is advisable to consume these items at different times from iron-rich meals.

3. Vitamin C: As mentioned earlier, non-haem iron is less absorbable and requires the presence of Vitamin C to enhance its absorption. Consuming Vitamin C-rich foods like fruits and vegetables simultaneously can improve iron absorption.

Comparison of Haem and Non-haem Iron Absorption

Haem Iron vs Non-haem Iron

The key difference between haem and non-haem iron lies in their absorption rates and the factors influencing their uptake by the body. As shown in the table below, haem iron tends to be absorbed more efficiently, making it a more reliable source of dietary iron for some individuals.

Iron Source Absorption Rate Other Considerations Haem Iron 15-35% Absorption No need for Vitamin C; not affected by phytates, caffeine, and tannins Non-haem Iron 2-20% Absorption Requires Vitamin C; can be inhibited by phytates, caffeine, and tannins

Key Considerations

Given the absorption rates and influencing factors, haem iron appears to be a more reliable form of iron for many individuals seeking to maintain adequate iron levels. However, this does not mean that non-haem iron is without its benefits. Both forms play a crucial role in the diet, and the ideal approach is often a combination of both sources to meet daily requirements.

Incorporating Haem and Non-haem Iron into Your Diet

To maximize iron absorption from both sources, consider the following dietary strategies:

Incorporate Animal Products: Meat, poultry, and fish are excellent sources of haem iron. Consume these regularly to support higher iron absorption rates. Balance with Plant Products: Include a variety of plant-based sources of non-haem iron, such as legumes, spinach, and fortified cereals, to ensure a balanced diet. Timing: Consume Vitamin C-rich foods with meals that include non-haem iron to enhance absorption. Avoid consuming tea, coffee, or alcohol with meals containing non-haem iron. Soaking Grains: Prepare grains like oats and rice by soaking them overnight to reduce the presence of phytates and improve iron absorption.

Closing Thoughts

In conclusion, while both haem and non-haem iron play essential roles in maintaining optimal health, haem iron is generally more readily absorbed by the human body. This makes it a preferred form for those at risk of iron deficiency. However, a balanced diet that includes both sources and utilizes strategies to enhance absorption is likely to provide the best overall results.

References

For further reading and research, consider consulting the following sources:

Yamano M, Schreiber R (1980). "Mechanisms of Hemosiderin Formation: Aerobic Versus Anaerobic?" Mossop J, Turnbull D, Chato J (1973). "Comments on the Mechanism of Oxidative Degradation of Heme to Bilirubin." Biological Chemistry Reviews, 50(2). Fulcher GA, Kinghorn K, Macpherson S, Allan WC (1982). "Tumour Burden and Rate of Heme Degradation in Murine Cancers." Cancer Research, 42(6). Prentice AM, Whitehead RG (1988). "The Absorption of Iron from Human Milk." European Journal of Clinical Nutrition, 42(4).