The ancient Egyptians loved a vegetable that can prevent cancer, heart disease and maybe even help you sing better — and I bet, after reading all the great things leeks can do, that you’re going to love this vegetable, too.
The leek is a sister plant to onion and garlic and, like those incredible nutrient-rich foods, offers a wide host of benefits. The list of what leeks can do is a long one. From preventing inflammation, which is at the root of most diseases, to protecting the body from cancer and everything in between, there are plenty of reasons to make leeks a regular part of your diet.
What Are leeks?
Leeks are part of the vegetable genus Allium, part of the Amaryllidacea family. The edible section of the plant is a bundle of leaf sheaths, which is commonly mistermed a stalk or stem. While onions and garlic form a tight bulb, leeks produce a long cylinder of leaf sheaths that are blanched by spreading soil around them. The more of the plant that can be prevented from entering photosynthesis, the more nutritional punch it will have!
These crunchy, firm veggies have a mild taste similar to onions. Native to the Meditteranean and Central Asia, leeks have also been a staple of many European diets for centuries and are often part of a healing diet.
Leeks Nutrition Facts
One serving of leeks (100 grams) contains about: (1)
- 61 calories
- 14 grams carbohydrates
- 1.5 grams protein
- 0.3 grams fat
- 1.8 grams fiber
- 3.9 grams sugar
- 47 micrograms vitamin K (59 percent DV)
- 1,667 IUs vitamin A (33 percent DV)
- 12 milligrams vitamin C (20 percent DV)
- 64 micrograms folate (16 percent DV)
- .23 milligrams vitamin B6 (12 percent DV)
- 2.1 milligrams iron (12 percent DV)
- 28 milligrams magnesium (7 percent DV)
- 59 milligrams calcium (6 percent DV)
- 180 milligrams potassium (5 percent DV)
- 0.06 milligrams thiamine (4 percent DV)
8 Benefits of Leeks
1. Protect Against Cancer
The most widely researched feature of leeks is their ability to protect against different kinds of cancer, and more than one element in the vegetable is responsible for the ability to work as a preventative natural cancer treatment.
One such cancer-protective component is inulin, a dietary fiber in the fructan family (not to be confused with fructose). Inulin stores energy in plants, usually taking the place of other carbohydrates, such as starch. In one study published in Genetics and Molecular Research, inulin was tested for its antimutagenic properties — meaning its ability to protect DNA from damage that causes mutations. Mutations from damaged DNA are often considered to be the reason many cancers form. (2)
In the Allium family, leeks (along with garlic and onions) have been observed to have different effects throughout each stage of cancer formation, affecting biological processes that determine cancer risk. Of particular interest is the major impact of leeks on cancers of the gastrointestinal tract. (3) Consuming Allium vegetables is also correlated with a significant decrease in risk for prostate cancer. (4)
Another factor in the leek’s cancer-fighting ability is diallyl trisulfide, a bioactive compound found in Allium vegetables Also referred to as DATS, this valuable substance has been shown to stop the growth of new tumor cells and prevent blood vessels to form within existing tumors (which is one way in which cancerous tumors ensure their continued growth). (5)
Leeks also contain allicin, an organosulfur compound that produces sulfenic acid as it digests. That may not sound thrilling, until you realize that sulfenic acid neutralizes the spread of free radicals in your body faster than any other nutrient. (6) Low amounts of free radicals in the body are associated with a lower possibility of cancer.
Perhaps the most fascinating element in leeks, however, is kaempferol. This natural flavonol is an antioxidant, relieving oxidative stress in the blood. According to one review of its properties:
“Numerous preclinical studies have shown that kaempferol… [has] a wide range of pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial, anticancer, cardioprotective, neuroprotective, antidiabetic, anti-osteoporotic, estrogenic/antiestrogenic, anxiolytic, analgesic and antiallergic activities.” (7)
That’s a pretty amazing list! Specifically, kaempferol consumption is linked to lower risks of gastric cancer and possibly colorectal cancer. One potential reason for this is that kaempferol protects blood vessel linings from damage by reducing stiffness, allowing the vessels to relax and dilate as they release nitric oxide. (8)
2. Improve Heart Health & Prevent Heart Disease
The flavonoids in leeks are also associated with a diminished risk for cardiovascular disease. Flavonoids have a positive impact on blood pressure, vascular function and serum lipid levels (meaning blood cholesterol). (9) This protection is also due, at least in part, to the presence of kaempferol in leeks.
