WATERCRESS, Chinese cabbage, chard and beet greens are among the most nutrient-dense "powerhouse" vegetables, packing a huge dose of vitamins and minerals into every calorie.
However, raspberries, tangerines, garlic or onions do not offer huge amounts of nutrition, a new study reports.
National nutrition guidelines emphasize consumption of powerhouse fruits and vegetables, which are strongly associated with reduced risk of chronic disease.
Cruciferous and dark green leafy vegetables dominate the top 10. They are, in order, watercress, Chinese cabbage, chard and beet greens, followed by spinach, chicory, leaf lettuce, parsley, romaine lettuce and collard greens.
All the top vegetables contain high levels of B vitamins, vitamin C, vitamin K, iron, riboflavin, niacin and folate - nutrients that help protect people against cancer and heart disease, the researcher noted.
People who chop off the leafy part of vegetables such as celery, carrots or beets are "actually cutting away some very good nutrients."
The six fruits and vegetables that didn't make the list as powerhouse foods are raspberries, tangerines, cranberries, garlic, onions and blueberries. While all contain vitamins and minerals, they are not densely packed with important nutrients, the study said.