Did you know that iron deficiency is the most common nutrient deficiency in the US (and the world)? One of my students recently asked me how this could be so, since “Americans eat tons of red meat”. Let’s look at what factors contribute to making iron deficiency so prevalent (and clear up a myth or two in the process).
Who’s At Risk?
If you can say YES to ANY of the following, you are at risk of being iron deficient:
- Are you a pre-menopausal woman?
- Do you regularly use antacids or acid blockers?
- Do you engage in regular, intense exercise (like cross-fit, marathons, half-marathons or triathlons)?
- Are you a vegetarian or vegan?
- Do you eat a diet high in nuts, seeds, grains and legumes, especially soybeans, that are not soaked and/or sprouted?
- Are you an infant, child, teen or pregnant woman?
- Do you have celiac disease (or other malabsorption issues, like IBS)?
- Have you had gastric bypass surgery?
- Do you avoid eating organ meats, like liver, kidney, heart, spleen, giblets?
The Recommended Dietary Allowance (RDA) is the amount of a vitamin or mineral that a person needs to consume each day to avoid known disease or illness. (Keep in mind that this is not the amount needed for optimal health, but that is another blog post for another day…)
The current RDA for iron for the following age, sex and life stages:
- Infants 11 mg/day (7-12 months)
- Children 7-10 mg/day (depending on age)
- Teen boys 11 mg/day
- Teen girls 15 mg/day
- Pregnancy 27 mg/day
- Adult pre-menopausal women 18 mg/day
- Adults 8 mg/day (men and post-menopausal women)
The average intake for a US adult man is 16-18 mg of iron per day and the average intake for a women is 12 mg per day. To put things in perspective, a woman would need to consume over 23 ounces of beef per day to meet the RDA, 48 oz of DARK meat chicken, 60 oz of white meat (breast, without skin) chicken, 16 cups of kale or 22 cups of spinach (assuming that she could absorb ALL of the iron she consumed, but we will discuss that in a moment). As you are hopefully starting to see, the most common sources of iron in the American diet are not actually very rich source of iron at all.
Red meat is thought to be a “good source” of iron, so how can iron deficiency be so common if Americans eat “tons of red meat”? This “tons of red meat” myth is a common belief, however currently the US per capita consumption of chicken is actually higher than beef consumption. Red meat consumption has fallen in recent years because we’ve been told it is bad for us, when it actually is not (this is another blog topic – hopefully you can see a sneak peak about how nutrient-dense red meat is). As you can see from the examples above, chicken contains only 25-50% of the iron content of red meat. Chicken is not a very good source of iron and the cuts of beef that we eat in the US are also not great sources of iron.
Even if you’re eating pounds of beef and chicken every day and 16 cups of kale, there is another crucial piece to this iron deficiency puzzle: absorption.
There are two kinds or iron that we consume: heme and non-heme. Simply put, heme iron is iron that comes from food of animal source and non-heme iron comes from all other sources (plants, nuts, seeds, grains, and supplements). Human bodies absorb 25-35% of heme iron (animal source) and only 2-3% of non-heme iron (plant source). Soybeans, or foods made from soybeans, have the lowest absorption rates for iron – only 2% (except tempeh, miso and other fermented forms). Therefore, 65-98% of dietary iron is not absorbed at all from the food and supplements we consume. One of the reason there is such a staggering difference between animal and plant iron absorption is due to anti-nutrients that inhibit iron absorption. Anti-nutrients that interfere with iron absorption are phytic acid (in grains, seeds, nuts, soybeans), polyphenols (tannins in coffee and tea) and other compounds in soy protein (added to the phytic acid affect).
Now let’s look back at iron intake and factor in the absorption rates so that we can understand why iron deficiency is so common. To meet a woman’s daily needs for iron from beef, she would need to consume over 31 oz of beef per day, 64 oz of dark meat chicken, 545 cups of kale, 750 cups of spinach or 1,800 oz of tofu. For adult men, those amounts would be 14 oz of beef, 28 oz of dark meat chicken, 242 cups of kale, 333 cups of spinach or 800 oz of tofu. Are you starting to understand why you might be at risk for iron deficiency?
