Black beans and kidney beans are commonly eaten around the world and are used in a variety of dishes.
They both have many nutrients present that can help keep you healthy.
In this article, we will be discussing the differences between black beans and kidney beans across a range of different factors, including their nutritional composition and health.
Introduction to Black Beans and Kidney Beans
Black beans and kidney beans are both legumes of the pea family, Fabaceae. They are two separate varieties of beans that look different.
Kidney beans are a variety of the common bean Phaseolus vulgaris, as are black beans. Kidney beans come in different colors including white, beige, pink, and red, while black beans are black in color.
The red kidney beans have the compound phytohemagglutinin, which is toxic if the beans are eaten raw. Kidney beans must be cooked, particularly if they are the red variety. The beans are then perfectly safe to eat. (1).
Black beans and kidney beans are popular vegetables that are routinely cooked and added to meals. People also can substitute one for the other. For example, using black beans instead of kidney beans or vice versa.
- Black beans are also called black turtle beans. They are popular in Latin American dishes (2). The water from cooking black beans is also used as the base for a soup known as sopa de frijoles. They can be added to a dish with egg or added to tortilla or even made into a dip.
- Kidney beans are often made into chili but can also be used in soups and added to tortilla or rice.
There are many dishes that you can add kidney beans and black beans to. Both have many nutrients and health benefits when included as part of a meal plan.
Nutritional Composition Comparison
| Nutrient | Black Beans (mature, raw, per 100g) | Kidney Beans (mature, raw, per 100g) |
|---|---|---|
| Calories (kcal) | 341 | 333 |
| Carbs (g) | 62.4 | 60 |
| Sugars (g) | 2.12 | 2.23 |
| Protein (g) | 21.6 | 23.6 |
| Fats (g) | 1.42 | 0.83 |
| Cholesterol (mg) | 0 | 0 |
| Fiber (g) | 15.5 | 24.9 |
| Sodium (mg) | 5 | 24 |
| Vitamin A (IU) | 17 | 0 |
| Vitamin B1 – thiamine (mg) | 0.9 | 0.529 |
| Vitamins B2 – riboflavin (mg) | 0.193 | 0.219 |
| Vitamin B3 – niacin (mg) | 1.96 | 2.06 |
| Vitamin B5 – pantothenic acid (mg) | 0.899 | 0.78 |
| Vitamin B6 – pyridoxine (mg) | 0.286 | 0.397 |
| Vitamin B9 – folate (µg) | 444 | 394 |
| Vitamin C (mg) | 0 | 4.5 |
| Vitamin E (mg) | 0.21 | 0.22 |
| Vitamin K (µg) | 5.6 | 19 |
| Magnesium (mg) | 171 | 140 |
| Calcium (mg) | 123 | 143 |
| Potassium (mg) | 1480 | 1410 |
| Manganese (mg) | 1.06 | 1.02 |
| Phosphorus (mg) | 352 | 407 |
| Iron (mg) | 5.02 | 8.2 |
| Zinc (mg) | 3.65 | 2.79 |
| Selenium (µg) | 3.2 | 3.2 |
| Glycemic (GI) index | 20 | 20 |
This table contains the nutritional values for black beans and kidney beans. The data are from the USDA website (3, 4). All nutrients are given as amounts per 100 g.
Black Beans vs Kidney Beans Health Comparison
We will discuss the health benefits in terms of nutritional quality and content of both black beans and kidney beans. Read on to find out more about how including these beans in your diet can help you stay healthy.
Black Beans are Good For Your Eyes
You probably do not think about legumes being helpful for your eyes, but some like the black beans have vitamin A present. Kidney beans do not have vitamin A present.
Vitamin A helps vision and is also useful because it keeps skin healthy (5).
Our eyes and skin are, like the rest of our body, affected by ageing. It is, thus, a good idea to include a variety of foods, including beans, that contain nutrients that help our eyes and skin to stay healthy.
Black Beans Help Boost the Immune System
Believe it or not, black beans also help our immune system. This is because of vitamin A, which also acts as an antioxidant.
There is also quite a bit of vitamin E present in the beans. This also is good for our immune system and is an antioxidant (6).
Remember a healthy immune system protects you from diseases because your body can more easily fight off harmful bacteria and viruses.
A strong immune system has many benefits including helping to protect you from cancer-causing chemicals (7).
Vitamin E protects our cells from damage. Every day our bodies are exposed to harmful chemicals in the environment. Our own bodies make some harmful stuff that antioxidants help to repair.
Eating food rich in antioxidants like vitamins A and E is, therefore, a smart move in keeping yourself healthy.
But Kidney Beans Are Great for the Immune System Too
Kidney beans have some vitamin C present while the black beans have no vitamin C. We have already seen that black beans do have some antioxidant vitamins present like vitamin A and E.
- Kidney beans have vitamin E and vitamin C.
- The vitamin C is also an antioxidant that helps keep our bodies strong and healthy (8).
- Vitamin C is an important chemical for the proper functioning of the immune system.
- The selenium and zinc found in the beans also help with immunity (9).
