Prolonged fasting followed by refeeding may promote hematopoietic stem cell (HSC) regeneration and proliferation.

Cancer chemotherapy and the aging process cause significant damage to hematopoietic stem cells (HSCs). A recently conducted preliminary phase 1 trial in humans and a study on mice showed that more than 72 hours of prolonged fasting followed by a period of refeeding can reverse immunosenescence (loss of HSCs), as well as protect HSCs from the toxic effect of cancer chemotherapy. However, shorter fasting periods had no effect on the regeneration of aging and damaged HSCs in these studies.

According to these studies, low concentrations of insulin-like growth factor (ILGF) and protein kinase A (PKA) partly mediated the rejuvenation of damaged and worn-out HSCs by prolonged fasting and refeeding. The findings of these studies highlight the potentials of prolonged fasting and refeeding to improve cancer therapy and promote rejuvenation and proliferation of HSCs in older people.