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January 15, 2021
Leek benefits for health

Leek: an ingredient that cannot be missing in the kitchen of those who know it and a real discovery for those who try it for the first time. In this article you can find everything you want to know about this special bulb , its origin, properties and healthy benefits, ways of consumption, possible side effects … among other topics of interest.

What is leek?

Leeks, scientifically known as Allium porrum , are related to garlic , onion , shallots, and chives . Its appearance is similar to that of a large chive, but with a very small bulb ; Its long, cylindrical white stem is formed by superimposed layers that lead to green, flat and well-wrapped leaves.

This firm, crisp vegetable is native to Central Asia and the Mediterranean, where it has been a culinary staple for centuries. Its flavor is similar to that of onion, but softer. They are ideal for adding a subtle touch to recipes without overpowering the other flavors .

Although these vegetables are available throughout the year in supermarkets, their season ranges from fall to the first part of spring.

Nutritional properties

For its unique combination of nutrients, flavonoids and sulfur compounds, the leek should be part of our regular diet, like other allium vegetables. Scientific evidence suggests the daily consumption of at least 1 serving of a vegetable of this type. When choosing leek, it is recommended that each individual serving be 1/2 cup or more .

A cup of leek (100 grams) contains approximately: 1

  • Calories: 61
  • Carbohydrates: 14 g
  • Protein: 1.5 g
  • Fat: 0.3 g
  • Fibra: 1.8 g
  • Azúcar: 3.9 g
  • Vitamina K: 47 mcg (59%)
  • Vitamin A: 1,667 IU (33%)
  • Vitamina C: 12 mg (20%)
  • Folic acid: 64 mcg (16%)
  • Vitamina B6: 0.23 mg (12%)
  • Iron: 2.1 mg (12%)
  • Magnesio: 28 mg (7%)
  • Calcium: 59 mg (6%)
  • Potasio: 180 mg (5%)
  • Tiamina: 0.06 mg (4%)

Note : Percent values ​​(%) are for adults or children over 4 years of age and are based on a 2,000 calorie daily reference diet. These daily values ​​can be higher or lower depending on the individual needs of each person .

A very important fact to keep in mind is that the flavonoids in leeks are more concentrated in the lower portion of the leaves and bulbs. This is the case of kaempferol , one of its main flavonoids, whose concentration is higher towards the lower part of the vegetable. The kaempferol content is higher in leeks than in white onions, but slightly lower than the kaempferol content in red onions. As for other types of flavonoids, for example quercetin , leeks are said to provide lower concentrations than most onions.

Leek benefits for health

Considering that leek belongs to the same plant family as onion and garlic, it is not surprising that it offers several benefits for our health. From preventing inflammatory processes to protecting the body against cancer and heart disease, this bulb has very interesting healing properties.

Learn below the main reasons why you should include leeks in your diet on a regular basis:

Promotes protection against cancer

This is arguably the most researched characteristic of leeks, that is, their ability to prevent the development of different types of cancer.

  • One of the components of the leek responsible for its anti-cancer effects is inulin , a dietary fiber of the fructan family (other than fructose). Inulin stores energy in plants taking the place of other carbohydrates, such as starch. It has been highly studied due to its antimutagenic properties ; researchers have observed its ability to protect DNA from damage caused by mutations and cancer2.
  • Leek consumption (along with garlic, onions, and other members of the Allium family ) has been correlated with a significant decrease in the risk of prostate cancer and cancer of the gastrointestinal tract.34.
  • Another key component of leek to help fight cancer is dialylyl trisulfide , a bioactive compound found in Allium vegetables . This substance has been shown to stop the growth of new tumor cells and prevent the formation of blood vessels within existing tumors (a mechanism cancer tumors use to ensure their continued growth).5.
  • Leek also contains allicin , a compound that neutralizes the spread of free radicals in the body faster than any other nutrient6 . Low levels of free radicals in the body are associated with a lower chance of developing cancer.
  • Likewise , kaempferol , another compound present in said bulb, is a powerful flavonoid with antioxidant, anti-inflammatory, antimicrobial, anticancer, cardioprotective, neuroprotective, antidiabetic, anti-osteoporotic, estrogenic / antiestrogenic, anxiolytic, analgesic and antiallergic action.7.

Improves heart health and prevents heart disease

The flavonoids in leeks are also associated with a lower risk of cardiovascular disease. These antioxidants have a positive impact on blood pressure, diabetes, vascular function, and serum lipid (blood cholesterol) levels.8.

  • In addition, the leek contains a high concentration of folates (vitamin B). Folate plays a critical role in heart health by reducing blood levels of homocysteine, a compound linked to the risk of heart attack and stroke9.
  • On the other hand, its concentration of polyphenols helps protect blood vessels and cells against oxidative damage, which also translates into a lower risk of cardiovascular conditions10.

Promotes the proper development of pregnancy

Leeks are rich in folic acid , an essential vitamin for healthy pregnancy development11.

