You should consult with your physician or oncologist before practicing intermittent fasting during any type of cancer treatment, especially if you are experiencing muscle wasting, poor nutrition or other side effects from treatment. However, there is evidence from in vitro studies, animal studies and early clinical studies in humansconducted by Dr. Valter Longo of the USC Longevity Institute and colleagues that periodic fasting or low-protein fasting-mimicking diets may sensitize cancer cells to the impacts of chemotherapy while protecting healthy immune cells and other cells against side effects. The IGF-1R (Insulin-like growth factor 1 receptor) pathway appears to play a key role in the impact of dietary restriction on tumor progression and treatment sensitivity.
Research findings on the benefits of IF for cancer patients undergoing chemotherapy, based on the differential stress resistance of cancerous versus non-cancerous cells, are promising but preliminary. Long-term fasting on the order of several days may have other side effects and should never be undertaken without consultation with a physician, oncologist or other healthcare expert.