Known in Europe for centuries, kale used to be common in poorer regions and was also promoted during wartime, when food supplies were rationed and nutrition levels difficult to maintain. Nowadays it is popular as the so-called 'king of superfoods'.
Kale is cheap and easy to grow and is an excellent source of the vitamins A, C and K, the latter retaining its value even after boiling. Eating it raw, however, is the best method of maximising kale's nutritional value, and you can get 20% or more of the recommended daily intake of these nutrients from a 100 gram serving. Try it in salads or smoothies, or lightly stir-fry to avoid dissolving its nutrients in water.
Kale contains both protein and fibre, together with carotenoids, which function as the anti-oxidants that help to protect the body's tissues and cells from damage caused by free radicals. Flavonoids found in kale can also have anti-inflammatory effects, and can help reduce the pain of osteoarthritis.
Kale supplies many of the B complex vitamins which are important for cell metabolism, such as riboflavin, thiamine, and pantothenic and folic acids, as well as vitamin E and several minerals, including sodium, magnesium, potassium, iron, copper and calcium.