Microgreens are just baby edible versions of many vegetables & herbs. They are cut & harvested usually around a week after germinating. Stored in the seed are a TON of nutrients when you consider it on a per weight basis. Seeds store nutrients to get themselves going. They need this energy to establish roots in order to extract nutrients from the ground. Since we're cutting it right as its developing roots, all that nutrition went up into forming its first set of true leaves, which are the ones we eat!
This same study took the time to point out 4 of the 25 microgreens which have the highest concentrations of four different vitamins and carotenoids:
Not 'science', but very well worth noting...
Besides the nutrition, the absolute best part of eating microgreens is that they require No Chemicals of any kind! Just pure H20.... (important tip - don't use tap water on micros. You don't like it, neither do they.) And since you can grow them on your own counter top, you are in complete control, you know what you are eating is completely clean. When else can you say that?
So, I think this is a good start. Microgreens are gaining in popularity, and with that increased consumer demand, the studies will continue to come in and shed light on these special little plants.