The World's Healthiest Foods

With a more delicate and sweeter flavor than onions, leeks add a subtle touch to recipes without overpowering the other flavors that are present. Although leeks are available throughout the year they are in season from the fall through the early part of spring when they are at their best.

Leeks are related to onions, shallots and scallions to which they bear a resemblance. They look like large scallions having a very small bulb and a long white cylindrical stalk of superimposed layers that flows into green, tightly wrapped, flat leaves.


Health Benefits

Leeks, like garlic and onions, belong to a vegetable family called the Allium vegetables. Since leek is related to garlic and onions, it contains many of the same beneficial compounds found in these well-researched, health-promoting vegetables.

Lower LDL Cholesterol While Raising HDL Cholesterol

A high intake of Allium vegetables has been shown to reduce total cholesterol and LDL, or “bad” cholesterol levels, while at the same time raising HDL, or “good” cholesterol levels. This can be very important for preventing the development or progression of the blood vessel plaques that occur in atherosclerosis and diabetic heart disease. If these plaques grow too large or rupture, the result can be a heart attack or stroke. Allium vegetables have also been shown to lower high blood pressure, another risk factor for heart attack and stroke.

Protection from Cancer

Regular consumption of Allium vegetables, as little as two or more times a week, is associated with a reduced risk of prostate and colon cancer. The research focused on colon cancer suggests that several of the compounds found in these foods are able to protect colon cells from cancer-causing toxins, while also stopping the growth and spread of any cancer cells that do happen to develop.

Although leeks contain many of the same compounds as those active in fresh garlic and onions, they contain them in smaller amounts. For this reason, larger amounts of leeks may need to be eaten to obtain the benefits provided by its Allium family cousins. Fortunately, the mild, sweet taste of leeks makes this easy to do.

Stabilize Blood Sugar Levels

In addition to their unique properties as Allium family vegetables, leeks also emerged from our food ranking system as a very good source of manganese and a good source of vitamin B6, vitamin C, folate, and iron. This particular combination of nutrients would make leeks particularly helpful in stabilizing blood sugar, since they not only slow the absorption of sugars from the the intestinal tract, but help ensure that they are properly metabolized in the body.


Leeks, known scientifically as Allium porrum, are related to garlic, and to onions, shallots and scallions to which they bear a resemblance. Leeks look like large scallions, having a very small bulb and a long white cylindrical stalk of superimposed layers that flows into green, tightly wrapped, flat leaves. Cultivated leeks are usually about 12 inches in length and one to two inches in diameter, and feature a fragrant flavor that is reminiscent of shallots but sweeter and more subtle. Wild leeks, known as “ramps,” are much smaller in size, but have a stronger, more intense flavor.


Leeks enjoy a long and rich history, one that can trace its heritage back through antiquity. Thought to be native to Central Asia, they have been cultivated in this region and in Europe for thousands of years.

Leeks were prized by the ancient Greeks and Romans and were especially revered for their beneficial effect upon the throat. The Greek philosopher Aristotle credited the clear voice of the partridge to a diet of leeks, while the Roman emperor Nero supposedly ate leeks everyday to make his voice stronger.

The Romans are thought to have introduced leeks to the United Kingdom, where they were able to flourish because they could withstand cold weather. Leeks have attained an esteemed status in Wales, where they serve as this country’s national emblem. The Welsh regard for leeks can be traced back to a battle that they successfully won against that Saxons in 1620, during which the Welsh soldiers placed leeks in their caps to differentiate themselves from their opponents. Today, leeks are an important vegetable in many northern European cuisines and are grown in many European countries.

How to Select and Store

How to Enjoy

For some of our favorite recipes, click Recipes.

Tips for Cooking with Leeks:

Before preparing leeks, clean them thoroughly to remove any soil that may have gotten caught within the overlapping layers of this root vegetable. First, trim the rootlets and a portion of the green tops and remove the outer layer. For all preparations except cutting into cross sections, make a lengthwise incision to the centerline, fold it open, and run the leek under cool water. If your recipe calls for cross sections, first cut it into the desired pieces, then place the sliced leek in a colander and run under cool water.

A Few Quick Serving Ideas:

Healthy Sauté leeks and fennel. Garnish with fresh lemon juice and thyme.

Add finely chopped leeks to salads.

Make vichyssoise, a cold soup made from puréed cooked leeks and potatoes.

Add leeks to broth and stews for extra flavoring.

Braised leeks sprinkled with fennel or mustard seeds makes a wonderful side dish for fish, poultry or steak.

Add sliced leeks to your favorite omelet or frittata recipe.


Leeks and Oxalates

Leeks 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 leeks. 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 leeks, or if taking calcium supplements, may want to eat leeks 2-3 hours before or after taking their supplements. .

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.


Leeks, Boiled
0.50 cup
16.12 calories
Nutrient Amount DV
World's Healthiest
Foods Rating
manganese 0.13 mg 6.5 7.3 very good
vitamin C 2.18 mg 3.6 4.1 good
iron 0.57 mg 3.2 3.5 good
folate 12.64 mcg 3.2 3.5 good
vitamin B6 (pyridoxine) 0.06 mg 3.0 3.3 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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  • Ensminger AH, Esminger M. K. J. e. al. Food for Health: A Nutrition Encyclopedia. Clovis, California: Pegus Press; 1986.
  • Fortin, Francois, Editorial Director. The Visual Foods Encyclopedia. Macmillan, New York.
  • Hsing AW, Chokkalingam AP, Gao YT et al. Allium vegetables and risk of prostate cancer: a population-based study. J Natl Cancer Inst 2002 Nov 6;94(21):1648-51.
  • Wood, Rebecca. The Whole Foods Encyclopedia. New York, NY: Prentice-Hall Press; 1988.

This page was updated on: 2004-11-20 14:53:28
© 2002 The George Mateljan Foundation