https://en.wikipedia.org/wiki/Nixtamalization
This complicated process of preparing maize makes more nutrients bioavailable.
The Aztecs figured it out somehow.
I learned about this when trying to buy maize flour and discovering that there are 2 types: nixtamalized and non.
Reminds me of how certain South American indigenous tribes have this very complicated ritual to prepare Cassava/Tapioca. They didn't know it, but it removes cyanide and makes it much safer to consume (https://www.bbc.com/news/business-48859333 ).