Getting Iron on a plant based diet

Nutrition, April 30, 2018

One of the biggest concerns with cutting or even decreasing meat and dairy from the diet is getting enough Iron. Here is some great information gleamed from Dr. Michelle McMacken (who you can follow on Instagram @veg_md) with some added information

The heme iron found in blood and muscle is more readily absorbed than non-heme iron found in plants but this isn't necessarily a good thing. It results in us tending to store Iron even though our bodies don't need it. Higher iron stores correlate with type 2 diabetes, certain types of cancer, heart disease and premature mortality. In a recent study (R. Sinha et al, Meat Intake and Mortality, Arch Intern Med. 2009, March 23: 169 (6):562-571) of almost half a million adults heme iron was strongly linked to death from nine different causes. This may be because heme iron is a pro-oxidant molecule that can form carcinogens (contributing to the development of atherosclerosis by oxidizing cholesterol with free radicals. The risk has been quantified as a 27% increase in coronary heart disease risk for every 1 milligram of heme iron consumed daily). and create DNA damage, oxidative stress and inflammation.

In contrast, when we get iron from plants in the form of non-heme iron (examples below) our bodies are better able to regulate absorbtion - if our iron stores are low, we absorb more and if too high we don't take on as much. People eating plant based diets can adapt over time to absorb more iron. Non-heme iron has not been tied to chronic diseases and it has the added benefits of phytonutrients found in plants.

Iron is abundant in many plant foods. Phytates in some plant foods can decrease absorbtion but this can be overcome by pairing these foods with Vit C or citrus. It has been shown that 50mg of Vit C (found in 3/4 cup of broccoli, brussel sprouts, cauliflower, bell peppers, papaya or strawberries) raises iron absorbtion 4-6 times! To maximise iron absorption avoid drinking coffee and tea with meals as these inhibit absorption as do calcuim supplements, and dairy. Try to have these an hour either side of meals.  

Vegans and vegetarians are no more likely to have iron deficiency anemia compared to omnivores. In fact vegans consume as much or more. Moderate to severe iron-deficiency anemia may require iron supplements with the help of a health professional. Eating meat is not the best answer. If you do have iron-deficiency anemia the first step is finding out why. The cause is almost never a well planned plant based diet. More common reasons are menstrual blood loss, gastrointestinal bleeding, or another health issue. 

Whole grains generally contain more iron than refined grains. They also have several other nutrients and plant compounds beneficial to health. Nuts and seeds are good sources of non-heme iron as well as an array of other vitamins, minerals, fiber, healthy fats, and other awesome plant compounds. Beans, peas, and lentils are rich in iron and contain good amounts of protein, fiber, vitamins, minerals plus other compounds that will reduce your risk of various diseases. 

A lack of Iron should not be a barrier stopping you switching to plant based diet and reducing (or eliminating) meat, eggs, and dairy. Note the mg of Iron will vary - I have taken the average many different sources.

- Lentils (6.6mg per cup cooked or 37% of RDI)

- Beans (especially soy - 8.8mg per cup or 49% of RDI)

- Leafy greens (spinach, kale, beet greens 2.5-6.4mg per cup cooked or 14-35% of RDI)

- Broccoli (1mg per cooked cup or 6% of RDI)

- Oats (3.4mg per cooked cup or 19% of RDI)

- Olives (3.3mg per 100grams or 18% of RDI)

- Quinoa (2.8mg per cup cooked or 16% of RDI) 

- Seeds (Pumpkin, sesame, hemp and flaxseeds contain 1.2-4.2mg per 2 Tablespoons or 7-23% of RDI)

- Dark Chocolate (3.3mg per 28 grams)

The recommended daily intake of Iron (NZ Nutrition Foundation site) varies depending on age and stage. For example the recommended Iron intake for a women aged between 19-50 years is 18mg/day, a pregnant women up to 27mg/day. Children between 1-13 years should have between 8-10mg/day and infants under 1 year 11mg/day. The average man requires 8mg/day.  If you are an endurance runner then you will need more than these recommendations as there is a loss of iron during sweating.

Feel free to view this informative video by Dr. Michael Greger on the safety of Heme vs Non heme iron.