Heme Iron

An important mineral, iron helps maintain blood health. It is a primary component of hemoglobin, a protein in red blood cells that carries oxygen to all parts of the body from the lungs, and part of myoglobin, a protein that transports and stores oxygen in our muscles. Iron is important for childhood brain development and growth, as well as the production and functioning of myriad hormones and cells.

Iron from food comes in two forms: heme and non-heme. Heme iron is found predominantly in blood and muscle, whereas non-heme iron is primarily found in plants, such as whole grains, nuts and seeds, legumes, and leafy greens. We used to think of heme iron as coming exclusively from animal products and non-heme iron as found only in plants, but that isn’t the case. The plant-based Impossible Burger contains heme iron derived from soybean plants, for example, and non-heme iron can be found in meat if the animal had consumed plant foods with non-heme iron.

Similarly, we used to associate heme iron—but not non-heme iron—with greater risk of some cancers, heart disease, and diabetes. But, in many studies with these findings, heme intake may have simply been a marker for meat intake.

We know with certainty, though, that the healthiest sources of iron are whole grains, legumes, nuts, seeds, dried fruits, and green leafy vegetables. We should avoid drinking tea with meals, as that can inhibit iron absorption, whereas consuming vitamin C-rich foods can improve it. The amount of vitamin C in a single orange, for example, can enhance iron absorption as much as three- to sixfold, so those trying to boost their iron absorption should reach for some fruit instead of a cup of tea.

The information on this page has been compiled from the research presented in the videos listed. Sources for each video can be found by going to the video’s page and clicking on the Sources Cited tab.