Until the end of the Middle Ages, kale was one of the most common green vegetables in Europe.
A whole culture around kale has developed in northern Germany, especially around the towns of Bremen, Oldenburg and Hannover and the region of Dithmarschen. There, most social clubs of any kind will have a Grünkohlessen or Kohlfahrt (“kale tour”) sometime between October and February, visiting a country inn to consume large quantities of kale stew, Pinkel sausage, Kassler, Mettwurst and Schnapps.
Kale is very high in beta carotene, vitamin K, and vitamin C, and is rich in calcium. Kale is a source of two carotenoids, lutein and zeaxanthin. Kale, as with broccoli and other brassicas, contains sulforaphane (particularly when chopped or minced), a chemical with potent anti-cancer properties.