Adzuki bean nutrition, glycemic index, calories, net carbs & more
Adzuki beans, otherwise known as red beans, red mung beans, aduki beans, azuki beans, red chori, or sweet beans, are small and round beans, that are incredibly rich in nutrients. These beans are mostly grown in East Asia but are used throughout the world.
In this article, we will discuss the properties of adzuki beans in detail, with a central focus on their nutrients and impact on health, as well as looking at some of the bean’s historic and economic aspects.
The scientific name for the adzuki bean species is Vigna angularis. These beans belong to the Vigna genus and the Fabaceae family.
The Fabaceae family is also known as the bean, legume, or the pea family. Adzuki beans share this family with other well-known crops, such as common beans, soybeans, peas, chickpeas, peanuts, licorice, etc.
The Vigna genus that adzuki beans belong to also includes the black gram, the cowpea, and the mung bean species. If interested, you can read our complete nutrition and health benefits analysis for black gram.
The adzuki bean plant is believed to be domesticated from its wild progenitor Vigna angularis var. Nipponensis (1).
Taste and Appearance
Adzuki beans are round and small in size. The average adzuki bean is about 7mm in length and 5mm in width (2). These beans have a small hilum, a seed scar, on the sides.
These beans can come in various colors, such as black, white, grey, or spotted. However, the most widely used adzuki beans are the red beans.
Adzuki beans have a nutty and mildly sweet taste. Due to the mild taste, adzuki beans work well in the kitchen with various spices. The sweetness of adzuki beans is often used in confectionery and bakery products in the form of a bean paste.
Varieties of adzuki bean can have somewhat different nutrient levels, physical properties, and cooking requirements.
Depending on the variety, the adzuki beans can have seed coats of varying shades and colors. The seed coat color has been studied to be correlated with the amount of sunshine on the seed, as well as the temperature and the growing period. The more sunshine the seed absorbs, the darker it becomes (3).
The leading variety of adzuki beans in Japan is the Erimoshouzu variety, while the main variety in Australia is the Bloodwood variety (4).
Some other varieties of adzuki beans include the Japanese Red, the Chinese Red, the Adzuki Express, the Takara, and the Minoka (5).
In the US, the most widely grown variety in the Upper Midwest is the Takara which was first imported from Japan in 1978. The Minoka variety, a large-seeded adzuki bean, was released by the Minnesota Agricultural Experiment Station in 1980 but has not been widely grown (6).
Naturally, the nutrition of adzuki beans can differ depending on the variety and cooking method. In this article, we will be focusing on mature adzuki bean seeds, boiled without salt. For comparison, we will also use raw, mature adzuki beans and sweetened, canned, mature adzuki beans (7, 8).
Red adzuki beans are not to be confused with red kidney beans. On our website, you can find an in-depth nutrition comparison of the two red beans.
Macronutrients and Calories
Adzuki beans are dense in nutrients, with boiled adzuki beans consisting of 66.3% water and 33.7% nutrients. Raw adzuki beans are even more nutritionally dense, containing only 13.4% water and 86.6% nutrients.
Sweetened, canned adzuki beans are denser than boiled beans but less dense than dry adzuki beans. Canned adzuki beans consist of 40.6% water and 59.4% nutrients.
A 100g serving of cooked adzuki beans provides 128 calories. The same serving size of canned, sweetened adzuki beans contains almost double the number of calories - 237.
However, being the most dense in nutrients, raw beans provide 329 calories per 100g serving.
One average serving size of cooked adzuki beans is 130g. Therefore, an average serving size of boiled beans provides 166 calories, while the average serving size of sweetened, canned beans contains 308 calories.
This shows that the adzuki bean is a high-calorie food.
Adzuki beans are incredibly rich in protein, falling in the top 18% of foods as a source of protein. Boiled adzuki beans provide 7.52g of protein per every 100g serving.
This protein is of good quality, as it contains some levels of all essential amino acids. However, adzuki beans have a limiting amino acid - methionine. Compared to the other essential amino acids, methionine is found in the lowest quantity.
A 100g of boiled adzuki beans cover above 20% of the daily needed values for all the essential amino acids, except for methionine.
Of the non-essential amino acids, adzuki beans are rich in glutamic acid.
