HEALTH BENEFITS/RISKS OF BEANS

What are the health benefits of beans?

Beans are a strong, plant-based source of protein, fiber, iron, and vitamins that offer many health benefits.

Beans: The basics

Beans are the seeds from flowering plants in the Fabaceae family and are classified as legumes.

Several beans grow in pods or capsules that develop from flowers. Other legumes include peas, peanuts, and lentils. These beans are available dry, canned, or frozen.

They differ nutritionally from green beans or wax beans where a person eats the entire pod.

Beans contain amino acids, which are the protein building blocks that the body uses to heal and to make new tissues, such as bone, muscle, hair, skin, and blood. Protein is an essential nutrient.

There are many types of beans. Dried beans need cooking to make them tender enough to eat. Canned and frozen beans are typically ready to eat after warming on the stove or in the microwave. Some of the most popular bean varieties include:

lima beans

black beans

black-eyed peas

soybeans

kidney beans

garbanzo beans

navy beans

pinto beans

red beans

Health benefits of beans

Beans offer several health benefits.

1. Protein

Protein is a vital nutrient that plays a key role in maintaining and repairing the body. Beans are high in amino acids, the building blocks of protein.

There are 20 amino acidsTrusted Source, and nine of these are essential. There are also two types of protein sources: complete and incomplete.

Animal products, soy, and quinoa are all complete proteins, which means they contain all nine essential amino acids.

However, of all the types of beans, only soybeans contain all nine amino acids.

People can combine incomplete proteins with nuts, seeds, dairy products, or grains at a single meal or throughout the day to make complete proteins.

For example, a person can:

eat beans with rice or couscous for lunch

have black beans at lunch with almonds or cheese

Beans make an excellent source of protein for vegetarians and vegans.

They are also lower in calories and saturated fat than some other protein sources, such as meat and full fat or low fat dairy products.

Examples of the protein content of beans are:

A 1-cup, or 40 gramsTrusted Source (g), serving of canned black beans provides 14.5 g of protein, 16.6 g of fiber, and 4.56 milligrams (mg) of iron.

A 1-cup, or 155 gTrusted Source, serving of shelled edamame beans provides 18.5 g protein, 8.06 g fiber, and 3.52 mg iron.

2. Folate

Beans contain several vital nutrients, including folate. Folate is essential for overall health, to make healthy red blood cells, and help prevent neural tube defects in a fetus during pregnancy.

A 1-cup, or 155gTrusted Source, serving of shelled edamame beans provides 482 micrograms (mcg) of folate.

3. Antioxidants

According to researchTrusted Source, beans are rich in polyphenols, which are a type of antioxidant.

Antioxidants fight the effectsTrusted Source of free radicals, which are damaging chemicals that the body produces during metabolism and other processes.

Free radicals can cause cell damage that can result in various diseases. Antioxidants help the body remove free radicals. In this way, antioxidant-rich foods, such as beans, can help protect the body from disease.

4. Heart health

People who consume beans regularly may be less likely to die of a heart attack or other cardiovascular problem. The authors of a 2017 meta-analysisTrusted Source suggested that one reason for the decrease in cardiovascular risk was that people had replaced higher fat animal meat proteins with beans.

A 2013 review and meta-analysisTrusted Source found a clear correlation between eating beans and a lower risk of coronary heart disease.

Other research suggests that nutrients in beans may help lower cholesterol. High cholesterol is a risk factor for heart disease and heart attacks.

There is evidenceTrusted Source that a high fiber diet may help reduce the risk of cardiovascular disease.

A half-cup, or 88 gTrusted Source, serving of black beans provides about 14 g of fiber, which is over half an adult’s daily requirement for fiber.

5. Reduced risk of cancer

Some studies have shown that beans act as antioxidants and anti-inflammatory agents. These effects could reduce the risk of cancer.

6. Diabetes and glucose metabolism

Beans may help stabilizeTrusted Source blood glucose levels or even prevent diabetes. Beans are high in fiber, which can help lower blood glucose.

The author of a 2018 reviewTrusted Source concluded that consuming a high fiber diet could reduce the risk of type 2 diabetes. There was also evidence that it may help lower blood sugar in people who already have the condition.

Another studyTrusted Source looked specifically at the effect of adding a cup of legumes to the daily diet of people with type 2 diabetes. This study showed a reduction in blood sugar levels and lower blood pressures in the group who ate beans over the control group who included more whole wheat fiber.

7. Preventing fatty liver

Fatty liver happens when fats accumulate in the liver. It can develop alongside obesity, high cholesterol, high blood pressure, and other aspects of metabolic syndrome. 

Doctors base the treatment of fatty liver disease on weight loss and controlling blood sugars, as well as reducing blood levels of fats, such as triglycerides and low-density lipoprotein (LDL), or bad cholesterol. Replacing higher fat animal proteins with beans is a good step towards better liver health.

8. Controlling appetite

When a person eats beans, the fiber and healthful starches they contain can help create a feeling of fullness and satisfaction.

As a long-term dietary strategy, this could help prevent overeating and may lead to weight loss.

9. Improving gut health

a variety of beans, especially black beans, enhance gut health by improving intestinal barrier function and increasing the number of beneficial bacteria. This may help prevent gut-associated diseases.

Healthful gut bacteria also support immune system function and may promote weight loss. Beans feed the healthful gut bacteria colonies.

Risks

Some people have an allergy to beans or members of the legume family. Peanuts and soy are common triggers. People who have an allergy to one type of legume should take care when consuming other types.

Many beans and pulses contain lectins, which are proteins that are potentially toxic to humans. Soaking and boiling beans reduce the lectin content. People should boil beans for at least 10 minutesTrusted Source to ensure they are safe.

The most common side effects of eating beans are gas and intestinal discomfort. These are not dangerous but can be unpleasant and even painful for some people. When a person adds beans to their diet, they should increase the amount gradually to give their gut time to adjust.

Beans may not be suitable for a person with irritable bowel syndrome (IBS). Many people with inflammatory bowel disease (IBD) find that following a low-FODMAP diet— which restricts certain carbohydrates — reduces their symptoms.

Hot-soaking beans and discarding the water used for soaking, or sprouting, boiling, or cooking them may help reduce digestive symptoms. People can take digestive enzymes as supplements to help the body digest beans.

Adding beans to the diet

The time it takes to cook beans will depend on the type of bean.

When preparing dried beans:

Wash them before cooking and remove any that are shriveled or discolored.

Soak beans overnight to soften them and shorten the cooking time. Discard water and rinse.

Bring beans to the boil in plenty of fresh water, boil for at least 10 minutes, then simmer until they are soft.

Canned beans are precooked. People can add them to a variety of dishes without additional preparation. People should check the label before buying canned beans, however, as some cans contain a lot of added salt. Canned beans that contain no extra salt are available and are an excellent choice.

Some simple strategies for adding beans to a regular diet include:

Replacing meat with beans. Try adding beans instead of meat to soups, casseroles, and pasta dishes.

Eating chilled bean salads. Beans are tasty and filling as the main ingredient in a salad or as a garnish to other salads.

Mixing beans and grains. Adding beans to grains can turn an incomplete protein into a complete one. This is useful for people who follow a plant-based diet.

A person may need to try different types of bean to see which ones suit them best.

Summary

Beans provide protein, fiber, iron, and antioxidants that can make them a healthful addition to the diet. People should increase their intake of beans gradually to reduce the risk of intestinal discomfort.