Overview
This article explains the differences between heme and non-heme iron in foods and their significance for people with hemochromatosis, particularly concerning iron absorption and dietary management.
Types of Dietary Iron
- Heme iron is found only in meat, poultry, seafood, and fish (animal proteins).
- Non-heme iron is present in plant-based foods and also in dairy, eggs, and more than half the iron in animal meat.
- Animal meat contains both heme (40-45%) and non-heme (55-60%) iron.
Iron Absorption Differences
- Heme iron is absorbed more efficiently by the body than non-heme iron.
- Non-heme iron absorption is generally low (5–12%), but heme iron absorption is higher (20–30%) in people without hemochromatosis.
- In hemochromatosis, heme iron absorption can reach 80–100%, significantly increasing overall iron uptake.
Dietary Implications for Hemochromatosis
- Managing iron intake is vital for people with hemochromatosis to prevent iron overload.
- Most iron absorption blockers affect non-heme iron, not heme iron.
- Combining certain foods can unintentionally increase or decrease non-heme iron absorption.
- Understanding which type of iron is in food is key to dietary planning for hemochromatosis.
Highest Food Sources of Heme Iron
- Top sources: clams, liverwurst, chicken liver, oysters, beef liver, mussels, venison, ground beef, sardines, lamb chop.
- General high-heme foods: beef & chicken liver, shellfish, beef, sardines, turkey, chicken, fish, ham, veal.
Highest Food Sources of Non-Heme Iron
- Top sources: cooked soybeans, blackstrap molasses, lentils, cooked spinach, tofu, enriched bagels, chickpeas, tempeh, lima beans, black-eyed peas.
- General high non-heme foods: cooked spinach, seeds, firm tofu, beans & lentils, fortified cereals, baked potatoes with skin, dried fruits, nuts.
Recommendations / Advice
- People with hemochromatosis should minimize intake of high-heme iron animal foods.
- Focus on dietary strategies and nutrients that inhibit non-heme and, where possible, heme iron absorption.
- Meal composition can significantly impact iron absorption, especially for non-heme iron.
References
- USDA Food Composition Database
- American Journal of Clinical Nutrition
- Iron Disorders Institute
- HealthCastle.com
- Annals of the New York Academy of Sciences, vitamin C and iron interaction study