Kale is one of the most nutritious of the dark, leafy green vegetables; its high Vitamin C content helps to boost the immune system, and it is one of the best sources of a carotenoid that helps protect eyesight. With all the anti-cancer properties of the cabbage family, and a huge amount of Beta-carotene, we should all be eating more of this delicious vegetable.
Kale is a member of the "headless" cabbage family, which also includes broccoli, cauliflower and Brussels sprouts. There are many varieties of kale, including curly kale, ornamental kale and plain leaved, all of which differ in taste, texture and appearance.
Kale's nutrient density makes it one of the healthiest foods that you could add to your diet. It is an excellent source of Vitamin A, Vitamin C and potassium. Kale is also a good source of calcium, iron and folate. It contains a variety of phytochemicals including eyesight-promoting, cancer-fighting lutein.
Cancers of the Lung, Esophagus, Mouth and Pharynx
Research is revealing that phytonutrients in crucifers, such as kale, work as antioxidants in the body to neutralize free radicals before they can damage cells, which can lead to diseases such as cancer. These compounds actually signal our genes to increase production of enzymes involved in detoxification, the cleansing process through which our bodies eliminate harmful compounds.
Additionally, fruits and vegetables that are high in carotenoids, including leafy greens like kale, lower the risk of lung cancer, esophageal cancer, and mouth and pharynx cancers, according to research.
In a study of 130 bladder cancer patients and an equal number of control subjects, those who consumed kale regularly had a lower risk for bladder cancer.
Kale contains the carotenoids lutein and zeaxanthin. Studies have shown the protective effect of these nutrients against the risk of cataracts, where increased eye cloudiness leads to blurred vision. In one study, people who had a diet history of eating lutein-rich foods like kale had a 50% lower risk for new cataracts.
Tips on Using Kale
- Smaller leaves are milder-flavored. Choose deeply colored leaves for tenderness and optimum flavor.
- Remove the center vein in the leaves and stems, as these tend to be tough to chew. If using kale raw in a salad, do not chop or tear the leaves until you are ready to use. This preserves the Vitamin C content.
- Kale can be steamed, simmered, blanched, braised and baked. Cooking kale takes about 8 to 15 minutes depending on the method.
- Mangels AR, Holden JM, Beecher GR, Forman MR, Lanza E. Carotenoid content of fruits and vegetables: An evaluation of analytic data. J Am diet Assoc. 93;3:284-296. 1993.
- Radosavljevic V, Jankovic S, Marinkovic J, Dokic M. Diet and bladder cancer: a case-control study. Int Urol Nephrol. 2005;37(2):283-9.
- Kopsell DE et al. Kale carotenoids remain stable while flavor compounds respond to changes in sulfur fertility. J Agric Food Chem. 2003 Aug 27;51(18):5319-25.
- Brown L et al. A prospective study of carotenoid intake and risk of cataract extraction in US men. Am J Clin Nutr. 1999 Oct;70(4):517-24.