Keto for Cancer: Research documenting benefits and downsides

I’ve been advocating for a ketogenic diet to fight cancer since about a week after I was diagnosed. I’ve been slowly dribbling out the reasons why I’m such a fangirl as I’ve come across experiment after experiment and anecdote after anecdote that demonstrate the benefits of this way of eating. I think it’s finally time that I compile all that evidence in a single place to illustrate why keto should be part of the standard of care for most cancers. (Fasting, too, but I’ve already covered that.) It is a fact that a ketogenic diet can shrink tumors and prolong survival when used alone and in combination with traditional therapy.

Before I begin laying out the evidence, a quick note about cancer research as I understand it and why you so often read about a study proving XYZ kills cancer cells and then stumble across seemingly conflicting information about how XYZ is not recommended because it’s not proven “safe and effective.”

First, there are in vitro studies. These are essentially experiments conducted in petri dishes and test tubes with cancer cells disconnected from body parts. They’re the least expensive and therefore the most common form of research. You want to test a hypothesis in vitro before shelling out the big bucks to test it in vivo, or in the context of an actual living body.

If your in vitro results impress, you write up a grant request to try and fund an in vivo experiment in mice. Mice have similar genetic behavior to humans but they’re still just an animal model so what works in mice may or may not work in humans. Still, ain’t nobody gonna let you test on a human unless your treatment cured the mouse and didn’t kill it.

Only after in vitro and mouse model success, and after so much grant writing or petitioning of whoever runs your company’s R&D budget, is it time for the actual human clinical trials overseen by the FDA. These are wildly expensive, as you can imagine, and designed within a framework of ethics that prevents withholding the prevailing standard of care. There may be some cases where individuals choose their own path and have the foresight to register their experience as a trial with the FDA in what’s known as a case study. These provide insight but it’s the larger controlled studies that carry weight. If you’re looking to have your treatment approved by the FDA, you’ll need to run a phase 1 clinical trial to determine a safe dosage, and a phase 2 to prove it’s effective at that dosage. When it gets that seal of approval from the FDA, it’s considered “safe and effective” and your favorite health and wellness website is allowed to recommend it.

With this context, I present you the evidence supporting keto as standard of care for cancer.

In vitro experiments showing benefits of keto for cancer

Dr. Thomas Seyfried has been running these tests out of his Boston University lab for over a decade and his 2015 paper published with Dom D’Agostino, Angela Poff and Roberto Flores pretty much sums up their work. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3941741/

Seyfried’s 2012 textbook Cancer as a Metabolic Disease and Travis Christofferson’s Tripping over the Truth (foreword by Dom D’Agostino), which relates the same findings through an incredibly readable narrative, helped initiate the metabolic paradigm shift and accelerate research.

Cancer as a Metabolic Disease: On the Origin, Management, and Prevention of Cancer by Thomas Seyfried, 2012

Tripping over the Truth: How the Metabolic Theory of Cancer Is Overturning One of Medicine’s Most Entrenched Paradigms by Travis Christofferson, 2019

Mouse model research showing benefits of keto for cancer

• 2014 Mice with metastatic brain tumors had their diets supplemented with ketones and had improved survival compared to a control group of mice. Ketone supplementation prolonged survival by 51% (diets supplemented with 1,3-butanediol , a precursor to β-hydroxybutyrate ketone), and 69% (diets supplemented with a ketone ester). Equally as exciting, “Ketone administration elicited anticancer effects in vitro and in vivo independent of glucose levels or calorie restriction.”
  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4235292/
• 2017 Mice given pancreatic cancer and “treated with KD [ketogenic diet] and radiation had a slower tumor growth rate than mice treated with radiation alone.”
  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5510645/
• 2018 Twenty of 25 mice were given colon cancer with 5 remaining as control. Half the mice with colon cancer were fed normal chow and the other half were fed a ketogenic diet. With no other treatment, tumors were significantly smaller in the keto mice and body composition better. The results show keto “can suppress colon tumor progression and systemic inflammatory responses, and improving body and muscle weights, which might help to prevent cancer cachexia.”
  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5852782/
  Note that another 2018 study showed that keto alone wasn’t enough to stop progression of established liver tumors. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6162796/

