As per my experience and observation what I think is that the human body is meant to live longer than just 100-120 years (or the average 75 years). It is because the action of pathogens on the body (most of which go undetected) that the body ages and the cell die.Of course I am not a doctor or a clinical pathologist but this is my strong feeling. And may be I will become a doctor, do research to prove this point. Even the body color is (black, brown or white) is because of pathogens like bacteria and fungi. I lost my color from being fair to brown! Imagine if I am successful on this we could change the course of human life and never die or age or look ugly!
Here is what I think about human life and pathogens