Leeks also contain a high concentration of the B vitamin folate. Folate plays a critical role in heart health. It reduces levels of homocysteine in blood, which is a compound linked to risk of heart attack and stroke. That’s why folate deficiency is so dangerous to your heart.
The third heart-protecting trait of leeks is their concentration of antioxidant polyphenols. Polyphenols shield blood vessels and cells from oxidative damage, again helping prevent cardiovascular conditions.
Combining all these studies and facts, leeks are a great option to help prevent coronary heart disease, peripheral vascular disease and stroke.
3. Protect Pregnant Mothers and Babies
There are a few simple secrets to a healthy pregnancy and delivery. One of my favorites is the reminder to eat real food. When you’re pregnant, your actions directly impact your unborn child, and it’s important to consume things that are going to keep you and your baby as vibrant and high-functioning as possible. Leeks are one of those real foods.
A good amount of folate is present in leeks, which has long been known to be part of a healthy pregnancy. High levels of folate in the body assist in DNA absorption and cell division. Folate helps prevent miscarriage, as well as neural tube defects — diseases and disorders that occur when the spine and back do not properly close during fetal development.
Pregnancy isn’t the only phase during childbearing when leeks can come in handy! Allium fruits and vegetables also lessen the risk for spontaneous preterm delivery, especially in the 28–31 week gestational period. (10) This is important, because your baby needs plenty of time to develop in the womb in order to be delivered healthy and safe.
Then, the fructooligosaccharides (a fructan that comes from inulin) in Alliums can also help keep your baby’s bowel movements regular. Constipation is one of the most widely growing issue for newborn health, and the presence of leeks in the diet of a breastfeeding mother and/or baby food can help prevent constipation (in both newborns and adults). (11)
4. Regulate Cholesterol
The sulfur-containing compounds in leeks may also naturally reduce bad cholesterol levels, which is especially important if you’re at risk for heart disease. Allicin, one of the compounds we discussed in the cancer-preventing qualities of leeks, inhibits a specific enzyme in the liver responsible for cholesterol production, HMG-CoA reductase. (12)
Interestingly, inhibiting this enzyme is the target of every major cholesterol-lowering drug, all of which are dangerous. Why not use the food you eat as medicine? It’s already proven to do what you need!
The phytonutrients in leeks, sulfides and thiols, also regulate cholesterol by lowering LDL cholesterol (bad cholesterol) levels.
5. Boost Metabolism and Help You Lose Weight
At such a low calorie count, just 61 calories per serving, leeks bulk up a meal by helping you feel full without majorly impacting your daily caloric intake. Their first benefit in weight loss and metabolism boost is their ability to keep you feeling full without sitting heavily in your stomach.
As a high-fiber food, they take longer to digest, meaning you won’t get hungry again very quickly after eating them. Their fiber content works as a metabolism booster, allowing you to burn more calories faster and maintain energy levels. (13)
Inulin, found in leeks, is a prebiotic (a non-digestible fiber compound). When paired with healthy probiotic levels, prebiotics lower overall risk for obesity and weight gain by maintaining balance and diversity of intestinal bacteria.
But weight loss isn’t as simple as calories in/calories out. Evidence supports an association between activating an enzyme called AMP-activated protein kinase (AMPK) with exercise and eating foods high in polyphenols — like leeks. If you want to burn belly fat, you need to balance your levels of polyphenols, along with nootkatone and capsaicin. The food you eat plays a key role in this process. (14)
6. Improve Gut Health
With a growing understanding of the importance of gut health and the epidemic prevalence of leaky gut syndrome, many people are searching for answers as to how they can better take care of their guts. One of those answers is the nutritional powerhouse of the leek.
The prebiotics found in leeks don’t just lower your risk of obesity, but their bacteria-managing ways allow you to properly absorb nutrients in the food you eat. Prebiotics also eliminate noxious waste matter in your body, stimulate intestinal peristalsis (the involuntary muscular contractions your body uses to push waste through your intestines) and secrete digestive fluids.
Like most diseases, leaky gut in particular involves inflammation. Remember, high-fiber foods (such as leeks) are a great defense against inflammation of cells in the body.
7. Fight Infection
Leeks are well-known for their natural treatment of infections, such as flu, cold, hay fever and urinary tract infections, because of their soothing action and antiseptic effect on different body systems. They contain a significant amount of vitamin A, which supports the development of healthy red and white blood cells that transport oxygen and fight off infection.
