Chemotherapeutic agents, powerful drugs used in cancer treatment, kill cancer cells but can also damage healthy cells. Chemotherapy administered to shrink a tumor prior to surgery is known as neoadjuvant chemotherapy. Findings from a recent study suggest that following a fasting-mimicking diet before neoadjuvant chemotherapy impacts both the toxicity and efficacy of the treatment.
A large body of evidence indicates that prolonged fasting can reduce the risk of chronic diseases by improving overall metabolic health. A fasting-mimicking diet, or FMD, is designed to achieve effects similar to a multiple day water-only fast while being easier to follow.
Previous preclinical research has demonstrated that prolonged fasting sensitizes cancer cells to chemotherapy while protecting healthy cells. Studies in animal models indicate that during prolonged fasting, healthy cells shift to a resting metabolism that protects them from nutrient scarcity; however, cancer cells are unable to do this. The current study investigated whether the fasting-mimicking diet influenced the toxicity or effectiveness of chemotherapy in women with early-stage breast cancer.
The authors of the randomized controlled study assigned 131 women with stage II/III breast cancer to receive either an FMD or their regular diet three days before and throughout neoadjuvant chemotherapy. Both groups of women experienced similar side effects, despite the fact that only those on the regular diet were given dexamethasone — a drug to lessen side effects. The authors suggest that these findings might eliminate the need for drugs to manage side effects. Researchers observed that women on the FMD were more likely to experience a 90 to 100 percent tumor cell loss as compared to women on a regular diet. Furthermore, patients on the FMD had less DNA damage in T-lymphocytes from chemotherapy than those on the regular diet.
These findings suggest that an FMD can curb damage to normal cells while increasing a cancer cell’s vulnerability to chemotherapy in women with breast cancer. Further clinical trials will determine if fasting or an FMD in conjunction with standard of care will be helpful in the treatment of other cancers.