Leeks

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.

This chart graphically details the %DV that a serving of Leeks provides for each of the nutrients of which it is a good, very good, or excellent source according to our Food Rating System. Additional information about the amount of these nutrients provided by Leeks can be found in the Food Rating System Chart. A link that takes you to the In-Depth Nutritional Profile for Leeks, featuring information over 80 nutrients, can be found under the Food Rating System Chart.

• Health Benefits
• Description
• History
• How to Select and Store
• How to Enjoy
• Individual Concerns
• Nutritional Profile
• References

Health Benefits

Leeks, like garlic and onions, belong to a vegetable family called the Allium vegetables. Since leeks are related to garlic and onions, they contain 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.

Promote Optimal Health

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 intestinal tract, but help ensure that they are properly metabolized in the body.

Description

Leeks, known scientifically as Allium porrum, are related to garlic, and to onions, shallots and scallions. 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.

History

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

Leeks should be firm and straight with dark green leaves and white necks. Good quality leeks will not be yellowed or wilted, nor have bulbs that have cracks or bruises. Since overly large leeks are generally more fibrous in texture, only purchase those that have a diameter of one and one-half inches or less. Try to purchase leeks that are of similar size so as to ensure more consistent cooking if you are planning on cooking the leeks whole. Leeks are available throughout the year, although they are in greater supply from the fall through the early part of spring.

Fresh leeks should be stored unwashed and untrimmed in the refrigerator, where they will keep fresh for between one and two weeks. Wrapping them loosely in a plastic bag will help them to retain moisture. Cooked leeks are highly perishable, and even when kept in the refrigerator, will only stay fresh for about two days. Leeks may be frozen after being blanched for two to three minutes, although they will lose some of their desirable taste and texture qualities. Leeks will keep in the freezer for about three months.

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 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.

Individual Concerns

Leeks and Oxalates

Leeks are among a small number of foods that contain measurable amounts 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. Laboratory studies have shown that oxalates may also interfere with absorption of calcium from the body. Yet, in every peer-reviewed research study we've seen, the ability of oxalates to lower calcium absorption is relatively small and definitely does not outweigh the ability of oxalate-containing foods to contribute calcium to the meal plan. If your digestive tract is healthy, and you do a good job of chewing and relaxing while you enjoy your meals, you will get significant benefits - including absorption of calcium - from calcium-rich foods plant foods that also contain oxalic acid. Ordinarily, a healthcare practitioner would not discourage a person focused on ensuring that they are meeting their calcium requirements from eating these nutrient-rich foods because of their oxalate content. For more on this subject, please see "Can you tell me what oxalates are and in which foods they can be found?"

Nutritional Profile

Leeks are a very good source of manganese and a good source of vitamin C, iron, folate and vitamin B6. For an in-depth nutritional profile click here: Leeks.

In-Depth Nutritional Profile

In addition to the nutrients highlighted in our ratings chart, an in-depth nutritional profile for Leeks is also available. This profile includes information on a full array of nutrients, including carbohydrates, sugar, soluble and insoluble fiber, sodium, vitamins, minerals, fatty acids, amino acids and more.

Introduction to Food Rating System Chart

In order to better help you identify foods that feature a high concentration of nutrients for the calories they contain, we created a Food Rating System. This system allows us to highlight the foods that are especially rich in particular nutrients. The following chart shows the nutrients for which this food is either an excellent, very good, or good source (below the chart you will find a table that explains these qualifications). If a nutrient is not listed in the chart, it does not necessarily mean that the food doesn't contain it. It simply means that the nutrient is not provided in a sufficient amount or concentration to meet our rating criteria. (To view this food's in-depth nutritional profile that includes values for dozens of nutrients - not just the ones rated as excellent, very good, or good - please use the link below the chart.) To read this chart accurately, you'll need to glance up in the top left corner where you will find the name of the food and the serving size we used to calculate the food's nutrient composition. This serving size will tell you how much of the food you need to eat to obtain the amount of nutrients found in the chart. Now, returning to the chart itself, you can look next to the nutrient name in order to find the nutrient amount it offers, the percent Daily Value (DV%) that this amount represents, the nutrient density that we calculated for this food and nutrient, and the rating we established in our rating system. For most of our nutrient ratings, we adopted the government standards for food labeling that are found in the U.S. Food and Drug Administration's "Reference Values for Nutrition Labeling." Read more background information and details of our rating system.

Leeks, boiled 0.50 cup 52.00 grams 16.12 calories Nutrient Amount DV (%) Nutrient Density 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 Rule 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%

In-Depth Nutritional Profile for Leeks

References

• Ensminger AH, Ensminger, ME, Kondale JE, Robson JRK. Foods & Nutriton Encyclopedia. Pegus Press, Clovis, California 1983.
• Ensminger AH, Esminger M. K. J. e. al. Food for Health: A Nutrition Encyclopedia. Clovis, California: Pegus Press; 1986 1986. PMID:15210.
• Fortin, Francois, Editorial Director. The Visual Foods Encyclopedia. Macmillan, New York 1996.
• Gates MA, Tworoger SS, Hecht JL, De Vivo I, Rosner B, Hankinson SE. A prospective study of dietary flavonoid intake and incidence of epithelial ovarian cancer. Int J Cancer. 2007 Apr 30; [Epub ahead of print] 2007. PMID:17471564.
• 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 2002.
• Manach C, Scalbert A, Morand C, Rémésy C, Jiménez L. Polyphenols: food sources and bioavailability. Am J Clin Nutr. 2004 May;79(5):727-47. 2004. PMID:15113710.
• Wood, Rebecca. The Whole Foods Encyclopedia. New York, NY: Prentice-Hall Press; 1988 1988. PMID:15220.

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