Stem cells are a type of cells primarily responsible for cell division in the body. When damaged cells in a tissue die, stem cells divide and differentiate to produce new cells to fill the gap. Thus stem cells are critical for the body’s ability to heal and renew itself. It is well known that healing/regeneration capacity declines with age. At least in part, this decline appears to result from the dysfunction of stem cells. Indeed, it stand to reason that if stem cells are largely responsible for tissue renewal, then dysfunction of stem cells would impair healing/regeneration capacity and thus contribute to aging. Furthermore, the pro-aging role of stem cell dysfunction should presumably be more pronounced in the tissues with a lot of ongoing cell division, such as the skin or vascular & intestinal lining.
Indeed, there is growing scientific evidence that age-related stem cells dysfunction does indeed occur throughout the body and in the skin in particular. In a 2012 study, Dr Doles and colleagues (from the Center for Genomic Regulation [CRG], Barcelona, Spain) studied hair follicle stem cells in the skin of young and old mice and found a number of age-related impairments. As per Bill Keyes, group leader of the Mechanisms of Cancer and Aging lab at the CRG: