The World's Healthiest Foods
Green beans

Commonly referred to as string beans, the string that once was their trademark can seldom be found in modern varieties. Although these bright green and crunchy beans are available at your local market throughout the year, they are in season from summer through early fall when they are at their best and the least expensive.

Green beans are picked while still immature and the inner bean is just beginning to form. They are one of only a few varieties of beans that are eaten fresh. Although green beans vary in size they average about four inches in length. They are usually deep emerald green in color and come to a slight point at either end. They contain tiny seeds within their thin pods.


Health Benefits

Green beans, while quite low in calories (just 43.75 calories in a whole cup), are loaded with enough nutrients to not only power up the Jolly Green Giant, but to put a big smile on his face. Green beans are an excellent source of vitamin C, vitamin K and manganese. Plus green beans are very good source of vitamin A (notably through their concentration of carotenoids including beta-carotene), dietary fiber, potassium, folate, and iron. And, green beans are a good source of magnesium, thiamin, riboflavin, copper, calcium, phosphorous, protein, omega-3 fatty acids and niacin.

Helping You Bone Up

The vitamin K provided by green beans - a spectacular 122.0% of the daily value in one cup - is important for maintaining strong bones. Vitamin K1 activates osteocalcin, the major non-collagen protein in bone. Osteocalcin anchors calcium molecules inside of the bone. Therefore, without enough vitamin K1, osteocalcin levels are inadequate, and bone mineralization is impaired.

Cardiovascular Protection from Green Beans

For atherosclerosis and diabetic heart disease, few foods compare to green beans in their number of helpful nutrients. Green beans are a very good source of vitamin A, notably through their concentration of beta-carotene, and an excellent source of vitamin C. These two nutrients are important antioxidants that work to reduce the amounts of free radicals in the body, vitamin C as a water-soluble antioxidant and beta-carotene as a fat-soluble one. This water-and-fat-soluble antioxidant team helps to prevent cholesterol from becoming oxidized. Oxidized cholesterol is able to stick to and build up in blood vessel walls, where it can cause blocked arteries, heart attack or stroke. Getting plenty of beta-carotene and vitamin C can help prevent these complications, and a cup of green beans will provide you with 16.6% of the daily value for vitamin A along with 20.2% of the daily value for vitamin C.

Green beans are also a very good source of fiber, a very good source of potassium and folate, and a good source of magnesium and riboflavin. Each of these nutrients plays a significant cardio-protective role.

Magnesium and potassium work together to help lower high blood pressure, while folate is needed to convert a potentially dangerous molecule called homocysteine into other, benign molecules (the riboflavin in green beans may also serve to protect against the build up of homocysteine in certain individuals). Since homocysteine can directly damage blood vessel walls if not promptly converted, high levels are associated with a significantly increased risk of heart attack and stroke. Lastly, fiber, which is also found in green beans, has been shown to lower high cholesterol levels. A cup of green beans supplies 16.0% of the daily value for fiber, 10.7% of the DV for potassium, 7.8% of the DV for magnesium, anmd 10.4% of the DV for folate. What this all adds up to is a greatly reduced risk of atherosclerosis, diabetic heart disease, heart attack, and stroke.

Colon Cancer Prevention

Green beans can also help prevent colon cancer. The vitamin C and beta-carotene in green beans help to protect the colon cells from the damaging effects of free radicals. Green beans' folate helps to prevent DNA damage and mutations in colon cells, even when they are exposed to cancer-causing chemicals. Studies show that people who eat foods high in vitamin C, beta-carotene, and/or folate are at a much lower risk of getting colon cancer than those who don't.

Green beans' fiber can help prevent colon cancer as well, as it has the ability to bind to cancer-causing toxins, removing them from the body before they can harm colon cells.

Anti-Inflammatory Nutrients

Beta-carotene and vitamin C both also have very strong anti-inflammatory effects. This may make green beans helpful for reducing the severity of diseases where inflammation plays a major role, such as asthma, osteoarthritis, and rheumatoid arthritis.

Green beans are a good source of riboflavin, which has been shown to help reduce the frequency of migraine attacks in people who suffer from them. Riboflavin's protective role in energy production may explain why. The oxygen-containing molecules the body uses to produce energy can be highly reactive and can inadvertently cause damage the mitochondria and even the cells themselves. In the mitochondria, such damage is largely prevented by a small, protein-like molecule called glutathione. Like many "antioxidant" molecules, glutathione must be constantly recycled, and it is vitamin B2 that allows this recycling to take place. (Technically, vitamin B2 is a cofactor for the enzyme glutathione reductase that reduces the oxidized form of glutathione back to its reduced version.) A cup of green beans supplies 7.1% of the DV for riboflavin.

