'Powerhouse' Produce: Researchers Rank the Top Fruits and Vegetables for Health	Among fruits and vegetables leafy greens rank as the top powerhouse foods according to a new ranking of produce items based on their nutrient content.	Watercress snagged the No. 1 spot and other leafy greens rank in the top 10 according to the study. [Full story: Watercress Named Top 'Powerhouse' Veggie]	To be called a powerhouse a 100-calorie serving of the food had to provide at least 10 percent on average of the daily recommended intake of 17 important nutrients. The foods that scored higher are those that provide more of these nutrients.    	Here is the full list of all 41 foods with their nutrient density scores:	Watercress: 100.00	Chinese cabbage: 91.99	Chard: 89.27	Beet greens: 87.08	Spinach: 86.43	Chicory: 73.36	Leaf lettuce: 70.73	Parsley: 65.59	Romaine lettuce: 63.48	Collard greens: 62.49	Turnip greens: 62.12	Mustard greens: 61.39	Endive: 60.44	Chive: 54.80	Kale: 49.07	Dandelion greens: 46.34	Red pepper: 41.26	Arugula: 37.65	Broccoli: 34.89	Pumpkin: 33.82	Brussels spouts: 32.23	Scallions: 27.35	Kohirabi: 25.92	Cauliflower: 25.13	Cabbage: 24.51	Carrot: 22.60	Tomato: 20.37	Lemon: 18.72	Iceberg Lettuce: 18.28	Strawberry: 17.59	Radish: 16.91	Winter squash (all varities): 13.89	Orange: 12.91	Lime: 12.23	Grapefruit (pink and red): 11.64	Rutabaga: 11.58	Turnip: 11.43	Blackberry: 11.39	Leek: 10.69	Sweet potato: 10.51	Grapefruit (white): 10.47