Beans have a lot going for them.
For starters, they're inexpensive, simple to prepare and a great addition to many dishes.
In fact, beans can count as both a protein and a vegetable source in your diet.
Yet while beans have many health benefits, they may cause issues for some people.
Read on to find out more about the nutrient content and health effects of beans.
Beans are seeds from plants in the Phaseolus genus. They are a type of legume ().
They are native to Central and South America, and have been grown there for thousands of years. Today, beans are an important food source for people all over the world.
Types of beans that are popular in the US include black, kidney, navy, fava and pinto beans ().
The nutritional profile differs from one bean to another. However, as an example, a cup (171 gram) of boiled pinto beans will provide ():
- Protein: 15 grams.
- Fat: 1 gram.
- Carbs: 45 grams.
- Fiber: 15 grams.
- Iron: 20% of the RDI.
- Calcium: 8% of the RDI.
- Magnesium: 21% of the RDI.
- Phosphorous: 25% of the RDI.
- Potassium: 21% of the RDI.
- Folate: 74% of the RDI.
- Decent amounts of B-vitamins (B1, B6), vitamin E, vitamin K, zinc, copper, manganese and selenium.
Many other types of beans are just as impressive in the nutrient department.
Take note of the high protein content of beans, which is rare among plant foods. For this reason, they are considered to be an important protein source on a vegetarian diet.
Bottom Line: Beans come in many varieties. They are high in protein and fiber, but low in fat and calories. They are also exceptionally high in a wide variety of vitamins and minerals.
Beans may be among the most weight loss-friendly foods you can eat.
They are high in both protein and fiber, but low in calories. Protein and fiber are two of the most powerful nutrients for weight loss (, ).
One study found that people on a high-fiber diet with beans had reduced feelings of hunger. They also lost 3 pounds (1.4 kg) in 4 weeks ().
Another study found bean consumption to be associated with improved nutrition, a lower body weight and reduced belly fat ().
Bottom Line: Beans are very high in both protein and fiber, but low in calories. Eating more beans can help you lose weight.
Heart disease is a leading cause of death worldwide.
Interestingly, eating beans and other legumes regularly may help reduce this risk ().
A review of 26 studies found that a diet rich in beans and other legumes can lower significantly, which is an important risk factor for heart disease ().
Eating beans may also lead to improvements in other heart disease risk factors. They have been linked to lower blood pressure, higher HDL ("good") cholesterol levels and reduced inflammation (, ).
Bottom Line: Beans may help reduce your risk of heart disease by lowering LDL cholesterol, blood pressure and inflammation.
There is also evidence that beans are a good food choice for diabetics.
Beans are high in fiber, averaging around 5 to 8 grams per serving. They also have a very low glycemic index ().
Foods low on the glycemic index raise blood sugar slowly, which is important for diabetes management.
A diet rich in beans can therefore lower blood sugar and HbA1c levels, which measure blood sugar control over time ().
A review of 41 controlled trials also found that beans and other legumes can lower fasting blood sugar, insulin levels and HbA1c ().
Bottom Line: Studies show that beans can lead to major improvements in people with type 2 diabetes. This is largely due to the high fiber content and low glycemic index.
Although beans are a healthy food overall, some do contain toxins. Fava beans, for example, have toxins that affect people who lack an enzyme called G6PD.
For these people, eating fava beans can cause a condition called favism. Favism can cause anemia, through the destruction of red blood cells (, , ).
Other beans -- especially red kidney beans -- contain a toxic lectin called phytohemagglutinin, which is present in raw or undercooked beans. It can cause nausea, vomiting and stomach pain ().
You can avoid phytohaemagglutinin by thoroughly cooking beans before eating ().
Beans also contain a substance called phytic acid, which can reduce the absorption of minerals. However, this can also be degraded using the right preparation methods.
Here are some tips on neutralizing potentially harmful substances in plant foods, such as lectins and phytic acid: How to Reduce Antinutrients in Foods.
Bottom Line: Certain beans can be toxic if they are undercooked or eaten by people who lack certain enzymes. Make sure to cook beans thoroughly.
For some people, beans can cause flatulence, stomach pain or bloating.
The reason, is that beans contain little sugars called oligosaccharides, which can cause digestive problems ().
However, using products like , soaking beans or thoroughly boiling dry beans can all reduce the oligosaccharide levels by up to 75% ().
One study found that consumer perception of beans and flatulence may be exaggerated. Only around half of people who eat beans experience symptoms ().
Bottom Line: While beans may cause flatulence for some people, there are several methods that help to prevent this problem.
At the end of the day, beans are pretty close to being the perfect food.
They are highly nutritious, incredibly healthy and contain at least a little bit of almost every nutrient that the body needs.
Although beans may cause digestive problems for some people, most of these can be avoided with the right cooking and preparation methods.
Another important fact is that beans are very cheap compared to most other nutritious, whole foods.
This makes beans one of the most nutrient-dense foods on earth, both per calorie and per dollar.