Kale contains vitamin C, which has been shown to fight cancer. It also is high in vitamin A, which contributes to healthy hair and skin. Kale has more iron per calorie than beef. Iron is important for proper liver function. Kale also contains omega-3 fatty acids, which have been shown to reduce inflammation.
Kale: A 31⁄2 oz. serving contains 53 calories and about twice the RDA of vitamins A and C.