Once processed into masa, it's a pretty solid cereal. The processing is pretty ingenious, too. Soak it in ash water until the hull dissolves and the kernel sets up into a digestible starch.
Nixtamalization - the technical term for the process you're talking about, also make several trace elements in the corn more readily available for digestion and absorption. The Navajo burn fresh juniper branches and collect the ash for use in doing this. I bought a big jar of it when I was in AZ several years ago. If you buy blue cornmeal, mix it with an ash slurry and let it rest overnight, the cornmeal turns really dark blue. Pretty cool process!
Ain't it? I remember studying in history that the biggest issue early English settlers faced was a disease called palegro. The Indians gave them some corn to work with since it was the local cereal crop. But they ate it straight up, and wound up with bad mineral diffinencies. Pretty gnarly stuff
I studied up on Navajo food a while back. Turns out that they're mostly lactose intolerant - dairy was never a big part of their diet. When they got stuck on the res and had foods from traditional European diets thrust upon them, a lot of them started experiencing symptoms of malnutrition. They figured out cheese and dairy didn't agree with them, so didn't eat it. But a lot of their traditional foods were unobtainable for a while. Well it turns out they got most of their calcium through the addition of ash to their cornmeal - simple cornmeal mush was a staple of their diet. I think they figured this out in the 1970s, so it took a hundred years to sort that shit out.