The Impact of Intermittent Fasting for Breast Cancer Patients

If fasting is a new concept to you, it might not sound like much fun because we are conditioned to eat frequently. However, if you are actively battling breast cancer, or are a breast cancer survivor, there are ample reasons for choosing to fast now and then, and today I’m going to share with you exactly what fasting can do for you.

To fast is to purposely withhold food for a finite period of time. Fasting is nothing new – it was used by our ancient ancestors for millennia. Whether they were fasting due to the scarcity of food, or for spiritual or healing reasons, our ancestors frequently utilized fasting. Fasting only fell out of favor as a method of healing in recent decades. Doctors who practiced in the earlier part of the 20th century knew about the benefits of fasting and frequently prescribed it for their patients.

There are at least 19 science-backed reasons for fasting [1], [2], [3], [4], [5]. Fasting has the ability to:

1. Stimulate genetic healing mechanisms
2. Turn off “bad” genes
3. Regenerate the immune system
4. Stimulate autophagy, the body’s ability to break down old cells and reuse them to make new cells
5. Regenerate healthy stem cells
6. Reduce chronic inflammation (and cancer is an inflammatory process)
7. Help reset and optimize hormone levels
8. Create more efficient energy
9. Take stress off digestive system, regenerate tight junctions in the gut, repair gut microbiome
10. Decrease healing and repair times because energy isn’t being used to digest food
11. Improve cell-to-cell communication
12. Enhance fat burning and weight loss
13. Optimize release of human growth hormone
14. Improve cognitive function and mental health
15. Help body rid itself of viruses, bacteria and fungi
16. Help body make stronger, healthier, more stress-resistant cells
17. Improve insulin sensitivity
18. Reduce chronic disease risk
19. Improve your relationship with food

What Happens During Intermittent Fasting?

When you are fasting and only drinking water, you use up immediately available sources of energy in the form of glucose. Once the glucose is burned, glycogen stored in the liver is burned. Once those two are depleted, the body is forced to use stored fats for energy, a process known as ketosis. It is important to note that muscle proteins are NOT used for fuel during fasting. This only occurs during periods of starvation or certain disease processes, but not when you are fasting intermittently.

Fasting to Reduce Breast Cancer Recurrence

We have several studies that indicate fasting for short periods of time is especially beneficial to reduce risk of breast cancer. [6], [7] One of the most compelling studies appeared in 2016 in the journal JAMA Oncology [7]. Researchers investigated the benefits of fasting with breast cancer survivors, analyzing data from the Women’s Healthy Eating and Living (WHEL) study. They found that those women who fasted for at least 13 hours overnight had a huge 36% risk reduction for breast cancer recurrence. 13 was definitely the “lucky” number – fasting for only 12 hours did not have the same effects of risk reduction.

The lead author of the study, Dr Catherine Marinac, stated “Increasing the duration of overnight fasting could be a novel strategy to reduce the risk of developing breast cancer. This is a simple dietary change that we believe most women can understand and adopt. It may have a big impact on public health without requiring complicated counting of calories or nutrients.”

For one thing, blood sugar levels decrease with prolonged periods of fasting. Researchers found that women who fasted for longer periods of time overnight had better blood glucose control. Each 3-hour increase in overnight fasting was associated with a 4% lower glucose level, regardless of how much women ate.

The best part is that fasting doesn’t cost a thing – just your dedication. 13 hours of fasting is pretty easy to do. You simply stop eating at a predetermined time, say 7:00 pm (the time you begin is up to you), and have nothing but water until 8:00 am the next day when you break your fast. Most of that time you’ll be asleep, so 13 hours of fasting poses no real difficulty. I’m speaking from experience, I do this almost every day and it’s easy. Fasting for longer than 13 hours provides even more benefits, although it can be more challenging to do. Read on.

Regenerating Healthy Stem Cells with Fasting

Stem cells are the cells that give rise to other necessary cells. They are basically building blocks for cells and their role is to create different types of cells. They do this by dividing – when a stem cell divides, each new cell will either be a stem cell or will morph into one of many different cells such as muscle, nerve, red blood cells, and so on. These are specialized cells required for growth and repair, they help rebuild damaged or diseased tissues.

Creating healthy stem cells is super important for breast cancer survivors, because if you’ve been through the gamut of conventional medicine like chemotherapy or radiation, it has been observed that those two therapies induce cancer stem cells – stem cells that give rise to more cancer. Also, increasingly, there exists a rare sub-population of cancer stem cells which are resistant to chemotherapy. [8], [9]

So when I found out that intermittent fasting helped to create healthy stem cells, I knew you’d want to know about this. Here’s what I found out. In order to promote healthy stem cells using intermittent fasting, you need to fast for at least 2 days. 3 days of fasting appears to work even better. For more information, see the section “Here’s How to Go About Longer Periods of Fasting”, below.

