Pop quiz: kale vs. arugula vs. spinach, which is most nutritious? You probably answered incorrectly, as it's actually arugula which has the most antioxidants among them. The ORAC value of arugula is about 7% higher than raw kale and 27% higher than spinach. It's not fair that kale has been the hyped superfood of the last decade, when arugula beats it fair and square, right?
ORAC Source
USDA Database for the Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2 - Prepared by Nutrient Data Laboratory, Beltsville Human Nutrition Research Center (BHNRC), Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA) - May 2010