Adzuki Beans: Nutrients, What Research Shows and Safety

Adzuki beans are small, dark red seeds of Vigna angularis (family Fabaceae, the legume family), grown mainly in East Asia. The part eaten is the seed, cooked. People eat them for fiber, plant protein and folate. This page covers the plain cooked bean; sweetened red bean paste and desserts are different foods. Health claims about adzuki mostly come from lab and mouse studies, and we say so.

Read this first

• High in folate, zinc and fiber: 1 cup cooked (230 g) has about 278 mcg DFE of folate (70% of the Daily Value), 16.8 g of fiber (60%) and about 294 kcal. [1]
• Cook dried beans fully. Raw legumes contain lectins; the FDA gives soaking and boiling steps for kidney beans. [3] [4]
• Evidence in one line: pooled trials of pulses as a group show a small fall in LDL cholesterol. [6] We found no human trial of adzuki beans in the sources we read; adzuki findings are from cells and mice. [16]
• Allergy: a review found no clinical adzuki allergy cases, only a predicted allergen protein, but cross-reactions between legumes are described. For trouble breathing or swelling of the face or throat call 911 (or your local emergency number). [11] [14]
• Kidney disease: most people not on dialysis do not need to limit beans for potassium or phosphorus; ask a kidney dietitian if you are on dialysis. [10]

What is in it (USDA values)

The table is for cooked adzuki beans, boiled without salt (USDA FoodData Central item 173728, SR Legacy). [1] The serving column is the USDA household portion of 1 cup, 230 g. [1] Dry, uncooked beans (item 173727) have much more of everything per 100 g because they contain about 13% water instead of about 66%, so do not compare the raw and cooked columns directly. [2]

% Daily Value uses the FDA 2016 Daily Values; values vary with variety, growing place and how long the beans are cooked. The cup figures are the 100 g values multiplied by the USDA gram weight. [1] USDA lists no value for some nutrients in this item; where a row is missing, USDA has no value. USDA's raw (dry) adzuki item lists 622 mcg of folate and 12.7 g of fiber per 100 g; those are dry-weight figures and cannot be compared with the cooked column. [2]

Plant compounds: USDA lists phytosterols (76 mg per 100 g in the raw item). [2] A 2026 study tested saponin-rich extracts from adzuki beans in cells and in mice fed a high-fat, high-cholesterol diet: the extracts reduced weight gain, fat mass and blood lipids and shifted gut bacteria. This is lab and animal evidence using concentrated extracts, not eating the bean, and it does not show the same happens in people. [16]

What research says

Eaten as food vs taken as extract or supplement. The trials above fed whole pulses (cooked or dried beans, peas, lentils). Extracts, protein isolates and flours are different products; we did not read trials of them for adzuki beans. Authors of the pulse analyses are often affiliated with groups that receive pulse-industry or government support; the abstracts we read do not show funders, so we cannot say. Adzuki saponin extracts in the mouse study are not sold products we reviewed.

How much is a normal serving

The USDA household portion is 1 cup of cooked beans (230 g), which has about 294 kcal. [1] The NHS counts 80 g of beans and pulses as one portion of 5 A Day, and says they count only once a day however much you eat, because they have fewer nutrients than other fruit and vegetables. [13] In the 2026 pooled analysis of LDL, the trials used a median of 130 g of pulses a day. [6] These are descriptions of what USDA, the NHS and the trials used, not a prescription or a target for you. Canned beans are already cooked; dried beans take longer and must be cooked through (see safety below).

Safety, allergy and medicines

• Raw or undercooked beans can make you ill. The FDA says the lectin phytohaemagglutinin in raw or undercooked beans can cause nausea, severe vomiting and diarrhea at high levels. Its advice for kidney beans is to soak at least 5 hours and boil in fresh water for at least 30 minutes; canned and properly cooked beans have only low levels. [3] The FDA page names kidney beans; adzuki beans are a different genus (Vigna) from kidney beans, but the Harvard page says raw legumes in general contain some of the highest amounts of lectins. [4] Harvard also says raw beans simmered at low heat (for example in a slow cooker) or undercooked beans will not remove all lectins. [4]
• Gas and digestion: beans can cause extra gas. [5] Harvard notes that people with digestive sensitivities such as irritable bowel syndrome may react more strongly to lectin-rich foods. [4] We did not read a tested low-FODMAP serving size for this bean from a primary source, so we give none (see the site page on beans, gas and FODMAPs below).
• Kidney disease: the National Kidney Foundation says the phosphorus and potassium in beans are absorbed less well than from animal foods or additives, and that most people with chronic kidney disease not on dialysis, or after a transplant, do not have to limit beans for those minerals. People on dialysis should plan bean intake with a kidney dietitian. It also advises people with a history of calcium oxalate stones to ask about oxalates, since many beans are high in them. [10]
• Allergy: bean allergy is rare, and reported cases are mostly mouth itching, skin reactions and work-related asthma; allergy to one legume can cross-react with others such as soy and peanut. The review behind this is narrative and based largely on case reports. [11] Peanut is a legume (see peanuts). Peanut and soy are among the main US food allergens. [14] For trouble breathing, swelling of the face or throat, or fainting after eating, call 911 (or your local emergency number). [14]
• Pregnancy and breastfeeding: beans are a natural source of folate. [12] MedlinePlus lists 600 mcg of folate a day for pregnancy, and advises women of childbearing age to take a folic acid supplement in addition to fortified foods, to help prevent neural tube defects. [12] We did not find a warning against fully cooked beans in the sources we read. See what official bodies advise in pregnancy.
• Medicines: we did not find a source we could read describing a direct interaction between cooked adzuki beans and a specific medicine. See foods and medicine interactions.
• Canned beans and sodium: a University of Tennessee study reported in Today's Dietitian found draining canned beans cut sodium by 36% and draining plus rinsing by 41%. [15] The article does not say who funded it. Our USDA table is for beans cooked without salt, so canned beans will have more sodium.

Choosing, storing and food safety

• Dried beans must be fully cooked before eating (see the FDA cooking steps above). [3]
• Canned beans are already cooked; choosing no-added-salt cans, or draining and rinsing, lowers sodium. [15]
• We did not read an official source with shelf-life advice for dried beans. For leftovers, see food storage, leftovers and food safety basics.

Related pages

• Lectins in beans: cooking dried beans safely
• Beans, gas, FODMAP and digestion
• Dried vs canned beans: soaking and sodium
• Mung beans
• Kidney beans
• Black beans
• Foods for blood sugar control
• Food allergy basics and emergency signs