Regenerating the Immune System with Fasting

A 2014 clinical study [10] asked participants to fast for 2-4 days on a regular basis over a 6-month period. Researchers found that there was a significant decrease in the production of PKA, an enzyme associated with an increased risk of cancer and tumor growth. There was also a reduction in Insulin Growth Factor-1 (IGF-1), known to promote each of the key stages of cancer development including growth of cancer cells, blood vessel growth in cancerous tissue, and spread (metastasis). As if that weren’t enough, researchers also found that the immune systems of the participants appeared to regenerate. These findings are especially exciting for those who have had their immune systems blasted away by chemotherapy and radiation.

Professor Valter Longo, lead researcher of the study, said “When you starve, the system tries to save energy, and one of the things it can do to save energy is to recycle a lot of the immune cells that are not needed, especially those that may be damaged.” This is a process called autophagy. According to the study’s findings, by fasting for 3 days, followed by eating a healthy diet full of vitamins, minerals and antioxidants, this regenerates the cells of the immune system.

The study’s co-author, Dr Tanya Dorff, stated “While chemotherapy saves lives, it causes significant collateral damage to the immune system. The results of this study suggest that fasting may mitigate some of the harmful effects of chemotherapy. More clinical studies are needed, and any such dietary intervention should be undertaken only under the guidance of a physician.”

Intermittent Fasting Improves Chemotherapy

Cancer patients are generally told to eat whatever they want when undergoing chemotherapy. It’s pretty bad advice, too. Integrative oncologists and oncology naturopaths know better, and advise their patients undergoing chemotherapy to eat loads of fruits and vegetables to help offset the collateral damage of chemotherapy. We are also finding out that intermittent fasting can assist. For cancer patients, water fasting for 2-3 days prior to treatment and up to 1 day following treatment not only helps the chemotherapy work better, but it reduces treatment-related side effects and toxicity. Several studies [11], [12], [13], [14] have found that short-term fasting retards cancer growth, selectively protects normal cells from chemotherapy toxicity, and does not interfere with the therapeutic effect of the chemotherapy. Prior to fasting, however, please ask your oncologist if you are well enough and strong enough to do this.

Here’s How to Go About Longer Periods of Fasting

If shorter periods of fasting – from 12-16 hours – goes well for you, and you have stable blood sugar levels and your doctor says it’s okay, try some longer periods of fasting. They will definitely be more challenging for you, but if you are wanting to improve stem cell regeneration and immunity, this is definitely worth pursuing. You will probably notice that the first few hours goes just fine, but as you approach lunch time and dinner time, your body is going to expect to be fed. You will be uncomfortable at times. It’s crucial to prepare yourself mentally prior to fasting. See below for other tips on longer periods of fasting for ideas on how to get through it.

36 Hours of Fasting – 1-1/2 days

With this fast, it is recommended that you eat your last meal on a Saturday night (this is optional – the days you choose are up to you), fast all day on Sunday, and break the fast on Monday morning with some green juice. During this fast, you can have all the water you wish – filtered water or sparkling water from glass bottles is best. You may add the following things to your water (they are optional):

• occasional addition of a tiny bit of sea salt or pink Himalayan salt, which helps to replace lost electrolytes and minerals – useful if you get any muscle cramping while fasting
• a wedge of fresh lemon or lime for a little flavor and antioxidants
• a drop of your choice of essential oil (citrus oils are nice) for flavor and antioxidants
• 1 teaspoonful of coconut oil or a cup of non-sweetened herbal tea – only if you are really struggling with fasting and feeling quite hungry

3 Days of Fasting

This is the fast recommended for stem cell renewal and immune system regeneration. This one could be done monthly or even quarterly, or time it to changes of season. For this fast, you can drink as much filtered water as you like, herbal teas and organic bone broth. To prepare your body for this longer fast, it is recommended for the 2-3 days prior to fasting that you eat a healthy, mainly organic, raw food diet so that there are plenty of antioxidants and phytochemicals present in your body to aid the renewal process. Make sure blood sugar levels are well balanced. Be sure to read “8 Tips for Longer Fasts” below.

