Fasting During Chemotherapy

You may have heard about the benefits of short-term fasting for weight loss but what about fasting during cancer treatment?

A recent study evaluated the effects of a fasting mimicking diet during chemotherapy treatment in people with breast cancer. In this study, 131 women were randomized to receive either a fasting mimicking diet (a plant-based, low calorie and protein diet) or a regular diet, for 3 days prior to and then during their chemotherapy treatment.

The study found some fascinating and promising results:

  • The fasting diet group were about 3 times more likely to achieve partial or complete response to the chemotherapy, as shown by their scans, compared with the regular diet group.
  • In addition, the number of women with stable or progressive disease was 2.5-fold lower in the fasting group compared to the regular diet group.
  • Lastly, despite not being given steroids (dexamethasone) to prevent the side effects of chemotherapy, patients in the fasting group did not experience more adverse side effects than those who ate a regular diet.

The results of this study are very encouraging and suggest that fasting around chemotherapy could not only be equally as effective as steriods for preventing chemotherapy-induced side effects, but more importantly, could help enhance the efficacy of treatment!

Looking into the mechanisms to explain these benefits is future work, however, there are some cell and animal studies that suggest nutrient deprivation causes healthy cells to shift into a maintenance and repair state, however in this nutrient deprived state, tumour cells are starved of fuel, which could help slow down growth.

Short-term fasting is not suited for all patients – those with severe weight loss, muscle loss or malnutrition should seek support from their doctor before making dietary changes. Here at the CCNM Integrative Cancer Centre, we recommend speaking with your naturopathic doctor before initiating any fasting regimen.

Please note that this blog posting is not meant to substitute medical advice from a health-care practitioner.

Author: Irina Chan, CCNM Integrative Cancer Centre Intern