Kale, also known as borecole, has been cultivated for over 2,000 years. The wild Brassica oleracea plant is native to the Mediterranean region. Soon after the domestication of plants began, people in the Mediterranean region began growing the plant as a leafy vegetable. Because people grew the plants for their leaves, they selected the seeds from the largest-leafed plants to plant the following year. By the 5th century B.C., continued propagation of ever-larger leaves had led to the development of the vegetable we now know as kale.
Over the centuries, some people preferred plants with a tight cluster of tender young leaves in the center of the plant at the top of the stem, and they selected and propagated for those characteristics. Continued selective breeding of these plants over the centuries resulted in the gradual formation of a dense cluster of leaves at the top of the plant. Eventually, the cluster of leaves became so large, it tended to dominate the whole plant, and the head of cabbage had developed. Although they appear very different, kale, collards, cabbage, kohlrabi, cauliflower, broccoli, and Brussels sprouts are all varieties of the same species, Brassica oleracea. The only difference between these plants are the differences that humans introduced over thousands of years of selective cultivation. All of these Brassica oleracea vegetables are in the Brassicaceae family, along with along with bok choy, rapini, napa cabbage, turnips, mustard, watercress, arugula, radishes, horseradish, daikon, land cress, rutabaga, and shepherd’s purse. Kale (along with collards) is known botanically by the name Brassica oleracea acephala which translates to “headless garden cabbage.”
In much of Europe, kale was the most widely eaten green vegetable until the Middle Ages, when many people began to prefer the newer varieties of cabbage. Historically, kale has been particularly important in colder regions due to its resistance to frost. Kale was grown as a staple crop in the the Scotland due to its extreme hardiness, and people built walled kale yards to give it protection from the elements. Almost every house had a kale yard and preserved kale in barrels of salt, similar to sauerkraut in Germany. They also fed it to livestock through the winter. In nineteenth century Scotland, kail was used as a generic term for ‘dinner’ and all kitchens featured a kail-pot for cooking. Kale continued to be extremely important in the British Islands until potatoes surpassed them towards the end of the 18th century.
- Alpha and beta carotene, which protect your cells from the damaging effects of free radicals, provide a source of vitamin A, enhance the functioning of your immune system, and help your reproductive system function properly.
- Lutein and zeaxanthin, which defend your cells from the damaging effects of free radicals, and protect your eyes from developing age-related macular degeneration and cataracts.
- Chlorophyll, which can bond tightly to certain carcinogens, such as those in tobacco smoke, cooked meats, and aflatoxins.
- Pinoresinol, which may fight colon cancer.
- Lariciresinol, which fights breast and ovarian cancer, reduces vascular inflammation, fights fungal infections and free radicals, inhibits lipid oxidation, and may reduce deaths from coronary heart disease, cardiovascular diseases, and cancer.
- Caffeic acid, which is highly protective in the human body and acts as an anti-inflammatory and an antioxidant, and may also prevent cancer and diabetes.
- Kaempferol, which is a strong antioxidant that helps to prevent oxidative damage of your cells, lipids, and DNA, seems to prevent arteriosclerosis by inhibiting the oxidation of low density lipoprotein and the formation of platelets in the blood, and acts as a chemopreventive agent, which means that it inhibits the formation of cancer cells. It has anti-inflammatory, antimicrobial, anticancer, cardioprotective, neuroprotective, antidiabetic, anti-osteoporotic, estrogenic/antiestrogenic, anxiolytic, analgesic and antiallergic activities.
- Sulforaphane, which exhibits anti-cancer and antimicrobial properties.
- Indole-3-carbinol (I3C), a metabolized from a substance called glucobrassicin, which is an antioxidant that inhibits cancers of the breast, uterus, colon, lung, and liver, and can stimulate detoxification enzymes in the gut and liver.
- Glutathione, which is a detoxifying compound that helps break down carcinogens and other harmful compounds like free radicals and may help fight certain forms of cancer, such as bone, breast, colon, larynx, and lung cancers.
Nutrients in 1 cup cooked Kale (130 grams)
To find the freshest kale, look for firm, deeply colored leaves with hardy stems. Smaller leaves will be more tender and milder in flavor. Leaves range from dark green to purple to deep red in color.
Store kale, unwashed, in an air-tight container for up to five days in the refrigerator.
You can eat this leafy green raw or cooked. Rinse kale, chop it finely, and add it to salads, soups, stews, stir-fries, scrambles, casseroles, pizzas, and smoothies. Quick cooking preserves kale’s nutrients, texture, color, and flavor. Steam or saute kale for five minutes to make it more tender or eat it raw. You can also substitute it for spinach or collard greens in recipes.
A little bit of bitterness in the taste of kale is not necessarily a bad thing when it comes to your health. One of the bitter-tasting glucosinolates in kale, sinigrin, is the source of the anti-cancer substance allyl-isothiocyanate. It’s healthiest to incorporate kale into recipes that include differently flavored foods in such a way that the kale is allowed to retain a little of its natural and noticeable bitterness but within a blended-flavor context of a delicious dish. I like to steam it or saute it with a little baby garlic. You can add a splash of vinegar to give it a little sour flavor, or a squeeze of orange juice for a bit of sweet.
Other fast and easy ways to prepare kale:
- Make a simple salad with a bunch of thinly sliced kale, red pepper, onion, raisins, and your favorite salad dressing.
- Braise chopped kale and apples, garnish with chopped walnuts, and add a splash of balsamic vinegar.
- Toss whole-grain pasta with chopped kale and pine nuts.
- Cover and cook a pound of chopped kale with a few garlic cloves for 5 minutes; season with salt, pepper, and a tablespoon of red wine vinegar.
- Make kale chips by slicing kale into bite-size pieces, toss with a pinch of salt, and bake for 10-15 minutes at 350 degrees in the oven.
Make kale part of your weekly shopping list to enrich your diet and help you get the most bang for your calorie buck.
This blog uses the latest nutritional data available from the USDA (United States Department of Agriculture), and the FDA (United States Food and Drug Administration), as well as nutritional data provided by food growers and manufacturers about their products. We believe the information on this blog to be accurate. However, we are not responsible for typographical or other errors. Nutrition information for recipes is calculated by Living Cookbook based on the ingredients in each recipe based on statistical averages. Nutrition may vary based on methods of preparation, origin and freshness of ingredients, and other factors.
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