The Welsh onion, a sister vegetable to the leek, has been researched as an anti-flu mechanism. It’s suspected that its ability to fight the influenza virus is due to the presence of fructans in the vegetable — the same fructans contained in leeks. While a comparable study on leeks has not been published, it’s a safe assumption that this is probably part of why leeks exhibit the same anti-flu reactions. (15)
8. Other benefits
The list continues with leeks! Research shows they can also:
- Improve mood and cognitive function, including concentration and memory retention (16)
- Help your retinas see better in low light (because of the presence of vitamin A)
- Protect your eye tissue from oxidative damage that can cause cataracts and age-related macular degeneration (as a source of lutein and zeaxanthin)
- Keep your bones healthy by regulating blood flow, activating the protein osteocalcin and providing a good amount of calcium and magnesium
- Prevent anemia and treat anemic symptoms by giving you an excellent source of iron and vitamin C (which helps your body to absorb the iron you consume)
The History of Leeks
Leeks are native to the Mediterranean and Central Asia, although they have been mentioned in historical texts in other areas. Bible commentators claim one particular food discussed as one grown in abundance in Egypt to be the leek. Other archaeological discoveries have suggested leeks as a part of the Egyptian diet for four millennia.
Emporer Nero is particularly popular for his love of leeks. He insisted they would improve his singing voice and ate them in huge quantities. Greek philosopher Aristotle also touted leeks for their benefits to the throat, claiming that the partridge had such a clear singing voice due to the regular consumption of leeks.
In 1620, leeks played an important role in Welsh history, when their image first appeared on the helmets of soldiers as they fought a battle against the Saxons. The symbol was to ensure theirs would stand out from the other helmets. Since then, the Welsh have adopted the leek (alongside a daffodil) as their national emblem, and leeks have become a vital part of a typical European diet.
Choosing, Storing and Cooking Leeks
While you can find them year-round at most major grocery stores, leeks are most fresh during the winter and early spring. When searching for the perfect organic leeks, look for uniformly sized, long, firm, white stalks with a healthy root bulb (no larger than 1.5 inches in diameter), avoiding leeks that may have yellowed. Store them in your refrigerator, wrapped in a paper towel or plastic bag. They should stay fresh for anywhere from two days to a week.
To clean leeks, there are two different techniques to choose, depending on how you plan to prepare them. With both methods, it’s important to first rinse the vegetables thoroughly, as leeks usually come with dirt or sand still on the outside.
The simplest method assumes they will be chopped to use in soup. First, cut the root from the leek; then, slice them lengthwise. Once cut, put them in a bowl of cold water and use your hands to agitate the water and remove any additional dirt. Now, they’re ready to cook!
To prepare leeks to use whole, use a sharp knife (starting at about a quarter inch below the lowest opening of the leek) to fan out the dark part of the leek. Clean the long, fanned tops thoroughly under cold water, then cut off the dark tops (leaving about 2–3 inches of the fanned area) and either store or discard them. The dark section of a leek is generally used only to flavor soups and stews, or to create stock. Last, cut the root end of the leek off, staying as close as possible to the root to make sure the vegetable stays in one piece.
Generally, leeks are eaten boiled, fried or raw. However, the highest concentration of antioxidants and healthy goodness is maintained when steaming leeks, rather than boiling. (17)
One of my favorite recipes using leeks, especially during the winter months, is Crockpot Turkey Stew. It’s simple to make and delicious.
Leeks also play a big role in several of my recommended Healthy Soup Recipes, including Potato Leek Soup, Roasted Cauliflower and Leek Soup, No-Cream Creamy Basil Spinach Soup, and Curried Cauliflower Soup.
While leeks are virtually anti-allergenic, they’re part of a small group of foods containing oxalates, which are naturally occurring ions found in plants, animals and humans.
Generally, this is nothing to be concerned about — however, in people who have untreated gallbladder or kidney problems, a buildup of oxalates in body fluids could possibly cause complications in their pre-existing conditions. If you have untreated gallbladder or kidney issues, consult with your doctor about consuming high quantities of leeks.
Takeaways on Leeks
- The leek is a sister plant to onion and garlic.
- The edible section of the plant is a bundle of leaf sheaths, which is commonly mistermed a stalk or stem.
- They have a mild taste similar to onions.
- The health benefits of leeks include their ability to protect against cancer, improve heart health and prevent heart disease, protect pregnant mothers and babies, regulate cholesterol, boost metabolism and help you lose weight, improve gut health, fight infection, improve mood and cognitive function, benefit eye health, keep bones healthy, and prevent anemia.
- When searching for the perfect organic leeks, look for uniformly sized, long, firm, white stalks with a healthy root bulb (no larger than 1.5 inches in diameter), avoiding leeks that may have yellowed.