Corn is used as animal feed to produce meat and dairy. Land that might have been used to grow other grains, such as wheat, rye or oats is now being used to grow corn for ethanol. The policy is insane.
Another non-healthy use. Cows are much better off - and taste better - when they're grass fed. Plus, they get no more nutrition from the crap we now call corn than we do. They get fat from it, fast, just like we do.
The fact is that we grow way more corn than we need and it has precious little nutritional value. There may be really good arguments against ethanol, but the loss of the food value of the corn is not one of them.