A new study ranked 41 fruits and vegetables by the amount of key nutrients (associated with reducing chronic disease) they contain, including potassium, fiber, protein, calcium, iron, thiamin, riboflavin, niacin, folate, zinc, and vitamins A, B6, B12, C, D, E, and K. Watercress scored the highest (was the most nutrient dense). In all, cruciferous (watercress, Chinese cabbage, collard green, kale, arugula) and green leafy vegetables (chard, beet green, spinach, chicory, leaf lettuce) scored the best, whereas fruits had lower overall scores.
Here’s the full list:
Source: http://www.cdc.gov/pcd/issues/2014/13_0390.htm