ENVIRONMENTAL NUTRITION: Kale: Strong on nutrition and flavor
A descendant of wild cabbage, kale has been cultivated for 2,000 years in the Mediterranean region, where it was the most widely eaten green vegetable until the Middle Ages. Also known as borecole, kale stood out for its ability to grow during winter, making it a staple crop in places like Scotland, where every kitchen had a "kail pot" for cooking. With the exception of kale's role in Southern cooking, this green leafy vegetable has mainly been featured as a garnish for other foods, enhancing them with its fancy ruffled leaves. But these days, kale is often featured on the plate, recognized for its flavor and nutritious benefits.
Kale (Brassica oleracea) is one of many primitive cabbages that are leafy but non-heading, such as collards and bok choy. In fact, its variety acephala means "without a head." A member of the Brassica (cruciferous) family, along with broccoli and Brussels sprouts, kale is often confused with collards, which are similar in many respects, though kale has a darker color, stronger flavor and different leaf shape. The many varieties of kale, which include plain leaf, curly leaf and Tuscan (also called dinosaur,) differ in taste, texture and appearance yet each provides cancer-fighting antioxidants and more than 45 flavonoids, including eye-healthy lutein, zeaxanthin and beta-carotene. One cup packs over 200 percent of the daily value of vitamin A, 134 percent DV of vitamin C, and six times the daily value of bone-healthy vitamin K.
As a cruciferous vegetable, kale takes a bite out of cancer risk when it is chopped or chewed, releasing compounds called sulforaphanes, which help to clear carcinogens from the body, according to a study in the June 2008 Cancer Letters. Its health benefits significantly increase when it's steamed, says a study published in the June 2008 Nutrition Research. Compared to its raw state, steamed kale leads the team of leafy greens tested for its ability to bind bile acids, which can lower blood cholesterol levels. Regular consumption of steamed kale is associated with lowered risk of cardiovascular disease and cancer.
Kale's blue-green, frilly leaves make an otherwise sparse growing season (mid-winter through spring) more festive. Choose firm, deep green plants with moist, strong stems. Smaller leaves are most tender and mildly flavored. Store in an airtight plastic bag up to five days, refrigerated, as age turns kale bitter. Chop leaves to half-inch lengths and stems to quarter-inch for even cooking. Serve kale raw as a lettuce alternative in salads, steamed for optimal health benefits, sautéed or simmered in warm soup. Drizzle with lemon juice to enhance the flavor.
1 cup raw, chopped kale
Vitamin A: 10,302 IU (206 percent DV)
Vitamin C: 80 milligrams (134 percent DV)
Vitamin K: 547 micrograms (684 percent DV)