Powerhouse fruits and vegetables - the ones that do you most good

That humble watercress is the pick of the crops. Researchers from William Paterson University in New Jersey have done the sums and rated it top based on the amounts of 17 critical nutrients contained in fruit and vegetables.
"National nutrition guidelines emphasize consumption of powerhouse fruits and vegetables (PFV), foods most strongly associated with reduced chronic disease risk; yet efforts to define PFV are lacking" says the study published this week in the Centers for Disease Control and Prevention journal Preventing Chronic Disease.
The foods are scored by their content of fiber, potassium, protein, calcium, folate, vitamin B12, vitamin A, vitamin D and other nutrients, all considered important to public health. Of 47 foods studied, all but 6 (raspberry, tangerine, cranberry, garlic, onion, and blueberry) satisfied the powerhouse criterion.For ease of interpretation, scores above 100 were capped at 100 (indicating that the food provides, on average, 100% DV of the qualifying nutrients per 100 kcal). Items in cruciferous (watercress, Chinese cabbage, collard green, kale, arugula) and green leafy (chard, beet green, spinach, chicory, leaf lettuce) groups were concentrated in the top half of the distribution of scores whereas items belonging to yellow/orange (carrot, tomato, winter squash, sweet potato), allium (scallion, leek), citrus (lemon, orange, lime, grapefruit), and berry (strawberry, blackberry) groups were concentrated in the bottom half.