Both dried and canned kidney beans are available throughout the year. Dried beans are generally available in prepackaged containers as well as in bulk bins.
True to their name, these popular beans are kidney shaped and are especially good in simmered dishes where they absorb the flavors of seasonings and the other foods with which they are cooked.
Kidney beans are a very good source of cholesterol-lowering fiber, as are most other beans. In addition to lowering cholesterol, kidney beans’ high fiber content prevents blood sugar levels from rising too rapidly after a meal, making these beans an especially good choice for individuals with diabetes, insulin resistance or hypoglycemia. When combined with whole grains such as rice, kidney beans provide virtually fat-free high quality protein. But this is far from all kidney beans have to offer. Kidney beans are an excellent source of the trace mineral, molybdenum, an integral component of the enzyme sulfite oxidase, which is responsible for detoxifying sulfites. Sulfites are a type of preservative commonly added to prepared foods like delicatessen salads and salad bars. Persons who are sensitive to sulfites in these foods may experience rapid heartbeat, headache or disorientation if sulfites are unwittingly consumed. If you have ever reacted to sulfites, it may be because your molybdenum stores are insufficient to detoxify them.
A Fiber All Star
Check a chart of the fiber content in foods and you’ll see legumes leading the pack. Kidney beans, like other beans, are rich in soluble and insoluble fiber. Soluble fiber forms a gel-like substance in the digestive tract that binds with bile (which contains cholesterol)and ferries it out of the body. Research studies have shown that insoluble fiber not only helps to increase stool bulk and prevent constipation, but also helps prevent digestive disorders like irritable bowel syndrome and diverticulosis.
Lower Your Heart Attack Risk
In a study that examined food intake patterns and risk of death from coronary heart disease, researchers followed more than 16,000 middle-aged men in the U.S., Finland, The Netherlands, Italy, former Yugoslavia, Greece and Japan for 25 years. Typical food patterns were: higher consumption of dairy products in Northern Europe; higher consumption of meat in the U.S.; higher consumption of vegetables, legumes, fish, and wine in Southern Europe; and higher consumption of cereals, soy products, and fish in Japan. When researchers analyzed this data in relation to the risk of death from heart disease, they found that higher legume consumption was associated with a whopping 82% reduction in risk!
Kidney beans’ contribution to heart health lies not just in their fiber, but in the significant amounts of folate and magnesium these beans supply. Folate helps lower levels of homocysteine, an amino acid that is an intermediate product in an important metabolic process called the methylation cycle. Elevated blood levels of homocysteine are an independent risk factor for heart attack, stroke, or peripheral vascular disease, and are found in between 20-40% of patients with heart disease. It has been estimated that consumption of 100% of the daily value (DV) of folate would, by itself, reduce the number of heart attacks suffered by Americans each year by 10%. Kidney beans are a very good source of folate.
Kidney beans’ good supply of magnesium puts yet another plus in the column of its beneficial cardiovascular effects. Magnesium is Nature’s own calcium channel blocker. When there is enough magnesium around, veins and arteries breathe a sigh of relief and relax, which lessens resistance and improves the flow of blood, oxygen and nutrients throughout the body. Studies show that a deficiency of magnesium is not only associated with heart attack but that immediately following a heart attack, lack of sufficient magnesium promotes free radical injury to the heart. Want to literally keep your heart happy?
Kidney Beans Give You Energy to Burn While Stabilizing Blood Sugar
In addition to its beneficial effects on the digestive system and the heart, soluble fiber helps stabilize blood sugar levels. If you have insulin resistance, hypoglycemia or diabetes, kidney beans can really help you balance blood sugar levels while providing steady, slow-burning energy. Studies of high fiber diets and blood sugar levels have shown the dramatic benefits provided by these high fiber foods. Researchers compared two groups of people with type 2 diabetes who were fed different amounts of high fiber foods. One group ate the standard American Diabetic diet, which contained 24 grams of fiber/day, while the other group ate a diet containing 50 grams of fiber/day. Those who ate the diet higher in fiber had lower levels of both plasma glucose (blood sugar) and insulin (the hormone that helps blood sugar get into cells). The high fiber group also reduced their total cholesterol by nearly 7%, their triglyceride levels by 10.2% and their VLDL (Very Low Density Lipoprotein—the most dangerous form of cholesterol) levels by 12.5%.
