While Popeye may have relied on spinach to keep him strong, spinach is not as iron-rich as meat sources. That's because spinach is a non-heme iron source, meaning it does not impact your iron levels as significantly as heme iron sources from meat products. Whenever possible, heme iron sources are preferred for keeping your iron levels in check. If you do not eat meat, there are ways you can maximize non-heme iron absorption.
Heme Iron Definition
Heme iron comes from hemoglobin, a protein found in red blood cells. Hemoglobin carries oxygen to your tissues, which is why an iron deficiency can leave you feeling short of breath. Heme iron is found in animal products whose blood also contains hemoglobin, such as red meat, fish and poultry.
Non-Heme Iron Definition
Non-heme iron comes from plant sources that do not naturally contain hemoglobin. Examples include soybeans, lentils, peas, spinach, raisins, sugarcane and whole grains. Only about 2 to 20 percent of non-heme iron is absorbed while 15 to 35 percent of heme iron is absorbed, according to "Cooking Light" magazine.
Iron Absorption Example
Consider a 4-ounce hamburger that has a total of 3 milligrams of iron. An estimated 1.2 milligrams of this iron is from heme sources, while 1.8 milligrams is from non-heme sources, according to the Iron Disorders Institute. Your body will absorb an estimated 0.33 milligrams of heme iron. The amount of non-heme iron absorbed will be even smaller. However, if you have a medical condition that causes you to absorb more iron than normal, such as hereditary hemochromatosis, you will absorb as much as four times more iron.
You can improve your body's ability to absorb non-heme iron by eating non-heme iron foods with certain foods that enhance absorption. For example, foods high in vitamin C increase iron absorption. This includes broccoli, cabbages, orange juice, melon, tomatoes, strawberries and citrus fruits. Pairing non-heme iron sources such as spinach with a heme iron source such as red meat helps heighten non-heme iron absorption. This makes a flank steak and spinach salad a good lunch choice. "The New York Times" recommends cooking with cast iron pans and skillets to increase iron levels in your foods. Avoid foods known to interfere with iron absorption, such as coffee, tea, dairy products and eggs.
Rachel Nall began writing in 2003. She is a former managing editor for custom health publications, including physician journals. She has written for The Associated Press and "Jezebel," "Charleston," "Chatter" and "Reach" magazines. Nall is currently pursuing her Bachelor of Science in Nursing at the University of Tennessee.