Nutritional Profile of Bean Sprouts

About The Nutrients in Bean Sprouts

Because beans use stored starches and sugars to produce green shoots called sprouts, sprouted beans have less carbohydrate than the beans from which they grow. But bean sprouts are a good source of dietary fiber, including insoluble cellulose and lignin in leaf parts and soluble pectin and gums in the bean. The sprouts are also high in the B vitamin folate and vitamin C.

One-half cup raw mung bean sprouts has 1.2 g dietary fiber, 31.5 mcg folate (16 percent of the RDA for a man, 17.5 percent of the RDA for a woman), and 7 mg vitamin C (11.5 percent of the RDA).

Raw beans contain anti-nutrient chemicals that inhibit the enzymes we use to digest proteins and starches; hemagglutinens (substances that make red blood cells clump together); and "factors" that may inactivate vitamin A. These chemicals are usually destroyed when the beans are heated. Sprouted beans served with the bean must be cooked before serving.

Buying Bean Sprouts

Look for: Fresh, crisp sprouts. The tips should be moist and tender. (The shorter the sprout, the more tender it will be.) It is sometimes difficult to judge bean sprouts packed in plastic bags, but you can see through to tell if the tip of the sprout looks fresh. Sprouts sold from water-filled bowls should be refrigerated, protected from dirt and debris, and served with a spoon or tongs, not scooped up by hands.

Avoid: Mushy sprouts (they may be decayed) and soft ones (they have lost moisture and vitamin C).

Storing Bean Sprouts

Refrigerate sprouts in a plastic bag to keep them moist and crisp. If you bought them in a plastic bag, take them out and repack them in bags large enough that they do not crush each other. To get the most vitamin C, use the sprouts within a few days.

Preparing Bean Sprouts

Rinse the sprouts thoroughly under cold running water to get rid of dirt and sand. Discard any soft or browned sprouts, then cut off the roots and cook the sprouts.

Do not tear or cut the sprouts until you are ready to use them. When you slice into the sprouts, you tear cells, releasing enzymes that begin to destroy vitamin C.

What Happens When You Cook Bean Sprouts

Cooking destroys some of the heat-sensitive vitamin C in sprouts. To save it, steam the sprouts quickly, stir-fry them, or add them uncooked just before you serve the dish.

How Other Kinds of Processing Affect This Food

Canning. Vitamin C is heat-sensitive, and heating the sprouts during the canning process reduces their vitamin C content.

Medical Uses and/or Benefits

Lower risk of some birth defects. As many as two of every 1,000 babies born in the United States each year may have cleft palate or a neural tube (spinal cord) defect due to their mothers' not having gotten adequate amounts of folate during pregnancy. The current RDA for Eolate is 180 mcg for a woman and 200 mcg for a man, but the FDA now recommends 400 mcg for a woman who is or may become pregnant. Taking folate supplements before becoming pregnant and continuing through the first two months of pregnancy reduces the risk of cleft palate; taking folate through the entire pregnancy reduces the risk of neural tube defects.

Lower risk of heart attack. In the spring of 1998, an analysis of data from the records for more than 80,000 women enrolled in the long-running Nurses Health Study at Harvard School of Public Health/Brigham and Woman's Hospital in Boston demonstrated that a diet providing more than 400 mcg folate and 3 mg vitamin B6 a day from either food or supplements, more than twice the current RDA for each, may reduce a woman's risk of heart attack by almost 50 percent. Although men were not included in the analysis, the results are assumed to apply to them as well. NOTE: Fruit, green leafy vegetables, beans, whole grains, meat, fish, poultry, and shellfish are good sources of vitamin B6.

Adverse Effects Associated with Bean Sprouts

Food poisoning: Reacting to an outbreak of Salmonella and E. coli O157:H7 food poisoning associated with eating raw alfalfa sprouts, the Food and Drug Administration issued a warning in 1998 and again in summer 1999, cautioning those at high risk of food-borne illness not to eat any raw sprouts. The high-risk group includes children, older adults, and people with a weakened immune system (for example, those who are HIV-positive or undergoing cancer chemotherapy). Tests conducted by the U.S. Department of Agriculture in 1999 suggest that irradiating raw sprouts and bathing them in an antiseptic solution at the processing plant may eliminate disease organisms and prolong the vegetable's shelf life; this remains to be proven.