Iron for Energy
In addition to providing slow burning complex carbohydrates, kidney beans can increase your energy by helping to replenish your iron stores. Particularly for menstruating women, who are more at risk for iron deficiency, boosting iron stores with kidney beans is a good idea—especially because, unlike red meat, another source of iron, kidney beans are low in calories and virtually fat-free. Iron is an integral component of hemoglobin, which transports oxygen from the lungs to all body cells, and is also part of key enzyme systems for energy production and metabolism. And remember: If you’re pregnant or lactating, your needs for iron increase. Growing children and adolescents also have increased needs for iron.
Maintain Your Memory with Thiamin (Vitamin B1)
Thiamin participates in enzymatic reactions central to energy production and is also critical for brain cell/cognitive function. This is because thiamin is needed for the synthesis of acetylcholine, the important neurotransmitter essential for memory and whose lack has been found to be a significant contributing factor in age-related impairment in mental function (senility) and Alzheimer’s disease. Alzheimer’s disease is clinically characterized by a decrease in acetylcholine levels.
Manganese for Energy Production and Antioxidant Defense
Kidney beans are a good source of the trace mineral manganese which is an essential cofactor in a number of enzymes important in energy production and antioxidant defenses. For example, the key oxidative enzyme superoxide dismutase, which disarms free radicals produced within the mitochondria (the energy production factories within our cells), requires manganese.
Protein Power Plus
If you’re wondering how to replace red meat in your menus, become a fan of kidney beans. These hearty beans are a good source of protein, and when combined with a whole grain such as whole wheat pasta or brown rice provide protein comparable to that of meat or dairy foods without the high calories or saturated fat found in these foods. And, when you get your protein from kidney beans, you also get the blood sugar stabilizing and heart health benefits of the soluble fiber provided by these versatile legumes. A cup of kidney beans provides over 15 grams of protein.
Just as its name suggests, the kidney bean is shaped like a kidney. Since these dark red beans hold their shape really well during cooking and readily absorb surrounding flavors, they are a favorite bean to use in simmered dishes. Kidney beans that are white in color are known as cannellini beans.
Kidney beans and other beans such as pinto beans, navy beans and black beans are known scientifically as Phaseolus vulgaris. They are referred to as “common beans” probably owing to the fact that they all derived from a common bean ancestor that originated in Peru.
They spread throughout South and Central America as a result of migrating Indian traders who brought kidney beans with them from Peru. Beans were introduced into Europe in the 15th century by Spanish explorers returning from their voyages to the New World.
Subsequently, Spanish and Portuguese traders introduced kidney beans into Africa and Asia. As beans are a very inexpensive form of good protein, they have become popular in many cultures throughout the world. Today, the largest commercial producers of dried common beans are India, China, Indonesia, Brazil and the United States.
How to Select and Store
Dried kidney beans are generally available in prepackaged containers as well as bulk bins. Just as with any other food that you purchase in the bulk section, make sure the bins are covered and that the store has a good product turnover rate.
Whether purchasing kidney beans in bulk or in a packaged container, make sure there is no evidence of moisture or insect damage and that the beans are whole and not cracked.