Iron for Energy

Popeye was mistaken, green beans have almost twice as much iron as spinach. Green beans are a very good source of iron, an especially important mineral for menstruating women, who are more at risk for iron deficiency. Boosting iron stores with green beans is a good idea, especially because, in comparison to red meat, a well known source of iron, green beans provide iron for a lot less calories and are totally fat-free. Iron is an integral component of hemoglobin, which transports oxygen from the lungs to all body cells, and is also part of key enzyme systems for energy production and metabolism. And, if you're pregnant or lactating, your needs for iron increase. Growing children and adolescents also have increased needs for iron. In one cup of green beans, you'll be provided with 10.7% of the daily value for iron; a cup of spinach also provides a good amount of iron - 8.9% of iron's daily value.

Rich in Minerals for Energy and Antioxidant Protection

As noted above, green beans are a very good source of iron. Iron is as essential part of hemoglobin, a molecule essential to energy production since it is responsible for transporting and releasing oxygen throughout the body. But hemoglobin synthesis also relies on copper. Without copper, iron cannot be properly utilized in red blood cells. Fortunately, both minerals are supplied in green beans, which also contain 6.5% of the daily value for copper.

In addition to its role in hemoglobin synthesis, copper may be helpful in reducing the symptoms of rheumatoid arthritis. Copper, along with manganese (yet another trace mineral for which green beans are an excellent source), is an essential cofactor of a key oxidative enzyme called superoxide dismutase. Superoxide dismutase disarms free radicals produced within the mitochondria (the energy production factories within our cells). Copper is also necessary for the activity of lysyl oxidase, an enzyme involved in cross-linking collagen and elastin, both of which provide the ground substance and flexibility in blood vessels, bones and joints. One cup of green beans provides 18.5% of the DV for manganese.

Vitamins C, A and Zinc for Optimal Immune Function and Acne-Free Skin

Green beans' vitamin A (through its concentration of beta-carotene) and vitamin C are part of the sine qua non of a healthy immune system. Beta-carotene and vitamin A are fat-soluble antioxidants, while vitamin C functions as an antioxidant in the water-soluble areas of the body. So, between their beta-carotene and vitamin C content, green beans have all areas covered against damage from oxygen free radicals.

In addition to its antioxidant activity, vitamin C is critical for good immune function. Vitamin C stimulates white cells to fight infection, directly kills many bacteria and viruses, and regenerates Vitamin E after it has been inactivated by disarming free radicals.

Maintain Your Memory with Thiamin (Vitamin B1)

Green beans are a good source of thiamin, providing almost 6.0% of the daily value for this nutrient in a single cup. Thiamin is an integral participant in enzymatic reactions central to energy production and is also critical for brain cell/cognitive function. This is because thiamin is needed for the synthesis of acetylcholine, a neurotransmitter essential for memory, whose lack has been found to be a significant contributing factor in age-related impairment in mental function (senility) and Alzheimer's disease. In fact, Alzheimer's disease is clinically characterized by a decrease in acetylcholine levels. Don't forget to make green beans a frequent contributor to your healthy diet.

The many nutrients in green beans can help you prevent a number of different conditions, including Alzheimer's, atherosclerosis, diabetic heart disease, colon cancer, asthma, arthritis, acne, ear infections, and maybe even colds and flu’s. Good reasons to add them to your shopping list the next time you head to the grocery store.


While green beans are typically referred to as string beans, many varieties no longer actually feature the fibrous ‘string’ that runs down the length of the earlier varieties. Green beans are also commonly known as snap beans. Haricots verts are French green beans that are very thin and very tender.

Green beans are in the same family as shell beans, such as pinto beans, black beans and kidney beans. Yet unlike their cousins, green beans' entire bean, pod and seed, can be eaten.

Green beans range in size, but they usually average four inches in length. They are usually deep emerald green in color and come to a slight point at either end. They contain tiny seeds within their thin pods.

The scientific name for green beans is Phaseolus vulgaris.


Green beans and other beans, such are kidney beans, navy beans and black beans are all known scientifically as Phaseolus vulgaris. They are all referred to as “common beans,” probably owing to the fact that they all derived from a common bean ancestor that originated in Peru. From there, they were spread throughout South and Central America by migrating Indian tribes. They were introduced into Europe around the 16h century by Spanish explorers returning from their voyages to the New World, and subsequently were spread through many other parts of the world by Spanish and Portuguese traders. Today, the largest commercial producers of fresh green beans include the United States, China, Japan, Spain, Italy and France.

