When I was vegetarian, I had a severe iron and B12 deficiency. I used to go to my doctor weekly for B12 injections and take iron supplements daily. It wasn’t until I went fully vegan that my nutrient deficiencies started to disappear.
You may be wondering how going vegan helped, but it did in tremendous ways! Many plant-based foods are rich in iron and beneficial nutrients, however there is a common misconception that you must consume animal products in order to maintain healthy iron levels. This is far from the truth, and the reality is that animal sources of iron have harmful effects on the body when compared to plant-based sources. So today I wanted to write a blog and present some interesting research on the topic!
What is Iron and Why is it Important?
Iron is an important mineral that helps to maintain healthy blood. A lack of iron is called iron deficiency anemia which is the most common nutritional deficiency, affecting about 4-5 million Americans per year. Iron deficiency occurs when our body doesn’t have enough iron to produce hemoglobin. Hemoglobin is a protein in red blood cells that is responsible for transporting oxygen to our body’s organs and tissues. Without enough iron, we are unable to produce healthy red blood cells to transport oxygen which leads to fatigue, dizziness and headaches.
Iron is necessary for healthy brain development and growth in children, as well as helping to maintain healthy red blood cells.
How Much Iron Do We Need?
The Recommended Dietary Allowance (RDA) for adults 19-50 years:
- Men: 8 mg daily.
- Women: 18 mg daily.
- Pregnant Women: 27 mg daily.
The higher intake amounts for women and pregnancy are due to blood loss during menstruation and the rapid growth of the fetus during pregnancy.
Heme vs Non-heme Iron
Now that we have talked a bit about what iron deficiency anemia is and the recommended daily intake, let’s differentiate between the two forms of iron.
Iron from food comes in two forms: heme and non-heme. Heme is only found in animal flesh such as meat, poultry, and seafood. Non-heme iron is found in plant foods such as whole grains, nuts, seeds, legumes, and leafy greens. Non-heme iron can also be found in animal flesh (animals consume plant foods with non-heme iron) and fortified foods.
About 40% of the iron found in animal sources is heme iron and about 60% is non-heme iron. Additionally, when heme iron is heated during cooking processes, much of it is denatured.
Although both forms of iron provide benefit to the body, high heme intake is associated with increased risk of several cancers, including colorectal cancer, pancreatic cancer and lung cancer.
Negative Health Effects Associated with Heme-Iron
The human body has no way to dispose of excess iron, which can lead to future health complications. As a result, excess iron is stored in our organs with the majority being put in our liver, heart, and pancreas. Too much iron in our organs can lead to damage and disease—eventually leading to life-threatening conditions such as liver disease, heart problems, diabetes, and certain types of cancers.
Because heme iron is absorbed at a higher rate (15%-35%) than non heme (2%-20%), it’s much easier to consume too much.
Meat is one of the largest dietary sources of heme. Many studies have suggested that the high heme content in red meat is associated with several diseases, including heart diseases, diabetes and cancer.
Red meat (beef, lamb and pork) has 10 times the heme content compared to white meat such as chicken. Research has shown that an increased risk of several types of cancer is associated with diets high in red meat. On the contrary, consumption of substantial amounts of green vegetables is associated with decreased risk of colon cancer, likely because vegetables contain low levels of heme iron.
Significantly Increases your risk of Coronary Heart Disease
Coronary heart disease (CHD) is caused by plaque buildup in the wall of the arteries that supply blood to the heart. Plaque is made up of cholesterol deposits and buildup causes the inside of the arteries to narrow over time. This process is called atherosclerosis.
Many studies have demonstrated a positive association between heme and coronary heart disease. The earliest evidence of this association was actually documented in 1994- findings included an increased risk of myocardial infarction among men consuming red meat as the main source of iron.
In another study, meat intake was used as a measure of dietary heme. Men who consumed meat six times a week compared to men who consumed meat less than once a week had a 60% increased risk of CHD.
Benefits of Non-Heme Iron
If you’re feeling confused as to where to get your iron from moving forward, I have one word for you- plants!! Plant based sources of iron are packed with beneficial antioxidants, nutrients and Vitamin C which aids in iron absorption. In addition, a plant-based diet has demonstrated the ability to protect our cells from inflammation and chronic diseases. Plant based sources of iron allow you to meet your nutritional requirements, without causing negative health effects.
Here are some of my favourite plant-based foods that are rich in iron:
- Lentils: Lentils come in three varieties: brown, green, and red. Lentils are not only packed with iron, but also high in potassium, fiber, and folate (a B vitamin). One cup contains 6.6 milligrams of iron.
- Tofu/Tempeh: Tofu and tempeh soy-based products are a big part of the vegan diet! Tofu has a higher iron content of 6.6 milligrams per half-cup. One cup of tempeh has 4.5 milligrams of iron.
- Spinach: one cup of cooked spinach contains 6.4 milligrams of iron. Try adding spinach to your smoothies, pastas or salads to naturally increase your iron intake!
- Beans: are an amazing source of iron! Kidney beans (5.2 milligram / cup), soybeans (4.5 milligrams / cup), and lima beans (4.5 milligrams / cup) have the highest iron content.
When it comes to iron, plant based sources are much healthier because they typically contain antioxidants and other crucial nutrients. In addition, plant-based foods have anti-inflammatory effects whereas animal derived foods are one of the main causes of inflammation in the Western diet. Try plant-based sources instead!
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Ascherio A;Hennekens CH;Buring JE;Master C;Stampfer MJ;Willett WC; (n.d.). Trans-fatty acids intake and risk of myocardial infarction. Circulation. Retrieved November 11, 2022, from https://pubmed.ncbi.nlm.nih.gov/8281700/
Centers for Disease Control and Prevention. (2021, July 19). Coronary artery disease. Centers for Disease Control and Prevention. Retrieved November 11, 2022, from https://www.cdc.gov/heartdisease/coronary_ad.htm#:~:text=Print-,Coronary%20Artery%20Disease,This%20process%20is%20called%20atherosclerosis.
Dutra, F. F., & Bozza, M. T. (1AD, January 1). Heme on innate immunity and inflammation. Frontiers. Retrieved November 10, 2022, from https://www.frontiersin.org/articles/10.3389/fphar.2014.00115/full
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Kaluza, J., Wolk, A., & Larsson, S. C. (2013). Heme iron intake and risk of stroke. Stroke, 44(2), 334–339. https://doi.org/10.1161/strokeaha.112.679662
Mayo Foundation for Medical Education and Research. (2022, January 4). Iron deficiency anemia. Mayo Clinic. Retrieved November 10, 2022, from https://www.mayoclinic.org/diseases-conditions/iron-deficiency-anemia/symptoms-causes/.