Raw adzuki beans are naturally significantly higher in protein, containing about 20g of it in a 100g serving.
Sweetened, canned adzuki beans, on the other hand, are about 2 times lower in protein, compared to boiled adzuki beans. A 100g serving of sweetened and canned adzuki beans contains 3.8g of protein.
Adzuki beans are very low in fats, containing 0.1g of fats in a 100g serving. Of this 0.1g, 55% consists of saturated fats, 32% consists of polyunsaturated fats and only 13% is made up of monounsaturated fats.
Raw adzuki beans contain 0.53g of fats in a 100g serving, while sweetened and canned adzuki beans contain 0.03g of fats.
As plant products, adzuki beans naturally contain no cholesterol.
Adzuki beans are high in carbohydrates due to their rich dietary fiber content. A 100g serving of boiled adzuki beans contains 25g of carbohydrates, of which 7.3g are made up of dietary fiber. Therefore, these beans have a net carbohydrate content of 17.47g.
Adzuki beans are very low in sugars. Most of the carbohydrates in adzuki beans consist of total starch, such as resistant starch and amylose (9).
Raw and sweetened, canned adzuki beans are unsurprisingly significantly higher in carbohydrates, containing 63g and 55g of carbohydrates respectively, in 100g serving sizes.
Adzuki beans are abundant in folate or vitamin B9, falling in the top 22% of foods as a source for this vitamin. These beans are also rich in vitamin B5.
Adzuki beans contain a moderate amount of vitamins B2, B3, B5, and B6, as well as vitamin A.
These beans are completely absent in vitamin B12, vitamin D, and vitamin C.
Raw beans, being denser in nutrients, are richer in all these vitamins. However, canned adzuki beans tend to have slightly lower levels of vitamins.
Adzuki beans are plentiful in minerals. These beans are particularly rich in potassium, magnesium, and copper.
Adzuki beans fall in the top 12% of foods as a source of potassium, in the top 21% of foods as a source of magnesium, and in the top 25% as a source of copper.
Vigna angularis beans are also very high in manganese, iron, zinc, calcium, and phosphorus.
Adzuki beans contain low amounts of selenium.
Unsalted, boiled adzuki beans are low in sodium, containing 8mg of it in a 100g serving.
According to the FDA, the average serving size of beans per one person is 130g for beans in sauce or canned in liquid and refried beans, 90g for beans prepared otherwise, and 35g for dry beans (10).
The glycemic index of red adzuki beans has been measured to be 26 (11). This shows that despite the high carbohydrate content the glycemic index of adzuki beans falls in the low category, probably due to the high fiber content.
A study has also been carried out about the glycemic index of adzuki bean powders, with a focus on different preparation methods. It was found that the adzuki bean powder prepared by roller cooking, a process including milling and mashing the beans into the powder, had the highest estimated glycemic index of 80. At the same time, adzuki bean powder prepared by extruded cooking and steamed cooking had estimated glycemic index values of 70 and 50, respectively (12).
Beans are known to be alkaline-forming foods and can be used as a source of protein for people avoiding acidic foods, such as meat and dairy.
Adzuki beans have been calculated to have a PRAL value of -6.7, showing that these beans are alkaline-producing.
The PRAL value or the potential renal acid load value of the food demonstrates how much acid or base the food produces in the body. The bigger the negative PRAL value number is, the more alkaline-forming the food.
Weight Loss and Diets
The adzuki bean is a high-calorie food, containing 128 calories per 100g serving. However, as adzuki beans are high in dietary fiber, protein, and low in fats, they can still fit well in healthy weight-loss diets.
Boiled adzuki beans are recommended over sweetened, canned adzuki beans, which contain 237 calories in a 100g serving.
Adzuki beans are a good fit for low glycemic index diets, as these beans have a low glycemic index of 26.
Black adzuki beans have been researched to have a positive effect on diet-induced obesity through an improvement of the lipid profile and a decrease in body weight (13).
Multiple other studies have demonstrated the anti-obesity properties of adzuki beans, due to the high polyphenol content found in these beans (14, 15, 16). Some of the polyphenols playing a role here are saponins and flavonoids.
Adzuki beans are high in carbohydrates but low in sugars, due to dietary fiber and starch. A 100g serving of adzuki beans contains 17.47g of net carbs, while a keto diet allows a daily total carbohydrate intake of 20 to 50g.
