Leeks

With long green stalks and soft white stems, leeks are likely known more for their appearance than their health benefits.  But it turns out this root vegetable can hold its own when it comes to providing nutrients and disease fighting compounds.  Their mild flavour and versatility make leeks a welcome addition to any cook's repertoire.

Leeks

Nutrition Notes

Leeks are part of the allium family of vegetables that also includes onions, garlic, chives, scallions and shallots.  Allium vegetables are high in disease-fighting phytochemicals and a range of other nutrients needed for good health.  Studies have shown that a high intake of allium vegetables can help reduce LDL ("bad") cholesterol levels and raise HDL ("good") cholesterol levels.  A high intake of allium vegetables has also been linked with a lower risk of colon and prostate cancer.

Leeks get top marks when it comes to their nutrient content - in fact a 1/2 cup (125 ml) serving delivers a fare share of manganese, iron, folate and vitamin B6 - all for less than 20 calories and 1 gram of fat.

Nutrient information per 1/2 cup (125 ml) chopped leeks, cooked:

Calories  17 kcal 
Fat 0.1 g 
Protein  0.5 g 
Carbohydrate  4 g 
Fibre  0.5 g 
Potassium  48 mg 
Iron  0.6 mg 
Vitamin C  2.3 mg 
Folate  13 mcg 
Vitamin B6  0.06 mg 
Manganese  0.14 mg 

Source: Canadian Nutrient File, 2007b

Leeks are among a small group of foods that contain measurable amounts of oxalates.  Oxalates, while harmless in small quantities, have the potential to become concentrated in the body and cause health problems in some people.  People with existing calcium oxalate kidney stones are advised to limit their intake of oxalate containing foods, including leeks.

Varieties

Leeks, also known as allium ampeloprasum, are closely related to onions and garlic.  Major commercial varieties of leeks include Pinola, Titan, Arkansas, Derik, Palino and Unique.  All commercial varieties share common traits of a thick white stem with long green leaves.

Wild leeks, also known as ramps, are much smaller in size than their commercially grown cousins and tend to have a stronger, more intense taste.  They're available for a very short time in specialty markets in early spring and are a prized ingredient by experienced chefs. 

Buying

Commercially grown leeks are available at major grocery stores year round, but they're at their peak from late fall to early winter. 

When buying fresh leeks, look for firm, undamaged tops with a bright green colour and white creamy bottoms.  Avoid wrinkled, bruised or very large leeks - since this is an indication they're old and less tender.  The edible portion of the leek is the creamy bottom and light green stalk, so look for leeks with a large white portion. 

Leeks are often sold in bunches of two or three - ideally they should be wrapped together in two or three places to avoid damage to the stalk. 

Storing

If stored properly, leeks last for quite some time.  Loosely wrap leeks in a plastic bag and store in the vegetable crisper of the refrigerator for up to 2 weeks.  Avoid washing leeks before storing them, as this will cause them to spoil more quickly.

Fresh, whole leeks can also be frozen if you don't plan on using them right away. Although this will soften them and cause them to lose some flavour, it's appropriate for leeks that will be added to cooked dishes such as soups or stews.  Wrapped tightly in a sealed plastic bag, leeks can be frozen for up to 3 months.

Preparing

When leeks are grown, farmers often push dirt around the stem to yield a larger white, edible portion.  As a result, there's often quite a bit of sand and grit between the thin layers of leaves.  The easiest way to clean a leek and remove the dirt is to cut the leek in half lengthwise and cut off the root section at the bottom.  Run each half of the leek under cold running water and gently separate the leaves to dislodge any dirt or sand between the layers.

Unless you finely chop leeks for an addition to a fresh salad, or as a garnish on homemade soup, leeks almost always need to be cooked since they can be quite fibrous when eaten raw.

If you're boiling leeks, such as in a soup, allow for 15 minutes of cooking time.  Sautéed over medium heat, leeks take about 8 to 10 minutes to cook.  If you plan to simmer leeks in an oven-baked dish, allow for 30 minutes to cook. 

Eating

Leeks have a subtle flavour that's more delicate than regular onions.  They can be used in place of green onions in many recipes, and offer a mellow sweet taste.  Leeks pair especially well with honey, sugar and maple syrup.  They're also delicious when served in dishes with potatoes, mushrooms and part skim cheese.

Healthy ways to enjoy

Breakfast

  • Make an egg white omelet with sautéed sliced leeks, diced red peppers and shredded spinach.
  • Sauté leeks, mushrooms and chopped garlic until soft and wilted.  Serve over baby spinach leaves on a piece of warm sourdough bread.
  • Make a low fat breakfast English muffin topped with sautéed leeks and broccoli, then topped with grated part skim cheddar cheese.

Lunch

  • Top a fresh green salad with thinly sliced sautéed leeks.
  • Make homemade Vichyssoise, a chilled soup made with potatoes and leeks.
  • Braise leeks with fennel seeds for a healthy side dish.

Dinner

  • Serve sautéed leeks with a warm vinaigrette as an appetizer.
  • Garnish a grilled burger with sautéed leeks in place of onions
  • Use sliced leeks as a garnish on homemade soups
  • Toss thickly sliced leeks with other root vegetables, such as carrots, potatoes and garlic and roast in the oven at 375°F (190°C) for 45 minutes, or until cooked through.
  • Grill leeks over the barbecue on medium heat for 10 to 12 minutes, or until slightly wilted and cooked through.

More Information

Foodland Ontario - http://www.foodland.gov.on.ca/english/vegetables/leeks/index.html

Wikipedia - http://en.wikipedia.org/wiki/Leek

The World's Healthiest Foods - http://whfoods.org/genpage.php?tname=foodspice&dbid=26

Did you know?

  • While large leeks aren't prized for their taste, every year Britain holds a yearly competition and awards a prize to the farmer who has grown the largest leek, which often ranges from 10 to 12 centimeters (4 to 5 inches) in diameter.
  • The leek is one of the national emblems of Wales - where according to legend, soldiers used to wear the vegetable on their helmets.
  • Thanks to a leek soup recipe in the 2004 bestseller Why French Women Don't Get Fat, there was near shortage of leeks in vegetable markets across the country.