Winged Beans: Nutrients, What Research Shows and Safety

Winged beans are the four-sided, frilly-edged pods and the seeds of Psophocarpus tetragonolobus (family Fabaceae, the legume family), grown mainly in tropical Asia, New Guinea and parts of Africa. Almost every part of the plant is eaten somewhere: young pods, leaves, flowers, tubers and the ripe seeds. [3] [4] This page covers the food. It treats the dry seeds with care, because they hold natural compounds that heat reduces, and it separates ordinary food from lab findings on extracts.

Read this first

• Cook the dry seeds thoroughly. Reviews list lectins (haemagglutinins), trypsin inhibitors (compounds that block digestive enzymes), tannins and phytate in the seed, and say heat destroys the lectins and the inhibitors. [3] [4] [7] We found no agency (FDA, Health Canada) with a cooking time for winged beans.
• Do not copy kidney-bean times. The FDA (soak at least 5 hours, boil at least 30 minutes) and Health Canada (at least 10 minutes of vigorous boiling) wrote those for red kidney beans. [8] [9] We found no source saying they are right for winged beans.
• Tubers are boiled: farmers in a Thai study described cutting, washing and boiling them for at least two hours. [5]
• Evidence in one line: we found no trial of winged beans in people. Pooled trials of pulses as a group show a small fall in LDL cholesterol. [12]
• Allergy: bean allergy is possible. For trouble breathing or swelling of the face or throat call 911 (or your local emergency number). [11]
• Kidney note: people with a history of calcium oxalate stones are told to ask about the oxalates in beans. [10]

What is in it (USDA values)

The main columns are for winged beans, mature seeds, boiled without salt (USDA FoodData Central item 172453, SR Legacy). [1] The serving is the USDA household portion of 1 cup, 172 g. [1] The last column is the same bean raw and dry (item 174283) per 100 g. [2] Do not compare raw and cooked columns directly: cooked seeds are about 67% water and dry seeds about 8%. [1] [2]

% Daily Value uses the FDA 2016 Daily Values and is our calculation from the USDA per-100-g figure times the USDA gram weight; values vary with variety, growing place and cooking. [1] USDA lists no fiber for the cooked item (the raw item lists 25.9 g per 100 g, a dry-weight figure). [1] [2] The vitamin D value is unusual for a plant food; USDA lists it, but we could not check how it was measured, so treat it with caution. PROTA's figures for seeds, young pods, leaves and tubers are on a different basis (pods are about 90% water and have 27 kcal per 100 g), so the parts are not interchangeable. [3] We did not read USDA values for pods or tubers.

Plant compounds: the sources describe trypsin inhibitors, chymotrypsin inhibitors, hemagglutinins, tannins, phytates and saponins in the seed. A review gives ranges (for example trypsin inhibitors 11,300 to 74,700 IU per g of seed, hemagglutinins 77 to 154 units per g) that vary by cultivar. [4] PROTA says the seed oil is about 67% oleic and linoleic acid and about 29% saturated fatty acids. [3] These are measurements of the food, not shown benefits.

What research says

Eaten as food vs taken as extract or supplement. The pulse trials above fed ordinary cooked pulses. The cancer-cell finding used a pod extract in a dish, which tells us nothing about eating pods. We read no trial of any winged-bean product in people. Funding: the heat-treatment study was paid by a Malaysian ministry grant and the Thai tuber and pod study lists conflicting funding statements. [5] [6]

How much is a normal serving

The USDA household portion is 1 cup of cooked seeds (172 g), about 253 kcal. [1] In the pooled LDL analysis the trials used a median of about 130 g of pulses a day. [12] These describe what USDA and the trials used, not a prescription. This is information, not advice. We did not read an official portion for the pods, tubers or leaves.

Safety, allergy and medicines

• Raw dry seeds: reviews list lectins and trypsin inhibitors in the seed and say heat destroys them. [4] [7] Harvard says raw legumes in general contain some of the highest lectin levels, that boiling or stewing inactivates most of them, and that simmering at low heat, as in a slow cooker, will not remove all lectins. [15] The FDA describes nausea, severe vomiting and diarrhea from the lectin in raw or undercooked red kidney beans. [8] We did not read a source that measured this for winged beans in people, so we cannot say how severe raw seeds are. Avoid slow-cooker-only cooking.
• Raw pods: several sources say young pods are eaten raw, steamed, boiled or pickled. [4] We found no source that measured lectins in the pods, so we cannot say whether raw pods are a concern.
• Gas and digestion: beans can cause extra gas. [14]
• Kidney disease: the National Kidney Foundation says the potassium and phosphorus in beans are absorbed less well than from animal foods or additives, and most people with chronic kidney disease not on dialysis do not need to limit beans for those minerals; people on dialysis should plan beans with a kidney dietitian. It advises people with a history of calcium oxalate stones to ask about oxalates, since many beans are high in them. [10] We did not read an oxalate value for winged beans.
• Allergy: MedlinePlus lists peanut and soy among the major food allergens and describes hives, swelling, vomiting, wheezing and anaphylaxis, a medical emergency (call 911). [11] We found no source we read on allergy to winged beans or on cross-reaction with peanut or soy. Peanut is a legume (see peanuts).
• Pregnancy, breastfeeding and children: we found no official guidance on winged beans. See what official bodies advise in pregnancy.
• Medicines: we found no source we could read on a direct interaction with a medicine. See foods and medicine interactions.

Choosing, storing and food safety

• Cook dry winged beans fully; do not rely on a slow cooker alone. [15]
• Tubers: the Thai study reported boiling at least two hours in the villages it visited, which is a description of local practice, not an official time. [5]
• We read no official source on storing dried winged beans. For leftovers, see food storage, leftovers and food safety basics.

Related pages

• Lectins in beans: cooking dried beans safely
• Soaking and cooking times for dried beans and lentils
• Hyacinth beans
• Beans, gas, FODMAPs and digestion
• Foods and kidney disease: potassium and oxalates
• Food allergy basics and emergency signs