Many people are concerned about where they will get their iron when they switch from a meat-eating diet to a vegan diet. In fact, it is poorly understood that iron is incredibly common in the plant-food world. After reading this article, you will be surprised to discover that over 20 iron rich plant foods exist, among many others!
What is Iron and what role does it play in the human body?
Iron is a micro-mineral that is key to good health – it is an essential component of hemoglobin (involved in oxygen transport), it’s involved in immune system efficiency, plays a role in activating enzymatic reactions and is necessary for collagen synthesis. It is also needed for regulation of cell growth and is required for good cognition and behaviour.
What about heme and non-heme iron?
I find a lot of people get confused when it comes to heme and non-heme iron. Heme iron is the iron found in animal products (meat, fish, and poultry) and is more readily absorbed by the body than non-heme iron, an iron form found in plant foods.
We must be aware that the human body has no mechanism to rid itself of excess iron, thus our bodies evolved to tightly regulate the absorption of iron (1) – when our iron stores are low, iron absorption is boosted in the intestines, and when our iron stores are high, iron absorption is blocked in the intestines. It is important to note that this mechanism ONLY works with NON-HEME iron! When we consume animal products and are receiving heme-iron as our main iron source, our bodies can no longer regulate this iron intake (2). Even if we consume too much heme-iron, our intestines cannot regulate the iron influx, and it passes right through the intestinal barrier, leading to a body that is technically considered “Iron Toxic.”
Iron toxicity leads to decreases in the absorption and utilization of vitamin E, diabetes, gut disturbances, hair loss, increased free radical production (Iron is a pro-oxidant (3), leading to oxidative stress and DNA damage, which can result in cancer, inflammation and worsened arthritis symptoms), liver disease and heart disease.
What is the recommended dose of iron?
Males should consume around 8-11mg of iron, and women 8-18mg of iron (depending on menstrual cycle, if cycling through menses, women should consume on the higher end of the spectrum), daily. Pregnant women should consume up to 30mg daily.
What plant-based foods are high in iron?
*Note: Listed describes how many milligrams of iron are in 100 grams of food
- Sea Vegetables (Kelp, Spirulina, Nori, etc.) = 100.0
- Hemp Seeds = 13.9
- Pumpkin/Squash seeds = 11.2
- Morel Mushrooms = 12.2
- Sunflower seeds = 7.1
- Chia Seeds = 6.4
- Parsley = 6.2
- Almonds = 4.7
- Dried Prunes = 3.9
- Cashews = 3.8
- Raisins = 3.5
- Jerusalem Artichokes = 3.4
- Dandelion greens = 3.1
- Dates = 3.0
- Lentils = 2.1
- Green peas = 1.8
- Brown rice = 1.6
- Cauliflower = 1.1
- Strawberries = 1.0
- Asparagus = 1.0
Below 1.0mg iron per 100g of food includes blackberries, red cabbage, pumpkin, button mushrooms, bananas, beets. carrots, eggplant, sweet potato, avocado, figs, potatoes, corn, pineapple, nectarine, watermelon, winter squash, tomato, orange, cherries, summer squash, papaya, celery, and apples (considering these foods should be eaten in large quantities when vegan, you get PLENTY of iron by eating plant-based foods – 100g of these food items is a very small amount, remember.)
What Foods Decrease Iron Absorption?
– Dairy (experienced this myself – I had chronic anemia when vegetarian, and it went away when I went vegan)
– Red Wine
– Isolated soy products (soy flour, isolated soy concentrate, etc.)
– Tea & Coffee
What Foods Increase Iron Absorption?
– Vitamin C – citrus fruits (oranges, lemons, grapefruit, lime), tomatoes, red peppers, cauliflower, brussels sprouts, papaya, strawberries, etc.
– Vitamin A – Sweet potatoes, carrots, broccoli, peas, beets, apricots, peaches & lemons
Should I supplement my diet with Iron?
I personally would not supplement with iron unless there is a confirmed diagnosis of anemia – in either case, diet is the main root of the problem, and if it is fixed, iron issues can also be fixed. A study found that supplementing your diet with iron (even if anemic), can lead to a significant increase in oxidative stress (4) – oxidative stress is not healthy for the body (as previously described it leads to DNA damage, which can result in cancer establishment). You can easily get iron from the plant foods you consume, and by combining these foods with other foods that increase absorption of iron (high vitamin C & A foods – see above), then you can properly establish an environment in your body that promotes healthy iron levels.
(1) Steele, T., Frazer, D., & Anderson, G. (2005). Systemic regulation of intestinal iron absorption. IUBMB Life, 57, 499-503.
(2) West, A., & Oates, P. (2008). Mechanisms of heme iron absorption: Current questions and controversies. World Journal of Gastroenterology, 14, 4101-4110.
(3) Kabat, G. & Rohan, T. (2007). Does excess iron play a role in breast carcinogenesis? An unresolved hypothesis. Cancer Causes Control, 18, 1047-1053.
(4) Tiwari, A., Mahdi, A., Chandyan, S., Zahra, F., Godbole, M., Jaiswar, S., Srivastava, V., & Negi, M. (2011). Oral iron supplementation leads to oxidative imbalance in anemic women: A prospective study. Clinical Nutrition, 30, 188-193.
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