Ageing isn’t fixed

here are hypotheses that damage to DNA probably affects cell renewal in stem cells, which in turn prevents repair in the body and contributes to loss of viability. Then there is the free radicals theory of ageing: the idea that as mitochondria in our cells burn energy with oxygen, it generates very highly reactive compounds, which creates damaging oxidative stress, which in turn accumulates with age and causes ageing. There are also things like telomeres, the tips of chromosomes that shorten with cell division. But because this also occurs with age (and is linked to cancer risk), people have said this drives the process of ageing.So after about age 30 your chances of dying double every eight years. This is fairly standard for human populations, no matter where you’re from or where you live. Third World countries may have higher mortality to begin with, but you still see this exponential increase in mortality.