The association between nutrition and disease has been of interest for a number of conditions, including obesity-related disease, allergies and sensitivities, and immune responses to pathogens and tumor development. The potential beneficial effects of diet have focused primarily on prevention – what to eat, how much to eat, and sometimes even when to eat – but recent studies have highlighted a potentially new area of interest for nutrition in the treatment of cancer.
Chemotherapy is the standard treatment against cancer, though it is often used in conjunction with other treatments. Chemo consists of drugs that damage the cell, but pinpointing the tumor as a target is still difficult, resulting in a number of systemic side effects as healthy cells are also attacked. Finding ways to minimize these adverse effects or reducing the amount of chemotherapy needed, in other words boosting the treatment’s effects against the tumor cells, would greatly benefit patients.
Cancer and nutrition
Alternative health treatments have focused on boosting the immune system to aid in cancer treatment, but now research is finding that nutrition deprivation may actually be the key to boosting chemo’s effects and protecting healthy cells. When deprived of nutrients, cells go into survival mode, ramping up their repair mechanisms. The results of a study in yeast in 2008 found that differences between normal and tumor cells, called “differential stress resistance”, which can occur when an organism is starved of nutrients, can be exploited.
Mouse studies on fasting and chemotherapy
The Italian and California researchers in 2008 also tested the effects of fasting in mice. Mice who were deprived of food before undergoing chemotherapy recovered better than mice fed normally. Another mouse study published in February 2012 used mice with breast cancer, melanoma, or glioma. The mice who had food withheld for two cycles of 48 hours before chemotherapy experienced more tumor shrinkage than those who did not fast. The researchers also saw decreased metastasis and longer cancer-free survival.
Human studies on fasting and chemotherapy
The 2 to 3 days of fasting in mice translates to 4 to 5 days in humans. However, as Scientific American points out, cancers that can be cured in mice often cannot be cured in humans. These differences require studies in humans to confirm the previous findings and determine whether fasting actually benefits cancer patients. The hypothesis currently being tested is that fasting for 48 hours before chemotherapy can reduce toxicity to healthy cells, increase the effect of chemo drugs on the tumor, and promote recovery after treatment. One such clinical trial is being sponsored by the Mayo Clinic, running from 2010 to 2015 according to the Clinical Trials registry. Another study is being carried out by University of Southern California Norris Cancer Center based on the successful reduction of side effects in 10 previous case reports.
Though the evidence is still being collected, the results thus far indicate potential for promising new approaches to chemotherapy that minimize its negative effects.