Low-cal ketogenic diet slows brain cancer in mice
Last Updated Aug 2007
Last Updated: 2007-03-29 16:39:40 -0400 (Reuters Health)
By Will Boggs, MD
NEW YORK (Reuters Health) - A calorically restricted ketogenic diet decreases the
growth of malignant brain tumors in laboratory mice, according to an online report
in the journal Nutrition & Metabolism.
A ketogenic diet is a high-fat, low-carbohydrate diet that induces excess
production of ketone bodies, which are incompletely burned fat molecules. This diet
has been used to control epileptic seizures that do not respond to drug treatment.
"In contrast to most conventional brain tumor therapies, which are largely
ineffective, are excessively costly, and can diminish the length and quality of
life, the calorically restricted ketogenic diet is a natural therapeutic approach
to brain cancer management that is based on the principles of evolutionary biology
and metabolic control theory," Dr. Thomas N. Seyfried told Reuters Health.
Seyfried and associates at Boston College, Chestnut Hill, Massachusetts, evaluated
the efficacy of KetoCal, a ketogenic diet formulated to treat unresponsive epilepsy
in children, in mice implanted with a malignant mouse brain tumor and a human
malignant glioma, a brain tumor that responds poorly to drug therapy.
The mice were fed a regular, high-carbohydrate diet, unlimited amounts of KetoCal,
or restricted amounts of KetoCal.
Growth of the two tumors was reduced from 35 percent to 65 percent in mice given
restricted KetoCal, compared with mice receiving normal or KetoCal diets that were
unrestricted, the researchers report.
Survival was also significantly longer among mice receiving the restricted KetoCal
diet, the results indicate.
Blood sugar levels were significantly lower and circulating ketone bodies
significantly higher in mice fed the restricted KetoCal diet, the researchers note.
The restricted KetoCal diet starves the brain cancer cells by removing molecules
needed for cell growth and survival. While the normal brain cells are sustained by
ketones, the tumor cells can't metabolize ketones.
This mouse study was motivated in part by the previous work of Linda Nebeling and
co-workers who showed that a calorie-restricted ketogenic diet was effective for
the long-term treatment of brain cancer in children, Seyfried explained. "Our work
in mice strongly supports the original study."
He concludes that it is important that human trials begin soon to study the effect
of the calorically restricted ketogenic diet on brain cancer. "These trials could
be conducted at any medical center or clinic currently using the ketogenic diet as
a therapy for refractory epileptic seizures."
SOURCE: Nutrition & Metabolism, February 21, 2007.
Dr. Sears Comment
Calorie restriction has been long recognized as a powerful technology to reverse
chronic disease conditions. The only problem is that it has to be continued
indefinitely. It's not the ketones of a very low-carbohydrate diet, but the simple
restriction of calories that is important. The only diet that can be followed for
a lifetime that also is calorie restricted is the Zone Diet.