Nutritional guidelines encourage Americans to consume more "powerhouse" fruits and vegetables — those foods that are most strongly associated with reduced risks of chronic disease. But there's been no clear directive on how exactly "powerhouse" foods should be defined.
Now, a Jun. 5 study in the CDC journal Preventing Chronic Disease puts forth a method for defining and ranking powerhouse foods.
Jump to the ranking »
Lead author Jennifer Di Noia, a sociologist at William Paterson University who specializes in public health and food choice, came up with a preliminary list of 47 "powerhouse" foods based on consumer guidelines and scientific literature. For example, berries and vegetables in the onion/garlic family were included "in light of their associations with reduced risks for cardiovascular and neurodegenerative diseases and some cancers."
Di Noia then ranked the foods based on their nutritional density. She focused on 17 nutrients "of public health importance per the Food and Agriculture Organization of the United Nations and Institute of Medicine." These are potassium, fiber, protein, calcium, iron, thiamin, riboflavin, niacin, folate, zinc, and vitamins A, B6, B12, C, D, E, and K.
Each food had to provide at least 10% of the daily value of a particular nutrient to be considered a good source. Providing more than 100% of the daily value of one nutrient conferred no extra benefit. The scores were calculated in favor of lower-calorie foods and weighted based on how "bioavailable" each nutrient is (i.e., how much the body can make use of a nutrient once it's been ingested in food form).
Six foods (raspberry, tangerine, cranberry, garlic, onion, and blueberry) on the original list of 47 did not satisfy the "powerhouse" criteria. Here are the remaining 41, ranked in order of nutrient density. Foods that are high in nutrients without also being high in calories will be at the top.
- Watercress (Score: 100.00)
- Chinese cabbage (Score: 91.99)
- Chard (Score: 89.27)
- Beet green (Score: 87.08)
- Spinach (Score: 86.43)
- Chicory (Score: 73.36)
- Leaf lettuce (Score: 70.73)
- Parsley (Score: 65.59)
- Romaine lettuce (Score: 63.48)
- Collard green (Score: 62.49)
- Turnip green (Score: 62.12)
- Mustard green (Score: 61.39)
- Endive (Score: 60.44)
- Chive (Score: 54.80)
- Kale (Score: 49.07)
- Dandelion green (Score: 46.34)
- Red pepper (Score: 41.26)
- Arugula (Score: 37.65)
- Broccoli (Score: 34.89)
- Pumpkin (Score: 33.82)
- Brussels sprout (Score: 32.23)
- Scallion (Score: 27.35)
- Kohlrabi (Score: 25.92)
- Cauliflower (Score: 25.13)
- Cabbage (Score: 24.51)
- Carrot (Score: 22.60)
- Tomato (Score: 20.37)
- Lemon (Score: 18.72)
- Iceberg lettuce (Score: 18.28)
- Strawberry (Score: 17.59)
- Radish (Score: 16.91)
- Winter squash (Score: 13.89)
- Orange (Score: 12.91)
- Lime (Score: 12.23)
- Grapefruit (pink/red) (Score: 11.64)
- Rutabaga (Score: 11.58)
- Turnip (Score: 11.43)
- Blackberry (Score: 11.39)
- Leek (Score: 10.69)
- Sweet potato (Score: 10.51)
- Grapefruit (white) (Score: 10.47)
Everyone has different dietary needs, and no one should make drastic dietary changes without consulting a dietitian or a doctor. But adding more "powerhouse" fruits and vegetables to your diet is a good first step on the way to a healthier lifestyle.
SEE ALSO: 15 Terrible Things That Happen If You Eat Too Much Sugar