Normally, your body uses iron from the food you eat or recycled iron from old red blood cells to make hemoglobin. However, if you are not consuming enough iron or your body loses too much iron, you will eventually develop anemia. Some of the main causes for this are:
- Lack of Iron in Your Diet: If you do not eat enough iron-rich foods, your body simply will not have enough iron to keep your body healthy. Read below for iron-rich foods and some tips for increased iron absorption.
- Inability to Absorb Iron: Our bodies don't always work perfectly and there are a few conditions such as Crohn's disease or celiac disease that affect our intestine's ability to absorb nutrients in food.
- Blood Loss: If you are losing blood, you are losing iron. Women with heavy periods are at a higher risk. Other conditions that cause slow but steady blood loss -such as a peptic ulcer, kidney or bladder tumor, a colon polyp, colorectal cancer or uterine fibroids- can also lead to iron deficiency. Be sure to tell your doctor if you ever realize blood in your urine or stools.
- At Risk Populations: Pregnant women, premature infants or infants born with a low birth weight, children going through growth spurts, people on dialysis, people with GI disorders and people who engage in regular, intense exercise may all be at increased risk for iron deficiency.
- Omnivores -
- Adult males: 8 mg/day
- Adult females who are menstruating: 18 mg/day
- Adult females who are post-menopausal: 8 mg/day
- Vegetarians and Vegans-
- Adult males: 14 mg/day
- Adult females who are menstruating: 32 mg/day
- Adult females who are post-menopausal: 14 mg/day
- The needs for children vary as they grow
The Top 10 Iron-Providing Foods:
- Red meat
- Egg yolks
- Dark, leafy greens (spinach, collards)
- Dried fruit (prunes, raisins)
- Iron-enriched cereals and grains (check the labels)
- Mollusks (oysters, clams, scallops)
- Turkey or chicken giblets
- Beans, lentils, chick peas and soybeans
- Other good sources include: spirulina, raw cashews, tahini, raw sunflower seeds, raw almonds, kelp, figs and quinoa.
Heme vs Nonheme:
As we previously discussed, iron is a touchy nutrient. You don't want too much but you certainly don't want too little. Fortunately, it is not that hard to get all you need from food sources, whether you eat meat or not. Iron is found in our food in two forms: heme and nonheme. Heme is found only in the red blood cells and muscle cells of animals and our bodies absorb this form more efficiently. In addition, the heme from the animal sources actually aids in the absorption of nonheme iron. This means that even when my vegetarian meal has just as much iron in it as the steak on my hubby's plate, he will naturally absorb more iron than me. The absorption of heme iron is not affected by the other nutrients in the meal. However, nonheme iron is. As if getting enough iron in a veggie diet was not already a little tricky, now you have to pay attention to food combinations.
The Following Foods and Nutrients Inhibit Nonheme Iron Absorption:
- Phytates - Present in maize, whole grains, legumes, nuts and seeds. Phytates use oxygen to bind to many minerals including zinc, copper and calcium. The phytates are insoluble and thus when binded to iron, cause it to be poorly absorbed.
- Polyphenols - Found in high concentrations in coffee, tea, red wine and fruitm polyphenols can reduce absorption over 60 percent.
- Phosvitin - protein containing phosphorylated serine residues found in egg yolks
- Foods high in calcium and calcium supplements - Several studies have demonstrated that calcium in amounts from 300-600 mg can decrease iron absorption by up to 70 percent!
- Milk protein
Hmm, seems like pretty much everything I eat interferes with iron absorption. Don't give up yet! Eating ascorbic acid (aka, Vitamin C) with your meal not only increases the absorption but completely wipes out the negative effects of the inhibitors, listed above. Good vegetarian sources of vitamin C include citrus fruits and juices, strawberries, green peppers, broccoli, cauliflower, tomatoes and tomato juice. In addition, soaking and sprouting seeds, beans and grains reduces the phytate levels, as well as fermenting food.
With nonheme iron, our bodies are less likely to get too much iron because the body absorbs more nonheme iron when our stores are low and less when our stores are high. However, heme iron is absorbed regardless of your body's stores. Iron is a pro-oxidant (opposite of those awesome antioxidants), meaning it activates free radicals which can cause damage to the DNA and produce LDL (the bad artery damaging cholesterol). Some researchers are concerned that high levels could increase the risk for heart disease and some cancers.
I hope you learned that iron deficiency is no joke! If left untreated, it can lead to heart problems, complications during pregnancy and delayed growth in children. Get your levels tested routinely if you find yourself with low concentrations. But before you run to the store to pick up a supplement, please check with a doctor. Our bodies don't have a magic mechanism to get rid of excess iron. High concentrations of iron are dangerous. You certainly don't need to eat meat to get your iron, but if you fall into any of the at risk categories, please do check with your doctor. Happy Eating!
- "Iron Deficiency Anemia." Mayo Clinic. http://www.mayoclinic.com/health/iron-deficiency-anemia/DS00323/DSECTION=causes
- Link, L. "Iron In Your Diet." Crazy Sexy Life. http://crazysexylife.com/2010/iron-in-your-diet/
- Gropper, S, Smith, J and Groff, J. Advanced Nutrition and Human Metabolism. 5th Edition. Wadsworth, 2009.