Looking at the numbers, adzuki beans can be used on a keto diet but only in strict moderation.
A DASH diet recommends including foods that are high in potassium, magnesium, calcium, fiber, and protein, whilst being low in sodium and saturated fats (17).
Fitting all the recommendations, adzuki beans are perfect for this diet.
On this diet, it is recommended to add a minimal amount of salt when boiling adzuki beans
Adzuki beans are to be avoided during the initial Induction phase of the Atkins diet.
During the second or the Balancing phase, adzuki beans are to be used only in strict moderation. For example, half a serving of adzuki beans can be consumed daily.
The third and fourth phases, known as Pre-maintenance and Lifelong maintenance, allow a higher intake of net carbs, however, adzuki beans still should be consumed mindfully.
While the adzuki bean originated in East Asia, it can still be consumed on a Mediterranean diet, as beans are an important element of this diet.
Beans are a controversial topic on the paleo diet. Besides the question of not being domesticated during the Paleolithic age, beans also include toxic antinutrients such as phytic acid and lectins (18). As a result, adzuki beans are not considered to be part of the paleo diet.
Vegan/ Vegetarian/ Pescetarian
Adzuki beans can play an important role as an alternative source of protein for people on these diets.
Adzuki beans do not contain gluten.
Adzuki beans are not allowed during the first and second or Attack and Cruise phases of this diet.
Starchy foods, such as adzuki beans, can be slowly added during the third or Consolidation phase and used throughout the fourth or Stabilization phase.
Like most other foods, adzuki beans can be consumed during the eating periods but not during the fasting phases.
Low Fat & Low Calorie
Adzuki beans are very low in fats, containing only 0.1g of fats in a 100g serving.
However, adzuki beans provide 128 calories per 100g serving, and therefore, cannot fit into a low-calorie diet.
Adzuki beans provide 17.47g of net carbs per every 100g serving. These beans may fit a low-carb diet only in moderation.
Beans overall fit into anti-inflammatory diets due to their high antioxidant, protein, and fiber contents.
Adzuki beans have also been studied to possess certain anti-inflammatory qualities (9, 11, 19)
Adzuki beans are high in fiber and therefore hard to digest. For this reason, it is recommended to avoid adzuki beans on a BRAT diet.
The nutritional characteristics mentioned above, along with other aspects, give adzuki beans qualities that impact health either negatively or positively. In this section, we will go over these qualities, by analyzing the scientific research available.
Studies on animals have shown adzuki bean extract to reduce triglyceride, total cholesterol levels, and lower systolic blood pressure, as well as decrease liver weight and markers of liver damage. Adzuki bean extract lowered blood pressure by decreasing the level of the enzyme partially responsible for constricted vessels (20).
Numerous studies have shown adzuki beans and their extract to lower blood serum lipid parameters, such as total cholesterol, triglyceride, and low-density lipoprotein (21).
Improving blood lipid and blood pressure levels can help decrease the risk of various cardiovascular diseases, such as atherosclerosis, cardiac arrest, and stroke.
As mentioned above, adzuki beans have a low glycemic index and can be used in a diabetes diet plan.
One study researching the effects of extruded adzuki bean convenient food showed the diet to improve glycemic control and ameliorate inflammation in type 2 diabetes mellitus patients (11).
Raw and cooked adzuki beans have been found to help improve glucose tolerance, while also preventing liver and pancreatic damage in diabetic patients. Raw adzuki beans contain a higher level of beneficial phytochemicals that help reduce fasting blood glucose (22).
Adzuki bean extract has also demonstrated inhibiting effects on α-glycosidase (9). α-glycosidase is an enzyme involved in glucose absorption from the intestines.
The adzuki bean has exhibited strong antiproliferative effects on digestive system cancer cell lines, as well as ovary and breast cancer cell lines (23).
The heat-stable adzuki bean extract has also been studied as a promising immune-enhancing food and dietary supplement for cancer prevention. These beans have the potential to stimulate the differentiation of bone marrow cells into immature dendritic cells. Dendritic cells play an important role in the immune system fighting cancer. Furthermore, adzuki beans can inhibit the growth of leukemia cancer cell lines by inducing cell death (24).
