Spinach may not give you superhuman strength to fight off villains like Popeye's nemesis Bluto, but this leafy green and other foods containing iron can help you fight a different type of enemy -- iron-deficiency anemia.
Iron-deficiency anemia, the most common form of anemia, is a decrease in the number of red blood cells caused by too little iron. Without sufficient iron, your body can't produce enough hemoglobin, a substance in red blood cells that makes it possible for them to carry oxygen to the body's tissues. As a result, you may feel weak, tired, and irritable.
How Your Body Uses Iron in Food
When you eat food with iron, iron is absorbed into your body mainly through the upper part of your small intestine.
There are two forms of dietary iron: heme and nonheme. Heme iron is derived from hemoglobin. It is found in animal foods that originally contained hemoglobin, such as red meats, fish, and poultry (meat, poultry, and seafood contain both heme and non-heme iron). Your body absorbs the most iron from heme sources. Most nonheme iron is from plant sources.
Very good sources of heme iron, with 3.5 milligrams or more per serving, include:
- 3 ounces of beef or chicken liver
- 3 ounces of clams or mussels
- 3 ounces of oysters
Good sources of heme iron, with 2.1 milligrams or more per serving, include:
- 3 ounces of cooked beef
- 3 ounces of canned sardines, canned in oil
Other sources of heme iron, with 0.6 milligrams or more per serving, include:
- 3 ounces of chicken
- 3 ounces of cooked turkey
- 3 ounces of ham
- 3 ounces of veal
Other sources of heme iron, with 0.3 milligrams or more per serving, include:
- 3 ounces of halibut, haddock, perch, salmon, or tuna
Iron in plant foods such as lentils, beans, and spinach is nonheme iron. This is the form of iron added to iron-enriched and iron-fortified foods. Our bodies are less efficient at absorbing nonheme iron, but most dietary iron is nonheme iron.
Very good sources of nonheme iron, with 3.5 milligrams or more per serving, include:
- Breakfast cereals enriched with iron
- One cup of cooked beans
- One-half cup of tofu
Good sources of nonheme iron, with 2.1 milligrams or more per serving, include:
- One-half cup of canned lima beans, red kidney beans, or chickpeas
- One cup of dried apricots
- One medium baked potato
- One cup of cooked enriched egg noodles
- One-fourth cup of wheat germ
- 1 ounce of pumpkin, sesame, or squash seeds
Other sources of nonheme iron, with 0.7 milligrams or more, include:
- One-half cup of cooked split peas
- 1 ounce of peanuts, pecans, walnuts, pistachios, roasted almonds, roasted cashews, or sunflower seeds
- One-half cup of dried seedless raisins, peaches, or prunes
- One medium stalk of broccoli
- One cup of raw spinach
- One cup of pasta (cooked, it becomes 3-4 cups)
- One slice of bread, half of a small pumpernickel bagel, or bran muffin
- One cup of brown or enriched rice
How to Get More Iron From Your Food
Some foods can help your body absorb iron from iron-rich foods; others can hinder it. To absorb the most iron from the foods you eat, avoid drinking coffee or tea or consuming calcium-rich foods or drinks with meals containing iron-rich foods. Calcium itself can interfere.To improve your absorption of iron, eat it along with a good source of vitamin C -- such as orange juice, broccoli, or strawberries -- or eat nonheme iron foods with a food from the meat, fish, and poultry group.
If you have trouble getting enough iron from food sources, you may need an iron supplement. But speak to your health care provider about the proper dosage first and follow his or her instructions carefully. Because very little iron is excreted from the body, iron can accumulate in body tissues and organs when the normal storage sites -- the liver, spleen, and bone marrow -- are full. Although iron toxicity from food sources is rare, deadly overdoses are possible with supplements.