A study from the University of Southern California has found that fasting for 72 hours can initiate a complete regeneration of the immune system.
Researchers found that prolonged fasting forces the body to consume its glucose and fat reserves, pushing it into a state of detoxification, where damaged cells and toxins are eliminated.
When normal nutrition is resumed, stem cells are activated, leading to the production of new, healthy white blood cells. This immune-restoring effect has been observed in both mice and humans — particularly in patients undergoing chemotherapy, who have shown improved immunity after cycles of fasting.
Lead researcher Dr. Valter Longo explains that during fasting, a gene called PKA is suppressed — and this is essential for stem cells to switch into regenerative mode.
As a result, the immune system eliminates the oldest and weakest parts and rebuilds itself from scratch. Although further research is needed to fully understand the benefits across all organs, the study suggests that fasting could be a powerful, drug-free strategy to boost immunity, especially for those suffering from weakened immune systems due to aging or cancer treatment.