  • High levels of folate in the body promote DNA uptake and cell division, helping to prevent miscarriage and neural tube defects (diseases and disorders that occur when the fetus’s spine and back do not form properly) .
  • Then fructooligosaccharides (a fructan that comes from inulin) can also be helpful after pregnancy by promoting regularity in a baby’s bowel movements . Constipation is known to be one of the most common problems in newborns, hence the inclusion of leek in the diet of a breastfeeding mother can help prevent constipation (in both newborns and adults)12.

Helps regulate cholesterol

Leek has been found to contain sulfur compounds that are capable of naturally lowering bad cholesterol levels; this is especially important in people at risk for heart disease13.

Promotes weight loss

With a relatively low number of calories (only 61 calories per 100g) and high fiber content, leeks can make us feel full longer without increasing our daily caloric intake too much 14.

  • Being a prebiotic (made up of indigestible fiber), the inulin present in leeks can be very beneficial for people with diabetes, obesity and overweight, since they maintain the balance and diversity of intestinal bacteria, especially when combined with an adequate level of probiotics.
  • All this contributes to a better elimination of waste, a better intestinal perstasis (involuntary muscular contractions of the intestines) and a more efficient secretion of digestive fluids 15.

Fight the development of common infections

Leeks are well known for their use as a natural remedy for fighting colds, flu, hay fever, and urinary tract infections. Its significant supply of vitamin A supports the development of healthy red and white blood cells that carry oxygen and neutralize infectious agents16.

Other benefits

Some research suggests that eating leeks can also:

  • Improve mood and cognitive function , including concentration and memory retention17.
  • Improve vision (vitamin A content) and protect eye tissue from oxidative damage responsible for causing cataracts and age-related macular degeneration (source of lutein and zeaxanthin)
  • Maintain healthy bones by regulating blood flow, activating osteocalcin protein, and providing a good amount of calcium and magnesium.
  • Help prevent anemia and treat its symptoms by being an excellent source of iron and vitamin C (increases the absorption of iron in the diet).

How to choose, store and cook leeks

Choosing the best leek

While leeks can be found year-round in most supermarkets, keep in mind that this vegetable will be cooler during winter and early spring .

When buying leeks, choose long, firm, straight , uniform stems that have dark green leaves, white necks, and a healthy root bulb. Avoid leeks that show a yellowish hue, are wilted, or have bulbs with cracks and bruises.

Because excessively large leeks generally have a more fibrous texture, choose those that are no more than 4 cm in diameter . Try to buy leeks of similar size to ensure more consistent cooking if you want to cook the leeks whole.

Whenever possible, opt for an organic product to avoid exposure to contaminants, such as pesticides and heavy metals.

Clean and save

First, cut the root of the leek and then cut it lengthwise. Once cut, place it in a bowl of cold water and use your hands to swirl the water so that you can remove any dirt. Now you are ready to cook!

Fresh leeks should be stored in the refrigerator unwashed and uncut. Loosely wrapping them in a plastic bag or kitchen paper will help retain moisture and stay fresh for 1-2 weeks.

Refrigerating leeks is also a highly recommended practice due to the changes that its main nutrients can undergo. There are 4 basic factors that affect the nutritional composition of food: exposure to air, exposure to light, exposure to heat, and storage time. Nutrients such as vitamin C, vitamin B6, and carotenoids are good examples of nutrients that are highly susceptible to heat, which is why cooling this bulb is so important.

If you want to keep them for longer (up to 12 months) you can freeze them, making sure to wash them well, chop them and dry them before placing them in a container.

Cooking leeks

In general, the leek can be eaten boiled, fried or raw . However, the higher concentration of antioxidants and the health benefits of this vegetable will be greater when it is steamed, rather than boiled.18.

Tips for preparing leeks:

  • Cut the green tops off the leeks and remove the tough outer leaves.
  • Cut the bulb and stem in half lengthwise.
  • Aerate the leeks and rinse them well under running water, leaving them intact.
  • Cut them into 2-inch lengths; Hold the leek sections cut side up and cut lengthwise to finish with thin strips, until you reach the green portion.
  • Make sure the strips are very thin to shorten the cooking time.
  • Let the leeks rest for at least 5 minutes before cooking.

Cooked leeks are highly perishable ; even when stored in the refrigerator they will only stay fresh for about 2 days. For durability, it is recommended to freeze them after blanching for two to three minutes, although it should be noted that this can affect their taste and texture.

Contraindications and side effects

Although consumption of leeks is considered safe for most people, they are foods that contain oxalates . Oxalates are ions that are found naturally in plants, animals, and humans; they are generally not a cause for concern, however in people who have untreated gallbladder or kidney problems, the buildup of oxalates in body fluids could cause complications in their pre-existing conditions.

If you have kidney or gallbladder problems , consult a doctor before consuming large amounts of leek.

Quick answers to frequently asked questions

What is the origin (history) of the leek?

Leeks are plants native to the Mediterranean and Central Asia, grown in abundance in ancient Egypt as part of their diet more than 4000 years ago.

Emperor Nero was particularly popular because of his love for leeks; He insisted that they improve his singing voice and therefore ate them in large quantities. The Greek philosopher Aristotle also hailed leeks for their throat benefits, claiming that the partridge owed its clear song to regular consumption of leeks.

