Intermittent Fasting – Part 6 – Cancer Treatment & Prevention


By: Kelly Gilthorpe Burkenstock, M.D.

Religions have long maintained that fasting is good for the soul, but its health benefits were not widely recognized until doctors began using various fasting diets to treat many issues such as diabetes, obesity and epilepsy. Interestingly, fasting as a treatment for epilepsy dates back to the Roman Era where people with epilepsy were caged and starved to rid them of their demons.

Whether an individual practices fasting for spiritual, health or medical reasons, most people will fast at some point in life.

Intermittent Fasting is a regimen that cycles between periods of fasting, with either no food or significant calorie reduction, followed by periods of unrestricted eating. It changes the body’s composition through loss of fat and weight, while also improving many health parameters associated with disease such as: blood pressure, cholesterol, inflammation, obesity, brain health, heart health, aging, andropause and menopause and possibly cancer. Intermittent Fasting drains the body of one’s glucose (sugar) reserves – the main energy source from the foods we eat. Without this glucose reserve, an individual’s body switches to burning fat as fuel – known as ketosis. There are many different versions of Intermittent Fasting; some notable examples include:

5:2 Fast, consisting of eating normally for five days every week and fasting for two days. On the two fasting days the client restricts their calorie intake to 500-600 calories per day. The other five days the client eats normally and unrestricted.
16:8 Fast, clients eat normally and unrestricted for eight hours and fast for the remaining 16 hours- drinking only water and calorie free drinks.
18:6 Fast, clients eat normally and unrestricted for six hours and fast for the remaining 18 hours – drinking only water and calorie-free drinks.
2:5 Juice Cleanse Fast, a quality juice cleanse is used for 48-72 hours, (two or three days), and then clients eats nutritious meals after the cleanse is complete. A low sugar, low salt, all natural juice cleanse, enriched with vitamins, minerals, fiber and PREBIOTICS is best. Clients eat normally (but nutritiously) for four or five days, then fast with a quality juice cleanse for two to three days.

When an individual switches to an Intermittent Fasting diet plan, they upgrade their body’s performance in a number of ways. Their body initiates a number of important hormonal changes which make fat more accessible to burn. There are diverse and powerful benefits thought to occur due to intermittent fasting such as: weight loss, cancer treatment, disease prevention, improved memory, brain restoration, heart health, mood improvement, decrease in insulin resistance, increase in lifespan (Anti-Aging), enhancement in stress tolerance and an upgrade to the immune system. Several trials have shown significant weight loss, without an overall increase in appetite. Though these benefits are proven in animal trials, we await final confirmation from ongoing human trials.

Part 6 Cancer Treatment & Prevention with Intermittent Fasting

Weight loss is just one benefit of intermittent fasting. Recent animal studies and a few preliminary human trials have shown a decrease in cancer risk and a decrease in cancer growth. These studies indicate this may be due to a decreased blood sugar (glucose) production, an increase in stem cell production (to upgrade and regenerate the immune system), a decrease in insulin resistance, as well as an increased production of cancer destroying tumor-killing cells.

In a 2016 study, research showed that a combination of fasting and chemotherapy slowed the progression of breast cancer and skin cancer. The combined treatment methods caused the body to produce higher levels of specialized white blood cells (common lymphoid progenitor cells and tumor-infiltrating lymphocytes), these white blood cells migrate into cancer cells and kill them. The same study demonstrated that fasting makes cancer cells more responsive to chemotherapy while protecting the body’s normal cells. Fasting also promotes the production of stem cells which are the healing, regenerative cells of the body.

Some research suggests that fasting helps fight cancer by lowering insulin resistance, blood sugar and levels of inflammation. Fasting may also reverse the effects of chronic conditions such as obesity and type 2 diabetes, which are both risk factors for cancer.

Also, researchers believe that fasting may make cancer cells more responsive to chemotherapy while protecting other cells. Fasting may also boost the immune system to help fight cancer that is already present.

Improving insulin sensitivity and blood sugar

Fasting may help improve the effectiveness of chemotherapy.
Insulin is a hormone that allows cells to extract glucose from the blood to use as energy.

When more food is available, the cells in the body become less sensitive to insulin. This insulin resistance means that the cells no longer respond to insulin signals, leading to higher levels of sugar (glucose) in the blood and higher fat storage.

When fasting the food supply is scarce, and the body tries to conserve as much energy as possible. One way it accomplishes this task is by making cells more sensitive to insulin. Cells can digest and metabolize insulin more efficiently, removing sugar (glucose) from the blood.

The main sources of refined junk carbohydrates are white flour, white bread, white rice, pastries, sodas, snacks, pasta, sweets, breakfast cereals and added sugars. Refined carbohydrates are also added to all sorts of processed foods and processed grains.

The combination of Intermittent Fasting and better carbohydrate choices (low refined sugar) improves insulin resistance and fights cancer.

Good complex carbohydrates include:

Fresh fruits- blueberries, apples, grapefruit, lemons, oranges, cantaloupes, melons and bananas

Vegetables- squash, cauliflower, broccoli, Brussel sprouts

Legumes- beans, peas, lentils, chick peas, yams and potatoes

Seeds and nuts- Almonds, macadamia, pistachio, sunflower, flax, and chia

Whole grains- quinoa, oats, couscous, barley, buckwheat

Organic and NON- GMO are better food options.

Better insulin sensitivity makes it harder for cancer cells to grow or develop.

