Green Beans: Nutrients, What Research Shows and Safety

Green beans (also called snap beans or string beans) are the young, tender pods of the common bean plant, Phaseolus vulgaris, in the pea and bean family (Fabaceae). The whole pod is eaten, with the small seeds inside, usually cooked. People eat them for fiber, vitamins and as a low-calorie side dish. This page keeps the food apart from supplements and from hype. It is information, not a prescription.

Read this first

• Warfarin (a blood thinner): green beans contain vitamin K, which affects how warfarin works. One USDA cup supplies about a third of the Daily Value. MedlinePlus advises eating consistent amounts of vitamin K foods from week to week and talking to your doctor before changing your diet. [1][2]
• Raw beans: FDA says a natural toxin called phytohaemagglutinin (a lectin) is found in raw or undercooked beans, and names kidney beans. It does not mention green beans, and we found no source that measured it in green bean pods. [3]
• Canned beans: salt is often added in canning. The one study we read on canned green beans found that heating them in fresh water instead of the canning liquid cut their salt content by a third. [6]
• Allergy to any food is possible. For trouble breathing or swelling of the face or throat, call 911.
• Evidence in one line: green beans are a nutritious vegetable that adds fiber, but we found no trials on green beans themselves showing that they treat or prevent a disease.

What is in it (USDA values)

Source: USDA FoodData Central, "Beans, snap, green, raw" (SR Legacy, ID 169961). [1] USDA's household portion of 1 cup of 1/2" pieces is 100 g, so the per-cup and per-100 g columns match. USDA also lists 10 beans (4" long) as 55 g. % Daily Value uses the FDA 2016 Daily Values; values vary with variety, ripeness and storage.

USDA lists lutein plus zeaxanthin (640 µg per 100 g) and beta-carotene (379 µg per 100 g), plant pigments of the carotenoid family. [1] We did not find a source we could read that tested these compounds from green beans in people, so we make no health claim for them.

What research says

Eaten as food versus taken as a supplement or extract. The studies above are about nutrients or other foods, not green bean supplements. We did not find a source on green bean extracts or powders, so we make no claim about them. Results for dry beans (the mature seeds of the same species) should not be assumed to apply to the green pod.

How much is a normal serving

• USDA lists 1 cup of green bean pieces as 100 g and 10 beans as 55 g. [1] These are database portions, not an advised amount.
• The NHS counts 80 g of fresh, canned or frozen vegetables as one portion of its 5 A DAY (reviewed June 2026), and the WHO recommends at least 400 g of fruits and vegetables a day for people older than 10 (fact sheet, January 2026). [10][11] These are public health figures, not advice for you.
• Frozen versus fresh: a laboratory comparison that included green beans found frozen produce had vitamin content similar to fresh, and sometimes higher; for beta-carotene it found no significant difference in green beans. [12]
• USDA values above are for raw beans. Cooked and canned green beans are separate foods in the database, and we did not read their values, so we give no numbers for them.

Safety, allergy and medicines

• Warfarin and vitamin K: USDA lists 43 µg of vitamin K per 100 g, 36% of the Daily Value. [1] MedlinePlus says vitamin K foods can change how warfarin works, advises consistent amounts week to week, advises against eating large amounts of leafy green vegetables, and says to talk to your doctor before changing diet. [2] Green beans are not named on that page and are not a leafy green. The aim is steadiness and telling your anticoagulation clinic. Other blood thinners work differently; ask your pharmacist. See foods and medicine interactions.
• Raw or undercooked beans (lectins): FDA describes phytohaemagglutinin, a lectin, as found in raw or undercooked beans, with high levels in raw beans able to cause nausea, severe vomiting and diarrhea. It names kidney beans, says canned and properly cooked kidney beans have low levels, and says soaking for at least 5 hours and boiling in fresh water for at least 30 minutes removes and destroys the toxin. [3] A 2025 paper measuring the lectin in dry beans (kidney, white, black, pinto) tested only mature seeds, not fresh pods, and found over 99% less lectin in commercially canned beans; poisoning reports involved a few raw soaked kidney beans, with symptoms within 1 to 3 hours. [13] Neither source says how much lectin green bean pods contain. Proper evidence not found for green beans, so we do not claim they are risky or risk-free raw. See raw sprouts, raw milk and undercooked foods.
• Canned beans and sodium: the USDA entry we read is for raw beans (6 mg sodium per 100 g). [1] We did not read a USDA value for canned green beans, so we give no figure. A 1983 study of canned green beans, tuna and cottage cheese found that rinsing had little effect on the beans, but replacing the canning liquid with water before heating reduced their salt content by 33%. [6] This is one older study. Labels on cans show the current sodium. See added sugars, sodium and saturated fat on labels.
• Allergy: proper evidence on green bean allergy not found in the sources we read. Stop eating it and seek care after any reaction; for breathing trouble or swelling of the face or throat call 911.
• Kidney disease and potassium: USDA lists 211 mg potassium per 100 g (4% of the Daily Value). [1] We did not read a source on green beans for people with kidney disease, so ask a clinician. See foods in kidney disease: potassium and oxalates.
• Pesticide residues: we could not read a source (EWG and USDA Pesticide Data Program pages were not used), so we make no statement on green bean residues. Washing is covered below.
• Pregnancy: green beans are an everyday vegetable; we did not find a source on them in pregnancy. MedlinePlus stresses folic acid before and during pregnancy in general. [7] Ask your clinician or midwife.

Choosing, storing and food safety

• Wash all produce thoroughly under running water before preparing or eating. Do not use soap, detergent or produce wash. Washing reduces bacteria but does not remove them all. [14]
• Refrigerate pre-cut or packaged produce, and keep perishable produce at 40°F or below. [14]
• Cook beans fully; see the FDA guidance on raw beans above. [3]
• For canned beans, read the label for sodium. [6]

Related pages

• Legumes
• Fresh, frozen and canned produce
• Foods and medicine interactions: vitamin K, grapefruit and others
• How much fiber per day and fiber side effects
• Added sugars, sodium and saturated fat on labels
• Raw sprouts, raw milk and undercooked foods: risks