Being rich in dietary fiber and resistant starch, adzuki beans have been researched to improve gut microbiota composition, as well as ameliorating high-fat diet-induced obesity (14, 28).
Black adzuki bean can also attenuate high-fat diet-induced colon inflammation by improving mucosal barrier protection, reducing endotoxemia, and decreasing inflammatory cytokines (19).
Adzuki beans have also been researched to possess certain anti-allergy, as well as liver and kidney protecting qualities (21).
Downsides and Risks
Despite the numerous beneficial cancer-preventive effects of adzuki beans, they may have a negative effect on estrogen receptor-positive (ER+) breast cancer. Ethanol extract of adzuki beans has been studied to have estrogen-like activities that may stimulate the proliferation of breast cancer cells (22).
Like most beans, raw adzuki beans contain certain amounts of antinutrient compounds that can reduce the intestine’s ability to absorb some of the essential nutrients.
The primary antinutrients found in adzuki beans are phytates, α-galactosides, and trypsin inhibitors (27).
Phytates can decrease the absorption of iron, zinc, magnesium, and calcium (28). The trypsin inhibitors can worsen the breakdown and subsequent absorption of proteins.
However, most of the antinutrients can be removed or deactivated by soaking, sprouting, or cooking the beans. The nutrient benefits greatly outweigh the negative effects of the antinutrients (28).
Despite the anti-allergic properties, cases of adzuki bean allergy have been reported. However, it is extremely rare and not very well researched (29).
Cooking and Use
Adzuki beans are most popular in East Asian cuisine, where these beans can be used to make savory foods, but are more often used in confectionaries. Adzuki beans are slightly sweeter than most similar bean crops.
These beans are used in confectionery usually in form of red bean paste or adzuki flour. Red bean paste is also called red bean jam, adzuki bean paste, or anko. It is made by mashing or grinding boiled adzuki beans, with or without adding sweeteners like sugar or honey. Red bean paste can be used for fillings and toppings in desserts.
Adzuki beans have been used to make traditional Japanese confections, such as wagashi, youkan, manju, and amanatto (30). Adzuki bean paste can also be used to make Japanese mochi.
Adzuki bean flour can be used to make noodles. Adzuki beans can be popped like popcorn, used as a beverage base, or as a substitute for coffee. A rice and adzuki bean dish, called sekihan, is often served on festive occasions, such as weddings and birthdays (31).
These beans can be fermented and used to make Japanese natto.
Adzuki beans may even be used to make vegan bacon.
As a substitute for adzuki beans in savory meals other beans can be used, such as red kidney or black turtle beans. However, it is difficult to find a substitute for adzuki beans in desserts and pastries.
Storage, Keeping, and Conservation
Raw adzuki beans are to be stored in a cool, dark, and dry space, preferably in airtight containers.
The perfect conditions for the preservation of adzuki beans have been researched to be 50°F (10°C) and 65% relative humidity. Storage at a higher temperature or lower humidity resulted in a significant loss of bean moisture, increase in hydration times, and hardness of the cooked beans (32).
Adzuki beans usually have an average shelf life of one year. Colder temperatures increase the shelf life.
The geographical origin of domesticated adzuki beans is generally considered to be Northeast Asia, while a specific location has not yet been specified. It has been suggested that China may have been the primary origin. However, earlier records have been found from Japan and Korea (33).
Japan is regarded as the center of the genetic diversity of adzuki and a possible origin of its domestication. The domestication of adzuki beans may have initiated a size increase of the bean (33).
Historic texts describe the relatively late occurrence of adzuki beans compared with other crops, first appearing in the Eastern Zhou, around 2 to 3 thousand years ago (33).
Cultivation and Botany
The adzuki bean plant or Vigna angularis is an annual vine. The growth conditions for this plant are similar to that of soybean plants. It is moderately drought tolerant and can be grown in various soils, including silt loams and sandy soils. The adzuki plant does not, however, tolerate water-logged soils and competes poorly with weeds (31).
The adzuki bean plant prefers soil with a neutral pH value. The plant seeds in the late spring. The warmer the climate, the faster the plant will emerge (31).
Production and Consumption
In 2019, the world export of adzuki beans exceeded $147 million, having grown by $21 million from the previous year (34).
