How would a body adapt to toxins?
That's like assuming your lungs and liver will adapt to smoking and alcohol.
There are various mechanisms in the body that are activated through prolonged fasting to name one. Autophagy is a process that is activated through extended fasting which helps clear the body of toxins and damaged cells. I believe many of these can processes can be activated through leading a healthy lifestyle and other things I do regularly. End of the day it's just my belief.
I am not claiming to be a medical expert and do not want to engage in detailed medical debates but I also believe that we put too much faith in modern medicine when there are LARGE parts about how the body works that is not understood. The placebo affect being the largest. Acute medicine has developed amazingly well over the years and I have full faith in it but our treatment of any chronic conditions another story.