The ketogenic diet is a fat-based diet that can provide benefits in the management of cancer through caloric restriction. There is preliminary scientific evidence demonstrating a ketogenic diet may have a significant impact on various types of cancer.
A ketogenic diet is one that uses fat, rather than carbohydrates, as it’s primary source of energy. As a result, the diet promotes the formation of ketone bodies within the body.
For basic reading on the differences between burning carbohydrates and burning fat for fuel in the body, please check out this blog: Merits of a Ketogenic Diet Part 1. As far as the optimal diet for an individual with cancer is concerned, a carbohydrate-based diet would be considered by some to be a poor choice when compared to fats and ketones. This is due to the understanding that most cancer cells are highly dependent on glucose (derived from dietary carbohydrates) to make energy but most cancer cells cannot use fat or ketones. In addition, even when healthy cells burn glucose it creates more free-radical damage than when they burn fat or ketones. Other draw-backs of burning glucose as a primary fuel are that 1) too much glucose leads to the development of metabolic syndrome and 2) many aging brain cells lose the ability to burn glucose over time leading to reduced cognitive function.
A large amount of the initial work in understanding how cancer cells make energy was done by Otto Warburg, Nobel Laureate, in the 1920s and 1930s. Warburg's work demonstrated that cancer cells do not use oxygen to create energy, instead they use an anaerobic process of fermentation. Limit glucose and glutamine and you limit cancer cell activity. Warburg stated that cancer is from a damage to cellular energy production (dependent on what is happening in the cytoplasm and organelles called mitochondria in the cell). So there are a couple of big "Ah-ha's" from his work if you are considering dietary therapies and cancer:
1) If you limit carbohydrates that break down to glucose, you can potentially limit or stop cancer cell activity and growth
2) If you limit glutamine (derived from protein or taken in supplements), you can also potentially limit or stop cancer cell activity
3) This pattern of energy production (fermentation) is common to cancer cells.
The last point is especially important to consider in light of current cancer study and treatment. Current cancer dogma promotes the idea that cancers vary in their genetic tendencies. It states that genetic mutations drive the development of cancer cells and that there are numerous different types of mutations making it difficult to have an over-arching treatment approach. Warburg found that all cancer cells have the same pattern of energy production. Some current cancer biologists are questioning the validity of the current paradigm that asserts that genetic mutations drive cancer. They say that instead, it may be impaired cellular energy production that drives cancer. Since this is a problem common to all types of cancer, we may be able to find a broader, more effective treatment for cancer by considering this basic observation and changing diet.
Thomas Seyfried is one of the current cancer biologists promoting a new paradigm in the study and treatment of cancer. His studies support the claim that cancer is a metabolic disease and thus can be treated successfully through caloric restriction. The ketogenic diet is just one way to accomplish caloric restriction. There are other diets, such as raw food diets that can also accomplish similar goals in managing cancer. He has published a book and multiple papers and I appreciated his lecture available on YouTube (1). Seyfried's work has demonstrated that healthy mitochondria within cells can suppress genes and gene mutation is not driving the development of cancer.
Dominic D'Agostino is another cancer biologist whose preliminary research on ketones indicates a ketogenic diet is a promising therapy for cancer with minimal trade-offs (2). A 2007 study in Nutrition and Metabolism conducted a 22-day study of mice and that showed the ketogenic diet reduced tumors by 65% and doubled survival time in most cases (3). Another study showed the ketogenic diet increased survival time by over 50% and when combined with oxygen therapy, survival time increased by almost 80% in mice (4). A 1991 study on humans looked at a high-carb diet vs ketogenic diet in 27 patients with digestive tract cancer. It found that tumors increased by 32% in those on a high carb diet and DECREASED by 24% in those on a fat-based diet. However, these impressive results were not statistically significant (5). A 2015 study involving brain cancer patients found 3 out of 5 patients on a ketogenic diet combined with chemotherapy and radiation experienced complete remission of their disease. The other two patients experienced disease progression after they stopped the ketogenic diet (6).
