Exfoliation: is regimen overkill possible?
I decided to research the impact of frequent and long-term exfoliation. There is some compelling evidence that over exfoliation (I mean deep exfoliation such as glycholic peels or microdermabrasion) will ultimately exhaust the skin's long-term capacity to regenerate. This is because successive stripping of the skin cells eventually leads to something called the Hayflick Limit.
In the 1960s, Dr Leonard Hayflick found that lung tissue appeared to die out after the cells had divided a certain number of times (roughly 50). As the cells approached the end of their division limit, the cells would take on the appearance of old tissue. This included age pigments (lipofuscin) which are also found in aged hearts and brain cells. With each division, a cell becomes less likely to divide again, until finally it stops dividing altogether and becomes what is called senescent. Cell senescence is the final step before cell death. Senescent cells are still alive and metabolically active, but they’re no longer capable of dividing. More importantly, though, senescent cells exhibit all of the characteristics of old age, such as wrinkles.
When the skin is stressed - ie by a peel - it starts to speed up the cell reproduction. Unfortunately the cells don't regenerate indefinitely. Since there is effectively a cellular clock (50 divisions until the Hayflick Limit is reached) then with each peel time is ticking by.
The Hayflick Limit hypothesis was disputed for a time. However, it is now largely endorsed by other scientists. There are various ideas about how to override it, but in practice they remain futeristic. In the meantime, deep peel in moderation.