Can prolonged fasting during cancer treatment renew the immune system?

A new study, whose initial results were published last week, has shown that prolonged fasting periods of 2-4 days not only protect against the side effects of chemotherapy, but also trigger dormant stem cells to transform into immune cells and the clearance of old/damaged ones.

Published in the Journal of Stem Cells and conducted by researchers from the University of Southern California, this study is the first to show that an organ or stem cell system can be regenerated through a natural intervention.

Immune system disorders are central to aging and a range of diseases. The researchers believe that these findings could benefit people with damaged immune systems, such as those undergoing chemotherapy for cancer treatment. They have also been shown to benefit older people with weakened immune systems, who are more susceptible to diseases.

Research has shown that prolonged fasting periods cause a significant decrease in white blood cells. In the first phase of the study, conducted with mice, it was found that activation was caused by triggering a change in the signaling pathways of hematopoietic stem cells (a group of stem cells that produce blood and immune system cells). When the mice were fed again, the quantity of blood cells returned to its previous level. The researchers then began considering what had caused this situation.

When you begin fasting, the body sequentially uses stored glucose, fat, and ketones; repeated fasting cycles also consume existing damaged immune cells. In mice, fasting periods lasting approximately 2-4 days were extended to 6 months, and as a result, it was found that the immune cells were replaced with new ones.

The researchers found that fasting for 2-4 days reduced an enzyme called PKA, which is found in simple organisms and is thought to be associated with extending lifespan. Other studies investigating the enzyme PKA have shown that this enzyme influences the control of stem cells’ transformation into other cell types.

Prolonged fasting also causes a decrease in levels of IGF-1, a growth factor associated with aging and cancer processes.

Genetic alteration to stop PKA production is a key step in the regeneration of stem cells. The occurrence of this step signals to the stem cells that they are ready to rebuild the entire system and begin proliferating.

Can 3 Days of Fasting Protect Cancer Patients from the Side Effects of Chemotherapy?

In a study conducted with a small group of cancer patients, those who were made to fast in a controlled manner for 3 days before chemotherapy were found to have fewer treatment-related side effects.

While chemotherapy saves lives, it causes significant damage to the immune system. The researchers hope that some of these side effects can be reduced through fasting. However, prolonged fasting of patients is a practice that must be carried out under medical supervision. Since more clinical research is needed to measure the effectiveness and side effects of this approach, studies are continuing in this direction.

They also stated that they would undertake a new study to measure the effect on organs and within the body system of the regeneration that occurs in the immune system during fasting [by rapidly reducing the number of cells (including blood cells) and the size of organs and tissues to minimize energy consumption] when the patient begins eating again.