Human trials showing benefits of keto for cancer

• 2010 A 65-year-old woman with glioblastoma multiforme (an especially aggressive brain cancer) used fasting and keto in addition to standard treatment to achieve a complete remission. Her tumor recurred 10 weeks after she stopped keto.
  https://www.ncbi.nlm.nih.gov/pubmed/20412570
• 2016 Six cancer patients with a variety of types and stages adopted a keto diet while receiving radiation. This was a poorly organized study and no results about impact on the cancer can be drawn but it’s worth noting that all patients experienced fat loss but no muscle loss/ cachexia. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4779584/
• 2017 A 29-year old woman with triple negative metastatic breast cancer (another extremely aggressive type of cancer) was treated with keto and hyperbaric oxygen therapy in addition to standard care and achieved complete remission.
  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5589510/
• 2019 60 women with late-stage breast cancer who needed chemotherapy prior to surgery joined the trial. 30 followed a calorie-restricted, MCT-based keto diet for 12 weeks while receiving chemo; 30 ate their standard diet. Thirty months later, 100% of the chemo+keto group survived while only 60% of the chemo-only group survived. https://www.ncbi.nlm.nih.gov/pubmed/31496287/

Keto is safe and well-tolerated

Keto has been used for centuries to treat epileptics and for decades to juice body building bros.

The most common medical concern I hear is that keto causes weight loss and weight loss isn’t desirable in cancer patients. However, the studies above have shown that keto causes fat loss, not the muscle loss that defines cachexia, the muscle wasting that kills so many cancer patients. While higher body weights have been shown to correlate with increased survival even as they correlate with higher risk in what’s known as the obesity paradox, a closer look shows that higher body fat is not so good for survival. In other words, muscle good, fat bad, according to cancer epidemiologists. And therapeutic fat loss is keto’s specialty.

Finally, fears that a ketogenic diet means an overload of glutamine-rich meats with their artery-clogging cholesterol and a dearth of cancer-fighting greens are unfounded. Keto doesn’t necessarily mean carnivorous. As you all know, I’ve been happily “mostly vegan” keto for a year now with my only animal products being fish oil supplements on non-fasting days; wild-caught fatty fish or organic, pasture-raised egg once a week; and occasional organic, pasture-raised chicken stock during extended fasts. Five days a week my total dietary cholesterol is 35 mg from fish oil supplements. Mondays it’s 0 and Sunday I get a little more from my salmon or egg. From October 2018-June 2019 I was completely vegan outside my supplements and I only added egg or salmon after starting metformin in July 2019. In short, reducing carbs does not mean reducing nutrition.

Arguments against Keto for Cancer

Detractors have two primary arguments. First is that keto hasn’t been proven to help all forms of cancer and can, in fact, fuel some types.

It’s true that some cancers can use ketones as fuel. However, preclinical research (in vitro + mouse model) has shown evidence that keto has an anti-tumor effect for most cancers – all cancers but kidney, melanoma and cervical cancer so far.
Summary as of 2017: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5842847/
Additional relevant study in 2018: https://www.ncbi.nlm.nih.gov/pubmed/29414764/

Not every type of chemotherapy works for every type of cancer – hell, my lifesaving targeted therapies only work for about 70% of lung cancer patients with my exact mutation. It doesn’t mean it shouldn’t be part of the standard of care for the cases where it can prolong lives.

The second argument against keto is that it may not be effective indefinitely.

Cancers are your body’s own cells, of course, and may still have remnants of those cells’ metabolic adaptability. It’s possible that, deprived of glucose long enough, they can develop pathways to better utilize other types of fuel. Nevertheless, as someone who once had only 6-8 months I can only say that every additional month that keto affords me is precious and worthwhile. I always emphasize that no diet is a cure for cancer and I’ve never had that expectation. The fact that a diet can extend my life while reducing symptoms of treatment, however, is a miracle itself. For others, that extra time may be all that’s needed for conventional treatments to do their job. 

Keto for Cancer Resources

This really is just an overview of the benefits of this way of eating for most cancers. If you’d like to learn more or are interested in implementing this diet for your own therapeutic benefits, I highly recommend some further reading:

Keto for Cancer is a great explainer on how to implement a therapeutic ketogenic diet. Miriam Kalamian is a nutritional consultant who extended the life of her son far beyond his expected survival through a ketogenic diet. Seyfried himself provides the foreword. The Metabolic Approach to Cancer by Dr. Nasha Winters is an excellent compliment.

Keto for Cancer: Ketogenic Metabolic Therapy as a Targeted Nutritional Strategy by Miriam Kalamian, 2017

The Metabolic Approach to Cancer: Integrating Deep Nutrition, the Ketogenic Diet, and Nontoxic Bio-Individualized Therapies by Dr. Nasha Winters and Jess Higgins Kelley, 2017

I want to add the usual disclaimer about consulting with your doctor before starting any new diet. Do that, but keep in mind you may need to educate your doctor. From personal experience, when I told my oncologists that I was a true believer in the metabolic theory and followed a plant-based keto diet, they had no idea what I was talking about. You’ll notice that almost all the books and research above were published in the last few years. We are riding the crest of this paradigm shift.

What do you think?

Is there research that I’m missing? Other compelling points in favor or against using keto in cancer treatment?

Let me know if the comments!