question is difficult to answer because each tissue in the body is different and has a different regenerative capacity
we do actually possess a telomerase (a reverse transcriptase – rna dependent dna polymerase) but it is mostly expressed in body stem cells, like basal epidermal cells or bone marrow stem cells
feel free to correct me, but i dont think its a matter of cumulative shortening of telomeres that you would be able to observe, but rather, passage of times inevitable addition of mutations/insults that kill off viable stem cells and reduce the regenerative capacity
Latest Answers