Canned kidney beans can be found in most markets. Unlike canned vegetables, which have lost much of their nutritional value, there is little difference in the nutritional value of canned kidney beans and those you cook yourself. Canning lowers vegetables’ nutritional value since they are best lightly cooked for a short period of time, while their canning process requires a long cooking time at high temperatures. On the other hand, beans require a long time to cook whether they are canned or you cook them yourself. Therefore, if enjoying canned beans is more convenient for you, by all means go ahead and enjoy them. We would suggest looking for those that do not contain extra salt or additives. (One concern about canned foods is the potential for the can to include a liner made from bisphenol A/BPA. To learn more about reducing your exposure to this compound, please read our write-up on the subject).
Store dried kidney beans in an airtight container in a cool, dry and dark place where they will keep for up to 12 months.
Cooked kidney beans will keep fresh in the refrigerator for about three days if placed in a covered container.
Tips for Preparing and Cooking
Tips for Preparing Kidney Beans
Before washing kidney beans, spread them out on a light colored plate or cooking surface to check for and remove stones and damaged beans. After this process, place the beans in a strainer and rinse them thoroughly under cool running water.
To shorten their cooking time and make them easier to digest, kidney beans should be presoaked (presoaking has been found to reduce the raffinose-type oligosaccharides, sugars associated with causing flatulence.) There are two basic methods for presoaking. For each, start by placing the beans in a saucepan with two to three cups of water per cup of beans.
The first method is to boil the beans for two minutes, take pan off the heat, cover and allow to stand for two hours. The alternative method is to simply soak the beans in water for eight hours or overnight, placing the pan in the refrigerator, so the beans will not ferment.
Before cooking the beans, regardless of pre-soaking method, drain the soaking liquid and rinse the beans with clean water.
The Healthiest Way of Cooking Kidney Beans
To cook the beans, you can either cook them on the stovetop or use a pressure cooker. For the stovetop method, add three cups of fresh water or broth for each cup of dried beans. The liquid should be about one to two inches above the top of the beans. Bring the beans to a boil and then reduce to a simmer, partially covering the pot. If any foam develops, simply skim it off during the simmering process.
Kidney beans generally take about one and one-half hours to become tender using this method. They can also be cooked in a pressure cooker where they take about one-half hour to prepare. Regardless of cooking method, do not add any seasonings that are salty or acidic until after the beans have been cooked. Adding them earlier will make the beans tough and greatly increase the cooking time.
How to Enjoy
A Few Quick Serving Ideas
- Combine cooked kidney beans with black beans and white beans to make a colorful three bean salad.
- Mix with tomatos and scallions and dress with olive oil, lemon juice, salt and black pepper.
- Serve cooked kidney beans over a piece of cornbread and top with grated cheese for a twist on the traditional tamale pie.
- In a food processor or blender, combine cooked kidney beans with garlic, cumin and chili peppers for a delicious spread that can be used as a crudité dip or sandwich filling.
- Make a pot of chili, the hearty Mexican soup that traditionally features kidney beans.
- Make tacos with a vegetarian twist by using kidney beans in place of ground meat.
Kidney beans have consistently been determined to have high oxalate content. Oxalates are naturally occurring organic acids found in a wide variety of foods, and in the case of certain medical conditions, they must be greatly restricted in a meal plan to prevent over-accumulation inside the body. Our comprehensive article about oxalates will provide you with practical and detailed information about these organic acids, food, and health.
Kidney Beans and Phytohemagglutinin
In raw form, kidney beans can contain excessively high amounts of a potentially toxic substance called phytohemagglutinin. This substance is classified as a lectin glycoprotein, and in sufficiently high amounts it has been shown to disrupt cellular metabolism. The amount of this toxin in beans is usually measured in terms of hemagglutinating units, or hau. In their raw form, red kidney beans can contain 20,000 to 70,000 hau. This number drops down to 200 to 400 hau with fully cooked red beans. White kidney beans start off with about 1/3rd less hemagglutinin than red ones.
Kidney beans are an excellent source of molybdenum. They are a very good source of folate, dietary fiber and copper. Kidney beans are a good source of manganese, phosphorus, protein, vitamin B1, iron, potassium and magnesium.