How to Select and Store

If possible, purchase green beans at a store or farmer’s market that sells them loose so that you can sort through them to choose the beans of best quality. Purchase beans that have smooth feel and a vibrant green color, and that are free from brown spots or bruises. They should have a firm texture and ‘snap’ when broken.

Store unwashed fresh beans pods in a perforated plastic bag kept in the refrigerator crisper. Whole beans stored this way should keep for about three days.

How to Enjoy

For some of our favorite recipes, click Recipes.

Tips for Preparing Green Beans:

Just prior to using the green beans, wash them under running water. Remove both ends of the beans by either snapping them off or cutting them with a knife.

A Few Quick Serving Ideas:

Green beans are a classic ingredient in Salad Nicoise, a French cold salad dish that combines steamed green beans with tuna fish and potatoes.

Healthy sauté green beans with shiitake mushrooms.

Prepare the perennial favorite, green beans almondine, by sprinking slivered almonds on healthy sautéed beans.

Roast green beans, red peppers and garlic, and combine with olive oil and seasonings to make a delicious salad.

Add chopped green beans to breakfast frittatas.


Oxalates and Green Beans

Green beans are among a small number of foods that contain any measurable amount of oxalates, naturally-occurring substances found in plants, animals, and human beings. When oxalates become too concentrated in body fluids, they can crystallize and cause health problems. For this reason, individuals with already existing and untreated kidney or gallbladder problems may want to avoid eating green beans. Oxalates may also interfere with absorption of calcium from the body. For this reason, individuals trying to increase their calcium stores may want to avoid green beans, or if taking calcium supplements, may want to eat green beans 2-3 hours before or after taking their supplements.

Pesticide Residues and Green beans

Even though pesticides are present in food at very small trace levels, their negative impact on health is well documented. The liver’s ability to process other toxins, the cells’ ability to produce energy, and the nerves’ ability to send messages can all be compromised by pesticide exposure. Since green beans are among the 20 foods on which pesticide residues have been most frequently found, individuals wanting to avoid these health risks may want to avoid consumption of green beans unless grown organically.

Nutritional Profile

Introduction to Food Rating System Chart

The following chart shows the nutrients for which this food is either an excellent, very good or good source. Next to the nutrient name you will find the following information: the amount of the nutrient that is included in the noted serving of this food; the %Daily Value (DV) that that amount represents (similar to other information presented in the website, this DV is calculated for 25-50 year old healthy woman); the nutrient density rating; and, the food's World's Healthiest Foods Rating. Underneath the chart is a table that summarizes how the ratings were devised. For more detailed information on our Food and Recipe Rating System, please click here.


Green Snap/String Beans, Boiled
1.00 cup
43.75 calories
Nutrient Amount DV
World's Healthiest
Foods Rating
vitamin K 97.56 mcg 122.0 50.2 excellent
vitamin C 12.13 mg 20.2 8.3 excellent
manganese 0.37 mg 18.5 7.6 excellent
vitamin A 832.50 IU 16.6 6.9 very good
dietary fiber 4.00 g 16.0 6.6 very good
potassium 373.75 mg 10.7 4.4 very good
folate 41.63 mcg 10.4 4.3 very good
tryptophan 0.03 g 9.4 3.9 very good
iron 1.60 mg 8.9 3.7 very good
magnesium 31.25 mg 7.8 3.2 good
vitamin B2 (riboflavin) 0.12 mg 7.1 2.9 good
copper 0.13 mg 6.5 2.7 good
vitamin B1 (thiamin) 0.09 mg 6.0 2.5 good
calcium 57.50 mg 5.8 2.4 good
phosphorus 48.75 mg 4.9 2.0 good
protein 2.36 g 4.7 1.9 good
omega 3 fatty acids 0.11 g 4.4 1.8 good
vitamin B3 (niacin) 0.77 mg 3.9 1.6 good
World's Healthiest
Foods Rating
excellent DV>=75% OR Density>=7.6 AND DV>=10%
very good DV>=50% OR Density>=3.4 AND DV>=5%
good DV>=25% OR Density>=1.5 AND DV>=2.5%


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This page was updated on: 2004-11-20 13:23:46
© 2002 The George Mateljan Foundation