From açaí berry to kale to baobab, you can’t look through a magazine, restaurant menu, or your Instagram feed without seeing certain foods labeled as superfoods. But exactly what does that mean? Do these snacks have superpowers, and should you eat them at the exclusion of others?
For the skinny on superfoods, we went to woman who literally wrote the book on them: Tonia Reinhard, M.S., R.D., F.A.N.D., the clinical nutrition course director of the School of Medicine at Wayne State University and the author of Super Foods: The Healthiest Foods on the Planet, Second Edition.
While researching her book, Reinhard learned that superfood was first used to describe wine in a 1915 edition of The Daily Gleaner in Kingston, Jamaica. The term started to gain traction in 1949, when it was added to the Oxford English Dictionary, and really picked up steam in the early 1990s, when the “nutraceutical” movement—foods that work like medicine—entered the mainstream.
There still isn’t an official definition that nutritionists universally accept, but Reinhard explains that a modern superfood is one that’s high in essential nutrients—vitamins, minerals, certain lipids—as well as phytonutrients, which give plants their color, smell, and taste. These are compounds that are not vitamins or minerals, she says, “but have chemical and biological properties that may be able to reduce our risk of chronic diseases.”
“Researchers have only begun to understand how beneficial phytonutrients may be for promoting healing and preventing disease,” adds Zach Breeding, M.S., R.D.N., L.D.N., a clinical nutrition manager at Kate Farms. All Kate Farms Komplete and Kate Farms Core Essentials shakes, Breeding explains, use a blend of phytonutrients extracted from fruits, vegetables, herbs, and spices, without any carbohydrates, dietary fiber, proteins, fats, or caffeine from the source ingredients.
Reinhard says a snack’s nutrient density—the ratio of good nutrients relative to the amount of calories—is also very important. “To me, superfoods are foods that are charged with these essential nutrients and phytonutrients, but also deliver them in a kind of lower-calorie format so they’re nutrient-dense,” she says. Examples include green leafy vegetables, berries, and other colorful foods.
A lot of these same qualities apply to so-called powerhouse foods. Like superfood, there’s no official definition of powerhouse, but a recent study in the journal Preventing Chronic Disease suggests that to qualify, a food must provide an average of at least 100 percent daily value per 100 calories of 17 qualifying nutrients. The scientists found 41 fruits and vegetables that meet the standard. The top 10, in order: watercress, Chinese cabbage, chard, beet green, spinach, chicory, leaf lettuce, parsley, Romaine lettuce, and collard green.
Though it’s often fruits and vegetables that score highest for their nutrient density, some herbs and spices can also offer big benefits from their phytonutrient composition alone. Oregano, for example, is loaded with disease-fighting antioxidants; in lab tests, the spice showed 42 times more antioxidant activity than apples, 12 times more than oranges, and four times more than blueberries, according to a study in the Journal of Agricultural and Food Chemistry.
If you’re tempted to rush to the supermarket and fill your cart with fresh watercress, well, that’s the exactly the point. Whether nutritionists agree on a definition of a superfood or powerhouse food isn’t important to most of them. The terms and the labels are raising awareness about some of nature’s healthiest foods, and we’re eating more of them than ever.
“When enoki mushrooms were first being called a superfood,” asks Reinhard, “how many people even knew what it was?”