cows being raised for meat aren't exactly healthy either. Corn is not what they're designed to eat, but it is what we feed them.
http://www.pbs.org/wgbh/pages/frontline/shows/meat/interview...
http://www.pbs.org/wgbh/pages/frontline/shows/meat/interview...
Interesting tidbit: "But a lot of it has to do with the way we grow our food, and the fact that we mix 100 different cows in a single burger. We never used to do that. The butcher used to take the scraps from that one animal and make his hamburger right in front of your eyes. ... Now, you get one infected carcass, and that meat can spread all around the country, because we have this centralized national system."