Peoples ancestors have been heating food for 1.9 million years https://www.livescience.com/15688-man-cooking-homo-erectus.h... so we've adapted to it by now, though theirs evidence that smoking or charing food contains carcinogens.

There is a scale of processed foods from minimally processed to ultra processed https://www.theguardian.com/science/2018/feb/02/ultra-proces... less processing is best.