The benefits of a ketogenic diet (as a form of calorie restriction) for managing cancer include the following (7):
- Cuts off main fuel supply to cancer cells
- Reduces angiogenesis (the development of new blood vessels needed to fuel tumor growth)
- Restores normal cell suicide (apoptosis) in cancer cells
- Destablizes tumor tissue DNA thereby damaging cancer cells
- Reduces tumor size over time
- Reduces levels of insulin and IGF-1 (relates to insulin sensitivity)
- Enhances action of standard treatments while reducing common side effects
One final note about studies with ketogenic diets includes the use of exogenous ketone supplements which ome in the form of powders like Keto-FX. Such powders have been popular with athletes and have also shown benefits in other areas of nutrition especially neurological health. Interestingly, supplementing mice with ketone powders did help reduce tumor cells and prolong survival time (8). Despite these impressive results, I think we have a ways to go in terms of understanding the interplay between ketosis and cancer and supplementing with ketones. There are some forms of cancer that do not respond to the ketogenic diet (such as prostate cancer) so it is not a one-size fits all dietary solution. However, where the ketogenic diet is not supportive, another type of caloric restriction approach may be.
One tool promoted by Seyfried and his team of researchers is the use of the Glucose Ketone Index (GKI): (Glucose/18) / Ketones = GKI
This is an index that helps you know if you are in a state of ketosis therapeutic for cancer management. You would measure your glucose (and then divide by 18 to get it into proper units) and then divide by the level of ketones. You might consider a blood meter such as KetoMojo to measure these values. The GKI helps with verifying that a person is in the optimal state of ketosis for managing cancer. Here is a link to a guide that may help with interpreting your values.
Please check out these additional articles for more about the ketogenic diet and practical guidance (Merits of a Ketogenic Diet Part 1, Part 2, and Part 3). It can be critical when managing cancer to make sure to eat just the right amount of protein. Typically, this would be about 15% caloric intake but it may vary for some individuals. Too much protein may be converted to glucose through the process in the liver called gluconeogenesis. It may also be very important to have an alkaline diet. A final practical tip if you undergo a ketogenic diet; Be sure to include alkalinizing superfoods such as:
seaweed
broccoli
mushrooms
lemons and limes
black raspberry
asparagus
sprouts (like alfalfa sprouts)
basil
cilantro
These foods, which may comprise about 15% of total calories, add valuable cancer-fighting anti-oxidants and micro-nutrients to the other benefits of the ketogenic diet.
If you are considering adopting a ketogenic diet to help manage cancer, please work with a practitioner experienced in the ketogenic diet. In some cases, a ketogenic diet may be a successful way to manage cancer, but in other cases, other treatments may be more effective. It may be most effective to combine a ketogenic diet with other treatments for best success.
Sources:
1. Thomas Seyfried: Cancer: A Metabolic Disease With Metabolic Solutions. https://www.youtube.com/watch?v=SEE-oU8_NSU&feature=youtu.be
2. Starving cancer: Dominic D'Agostino at TEDxTampaBay https://www.youtube.com/watch?v=3fM9o72ykww
3. Zhou et al. 2007.The calorically restricted ketogenic diet, an effective alternative therapy for malignant brain cancer. Nutrition & Metabolism.4:5
4. Poff et al. 2013 The Ketogenic Diet and Hyperbaric Oxygen Therapy Prolong Survival in Mice with Systemic Metastatic Cancer. PLoS One. 2013; 8(6): e65522.
5. Rossi-Fanelli et al. 1991. Effect of energy substrate manipulation on tumour cell proliferation in parenterally fed cancer patients. Clin Nutr. 1991 Aug;10(4):228-32.
6. Schwartz et al. 2015. Treatment of glioma patients with ketogenic diets: report of two cases treated with an IRB-approved energy-restricted ketogenic diet protocol and review of the literature. Cancer Metab. 2015; 3: 3.
7. Allen et al 2014. Ketogenic Diets as an Adjuvant Cancer Therapy: History and Potential Mechanism” Redox Biology 2 (Aug 7, 2014): 963-70
8. Poff et al 2014. Ketone supplementation decreases tumor cell viability and prolongs survival of mice with metastatic cancer. Int J Cancer. 2014 Oct 1;135(7):1711-20.