I may be mistaken or we may be both using different myths to justify our food based belief systems but I was under the assumption that at least the larger pre-Columbian societies were done in by European diseases.

At least some pre-Columbian societies nixtamalized their corn (think hominy and masa harina), which unlocks many nutrients, greatly improving its nutritional value and making it a much better staple than non-nixtamalized corn.

https://en.wikipedia.org/wiki/Nixtamalization