Signs and Symptoms of Iron Deficient
How do you know if you are deficient? If you fit any of the risk categories above, you are likely not getting enough iron for optimal health. If you are unsure, consult your healthcare provider for appropriate blood tests. Here are some common signs and symptoms of iron deficiency:
- Rapid heart rate, palpitations, and rapid breathing on exertion
- Intolerance to cold
- Brittle, spoon-shaped nails
- Sores at corners of mouth
- Poor sense of taste and/or sore tongue
- Cravings for non-food items (pica)
- Pregnancy complications
- Impaired immune function
- Restless Leg Syndrome
How To Optimize Iron Intake and Absorption
To avoid deficiency, you need to eat enough iron-rich foods AND maximize your absorption. The will mean you need to emphasize foods high in iron along with limiting foods that are high in anti-nutrients that interfere with iron absorption.
–Foods to ADD
If you fit any of the categories at the beginning of this article, you will want to emphasize the following foods in your diet. Aim for 3 servings per day (3-4 oz at every meal and snack), but some is better than none.
- Organ meats (kidney, spleen, liver, giblets, heart) and foods made from them (liver pate, braunschweiger, liverwurst, blood sausage, etc.) – these foods are actually the most nutrient-dense foods we could eat, but we rarely eat them in the US any more. They all are very high in iron, plus they contain plenty of vitamin A, which enhances absorption and utilization within the body even more. These are the BEST sources because they are the most absorbable and utilizable sources of iron. (Do you still believe the myth that liver is full of toxins and should be avoided? OK, I’ll write another blog post on that, too…)
- Heme iron (iron from animal sources) – if you are vegetarian and experiencing iron deficiency, consider adding a few key concentrated sources of iron for therapeutic purposes. Some vegetarians are willing to create “liver pills” by cooking liver and cutting it into pill-sized pieces, then freezing. Swallow several “pills” at each meal or add to smoothies or other pureed dishes (like soups).
- Seafood – oysters, muscles, and clams are all great sources of highly absorbable iron.
- Dried fruits – when the water is removed, nutrients become more concentrated. Especially good sources of iron are raisins, apricots, prunes and peaches.
- Dried herbs and spices – most herbs and spices are concentrated sources of minerals and other nutrients. Use liberally in cooking.
- Soaked and sprouted grains, seeds, and legumes – these foods all contain anti-nutrients that inhibit iron absorption, so if you are deficient and still want to eat these foods, soaking and/or sprouting will be essential to optimize your absorption.
–Foods to AVOID
If you said YES to any of the categories in the first part of this article, you will want to avoid the following foods in order to maximize your absorption and avoid iron deficiency:
- Cereals, at breakfast or any other time – cereals, whether hot or cold, are made from grains and contain phytic acid, which blocks the absorption of iron. Despite what you may believe, oatmeal is not a great choice for breakfast (another blog post coming on this, too), especially if you are iron deficient.
- Grains and rice – all side dishes made with grains and things made from flour, like rice, risotto, quinoa, bread, pasta, muffins, cakes, and baked goods. Some phytic acid can be neutralized by sprouting, so sprouted grain products can be OK in limited amounts.
- Nuts and Seeds – these too contain phytic acid, which blocks iron absorption. Soaking and sprouting can help reduce phytic acid’s effects.
- Corn – unlike other grains where sprouting can neutralize the phytic acid, the phytic acid in corn is particularly hard to neutralize. If you are iron deficient, avoid corn to optimize iron absorption.
- Legumes – garbanzo beans, kidney beans, black beans, etc.; lentils; dried peas and the foods made from them, like, chili, dal, canned soups, hummus and bean dips. These also contain phytic acid.
- Coffee and tea – These beverages contain tannins that inhibit iron absorption. Drink these beverages away from meals, or better yet, avoid them all together if you are iron deficient.
- Any food made from soybeans – soybeans have the lowest iron absorption rate of any food–2% when not sprouted or fermented. Avoid tofu, edamame, soy protein, soy protein powder, vegetarian “meats”, texturized vegetable protein (common in frozen foods). when you eat them, they are taking the place of more iron-rich foods. Replace them with foods from the ADD list above.
Here is a suggested menu for maximum iron intake and absorption:
Breakfast: breakfast hash made of braunschweiger sausage + potatoes + onions + bell peppers + dried thyme
Dinner: New England clam chowder (with double clams, seasoned with thyme, parsley and marjoram) + sauteed greens + Pomegranate Molasses Vinaigrette
Snacks: chicken liver pate on crackers, smoked oysters, dried fruit (raisins, apricots, peaches, prunes)
An Evidence-based Approach to Vitamins and Mineral, 2012. Jane Higdon and Victoria J. Drake. Thieme Publishing.