Beans are a wonderful source of protein, dietary fiber, B vitamins, iron, folate and potassium. Choosing dried beans over canned is generally a healthy idea since canned beans tend to be loaded with sodium. However, certain dried beans can be very harmful if not prepared correctly.
Phytohaemagglutinin (PHA) is a natural toxin found in many types of dried beans. When consumed in high concentrations, it can cause a serious illness called red kidney bean poisoning (Phaseolus vulgaris). In reference to its name, it's not surprising that red kidney beans have the highest concentration of PHA, but white kidney beans and black (turtle) beans may also have high levels. Within just a few hours of eating these raw or undercooked beans, symptoms of nausea, vomiting, diarrhea and abdominal pain may appear.
PHA can be destroyed by rapidly cooking the beans to at least 176?F. Stove-top and oven baked recipes reach high enough temperatures to destroy the toxin, but the current trend is to cook dried beans in a slow cooker. However, slow cookers may not reach a high enough temperature to destroy the toxin. According to Utah State University Extension, these beans should be boiled on the stove-top for 10 minutes, drained, and rinsed prior to cooking in a slow cooker. Of course, if you tend to error on the side of caution, just use canned beans. Canned beans are processed at a high temperature and pressure so most of the PHA is destroyed, making the beans safe to eat.
Luckily, research has shown that other common dried beans, such as pinto or navy, have very low levels of PHA and therefore, are not a cause of concern.
Southwestern Salad (Printable PDF)
1 lb. lean ground beef
½ cup onion, chopped
1 Tablespoon chili powder
2 teaspoons dried oregano
1 teaspoon cumin
1 cup canned kidney beans, drained and rinsed
1 can (15 oz.) canned black beans, drained and rinsed
1 tomato, diced
2 cups lettuce, torn
½ cup shredded reduced-fat cheddar cheese
Brown beef and onions in large skillet and drain off grease. Stir in spices, beans and tomato into beef mixture and cook for 3 minutes. Spoon beef mixture onto torn lettuce and sprinkle with cheese.
Yield: 4 servings
Nutritional analysis per serving: 350 Calories, 9 grams fat, 540 milligrams sodium, 29 grams carbohydrate, 6 grams fiber, 37 grams protein