Your Healthiest Sources of Iron: Grains, Vegetables, Fruits and Beans 

Iron encourages the formation of cancer-causing free radicals. Of course, the body needs a certain amount of iron for healthy blood cells. But beyond this rather small amount, iron becomes a dangerous substance, acting as a catalyst for the formation of free radicals. Because of this, research studies have shown that higher amounts of iron in the blood mean higher cancer risk.

Once excess iron is absorbed by the digestive tract, the body stores it. Most of us accumulate much more iron than we need. In spite of the advertising from iron supplement manufacturers, "iron overload" is much more common in America than iron deficiency. Studies have shown that major contributors to iron excess are taking vitamin and mineral supplements that contain iron, excess consumption of red meat, and, to some extent, eating manufactured foods that have had iron added artificially. The iron present in these sources is highly absorbable. The iron in red meat, in particular, is a highly absorbable form (heme iron).

However, iron from vegetarian food sources (nonheme iron) may prove to be a better choice because, while it isn’t absorbed as well as heme iron, it is sufficient to promote adequate iron levels without encouraging iron stores above the recommended range. A diet of grains, vegetables, fruits, and beans provides adequate iron, without the risk of overload.

In fact, consuming just 100 calories of spinach gives you the same amount of iron as consuming 1,700 calories of a sirloin steak.