The ketogenic diet has recently taken off as a potential treatment option for many medical issues, including obesity, diabetes, and neurodegenerative disease. The potent improvement in metabolic dysfunction in those who are overweight or have coronary artery disease and those with other metabolic health issues has been shown multiple times in many important randomized trials.1-6 The ketogenic diet has also been shown to result in a spontaneous and often unintended decrease in overall food consumption due to decreased hunger. This has proven beneficial for those who are trying to lose weight and those who typically overeat.
The past century has unveiled a plethora of preclinical data that has suggested the potential of a ketogenic diet as an aid in cancer treatment.7,8 The benefits of a ketogenic diet, and dietary manipulation in general, may be a potent adjunct to current cancer treatments by synergistically working with chemotherapy and radiation therapy to starve cancer cells, leaving them more susceptible to damage from these treatments.7-10
Recent studies in mice have shown that when comparing radiation therapy with a reduction in calories in the form of carbohydrates, the radiation works much more effectively to kill cancer cells, decrease cancer growth, and inhibit its ability to spread.11 But other studies in mice have shown that a ketogenic diet, when implemented in conjunction with radiation therapy for the treatment of brain tumors in mice, resulted in the eradication of these tumors in the majority of the mice.12
From the amount of preclinical data that accumulates on a daily basis, several key facts are emerging regarding the potential of dietary manipulation and a ketogenic diet in the treatment of cancer…
1. First and foremost, the benefits of the diet have been shown when it is used alongside traditional treatments. There is no data to support that the diet by itself can treat, cure, maintain, or manage cancer. Hopefully this data will become available soon, but as of yet, there is no data to support the comments made by those claiming this in itself is a treatment for cancer.
2. The preclinical data is compelling, but this data is in animals. While we are targeting many of the pathways that we know are vital to cancer survival with multi-million dollar pharmaceuticals that the ketogenic diet also targets, there are no randomized trials in humans showing these benefits.
While this in itself does not discredit the diet, it provides caution that it should be approached carefully and in no way should preclude standard treatment.
What We Do Know in Humans
We know that those with metabolic states resulting from a high-carbohydrate diet — including high blood sugar levels, high insulin levels, and obesity — have higher rates of cancer and do more poorly during cancer treatment.13–16 We also know that multiple pathways that are downregulated by a ketogenic diet also render cells more susceptible to being killed by chemotherapy and radiation therapy.17
If this carries over to humans, it could be a potent, nontoxic treatment enhancer. However, while it is a somber thought, it could also just be one of many potential treatment options in its experimental stages that do not provide the same benefits in humans that they do in mice.
A ketogenic diet is likely safe with minimal toxicity. This has been shown in retrospective data and a Phase I trial.9,18 But it will likely never be shown in a large-scale study, as a dietary study with hundreds of cancer patients will be nearly impossible to run.
Also, while ketosis is a natural physiologic state of the human body, caution should be provided when it is used with chemotherapy and radiation therapy, as these treatments may create an unnatural environment within the body that is difficult to manage.
Elevated blood glucose levels in cancer patients result in drastically poorer outcomes from treatment.19 Unfortunately, many cancer patients have drastically elevated glucose levels from steroids and other medications they must receive during treatment.
A ketogenic diet has been shown to offset this potent rise in blood glucose levels.9 Hopefully trials that are currently being conducted will tell us if this leads to a survival benefit.
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2. Volek J, Phinney S, Forsythe C, et al. Carbohydrate Restriction has a More Favorable Impact on the Metabolic Syndrome than a Low Fat Diet. Lipids. 2009;44(4):297-309. doi:10.1007/s11745-008-3274-2.
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