The world’s largest exporter of adzuki beans is China, being responsible for about 40% of world exports. After China, the world’s largest exporters of adzuki beans are Canada, Brazil, and the Kyrgyz Republic (34).
However, the world’s largest importer of the bean is Japan, importing about 28% of the world’s imports. The largest importers of adzuki beans also include Afghanistan, Korea, and China (34).
In 2021, the approximate price range for adzuki beans in the US is between US$ 0.81 and US$ 0.92 per kilogram or between US$ 0.37 and US$ 0.42 per pound. The price in Euro is 0.92 per kg (35).
Adzuki beans are slightly more expensive in Canada. In 2021, the approximate price range for adzuki beans in Canada is between US$ 1.06 and US$ 1.14 per kilogram or between US$ 0.48 and US$ 0.52 per pound. The price in Canadian Dollar is 1.42 per kg (36).
- Azuki bean sizes (mm)
Important nutritional characteristics for Adzuki bean
Adzuki bean Glycemic index (GI)
Mineral coverage chart
Mineral chart - relative view
Vitamin coverage chart
Vitamin chart - relative view
Protein quality breakdown
Fat type information
Fiber content ratio for Adzuki bean
All nutrients for Adzuki bean per 100g
|Nutrient||DV%||In TOP % of foods||Value||Comparison|
|Net carbs||N/A||34%||17.47g||3.1 times less than Chocolate|
|Protein||18%||52%||7.52g||2.7 times more than Broccoli|
|Fats||0%||93%||0.1g||333.1 times less than Cheese|
|Carbs||8%||30%||24.77g||1.1 times less than Rice|
|Calories||6%||66%||128kcal||2.7 times more than Orange|
|Fiber||29%||14%||7.3g||3 times more than Orange|
|Calcium||3%||45%||28mg||4.5 times less than Milk|
|Iron||25%||37%||2mg||1.3 times less than Beef|
|Magnesium||12%||21%||52mg||2.7 times less than Almond|
|Phosphorus||24%||48%||168mg||1.1 times less than Chicken meat|
|Potassium||16%||12%||532mg||3.6 times more than Cucumber|
|Sodium||0%||87%||8mg||61.3 times less than White Bread|
|Zinc||16%||42%||1.77mg||3.6 times less than Beef|
|Copper||33%||25%||0.3mg||2.1 times more than Shiitake|
|Vitamin A||0%||69%||6IU||2784.3 times less than Carrot|
|Vitamin B1||10%||44%||0.12mg||2.3 times less than Pea|
|Vitamin B2||5%||77%||0.06mg||2 times less than Avocado|
|Vitamin B3||4%||73%||0.72mg||13.4 times less than Turkey meat|
|Vitamin B5||9%||63%||0.43mg||2.6 times less than Sunflower seed|
|Vitamin B6||7%||66%||0.1mg||1.2 times less than Oat|
|Folate||30%||22%||121µg||2 times more than Brussels sprout|
|Tryptophan||0%||82%||0.07mg||4.2 times less than Chicken meat|
|Threonine||0%||81%||0.26mg||2.8 times less than Beef|
|Isoleucine||0%||81%||0.3mg||3 times less than Salmon|
|Leucine||0%||79%||0.63mg||3.8 times less than Tuna|
|Lysine||0%||75%||0.57mg||1.3 times more than Tofu|
|Methionine||0%||85%||0.08mg||1.2 times less than Quinoa|
|Phenylalanine||0%||79%||0.4mg||1.7 times less than Egg|
|Valine||0%||80%||0.39mg||5.2 times less than Soybean|
|Histidine||0%||79%||0.2mg||3.8 times less than Turkey meat|
|Saturated Fat||0%||88%||0.04g||163.8 times less than Beef|
|Monounsaturated Fat||N/A||93%||0.01g||1088.8 times less than Avocado|
|Polyunsaturated fat||N/A||94%||0.02g||2246.4 times less than Walnut|
Check out similar food or compare with current
NUTRITION FACTS LABEL
Serving Size ______________
Adzuki bean nutrition infographic
The source of all the nutrient values on the page (excluding the main article and glycemic index text the sources for which are presented separately if present) is the USDA's FoodCentral. The exact link to the food presented on this page can be found below.