Kale

Kale: very high in beta carotene, vitamin K, vitamin C, lutein, zeaxanthin, and reasonably rich in calcium. Kale, as with broccoli and other brassicas, contains sulforaphane (particularly when chopped or minced), a chemical believed to have potent anti-cancer properties.  Boiling decreases the level of sulforaphane; however, steaming, microwaving, or stir frying do not result in significant loss.  Along with other brassica vegetables, kale is also a source of indole-3-carbinol, a chemical which boosts DNA repair in cells and appears to block the growth of cancer cells.  Kale is also a good source of carotenoids.