Get the facts on Iron
The widely-held stereotype of vegans as pale and anaemic doesn’t fit with the research, which clearly shows that Australian vegan women and men are no more likely to be anaemic (which means having low haemoglobin levels in their blood) or to have depleted iron stores than omnivorous men and women. Vegans tend to have lower iron stores (ferritin levels) than omnivores, but this may be a health advantage: high iron stores are associated with cirrhosis, liver cancer, cardiac arrhythmias, metabolic syndrome and diabetes, and possibly cancers of the colon and prostate.
Nonetheless, when you first switch to a plant-based diet it can take some time for your body to adapt to only having non-haem iron (the kind we get from plants) and no haem iron (the kind that’s in meat), so it’s important to eat plenty of plant foods that are high in iron.
Men and postmenopausal women only need 8 mg of iron per day, according to the National Health and Medical Research Council, while women in their fertile years need 18 mg per day, and pregnant women 27 mg per day.
Here’s a selection of high-iron plant foods:
Plant Based Iron Sources
As you can see, it’s not that difficult to get enough iron if you make wise food choices throughout the day.
It’s often argued that haem iron, the kind of iron we get from red meat, is ‘better absorbed’ than the non-haem iron we get from plant foods. The reality is that iron absorption is very tightly controlled by the cells that line our small intestine, so that we can absorb more iron if our stores are running low (for example, after an accident in which we lose a lot of blood, or in women during their menstrual period), and absorb less when we don’t need it (when our iron stores are sufficient). Haem iron bypasses these controls, forcing our bodies to absorb iron whether they need it or not, and pushing up iron stores to the point where they actually increase our risk of some rather nasty diseases, like type 2 diabetes.
How well does this absorption regulation process work? Pretty darn well. We typically only absorb about 5-10% of the iron we consume in food, but during their menstrual period, women can absorb up to 8 times as much iron as usual! The same process happens in pregnancy, during which absorption of non-haem iron increases from less than 1% in early pregnancy to 7% at 12 week’s gestation, 36% at 24 weeks and 66% at 36 weeks. Smart body, eh?
A note of caution: Even if you consume plenty of iron-rich foods, you may still run into problems with iron if your intake of substances that block its absorption is too high. The most common villains are:
1. Polyphenols (including tannins found in black tea and peppermint tea), coffee, some wines, chocolate and cocoa). Just 1 cup of coffee inhibits iron absorption by up to 60%!
2. Phosvitin, a protein found in eggs. 1 egg can reduce iron absorption by 28%.
3. Milk proteins.
4. Prescription and over-the counter- drugs for suppressing stomach acid, including proton pump inhibitors, H2 antagonists and antacids. Fortunately, adopting a plant-based diet clears up indigestion and reflux pretty quickly for most people!
So that’s the deal with iron: make like Popeye and eat your dark green leafy vegetables – along with legumes (dried beans, peas and lentils), whole grains and seeds, preferably with some vinegar, lemon juice or other vitamin C-rich food to boost absorption – keep your absorption-blockers to a minimum, and let your body take care of the rest.