In 1620, leeks played an important role in the history of Wales, when their image appeared on the helmets of soldiers while they were fighting a battle against the Saxons. Since then, the Welsh have adopted the leek (along with a daffodil) as their national emblem.

Today, leeks are an essential part of the typical European diet.

What characteristics does the leek have? (Summary)

  • Leek is a sister plant (in the same family) to onion and garlic.
  • The edible section of the plant is actually a bunch of leaf sheaths (bulb) that are commonly mistaken for leaves and a stem.
  • It has a mild flavor, similar to onion.
  • Its consumption provides great benefits to our health, including the prevention of cancer, heart disease, high cholesterol, intestinal problems, anemia and the development of infections, among others.
  • To select the perfect leeks, look for long, firm, uniform stems and healthy bulbs.

What is the leek plant like?

The plant leek comprises a bulb slightly developed, which binds to a cylindrical rod formed of sheets superimposed, thick and flat. It usually reaches a height of 0.6 to 0.9 meters.

This plant can produce clusters of flowers white, pink or purple, and seeds of black-blue color. Although the modern leek does not grow wild, it is believed to have been domesticated from a wild ancestor in the Mediterranean region.

How to grow the leek?

Basic requirements. Leeks grow optimally in climates with temperatures between 18 and 21˚C, with 8 hours of sunlight per day, in fertile, well-drained soil, with a pH between 5.5 and 7.0.

Propagation . In areas with short growing seasons, leeks should be planted from transplants, started indoors. The seeds should be sown at a depth of 0.6 and 1.3 cm, leaving a separation of 7.5 to 10 cm between each plant, as well as 20-40 cm between the rows.

Care and maintenance . The soil must remain moist to a depth of 45 cm and have reached a minimum temperature of 7 ° C to achieve successful germination. Transplants should be planted at a distance of 5-8 cm, in rows spaced at a distance of 30-90 cm.

To produce larger stems, it is necessary to plant the leek at a depth of 7-10 cm and cover the leaves gradually. Alternatively, leeks can be sown at ground level and soil added around the stem throughout the season.

Bleaching should not be done until the plants have reached a suitable size, about the size of a pencil. Keep in mind that this plant will benefit from the addition of nitrogen-based fertilizers during the growing season. Keep the bed of soil free of weeds, being careful not to damage the roots of the leek.

Harvest . These vegetables develop slowly and take 100 to 120 days to reach maturity. Leeks are ready for harvest when the stem reaches 3.5 cm in diameter. Harvest them by loosening the plant carefully with a garden fork, and pulling them out.

Does the leek give gas?

Leeks, like garlic and onions, contain fructans, a type of soluble fiber that can cause gas . In sensitive people, even in small amounts, these bulbs can cause flatulence, belching, bloating, and other digestive problems.

Can leeks be frozen?

Yes. If you want to keep the leeks for a long time (up to 12 months) you can freeze them, just be sure to wash, chop and let them dry very well before placing them in a freezer container.

Baby Leeks: Are They Safe?

Generally yes. In fact, leeks are used as a traditional remedy to relieve constipation in babies. The presence of leeks in the diet of breastfeeding mothers can help prevent constipation in newborns19.

Does the leek make you fat?

Quite the opposite. Being low in calories (only 61 calories per serving-100 grams), leeks can be part of a balanced and healthy diet. Its fiber content helps to keep you feeling full longer (fight cravings), and its abundant supply of the prebiotic compound inulin promotes good intestinal health, making digestions healthy and metabolism to function efficiently.20.

Does the leek constipate?

Generally not. In fact, due to its high content of dietary fiber and prebiotics, leeks have traditionally been considered a natural and home remedy to combat constipation.

What do you eat of the leek?

The edible parts of the leek are the white base of the leaves (above the roots and base of the stem), the light green parts and, to a lesser extent, the dark green parts on the leaves.

How to clean a leek?

  1. Wash all the vegetables with plenty of water.
  2. Cut the root of the leek and then cut it lengthwise.
  3. Once cut, place it in a bowl of cold water and use your hands to stir the water, trying to remove all the dirt.

How to preserve the leek?

These vegetables should be kept in the refrigerator, wrapped in kitchen paper or a plastic bag; in this way it should be kept fresh for 1-2 weeks. If you want to keep them for longer you can also freeze them (wash, chop and dry the leeks before placing them in the container to freeze).

What does leek taste like?

Leeks taste very similar to onion, but milder.

What other names does it have?

Leek is also known as soft garlic, elephant garlic, leek garlic, joint garlic, leek onion, joint and porrón. Its scientific name is Allium porrum .

In other languages ​​it is known as:

  • leek (English)
  • porree (German)
  • leek (inglés)
  • leek (Italian)


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My name is Louise Hammond, and I am the creator of this website, a place to find information about tubers, bulbs and medicinal roots. In I show the properties, benefits, characteristics, photos and images, ways of growing and how to make delicious meals from starchy vegetables.