Calorie reduction (CR) extends life span and ameliorates age-related pathologies in most species studied, yet the mechanisms underlying these effects remain unclear. A number of studies have shown that CR acts in part by enhancing the function of tissue-specific stem cells. Even short-term CR significantly enhances stem cell availability and activity, as observed in muscle tissue.
In the intestine, Paneth cells, a key constituent of the stem-cell (ISC) niche that reside adjacent to stem cells, augment stem-cell function in response to calorie restriction. Calorie restriction acts by reducing mechanistic target of rapamycin complex 1 (mTORC1) signalling in Paneth cells, and the ISC-enhancing effects of calorie restriction can be mimicked by rapamycin.
These studies indicate that metabolic factors play a critical role in regulating stem cell function and that this regulation can influence the efficacy of recovery from injury and the engraftment of transplanted cells.
Decreased calorie ingestion, without malnutrition, extends lifespan and promotes healthy aging in many animals and is, at least partially, attributed to enhanced stem cell function.
Nature (2012) doi:10.1038/nature11163
Cell Stem Cell. 2012 May 4;10(5):515-9.