That is a common misconception. But! Field Corn is 100% edible by people. All varieties of corn are. We eat it as corn meal, corn syrup, corn flakes, etc.
It isn't quite a sweet as, well, sweet corn when boiled/roasted on the cob. But it's no problem at all as a food.
https://www.gardeningknowhow.com/edible/vegetables/corn/dent...