In my inbox today from Mark Hyman
Most people are aware of the importance of iron but less aware of the nuances associated with it—and where potentially problematic sources might be lurking in our diet.
How Our Bodies Use—and Lose—Iron
Iron helps deliver oxygen from our lungs to our tissues. The oxygen we breathe into our lungs hitches a ride from hemoglobin, the iron-rich protein inside our red blood cells. Hemoglobin and iron “carpool” together, picking up oxygen and dropping it off at its destination (tissue) and scooping up carbon dioxide on the way back to the lungs to be exhaled.
Our bodies are also extremely thrifty with iron. We recycle and reuse the iron from old red blood cells and have mechanisms in place that convert any excess iron in our blood to ferritin, the storage form of iron we can use if our levels ever drop too low.
Women in their reproductive years require significantly more iron than men. Menstruating women need to replace the iron they lose every month (approximately 14 mg) to prevent iron-deficiency anemia. Pregnant women also require more iron to support increased blood volume and the nutrient requirements for a growing baby.
Heme Iron vs. Non-Heme Iron
There are two types of dietary iron: heme iron, and non-heme iron. Heme iron is bound to hemoglobin and myoglobin (the hemoglobin that’s in our muscles), which is why it’s only found in animal foods like meat, fish, eggs, and poultry.
Non-heme iron is found in both animal and plant foods. The non-heme iron in plants is bound to phytates, oxalates, and other “anti-nutrients” that inhibit its absorption. That’s one reason why iron is a nutrient of concern for vegetarians and vegans—they must make sure they’re maximizing iron absorption from iron-rich plants like beans, dark chocolate, lentils, spinach, pistachios, and pumpkin seeds (see below for my recommendations on accomplishing this in the best way).
Unfortunately, for the average American, the primary sources of non-heme iron come from refined flour and fortified grains, which as we’ll see is a big problem!
Enrichment, Fortification, and Fallacies—Oh My!
Over seventy-five years ago, the FDA declared that food manufacturers must enrich the wheat flour used to make breads, pasta, and desserts with ferrous sulfate (a synthetic form of non-heme iron), in addition to the B vitamins niacin, riboflavin, and thiamin, to help prevent iron-deficiency anemia and other diseases related to nutrient deficiencies.
Despite these efforts, however, iron deficiency is still the number-one cause of anemia in the US today. Attempting to correct nutrient deficiencies by enriching popularly consumed refined flours with artificial nutrients seemed like a good idea back then, but we now know that this approach underestimates the complex nature of our biology. It also comes with unintended consequences!
The Trouble with Iron
We have biological mechanisms that tightly regulate iron homeostasis, but ferrous sulfate (synthetic, non-heme iron) isn’t recognized by our bodies in the same way as the iron we get from real, whole foods. Today, the average American eats 132 pounds of flour every year, which makes up the majority of non-heme iron in our diet.
Non-heme iron is already tough to absorb, but synthetic, non-heme iron is even more difficult. This means all of the iron-fortified grains and enriched wheat flour we eat isn’t doing much for us nutritionally. They do have an impact biologically, though, but it's not one that we should get excited about.
Refined wheat flour is one of the most inflammatory ingredients in processed foods due to its high gluten content, glycemic index, and being riddled with glyphosate residue. Not only that, refined flour is often kept in warehouses with poor storage conditions that make ferrous sulfate susceptible to oxidation.
Because refined wheat flour is a staple in the standard American diet, this excess, poorly absorbed iron circulating in our bloodstream can oxidize and cause damage to our DNA and cell membranes while accelerating aging. Studies show that men who eat refined flour have lower antioxidant levels and an increased activity level of antioxidant enzymes.
Food First: Optimize Your Iron Levels
With all of these problems, what are we to do? How can we eat an iron-rich diet that doesn’t adversely affect our health? The answer is to get iron naturally from real, whole foods.
Here are the best ways to meet your iron needs naturally:
The Pegan approach. This is the approach I take and the diet I recommend for most of my patients. Get your iron from both plant and animal foods. To increase plant-based iron absorption, eat your dark, leafy greens with a small side of meat. The heme iron in meat will increase the absorption of the non-heme iron from plants.
Three ways to increase iron absorption:
Pair iron-rich plant foods with vitamin C. This also increases the absorption of non-heme iron. Pair lentils with tomato sauce or add lemon juice to some sautéed spinach.
Eat fruit with non-heme iron. This isn’t an excuse to overdo it on sugar, but fructose does increase iron absorption. Adding some pomegranate seeds or blood orange to your spinach salad will increase non-heme iron absorption—and it will taste good too!
Don’t eat iron-rich foods with calcium. Calcium inhibits iron absorption. If you want to increase iron absorption in your meal and can tolerate dairy, don’t eat them together. This could mean not adding cheese to your eggs or goat cheese to your spinach salad.
Eliminate refined grains and flour. As if its blood sugar impact wasn’t enough to kick it to the curb, the high fructose corn syrup in processed foods significantly increases ferrous sulfate absorption, promoting oxidative stress and an imbalance of other micronutrients.
Our bodies have mechanisms in place that regulate iron absorption based on how much we have in reserve. The iron in refined wheat flour bypasses these mechanisms and can cause oxidative stress in our bodies that’s similar to rust, like a bicycle that’s been left outside in the rain. I don’t know about you, but I’d rather wear out than rust out!
The bottom line is this: focus on getting your iron in naturally and remove the harmful sources from your diet. Your body will thank you.
Wishing you health and happiness,
Mark Hyman, MD