Ketogenic Diet

Awareness of the role sugar and carbohydrates play in various cancers has increased interest in low carbohydrate diets such as the ketogenic, Atkins, paleo, primal, Bulletproof, and Zone diets. What these eating patterns have in common is an emphasis on significantly decreasing carbohydrate intake in favor of increased fat and protein intake.

Animal studies show that the ketogenic diet has anti-cancer benefits. This has not been well-replicated in humans, but there are several published case reports that demonstrate improvement, especially in brain tumors and breast tumors. More studies are needed to confirm the anti-cancer effects in humans. The ketogenic diet relies on fat as the main source of calories, with some protein and extremely low amounts of carbohydrates. When a ketogenic diet is used to try to control cancer growth and development, it must also significantly reduce calories in order to force the body into a state of ketosis, which is metabolically similar to fasting.

While the ketogenic diet is generally considered safe, particularly when it is done under the supervision of a registered dietitian or other knowledgeable healthcare provider, there are concerns such as nutrient deficiencies, constipation, and cardiovascular issues. That’s why it is not routinely recommended for cancer patients. The ketogenic diet tends to be higher in animal proteins and fats, and increased animal fats, including excessive red meat, have been associated with an increased risk of breast and colon cancers.

Additionally, the ketogenic diet can be very low in fiber. Fiber is essential for gut health, and research is continually emerging about the importance of gut health, the microbiome. Poor gut health is also associated with a variety of chronic diseases including cancer. The ketogenic diet also does not supply sufficient B vitamins or vitamin D, so these need to be supplemented. Finally, this is a hard diet for many individuals to follow, limiting its potential value.

If you feel strongly about trying the ketogenic diet, or if it is recommended by your trusted medical provider, please see a qualified registered dietician (RD) for guidance. Many cancer centers have nutrition experts on their staff to help patients navigate the complicated world of specialized nutrition.