For more than a decade, one vegetable has been treated as the ultimate symbol of healthy eating. It has filled smoothies, salads and chip bags, and even showed up on T-shirts. But when researchers sat down to rank fruits and vegetables by the nutrients they actually deliver, it did not come close to first place. The winner was a small, peppery green that most shoppers walk past without a second look.
Which food came out on top?
It is watercress. In a study published in the CDC’s journal Preventing Chronic Disease, Jennifer Di Noia, PhD, then an associate professor at William Paterson University in New Jersey, ranked fruits and vegetables by their nutrient density. Watercress was the only one to reach a perfect score of 100.
The method was simple and strict. Each food was scored on 17 nutrients that matter for public health, including fiber, potassium, protein, calcium, folate, iron, zinc and vitamins A, B6, B12, C, D, E and K, calculated per 100 calories. To earn the title of “powerhouse,” a food had to provide, on average, at least 10% of the daily value of those nutrients. Of the 47 fruits and vegetables studied, 41 qualified.
The top of the list
Leafy greens dominate the ranking. Here are the first ten, with their scores:
- 1. Watercress: 100
- 2. Chinese cabbage: 91.99
- 3. Chard: 89.27
- 4. Beet greens: 87.08
- 5. Spinach: 86.43
- 6. Chicory: 73.36
- 7. Leaf lettuce: 70.73
- 8. Parsley: 65.59
- 9. Romaine lettuce: 63.48
- 10. Collard greens: 62.49
So where is kale?
In 15th place, with a score of 49.07, behind turnip greens, mustard greens, endive and even chives. That does not make kale unhealthy, far from it, but it does mean its superfood status owes as much to marketing as to measurement.
Some foods with a strong health reputation did not even make the cut. Raspberries, tangerines, cranberries, garlic, onions and blueberries were left off the powerhouse list, as the American Institute for Cancer Research pointed out. The reason is technical: the study did not measure phytochemicals, the plant compounds behind many of those foods’ benefits, because there are no clear standards for them. “So the scores are based on nutrients only,” Di Noia explained, adding that the rankings “may help consumers make nutrient-dense selections within the powerhouse group,” as reported by the Bangor Daily News.
How do you actually eat watercress?
Watercress has a fresh, slightly peppery taste, close to arugula. It is usually sold in bunches or bags near the salad greens. A few easy ways to use it:
- Raw in salads, mixed with milder greens if the pepperiness is too strong at first.
- On sandwiches and toasts, in place of lettuce.
- In soups, added at the very end so it keeps its color and nutrients.
- Blended into a green sauce with olive oil, lemon and garlic, like a pesto.
Rinse it well and eat it within a few days: like most tender greens, it wilts quickly. And if you are looking for other simple, research-backed ways to support your health, a cheap daily fiber supplement recently impressed researchers in adults over 60.
The bottom line
The healthiest food in the world, at least by this measure, is not an exotic powder or an expensive superfood. It is a humble green that costs a few dollars a bunch. Kale fans can relax, it is still on the list. But next time you pass the salad aisle, the bunch worth reaching for might be the one you have never tried.