Black Beans Help Control Blood Sugar Levels
Black beans are rich in dietary fiber and have a low glycemic index. The glycemic (GI) index is based on how quickly carbohydrates break down (10).
Carbohydrates that break down too rapidly cause spikes in blood sugar and these are classified as high GI foods. The carbohydrates in beans break down slowly and do not cause big spikes in blood sugar.
The low GI index and the high fiber in beans help control your blood sugar levels. This is a big benefit because many people develop insulin resistance over time without realizing it.
- Insulin resistance is when your cells do not respond properly to insulin meaning that sugar builds up in your blood.
- Scientists have found that black beans help prevent insulin resistance because they also help regulate gut bacteria (11).
Keeping your blood sugar under good control is important and may help to prevent the future development of type 2 diabetes.
Black Beans are Great for Heart Health
Black beans and kidney beans have folate, but black beans have the most.
- Folate and pyridoxine help prevent heart problems because they decrease homocysteine (12).
- Homocysteine is a compound that damages blood vessels and makes blood clots more likely.
The B vitamins help many organ systems in your body. Scientists have noticed that B vitamins decrease the risk of stroke and other cardiovascular problems (13).
Kidney Beans Contain Lots of Fiber
You have probably heard before that dietary fiber is good for you. It is true that including fiber in your diet is beneficial for your health.
- The obvious reason why is that it helps prevent constipation by keeping you regular. Kidney beans, thus, help keep your digestive system in top shape.
- However, there are other benefits to eating foods that are rich in dietary fiber. In fact, fiber helps reduce bad cholesterol in the blood (14).
Beans also help to make you feel full so you do not feel the need to snack or overeat. This is important in weight control. People who are overweight are at increased risk of diabetes (15).
Kidney Beans Contain More Vitamin K
There is a lot more vitamin K found in kidney beans than in black beans. This vitamin helps your blood to clot, which is obviously important if you have an injury.
Kidney beans have most of the B vitamins needed by the body. These, along with iron also help ensure we have healthy blood (16).
Kidney Beans Contains More Protein Than Black Beans
We all need to take in protein every day for the growth and repair of all the tissue in our body (17). Many of our enzymes that bring about reactions are also proteins.
There is slightly more protein per 100 g in kidney beans compared with black beans. Protein from kidney beans can be useful for dietary supplementation.
- Kidney beans are a useful source of protein for anyone but may be particularly helpful for people who do not eat meat or take in protein from animal sources (18).
- This means that vegans and vegetarians can get a good helping of protein by incorporating kidney beans into their meal plans.
How to Reduce Gas When Eating Beans
Bacteria release gases in our gut as they break down the food that we eat. This results in a buildup of gas in the intestines. Some types of food result in more gas being produced during this fermentation process (19).
The reason is linked to some of the carbohydrates, like the oligosaccharides, that are found in the beans (20).
How you prepare beans can be helpful for reducing gas. Some ways that help include:
- Pre-soaking the beans for at least one hour before starting to cook them is recommended because this helps make them more digestible.
- Some people sprout the beans to help decrease gas production during digestion.
- For people who really struggle with eating beans, there is also the option of buying enzymes to help stop excessive gas. These enzymes help digest the troublesome sugars in the beans.
Black Beans vs Kidney Beans Appearance
These two different bean varieties are named for how the seeds look.
- Black beans are black in color and oval in shape. While the outside skin of the black bean is black, the inner part of the seed is white in color.
- Kidney beans are in the shape of a human kidney and come in different colors.
There are red, pink, beige, and white-colored kidney beans.
Some kidney beans are also speckled. Regardless of the color of the outer skin, the inside flesh is a white color.
Black and kidney beans are similar sizes when we compare them based on length.
- Black beans are small in size, only about the size of a pea and are about 0.5 inches (21).
- Kidney beans range in length from 0.45 to 0.65 inches.
Black Beans vs Kidney Beans Taste
The taste of black beans has been described as like that of mushrooms with a sweetness to the flavor. Black beans do taste quite mild and have a nice creamy texture once cooked (22). They easily take up salt and other spices that are added to a dish.
Kidney beans also have a sweet taste and a nice creamy texture similar to black beans (23). They are a nutritious addition to many dishes, because they also take up spicey flavors similar to the way black beans do.
Which is Better?
Black beans and kidney beans are both nutritious vegetables that can add a lot of useful vitamins, minerals, and protein to a dish.
Kidney beans and black beans do not have cholesterol and have the same low GI index. They are also similar in the number of calories and the number of carbohydrates that are present. They both also contain beneficial dietary fiber.
However, kidney beans and black beans can cause a lot of gas if you fail to prepare them properly, so make sure to soak them well (for at least an hour) before you start to cook them.
Black beans do have a lot of vitamin A and B9, and more potassium and magnesium compared with kidney beans. In terms of nutritional quality, black beans are a better choice than kidney beans.
Kidney beans are also healthy when prepared properly. They do have vitamin C and many of the same nutrients in similar quantities as black beans.
In fact, you can include both types of beans as part of a healthy meal plan.