Scientists have been studying stem cells and how they regenerate for decades, but did you know these cells could regenerate on their own? A study published in the journal Cell Stem Cell showed that stem cells actually regenerate by themselves when the host fasts – that is, when it stops eating for periods of time. 

"Stem cells actually regenerate by themselves when the host fasts."

When USC researchers forced mice to fast, their body's white blood cell count dropped. However, it then began to regenerated hematopoietic stem cells.

Corresponding author Valter Longo said he and colleagues were shocked by the results, but also explained how the stem cell regeneration process worked.

"We could not predict that prolonged fasting would have such a remarkable effect in promoting stem cell-based regeneration of the hematopoietic system," Longo said. "When you starve, the system tries to save energy, and one of the things it can do to save energy is to recycle a lot of the immune cells that are not needed, especially those that may be damaged. "

He continued by saying that animals and humans lose white blood cells when they fast, but when they begin to eat again, the cells come back.

This begs us to ask the question: What kind of implications will this have on people? And it's this question that likely excites scientists the most.

This discovery could allow scientists to better address or treat serious conditions, such as autoimmune disorders or other immune-system problems, noted Suzanne Wu, currently a New York Times contributing writer but former Director of Research Communications at the University of Southern California. It could also play a role in anti-aging procedures because fasting also lowers the PKA enzyme, which factors into aging, cancer and even tumor progression. Scientists had previously studied mice with cancer who were being treated with fasting and chemotherapy, according to a USC press release. Those that fasted and received chemotherapy had a much greater chance of surviving than mice that were exposed only to chemotherapy.