The term has been thrown around for years, but there is no formal definition of a "superfood" and little research exists to support why some foods gain the moniker, Mayo Clinic's Phil Hagen tells the Wall Street Journal's Heidi Mitchell.
"The term is often used to grab your attention or sell you something, so I would say, buyer beware," says Hagen, who works as a preventive medicine specialist for Mayo's Healthy Living Program.
In fact, Hagen says he does not believe any food is truly "super." He explains, "There is not a food out there that has all 30 to 50 nutrients that we're supposed to consume regularly."
The trouble with existing lists and classifications
CDC experts in June released a list of "powerhouse fruits and vegetables" based on their nutrient density, and watercress, Chinese cabbage, and chard topped the list. Blueberries—generally recognized as a "superfood"—did not make CDC's list, while strawberries did, Hagen notes. "Blueberries have gotten media attention because they have a lot of bioflavonoids in them, but I don't consider them any more super than strawberries," says Hagen.
CDC: What are the 'powerhouse' vegetables?
To help navigate food selection, NIH has compiled a list of 40 substances—mostly vitamins, minerals, and fats—that experts recommend including in our diets.
But, Hagen says the list "sidesteps this whole group of compounds that we've come to think of as health-protective, like the bioflavonoids and the polyphenols and other antioxidants, which show promise in preventing disease, but are not fully understood." There is no recommended daily allowance for these compounds, so nutritionists cannot quantify what patients should consume, Hagen says.
Even though they are incomplete, lists of superfoods and nutrients can lead people to focus on certain foods, even though nutritionists emphasize the need to consume a wide variety of foods, Hagen says.
What should we be consuming?
When making recommendations to his patients, Hagen encourages liberal nut consumption, even though they are not generally considered superfoods. He notes that their calories come largely from beneficial oils.
In addition, Hagen recommends that patients consume eggs, low-fat yogurt, and skim milk, all of "which are high in protein and calcium but relatively low on calories."
And as a general rule, Hagen recommends that people consume a great variety of "fresh food" with lots of color diversity.
Study: You should eat seven servings of fruits and veggies a day
"What helps me sleep at night is knowing that the human body is capable of making what it needs from a really diverse set of foods," Hagen says, adding, "Even if kale turns out to truly be a superfood someday, if it made up a significant portion of our diet, that wouldn't be good" (Mitchell, Wall Street Journal, 7/28).
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