Microgreens—those young greens harvested when they're practically seedlings, and used primarily as garnishes—have long been rumored to pack a powerful nutritional punch. But now science is backing that up.

Researchers with the U.S. Department of Agriculture in collaboration with the University of Maryland, College Park have conducted the first scientific analysis of nutrients in microgreens, according to NPR's The Salt, and the results were very surprising:

The researchers looked at four groups of vitamins and other phytochemicals - including vitamin C, vitamin E, and beta carotene -- in 25 varieties of microgreens. They found that leaves from almost all of the microgreens had four to six times more nutrients than the mature leaves of the same plant. But there was variation among them - red cabbage was highest in vitamin C, for instance, while the green daikon radish microgreens had the most vitamin E.

The full report can be found in the latest issue of Journal of Agricultural and Food Chemistry, and while the results are promising, studies are still preliminary. Are microgreens ever likely to push aside full-grown vegetables? Probably not. They'll never have as much fiber as a leafy pile of salad greens, but "if you throw a big bunch of microgreens on anything, that's a pretty good shot of vitamins."

Read More: Introducing Microgreens: Younger, And Maybe More Nutritious, Vegetables at The Salt

Related: What's the Deal with Microgreens? And How To Grow Your Own

(Image: Dana Velden)