Improving quality of life during chemotherapy

Fasting may help reduce chemotherapy-related headaches and nausea.

Some researchers believe that fasting improves people’s response to chemotherapy because it promotes stem cell regeneration, protects the blood against the harmful effects of chemotherapy, and
reduces the impact of side effects – such as fatigue, nausea, headaches and cramps.

A 2018 study found that fasting can improve quality of life in people undergoing chemotherapy for breast cancer or ovarian cancer. The results show that participants fasting during chemotherapy reported higher tolerance to chemotherapy, fewer chemotherapy-related side effects, and higher energy levels when compared with those who did not fast.

Boosting the immune system to fight cancer

A 2014 study examined whether fasting produces any cancer-fighting effects in mice stem cells. Stem cells are important due to their regenerative and healing capabilities. Fasting also activates stem cells and white blood cells of the immune system to renew and repair themselves allowing the immune system to gain strength and fight disease.

The gut functions best on a 12 to 18 hour fasting cycle benefiting the gut’s microorganisms and the body’s immune system. In doing this practice, the body is benefited in many ways. Metabolism becomes less stressful, and the body is much more receptive to insulin due to it not being subjected to wide swings in blood sugar, known as insulin resistance. In addition, when an individual consumes a heavy dinner or late night snack, the following may occur: the food is digested less efficiently, sleep is impaired and gut motility slows down hampering the bowel movement process.

While inflammation is a good and normal response to injury or trauma, chronic inflammation can lead to lifelong disease and perforations of the gut lining. Some scientific research has found relationships between chronic inflammation and heart disease, diabetes, obesity and cancer. As noted in nutrition research, people following Ramadan fasting for religious or cultural obligations have decreased inflammation markers during their Ramadan fasting. This concurs with other scientific research that found longer duration nighttime fasting was associated with decreased inflammation and oxidative stress. Lower levels of both chronic inflammation and oxidative stress may prove to improve gut health, fight off many diseases, including cancer, and offer the body Anti-aging, vitality and longevity.

As opposed to Intermittent Fasting, severe long term fasting results in a reduction in size in most organs, except the brain. The human body goes to great lengths to preserve the most important organ, the brain. Severe long-term fasting is harmful and not recommended.

Foolproof? Unfortunately not. The main reason for success with intermittent fasting is that there is less caloric intake overall, so if an individual binges on massive amounts of food, eats before bed or indulges in high fat, junk carbs and/or processed foods or consistently eats against their personal DNA macronutrient profile, they may not lose any weight at all. They may also not experience many of the other health benefits of Intermittent Fasting.

Some animal studies have shown that food is processed differently at different times of the day. This could be due to fluctuations in body temperature, biochemical reactions, hormone levels, physical activity and/or absorption and digestion of food. In addition, a person’s unique DNA macronutrient profile determines what percent of each macronutrient (proteins, fats, and carbohydrates) they are personally built to metabolize most efficiently due to their genetic makeup. This explains why an individual may begin a certain diet plan with a friend (Atkins, Keto-Diet, South Beach Diet, etc.), but the weight lost by each individual may differ.
In essence, I recommend that everyone incorporate a juice cleanse detox into their life with a quality grade juice cleanse product plus raw greens, or one salad per day for several days. This acts as a method of Intermittent Fasting to slow aging and prolong lifespan as an easier alternative to water fasting. Water fasting has a rapidly decreasing effect at removing toxins, as nutrients necessary for the removal also decrease as the water fast progresses. Electrolyte imbalances can also appear.

Juice cleanse fasting with a quality product enables clients to continue to work, and is safer than water fasting. Juice cleanse fasting prevents dehydration, loss of electrolytes and fainting.

A few days of juice cleansing can be a great way to reset an individual’s taste buds, and jump start a new, healthful diet. However, there is no health benefit of trying to use a juice cleanse as a temporary detox. This will inevitably lead the individual to return to their unhealthy diet practices. This Intermittent Fasting magic only works if you stick with a nutritious diet long-term; such as one that is congruent with your DNA macronutrients, and also incorporates some juice cleansing and occasional caloric restriction.

In conclusion, Intermittent Fasting shows promise in cancer treatment and prevention, according to multiple studies. More research is needed to conclude which fasting schedule will produce the best results.

As always, please consult a physician before starting any diet plan if you have any medical conditions, especially if you are a DIABETIC, pregnant or nursing.
Stay tuned to part 7 – Erectile Dysfunction, Prostate Health and Intermittent Fasting

– Dr. Burkenstock’s articles can also be found on

– Dr. Kelly Gilthorpe Burkenstock is an internal medicine physician, and has studied abroad with several of the world’s foremost international luminaries. She has locations in Metairie and Mandeville.
For more information, please call 985-869-8400 or 504-502-7600.

BMC Cancer. 2018; The effects of short-term fasting on quality of life and tolerance to chemotherapy in patients with breast and ovarian cancer: a randomized cross-over pilot study, Stephan P. Bauersfeld,
Recent Results Cancer Research 2016
Fasting and Caloric Restriction in Cancer Prevention and Treatment, Brandhorst S

Documentary Eat Fast and Live Longer
NCBI/Pubmed 23112824
Dr. Krista Varady, University of Illinois
Dr. Sandrine Thuret, Neuroscientist
Dr. Mark Mattson, National Institute on Aging
University of Pennsylvania School of Medicine’s Center for Weight and Eating Disorders.

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