Iron, an essential mineral, exists naturally in animal products and some plant foods, including beans and other legumes. The body needs iron to produce hemoglobin, an oxygen-carrying protein found in red blood cells. Inadequate iron intake can lead to iron deficiency anemia, a condition that causes weakness, fatigue, decreased immunity and difficulty concentrating.
Type of Iron
Beans and other plant-based iron sources contain nonheme iron, a type of iron that the body absorbs less efficiently than heme iron from animal products. The body absorbs only 2 percent to 20 percent of nonheme iron. Several food components can hinder or boost nonheme iron absorption. Calcium, dairy products, tannins, polyphenols, phytates and soy protein can decrease nonheme iron absorption. Vitamin C can improve nonheme iron absorption, however. Consider eating beans and other nonheme iron sources with citrus fruit, tomato sauce or another source of vitamin C.
A 1-cup serving of boiled black or pinto beans provides 3.6 mg of iron. A 1 cup serving of boiled navy or lima beans provides 4.5 mg of iron, and a 1 cup serving of boiled kidney beans provides 5.2 mg of iron. Other legumes also provide good iron sources. A 1 cup serving of boiled black-eyed peas provides 1.8 mg of iron and a 1 cup serving of boiled lentils provides 6.6 mg of iron.
Percent Daily Value
The U.S. Food and Drug Administration has set a Daily Value, or DV, of 18 mg for iron. A serving of pinto or black beans provides about 20 percent of the Daily Value for iron and a serving of lima, kidney or navy beans provides about 25 percent of the Daily Value. Foods providing a greater percentage of the daily value include fortified cereal, fortified oatmeal and soybeans.
Beans also provide good sources of protein and dietary fiber. A ½-cup serving of adzuki, black, cranberry, garbanzo, great northern, kidney, lima, pink, pinto or navy beans provides 7 g to 8 g of protein. A ½-cup serving of pinto, navy, small red, garbanzo, great northern, kidney, lima, cranberry, adzuki, black or black-eyed beans provides 6 g to 13 g of dietary fiber. Most beans contain no cholesterol or sodium, and little fat.