What's So Special About Adzuki Beans?

  • Medical Reviewer: Mahammad Juber, MD
Medically Reviewed on 10/13/2022
Studies indicate that adzuki beans have both anti-inflammatory and anti-microbial properties. Phenols extracted from adzuki beans have demonstrated antioxidant properties in a laboratory setting. Image Source: Getty Images
Studies indicate that adzuki beans have both anti-inflammatory and anti-microbial properties. Phenols extracted from adzuki beans have demonstrated antioxidant properties in a laboratory setting. Image Source: Getty Images

Adzuki beans are a popular legume. They’re grown throughout the world. They’re also known as small red beans and azuki beans. Sometimes, these beans are even referred to as “weight loss beans” because of their low-fat content.

Regardless of what you call them, adzuki beans are both good for your health and compatible with a wide range of diets.

What are adzuki beans?

The scientific name for adzuki beans is Vigna angularis. They’re a type of legume. Other examples of legumes include:

  • Kidney beans
  • Faba beans
  • Broad beans
  • Black beans
  • Chickpeas
  • Red and green lentils

Adzuki beans were first domesticated in China 12,000 years ago. Today, they’re grown in over 30 countries. They’re commonly used in Asian foods and were considered a diuretic within traditional Chinese medicine.

There are over 60 different varieties of adzuki beans — each with slightly different properties. The beans range in size from small to large and can vary dramatically in color. Examples of bean colors include:

  • Red
  • Black
  • Speckled purple
  • Brown
  • Green
  • White

What nutrients are in adzuki beans?

The specific nutrients found in adzuki beans depends on both the variety and the growing conditions. Broadly speaking, they contain a large number of beneficial nutrients including proteins, carbohydrates, and fiber.

The proteins in adzuki beans are more water soluble than those found in some other legumes. This is useful when preparations rely on adzuki bean extracts. Their proteins are also easier to digest than those found in other legumes.

Adzuki beans are a much richer source of essential amino acids than many other plants — particularly cereals like wheat. Amino acids are the building blocks of proteins. There are nine essential amino acids that your body can’t produce by itself. Instead, you need to get these from your diet. Adzuki beans are a particularly good source of the essential amino acid called lysine.

These beans also contain a variety of carbohydrates. Adzuki beans have both easily digestible carbohydrates and a type that’s known as resistant starch.

Digestible carbohydrates can be turned into energy for your body. Resistant starches, meanwhile, are great for your gut microbiome. They can’t be digested by your small intestine. Instead, they’re fermented by the microbes that live in your gut. Eating resistant starch promotes a healthy microbiome — much like consuming a probiotic.

Adzuki beans are also a fantastic source of minerals and micronutrients, including magnesium, folate, and iron.

One cup of whole, boiled adzuki beans contains:

  • 17.3 grams of protein
  • 0.23 grams of total fat
  • 56.97 grams of carbohydrates
  • 16.79 grams of fiber
  • 64.4 milligrams of calcium
  • 4.6 milligrams of iron
  • 119.6 milligrams of magnesium
  • 386.4 milligrams of phosphorus
  • 1223.6 milligrams of potassium
  • 18.4 milligrams of sodium
  • 4.07 milligrams of zinc
  • 0.69 milligrams of copper
  • 1.32 milligrams of manganese
  • 2.76 milligrams of selenium
  • 13.8 international units of vitamin A
  • 0.26 milligrams of thiamin
  • 0.15 milligrams of riboflavin
  • 1.65 milligrams of niacin
  • 0.99 milligrams of pantothenic acid
  • 0.22 milligrams of vitamin B6
  • 278.3 milligrams of folate
  • 0.08 grams of fatty acids

One-half of a cup of adzuki beans is considered a full serving.


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What are the benefits of eating adzuki beans?

In general, legumes are a very healthy food group. However, only about 8% of adults in the U.S. eat beans on any given day. This means that a lot of people are missing out on the health benefits that come from incorporating legumes — like adzuki beans — into their diets.

