It was ranked number one among 41 “powerhouse” fruits and vegetables in a study published earlier this year in the Centers for Disease Control and Prevention journal “Preventing Chronic Disease.” Watercress, Chinese cabbage, chard, beet greens and spinach top the list of the healthiest vegetables and fruits, according to research conducted by Jennifer Di Noia, PhD, an associate professor of sociology at William Paterson University in Wayne, N.J.
The top four fruits are red pepper, pumpkin, tomato and lemon. The federal government’s Dietary Guidelines for Americans 2010 recommend consuming a variety of vegetables each day because different vegetables are rich in different nutrients. Research as shown that higher consumption of vegetables may protect against some diseases, including some types of cancer. National nutrition guidelines consistently emphasize consumption of powerhouse fruits and vegetables, foods most strongly associated with reduced chronic disease risk: yet efforts to define these PFV has been lacking before this study.
Di Noia describes a classification scheme defining PFV on the basis of 17 nutrients of public health importance per the Food and Agriculture Organization of the United Nations and Institute of Medicine, including potassium, fiber, protein, calcium, iron, thiamin, riboflavin, niacin, foliate, zinc, and vitamins A, B6, B12, C, D, E and K. Vegetables are categorized into five subgroups: dark-green, red and orange, beans and peas, starchy, and other vegetables. Cruciferous vegetables, such as watercress, fall into the “dark-green vegetables” category and the “other vegetables” category.
More information about vegetables and diet, including how much of these foods should be eaten daily or weekly, is available from the U.S. Department of Agriculture website Choose My Plate. This is the first time the nutritional values of nutrient-dense fruits have been ranked to provide a measurable too for nutrition educations and dietary guidance. The study developed and validated a classification scheme defining “powerhouse fruits and vegetables” as foods provide, on average, 10 percent or more daily value per 100kcal of the 17 qualifying nutrients. “Higher-ranking foods provide more nutrients per calories,” says Di Noia. “The scores may help focus consumers on their daily energy needs, and how best to get the most nutrients from their foods. The ranking provide clarity on the nutrient quality of the different foods and may aid in the selection of more nutrient- dense items within the powerhouse group.”