"The main benefits of alpha hydroxy acids come from its ability to exfoliate skin. Removal of the outermost layer of the skin stimulates the cells in lower layers to grow and divide, causing the skin to thicken and thus diminishing visible signs of aging. The more you exfoliate, the more cell divisions you have occurring in the lower skin layers. There is one problem though. Normal human cells cannot divide indefinitely. Fibroblasts (a key type of cells in the skin) will divide about fifty times and then enter a so-called stage of senescence. This is a state in which cell division becomes sluggish, inefficient and unresponsive to various signals from the body and unable to divide. This is similar to how a plant will slow its leaf and bloom production at the end of its growth cycle. Skin with many senescent cells is usually fragile, blotchy and easily wrinkled. This limit of about fifty cell divisions is called the Hayflick limit (after its discoverer, Dr. Leonard Hayflick).
http://en.wikipedia..../Hayflick_limit
this would imply that for a while, retinoids/aha's would give us younger looking/better skin but after a decade or two we may hit a 'telomere wall' where our skin cells would not be able to divide at the normal rate... dooming us to prematurely and permanently aged skin. for this to be true wouldnt we need to only have a limited number of skin cells to begin with? do we only have a limited about of skin cells each limited to 50+ divisions, or do we have a never ending supply of skin cells limited to 50+ divisions?
discuss
Edited by ajnast4r, 12 January 2008 - 09:33 PM.