An Accredited Practising Dietitian Explores the Latest Research on Fasting During Chemotherapy

If you or a loved one is facing breast cancer treatment, you may have come across the idea of fasting before chemotherapy. This concept suggests that short-term fasting, typically lasting for fewer than three days, can potentially reduce chemotherapy toxicity, alleviate side effects, and improve overall quality of life during treatment. But before you jump on the fasting bandwagon, it's important to understand the science behind it and separate fact from fiction.

The Fasting Hypothesis

The notion of fasting before chemotherapy is based on the hypothesis that temporarily depriving the body of nutrients may enhance the effectiveness of chemotherapy while minimising its adverse effects. But does the scientific evidence hold up to the claims?

Limited Human Studies

While the idea of fasting and its potential benefits have gained attention, there have been limited human studies available to draw any conclusions. Most of the research conducted so far has been either in vitro (test tube) or on animals. Additionally, the data from the few human trials conducted are characterised as low quality, which means they may not be entirely reliable and could contain some degree of bias.

However, a systematic review (good level of evidence) conducted in 2022 looked at fasting before chemotherapy. This review analysed eight studies on fasting before breast and gynecological cancer treatments. Here’s what they found - According to the review, fasting for short periods did not show a beneficial effect on the quality of life for cancer patients during treatment. Furthermore, evidence for fasting regimens reducing side effects and toxicities of chemotherapy was inconclusive. Two more recent human studies looking at fasting during treatment for breast cancer were ceased before the study could be finished, owing to poor adherence and potential complications.

To make matters more complicated, unintentional weight loss associated with fasting can significantly impact clinical outcomes, which raises concerns about the use of fasting in this context. It's important to note that malnutrition is prevalent among people with cancer, and it can have adverse effects on both treatment tolerance and survival rates. Therefore, ensuring adequate nutrition during cancer treatment takes precedence here.

We Need More Research

Ultimately, while fasting before chemotherapy has garnered interest, there simply isn't enough solid data to make a definitive conclusion. What the research has shown so far is that fasting may not provide the benefits we hope for, and it may indeed do more harm than good. It's important to remember that reliable scientific evidence is the key to making informed decisions about your health.

Looking Ahead

The good news is that more studies are being conducted in this area. Researchers are working to gather a more substantial body of evidence to determine whether fasting can be considered in clinical practice. Until then, it's wise to assume that fasting is not appropriate for those going through cancer treatment.

Safety First

If you do decide to explore fasting as an adjunct to your cancer treatment, it's crucial to do so under the supervision of a trained professional. Your well-being is of the utmost importance, and their expertise can help you navigate the process safely.

In summary, while fasting before chemotherapy may be tempting, tread with caution due to the limited and inconclusive scientific evidence. As more research emerges, we will gain a better understanding of whether fasting can be a helpful addition to breast cancer treatment. Until then, rely on the expertise of your healthcare professionals who are well-versed in oncology to make the best decisions for your health.

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