Maize (corn) linked with cannibalism

I was reading in the paper we were given Monday that has all those different species of life in them, the first page reading Cannabis in bold letters. Well I was looking at my species for the week: Maize, which we call corn. I was surprised when I found out that corn was linked with cannibalism. I would've thought it was the other way around and that corn helped prevent cannibalism because it provides food. Although corn does provide food, which many people are dependent on, including America, it does not provide all the nutrients needed for growth. So instead, some people would resort to cannibalism in order to get all the nutrients they needed as much of the wildlife had been cultivated for corn and game was longer very common. I mean that seems pretty serious to me. Why would they continue using corn when it caused that problem? Surely there is a crop that would work just as well or a combination of crops... Isn't there?