How To Fast For Chemotherapy Effectiveness

How To Fast For Chemotherapy Effectiveness
Photo courtesy of and Hordur Vilhjalmsson

How To Fast For Chemotherapy Effectiveness

Following yesterday’s article on the study that is currently underway investigating the benefits of fasting combined with chemotherapy, I thought it a good idea to share with you the best, safest way to fast should you decide to do this.

Let me preface this by stating that if you are undergoing chemotherapy for breast cancer, you most definitely should consult with your doctor regarding your fitness to undertake this kind of fasting prior to doing so.

Yesterday’s article mentioned the study done by Professor Valter Longo at the USC Davis wherein the effects of fasting for a time prior to chemotherapy and again one day post-chemotherapy were found to be quite effective for killing cancer cells in mouse models.  Now, I have to remind you that human studies are ongoing and the results won’t be known for a year or two.

Fasting is known, however, to be beneficial for many disease processes, many natural therapists highly recommend fasting for detoxification and improvement of health.  Fasting has been done for thousands of years by many different groups of people for reasons that range from religious ceremony to weight loss to detoxing organs like the liver.

The thing to be careful about is how and when to do fasting when you are going through chemotherapy.

The fast discussed by Prof Longo is of relatively short duration – 1-2 days prior to chemotherapy and then the day following.  The good thing about that kind of fast is that your metabolism doesn’t have a chance to slow down and you don’t need to be concerned about entering into starvation mode, which would be bad news for your muscles and your health in general.  The short duration of this kind of fast eliminates the risk of nutrient depletion.

How To Fast In Combination With Chemotherapy

Here’s the plan.  You devote just one day prior to your chemotherapy infusion and one day after your chemotherapy to fasting.  When you fast, you consume as much filtered water as you like and if you get too hungry (as in weak and dizzy or have a headache), you may juice fresh organic carrots, kale, beet, spinach (any combination) because the vitamins and enzymes from the juice also help to kill cancer cells.  Do not drink bottled juices because the living enzymes contained therein are wrecked by the bottling process, many have sugar, and will not assist your healing endeavors.  If you don’t like juicing, you can try drinking green tea or herbal tea along with your water.  When you do return to your normal diet, try to follow a healthy one, such as outlined on my page Diet and Cancer.

During the time you are fasting, don’t overdo anything.  Be gentle with yourself – don’t go on a 5-mile hike!  Try yoga or qigong or tai chi for some nurturing exercise.

I will say it again – make sure you check with your doctor about your fitness levels to ensure you are strong enough to undertake fasting combined with chemotherapy.

Spend 7 minutes and watch this video of Professor Valter Longo discussing his research on fasting.

If you would like my help with getting through breast cancer in an inspiring and ultra-healthy way, please sign up for my free e-newsletters on the right, or “like” me on Facebook (  It is my honor to help you through this.

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4 thoughts on “How To Fast For Chemotherapy Effectiveness

  1. I just had bi-lateral masectomy 2 weeks ago. I am BRCA 1 positive and still awaiting my pathology reports. I do know for certain that I will be needing chemo soon and I would really like to do this fasting along with it. I am a vegetarian cook, and holistic counselor. I am in good shape and exercise often. Thanks for your ear!


    1. Thanks Samantha for your comment! You and I have been chatting via email, so I won’t comment again here. I hope you found the articles I sent you thought-provoking and interesting! Wishing you all the very best on your breast cancer journey.

  2. hi, thank you for this informative article. I am going to be starting my second round of chemo for a local recurrence and am interested in what my oncologist will have to say about this. I do have a question about having green tea and making juice- are these not counterintuitive to chemo? I was advised the first time to avoid anything considered anti oxidant as this would work against chemo esp. green tea! Your opinion is welcomed, thank you!

    1. Hi Shari,
      That’s a great question and I’ll do my best to answer it. So there are a few oncologists who tell their patients not to use antioxidants during chemotherapy, but juicing is not all about the antioxidants. The benefits of juicing during chemotherapy far outweigh any other factors. Please see my article: Fresh juices contain live enzymes, cancer killing phytochemicals (plant chemicals), and create more alkalinity in the body (and cancer thrives much better in acid conditions). Every single person with whom I have worked that juices during chemotherapy just fares better. They have fewer incidences of colds and flu, fewer problems with “chemobrain”, and less incidence of peripheral neuropathy. I hope that this answer helps you, and if I can assist you further, please contact me.
      Warmest regards,
      Marnie Clark

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