Yardlong beans nutrition: calories, carbs, GI, protein, fiber, fats

Classification

Yardlong beans or asparagus beans are legumes cultivated for their edible pods. It belongs to the Vigna genus. Yardlong beans have alternative names: pea bean, long-podded cowpea, Chinese long bean, snake bean, etc.

Despite their superficial similarities, the yardlong is not very close to green beans. Despite both belonging to the legume family Fabaceae, unlike yardlong beans, green beans are part of the Phaseolus genus. 

Yardlong bean is a variety of cowpeas.

Taste and Appearance

Yardbeans resemble overgrown green beans. As the name suggests, yardlong beans are much longer than typical green beans. They can grow up to 1 yard (3 feet or approximately 90cm) in length, although they are usually harvested when they are about half that size for tenderness.

These beans are usually green, similar to common green beans, but they can also come in varieties with purple, red, or yellow pods.

The plant leaves are bright green, with three heart-shaped leaves. The flowers and the resulting bean pods usually form connected pairs.

The raw pods may sometimes have a mushroom flavor. Their texture is crisp and tender. Ripe seeds can be used, dried for storage, and then cooked as legumes. Young leaves and stem tips can be steamed like a vegetable.

Cultivation

Yardlong beans thrive in warm climates with full sun. They require well-drained soil with good organic matter. The ideal soil pH is around 6.0 to 6.8.

This vegetable, a traditional food plant in Africa, can improve nutrition, increase food security, promote rural development, and support sustainable agriculture. Since beans are legumes, you can use them to till the soil before planting. Coating the seeds with an inoculant will help the plants take nitrogen from the air.

Yardlong beans are one of Southeast Asia's most popular vegetables, particularly in southern China and Bangladesh. It is the most widely grown legume in the Philippines and is known as "poor man's meat." Yardlong beans are often grown as a little garden vegetable in some lowland tropical countries. It became popular in the Caribbean and is grown as a summer crop in California and parts of Europe, especially as a greenhouse vegetable.

Calories

As mentioned above, cooked yardlong beans are very low-calorie vegetables.

Boiled yardlong beans provide only 47 calories per 100g serving.

However, the same serving size of boiled mature yardlong beans provides 118 calories (1).

Minerals

Yardlong beans are relatively rich in minerals as well. It is high in magnesium, iron, and potassium. It falls in the top 25% of foods as a source of magnesium, containing 44mg per 100g.

A 100g serving of boiled yardlong beans covers 12% of the daily iron needed and 10% of the required magnesium amount.

These beans also fall in the top 36% and 39% of foods as a source of calcium and potassium, respectively. They contain sufficient amounts of copper, selenium, and zinc. 

Unsalted boiled yardlong beans contain very low sodium, only around 4mg in a 100g serving. However, the same serving size of yardlong beans, boiled with salt, provides 240mg of sodium (3).

Cardiovascular Health

Consumption of yardlong beans may help prevent some heart diseases due to their nutritional content.

Yardlong beans are high in magnesium, which may aid in relaxing the smooth heart muscle, reducing the risk of a heart attack. A daily intake of magnesium can help reduce the risk of high blood pressure by 5% (16).

Diabetes

Yardlong beans are low in total carbohydrates and have a low glycemic index value, meaning the consumption of these beans does not increase blood glucose levels rapidly.

Research has found yardlong beans can help prevent health complications, such as diabetes and obesity, due to their nutritional content (17).  

Cancer

Antioxidants are essential for the body; they help fight against free radicals, the leading mechanisms of tumor cell formation. Yardlong beans are a good source of potent antioxidants, providing vitamin C and anthocyanins. These antioxidant properties may prevent some types of cancer (15).

Gout

Gout is a common type of arthritis that can affect anyone at any age. It is characterized by sudden, severe pain, swelling, redness, and tenderness in one or more joints, most often in the big toe. Gout is caused by the high content of uric acid, which forms crystals in the joints. According to one study, those who consumed 1,000–1499mg of vitamin C were less likely to develop gout (18). Yardlong beans are a great source of vitamin C.

However, according to research, boiled yardlong beans provide almost 60mg of total purines per 100g serving (19). Therefore, these beans should be consumed in moderation for people with gout.

Immune System

Yardlong beans are a great source of vitamin C, a powerful antioxidant that can strengthen your body’s natural defenses. Antioxidants are molecules that strengthen the immune system. They can protect cells from harmful molecules like free radicals.

Based on studies, consuming more vitamin C can raise blood antioxidant levels by up to 30%. It helps the body's natural defenses fight inflammation (20).

Skin Health

Yardlong beans are a great source of antioxidants that can prevent acne and age spots.

Yardlong beans contain a high level of vitamin A. At 450IU per 100g, yardlong beans contain more of this vitamin than other legumes of the same family, such as lima beans, fava beans, green beans, etc. Vitamin A is one of the essential vitamins provided by the body through food. Vitamin A maintains mucosal integrity and enhances skin complexion (21).

Pregnancy

Yardlong bean is a practical vegetable during pregnancy that provides a variety of health benefits. It is rich in vitamins such as vitamin C, folate, and vitamin A. It contains minerals such as magnesium and potassium.

Besides, 100g beans provide 45mg of folate (vitamin B9) or 11% of the daily required value for this vitamin. Adequate folate intake before and during pregnancy aids in the prevention of neural tube defects in newborns.

Disadvantages and Risks

While yardlong beans have impressive health benefits, some people should avoid their consumption.

Allergy

People with allergies to legumes should avoid the consumption of yardlong beans.

Some people who are allergic to legumes are sensitive to all types of legumes. Common allergy symptoms include abdominal pain and vomiting, itching, redness of the skin, and hives, often around the mouth. Symptoms of severe cases may include wheezing and anaphylaxis. Some people may develop a rash when the skin comes in contact with legumes.

As with other types of food allergies, the primary approach is to identify and avoid cross-reactive legumes. Cooked legumes can be more allergenic than raw legumes. Even bean protein inhaled through cooking smoke can trigger an allergic reaction, such as asthma (22).

Cooking and Uses

Yardlong beans taste best when fried or deep-fried in oil; the flavor is enhanced while the texture remains firm and juicy. They are also delicious when cooked and served as a salad or in stews.

Yardlong beans are often cooked in woks. The plants' young leaves are usually cooked like spinach and eaten as a vegetable in the tropics. Yardlong bean shoots are sometimes referred to as asparagus beans because they can be utilized similarly to asparagus.