When thoroughly cooked, kidney beans are not bad for you. They are actually very beneficial, providing protein, fiber and a variety of vitamins and minerals. However, raw kidney beans are toxic—which makes adequate preparation imperative.
A variety of the common bean, kidney beans are native to Central America and Mexico, but consumed all over the word. They are a staple in northern India, used in classic creole dishes in Louisiana and stewed in Spain.
The primary reason that kidney beans are so popular is because they are very high in protein—yet low in cost. Kidney beans are the richest source of plant-based protein. Just one cup provides an impressive 15 grams of protein. That’s not quite as much as chicken, which averages about 38 grams per cup of chopped meat. However, if you’re a vegetarian or struggling to make ends meet, kidney beans can provide a good chunk of your daily protein at a fraction of the cost of most meat.
Kidney beans are also rich in fiber. One cup of cooked beans provides approximately 6.4 grams, or about 18% of your daily recommended fiber. And while fiber-rich foods can lead to flatulence and diarrhea for some, the benefits far outweigh the negatives. For instance, the insoluble fiber in kidney beans combines with resistant starch to help clear out the digestive tract, promote positive bacterial growth and improve colon health—which may lead to a reduced risk of colon cancer.
In addition to protein and fibers, vitamins and minerals are also abundant in kidney beans. They are a rich source of iron, which is essential for energy and tissue health. Kidney beans are also high in heart-healthy folate, potassium and magnesium.
But while kidney beans offer a host of health benefits, it’s important to never eat them raw—red kidney beans in particular. They contain hemagglutinin, a dangerous compound that causes clumping amongst red blood cells. So when red kidney beans are eaten raw (and in large quantities), they can lead to serious illness, ranging from mild nausea and abdominal cramping to severe diarrhea and vomiting. However, hemagglutinin is essentially tempered as kidney beans are cooked, so these side effects only occur with raw consumption.
How do you ensure kidney beans are cooked properly? The US Food and Drug Administration makes specific recommendations: boil the beans for 30 minutes. This should help ensure they reach a hot enough temperature to eliminate the toxic effects hemagglutinin. Do not use a slow cooker. Cooking at temperatures below boiling can actually increase the toxicity of kidney beans—they become five times as toxic as they are when eaten raw.
Possible short-term side effects
Ingredients to be aware of
- reduces risk of colon cancer
- decreases risk of heart disease
- inexpensive source of protein
- high in vitamins and minerals