A new study from the University of Southern California shows fasting for as little as two days can regenerate the body’s immune system.

The study showed that fasting worked not only for normal, “healthy” people but also the elderly and people whose immune systems have been compromised because of chemotherapy treatments.

The periods without eating would lower the amount of white blood cells in the body, which would trigger stem cells to begin regeneration of the white blood cells, rushing them into the body.  However, the scientists also found that the rush of white blood cells also repaired damage.

“[Fasting] gives the OK for stem cells to go ahead and being proliferating and rebuild the entire system,” Professor Valter Longo said.  “And the good news is that the body got rid of the parts of the system that might be damaged or old, the inefficient parts, during the fasting.”

A pilot clinical trial found that fasting for 72 hours prior to chemotherapy protected the patients against toxicity.