8 Tips for Longer Fasts

1. If you have diabetes (any type), you should speak to your doctor to see if longer periods of fasting are safe for you. For many, it will be okay and probably even encouraged because decreasing levels of glucose are good for you and fasting creates this. Some doctors (especially integrative doctors) believe that intermittent fasting and low carbohydrate or ketogenic diets are one of the best ways to deal with diabetes.
2. If you have cancer and also have cachexia (muscle wasting), longer periods of fasting may not be the best thing for you, so be sure to ask your doctor about it prior to undertaking fasting. For you, it may be better to do daily fasting (for instance the 13 hour fast discussed above).
3. If you get the go-ahead from your doctor for fasting, prior to doing an extended fast, transition into eating a healthy, mainly organic, plant-based diet and reduce meat eating. This will give your body the building blocks it needs to keep going during the fast.
4. Water drinking helps to suppress that feeling of hunger and you can drink as much water as you wish. Fill yourself up with water when fasting – take a big mouthful because that is similar to eating a mouthful of food – it keeps your digestive tract working. It will also make you urinate a lot, but that’s a god thing, it helps with the detoxification process.
5. Create an environment that is conducive to rest and fasting. Don’t plan on doing much during this 3 days of fasting. Give yourself permission to rest and relax. If you can, take time off work, perhaps go into the country where you can be out in nature and breathe in clean air, and focus on your body’s healing. Stay away from stress as much as possible – both physical and mental. Consider this a healing break. We should all be doing this!
6. During those times when you are struggling with fasting, employing mind-body techniques like yoga and meditation really help to take your mind off the urge to eat. Or go for a gentle stroll outside.
7. When you do resume eating, go slow. If you have fasted for 3 days, take the next 3 days to eat really mindfully, avoiding prepackaged and GMO foods. Avoid stuffing yourself full of any food, because after fasting for 3 days, your body will have decreased amounts of digestive enzymes, so don’t go out and eat a steak dinner. Allow at least one full day of slowly reintroducing food that is easy to digest like fresh juices (not bottled), kefir water, herbal teas, fruits, fermented foods for your gut, freshly prepared vegetable soups, and organic bone broth. Take digestive enzymes to help you digest the food you do eat.
8. Especially avoid eating junk food when you resume eating. As you begin to incorporate intermittent fasting into your life, you will notice that the junk food cravings ease over time anyway.

Mix Up Periods of Intermittent Fasting

Various studies have found that the best benefits of fasting occur when people mix up the types of fasting they do – it keeps their bodies constantly having to adapt and that appears to work very well for us. In other words, rather than keeping with the exact same type of fasting you always do, choose one day to fast for 16 hours, then several days later you could fast for 14 hours. Occasionally, do the 36-hour fast and quarterly, do the 3-day fast.

As you can see, intermittent fasting has some very real applications for the cancer patient. By combining a healthy organic diet with exercising at least 30 minutes per day, and doing some intermittent fasting, you can reduce inflammation, promote healthy stem cells, replenish your immune system – and all of these are vital for reducing breast cancer risk/recurrence. So start to develop your fasting discipline (and make no mistake, it is a discipline) – I think you’re going to love how you feel afterward.

References:

[1] Fasting: Molecular Mechanisms and Clinical Applications – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3946160/

[2] Impact of intermittent fasting on health and disease processes – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5411330/

[3] Fasting therapy for treating and preventing disease – current state of evidence – https://www.ncbi.nlm.nih.gov/pubmed/24434759

[4] Fasting and cancer treatment in humans: A case series report – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2815756/

[5] Calorie restriction and cancer prevention: metabolic and molecular mechanisms – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2829867/

[6] Biomarkers of dietary energy restriction in women at increased risk of breast cancer – https://www.ncbi.nlm.nih.gov/pubmed/19656771

[7] Prolonged Nightly Fasting and Breast Cancer Prognosis – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4982776/

[8] Radiation induces the generation of cancer stem cells: A novel mechanism for cancer radioresistance – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5103903/

[9] Therapeutic resistance and tumor-initiation: Molecular pathways involved in breast cancer stem cell self-renewal – https://ascopubs.org/doi/abs/10.1200/jco.2007.25.18_suppl.528

[10] Prolonged Fasting Reduces IGF-1/PKA to Promote Hematopoietic-Stem-Cell-Based Regeneration and Reverse Immunosuppression – https://www.cell.com/cell-stem-cell/fulltext/S1934-5909(14)00151-9?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS1934590914001519%3Fshowall%3Dtrue

[11] Fasting and differential chemotherapy protection in patients – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3048045/

[12] Fasting vs dietary restriction in cellular protection and cancer treatment: from model organisms to patients – https://www.nature.com/articles/onc201191

[13] Fasting Cycles Retard Growth of Tumors and Sensitize a Range of Cancer Cell Types to Chemotherapy – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3608686/

[14] Fasting Enhances the Response of Glioma to Chemo- and Radiotherapy – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3439413/

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