Research is currently ongoing about the health benefits of adzuki beans in particular. At this point, much of the evidence for this bean's benefits comes from animal studies. Combined with a handful of human studies, these early results are quite promising.

These studies indicate that adzuki beans have both anti-inflammatory and anti-microbial properties. Phenols extracted from adzuki beans have demonstrated antioxidant properties in a laboratory setting.

There’s also early evidence that adzuki beans can help treat type II diabetes and obesity. In one study, people with type II diabetes either consumed certain adzuki bean products or followed the traditional diabetic diet. Both dietary choices had similar positive effects on the human body.

Regular consumption of legumes can help you both lose weight and keep it off. This is most likely also true for adzuki beans.

Additionally, adzuki beans are gluten-free plant products. This means that they’re safe for people with celiac disease and gluten intolerance. They’re also compatible with vegetarian and vegan diets.

Are there any risks when eating adzuki beans?

You likely won’t have any problems when incorporating adzuki beans into your regular diet. Some legumes — like soybeans — commonly trigger allergic reactions. Luckily, allergies to adzuki beans aren’t common.

However, there has been at least one documented case of a young Japanese boy who developed lesions after eating adzuki products.

If you’ve never had an adzuki bean or adzuki bean product before, then you should be cautious the first time you eat them. Get immediate medical attention if you notice any signs of an allergic reaction, including:

You may also find that your body creates a lot more gas when you first incorporate beans into your diet. This can lead to gas pain and excessive flatulence. That’s mostly due to the large amount of fiber in beans.

Over time, your body will adapt and produce less gas. You just have to keep eating your beans and let your body adjust to this healthy new input.

How should you eat adzuki beans?

Adzuki beans are sold as both whole beans and as a sweetened paste. You can even make your own paste by boiling the beans with sugar. This finished product is commonly called red bean paste.

Adzuki beans are commonly incorporated into:

  • Pastries
  • Cake
  • Porridge
  • Adzuki rice
  • Jelly 
  • Adzuki milk
  • Adzuki ice cream

Although it may be tastiest to eat these beans as a sweetened paste, this isn’t the healthiest way to consume them. The added sugar can be problematic for your health and is incompatible with certain diets and lifestyles. Instead, you can try cooking and eating whole beans in a variety of dishes.

In general, legumes are a crucial part of the Mediterranean diet. For added health benefits, you could consider incorporating adzuki beans into a new routine that adheres to this popular dieting method.

The Mediterranean diet focuses on foods commonly found in that region of the world — like legumes, fish, and healthy grains. Research has shown that this diet can reduce your risk of developing:

Overall, when properly integrated into your diet, adzuki beans can improve both your nutritional intake and overall health.

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Medically Reviewed on 10/13/2022

Cleveland Clinic: “What You Should Know About Beans and the (Embarrassing) Gas They Cause.”

Clinical Diabetes: “Legumes: Health Benefits and Culinary Approaches to Increase Intake.”

Comprehensive Reviews in Food Science and Food Safety: “Adzuki bean (Vigna angularis): Chemical compositions, physicochemical properties, health benefits, and food applications.”

The FASEB Journal: “Effectiveness of legume consumption for facilitating weight loss: a randomized trial.”

International Journal of Health Sciences and Research: “Adzuki Beans- Physical and Nutritional Characteristics of Beans and Its Health Benefits.”

Journal of Food Lipids: “Antioxidant Activity of Extracts of Adzuki Bean and its Fractions.”

Juntendo Medical Journal: “Azuki Bean Allergy in a Japanese Child: a Case Report.”

Legume Information System: “Vigna (Vigna Savi).”

Nemours Kids Health: “Serious Allergic Reactions (Anaphylaxis).”

Therapeutics and Clinical Risk Management: “Convenient food made of extruded adzuki bean attenuates inflammation and improves glycemic control in patients with type 2 diabetes: a randomized controlled trial.”

University of Rochester Medical Center: “Beans, adzuki, mature seeds, cooked, boiled, without salt, 1 cup.”