What is the ketogenic diet?
Ketogenic diet is a high fat, low carbohydrate diet. When our body does not get enough carbohydrates or sugar, it converts fat in our body into ketones for energy.
Why is the ketogenic diet thought to be useful in cancer?
This is based on the work of Otto Warburg and is called the Warburg hypothesis. Cancer uses carbohydrates or sugar for energy to grow. Many of the normal cells in our body use carbohydrates for energy, but if there are not enough carbohydrates around for them to use, then they can use ketones for energy. Based on the Warburg hypothesis, it was previously thought that cancer cells cannot use ketones for energy because cancer cells are too immature. However, now we know it is more complicated that that.
Can brain tumor cells use ketones for energy?
A group of researchers experimented with animal models looking to see if ketones were taken up by the brain tumors. They found that not only did the brain tumors take up the ketones, they used them for energy to grow.
Why, then, should we use the ketogenic diet to treat brain tumors?
Another group of researchers used animal models to test the effect of the ketogenic diet with tumor response and survival. When the ketogenic diet alone was used with brain tumors, he observed a modest improvement in survival. However, when the ketogenic diet was used with radiation therapy, there seemed to be a significant increase in survival. In fact, 9 out of the 11 animals were cured of their tumors.
Do ketones help radiation work better in brain tumors?
We are still unsure about this question, and more research needs to be done. What we do know, from work that my team has conducted at the University of Cincinnati Cancer Center, is that patients who were on the ketogenic diet or a modified Atkins diet seemed to have an increase in pseudoprogression on their MRI scans. Pseudoprogression is inflammation that is seen on the MRI that comes from the radiation working on the brain tumors. It is usually a marker of increased survival and better outcomes. Perhaps the ketones that the brain cancer cells are taking up are making the cancer cells more susceptible to the radiation. The way to further explore this would be to combine a ketogenic diet with radiation in brain cancer. These results are intriguing, but they are still early, and the study is still ongoing.
What is the best diet for cancer prevention?
Since we originally thought that cancer cells could not use ketones for growth, it made sense to use the ketogenic diet in cancer. We now know it is more complicated than that, and brain cancer cells can take up ketones and use them for energy. The best diet for cancer prevention is a diet with no processed food, especially processed meat. The World Health Organization has stated that processed meat is a carcinogen (cancer-causing substance) and should be limited in the diet. I recommend to my cancer patients a diet with very little or no processed carbohydrates (sugar, flour, etc.) and that patients have the majority of their calories come from whole grains, fruits, vegetables, nuts and seeds.