“Superfoods” fly around in your stomach with tiny capes, delivering key nutrients to every critical system in your body.
At least that’s what the term makes it sound like they do. In reality, there is no legal or medical definition for what counts as a “superfood.” Nutritionists and public health experts rarely use the term.
But that doesn’t mean it’s completely bogus. In fact, there is some scientific basis for calling a food “super.”
According to the CDC, which published a ranking of what it called “powerhouse” foods in 2014, these types of fruits and veggies pack a lot of key nutrients into each calorie and are linked with a reduced risk of chronic disease. Studies also suggest that people who eat more of them tend to be thinner and live longer than those who rarely or never eat them.
Jennifer Di Noia, a sociologist and public health expert at William Patterson University, created the list and ranked her selections based on how much good stuff (vitamins, fibre, protein, etc.) gets packed into each bite of a particular food, a concept known as nutrient density.
When looking at nutrient density, Di Noia focused on 17 nutrients, including:
- Potassium: a key mineral that helps nerves and muscles communicate and may help offset some of sodium’s harmful effects on blood pressure
- Fibre: important for digestion and to help us feel full
- Protein: critical for building and maintaining muscle
- Calcium: key to strong bones
- Iron: helps our muscles store and use oxygen
- Zinc: for a healthy immune system
- Vitamins A, B6, B12, C, D, E, and K
To make the cut, each food had to provide 10% or more of the daily value of these key nutrients. Lower-calorie foods got higher scores, as did foods with more “bioavailable” nutrients, or those that could be readily absorbed by the body.
The number one winner on the CDC’s powerhouse list? A green you’ve probably eaten without even knowing its name: watercress. Swiss chard, spinach, kale, red peppers, and broccoli also made the cut.