"Perhaps the most extreme example of how this can play out was reported in 2014, when researchers described a 115-year-old woman. Nearly her entire supply of white blood cells was generated by mutated stem cells in her bone marrow."

Erm... Getting to 115 sort of negates the argument doesn't it? She managed to get through decades of 50% heart attack risk. A single counter example isn't evidence, but given with all the given issues this does seem to be anomalous.