Talk:Stem cell theory of aging

Not a root cause?

Like most theories of aging, the stem cell theory explains a part of the aging process, but lacks the characteristics of a root cause. Stem cells have the capacity for self renewal. Therefore, a reason must exist for the relative abundance of stem cells in youth and their depletion with age. If the decline in stem cell numbers is gradual throughout life (there is no mechanism that regulates stem cell self renewal in the young) and the decline is a intrinsic characteristic of the system then it could be considered a root. cause. However, the fact that stem cell niches were originally filled from embryonic stem cells abd through self proliferation as a fetus develops would argue there must be an underlying mechanism that regulates stem cell self-renewal and that mechanism is being switched off or at least attenuated at some point in development. In any event, it seems, a better understanding of the mechanics underlying stem cell niche depletion Is needed before the stem cell theory of aging can be considered a root cause rather than just another symptom of aging. 96.60.0.24 (talk) 20:31, 19 November 2022 (UTC)