Vesanto Melina MS, RD with Alessia Vaz and Sophia Jhajj (U.B.C students)
A common misconception is that those eating plant-based diets are more prone to develop iron deficiency. In fact, it has been found that vegetarians and vegans are no more likely to suffer from iron deficiency anemia than are their meat-eating counterparts. Continue reading for answers to some common questions about iron!
What is iron and why is it important?
Iron is fundamental in oxygen transport, plus it plays a role in many important pathways in our bodies. Iron is present in food in two forms: non-heme and heme iron. Non-heme iron is found primarily in plant foods and eggs, while meat provides both non-heme and heme iron. Ferritin is the body’s iron storage form, which helps manage iron absorption. Our bodies can control the absorption of non-heme iron, taking up less when iron stores are full, whereas heme iron is not regulated, introducing the risk for iron overload.
What plant-based foods contain iron?
Whether you’re moving towards or are currently following a plant-based diet, it is important to be mindful to eat a variety of foods to ensure adequate iron intake. Legumes, including beans, peas, lentils, and peanuts are great sources of iron. For example, lentils contain between 4.1mg and 4.9 mg per ¾ cup cooked. (Compare this to recommended intakes of 19 mg per day for premenopausal women, who lose iron in menstruation, and 8 mg per day for men and for postmenopausal women.) Dark green leafy vegetables like kale also contribute to iron intake, as do other vegetables and fruits like potatoes, asparagus, peas, snow peas, tomatoes, raisins, and dried apricots, as well as oatmeal, soymilk, seeds, and certain nuts (cashews, almonds). You can also boost your intake by including iron-fortified cereals and meat alternatives in your diet.
How are iron stores affected in plant-based diets?
Those following a plant-based diet tend to have lower ferritin levels than those eating meat, which recent research shows may be advantageous. Limited evidence connects lower ferritin to a reduced risk of coronary heart disease, colon or other hormone-related cancers, and type 2 diabetes. Our bodies are able to considerably increase iron absorption when iron stores a low. Despite this, recommendations are 1.8x higher for those on plant-based diets. However, this recommendation, based on a single 1991 study, is controversial as plant-based diets are typically lower in absorption inhibitors and higher in absorption enhancers.
What impacts my iron absorption and how can I enhance it?
The amount of iron absorbed from plant foods varies greatly depending on your iron status and the composition of the meal. Some foods contain substances that inhibit the mineral’s absorption. Phytic acid (phytate) found in whole grains, nuts, seeds, and legumes, can reduce iron absorption though phytate has significant health benefits. If you’re short on iron, don’t count on spinach and chard, as naturally present oxalates bind the iron, reducing its absorption. Similarly, try to limit coffee, tea, and cocoa, as they contain polyphenols that bind to iron and limit its absorption. On the other hand, vitamin C-rich foods like citrus fruits, red bell pepper, and cabbage, eaten with non-heme iron sources can increase the mineral’s absorption by up to 6 times. Other absorption enhancers are onions, garlic, foods rich in beta-carotene like carrots, and spices including pepper, turmeric, and ginger. Certain food preparation techniques like soaking, fermenting, yeasting, and sprouting can also enhance iron absorption as they degrade phytate, reducing the presence of an inhibitor in the food.
Including a diverse range of iron-rich plant-based foods helps ensure you achieve a healthy, energetic and active lifestyle!
References
Melina V et al. Position of the Academy of Nutrition and Dietetics: Vegetarian Diets.
J Acad Nutr Diet. 2016 Dec;116(12):1970-1980.
https://www.ncbi.nlm.nih.gov/pubmed/27886704 and
Davis, B., Melina, V., Berry R. (2010). Becoming Raw: The Essential Guide to Raw Vegan Diets.