Deadly Brain Tumor May Respond to Specialized Diet
About 18,000 Americans each year are diagnosed with a brain cancer known as malignant glioma, but unfortunately, many do not survive. Researchers studying mice with these types of brain tumors have found that a specialized low-carbohydrate diet, known as the ketogenic diet, may enhance radiation treatment and could possibly extend survival.
Adrienne C. Scheck, from Barrow Neurological Institute at St. Joseph’s Hospital and Medical Center in Phoenix, Arizona, and colleagues divided mice with high-level malignant gliomas into one of two groups. The first group was kept on a standard diet while the remaining mice followed a ketogenic diet known as KetoCal, a nutritionally complete, commercially available formula. Both groups received radiation therapy and had regular brain scans to monitor tumor growth.
The ketogenic diet is high in fat (80% of calories) and low in carbohydrate and protein. The diet forces the body to burn fat instead of glucose for energy, a process that mimics starvation. A ketogenic diet is often used to decrease seizures in children with epilepsy, although doctors aren’t exactly sure how it works. There is also evidence that the diet's effect on brain regulation or homeostasis has potential for treating other brain disorders.
In this study, the ketogenic diet appeared to enhance the anti-tumor effect of radiation. Dr. Scheck speculates that the diet works with the therapy to stop tumor growth by reducing the stimulation of growth factor hormones. It may also reduce inflammation and edema around the tumors.
The diet also increased survival. None of the mice on the standard diet survived more than 33 days, but many of the animals on the ketogenic diet survived with no sign of tumor recurrence for over 200 days.
The ketogenic diet typically begins with a period of fasting that lasts until the body produces a moderate to large amount of ketones (a by-product of fat metabolism). This is usually done in a clinical setting so a patient can be monitored for adverse effects such as vomiting, low blood sugar, and dehydration. People on the ketogenic diet should be monitored by a doctor (preferably a knowledgeable neurologist) and a dietitian.
A meal planning spreadsheet is available through Packard Children’s Hospital at Stanford University Medical Center.
Should the approach succeed in human trials, they say the diet could quickly and easily be added to current human brain tumor treatments without the need to go through federal regulators. Doctors are also working on pill which uses specific fatty acids from the ketogenic diet without patients having side effects such as constipation, hypoglycemia, retarded growth, and bone fractures.
Abdelwahab MG, Fenton KE, Preul MC, Rho JM, Lynch A, et al. (2012) The Ketogenic Diet Is an Effective Adjuvant to Radiation Therapy for the Treatment of Malignant Glioma. PLoS ONE 7(5): e36197. doi:10.1371/journal.pone.0036197