A new study reveals that people with brain tumor growth may benefit from the keto diet. The ketogenic diet is a modified version of the Atkins diet. It includes high-fat, low-carb foods and moderate amounts of protein. Physicians initially prescribed this type of diet to epilepsy patients in the 1920s. Today, many people follow the keto diet to lose weight, have more energy, and have other benefits.

While the keto diet has exploded in popularity recently, the dietary constraints make it difficult to follow long-term. However, researchers found that a modified version of this diet may benefit people with brain tumor growth. The study appeared in the July 7, 2021, online issue of Neurology®, the medical journal of the American Academy of Neurology.

The small study discovered that people with brain tumors called astrocytomas could safely eat a keto diet. All participants in the study had undergone radiation treatment and chemotherapy. Scientists found that the diet caused metabolic changes in their bodies and brains. However, it’s important to note that the study did not determine whether the keto diet could slow tumor growth or increase longevity.

“There are not a lot of effective treatments for these types of brain tumors, and survival rates are low, so any new advances are very welcome,” said study author Roy E. Strowd, MD, MS, MEd, of Wake Forest School of Medicine in Winston-Salem, N.C., and a Fellow of the American Academy of Neurology.

“These cancer cells rely on glucose, or sugar, to divide and grow. Since the ketogenic diet is low in sugar, the body changes what it uses for energy — instead of carbohydrates, it uses ketones. Normal brain cells can survive on ketones, but the theory is that cancer cells cannot use ketones for energy.”

The study showing how the keto diet benefits people with brain tumor growth

brain tumor growth
Researchers recruited 25 people with astrocytomas for the study. Participants followed a ketogenic diet with intermittent fasting for eight weeks. They ate fish, bacon, eggs, butter, heavy cream, and leafy green vegetables. All of these foods are high in fat and relatively low in carbs.

The volunteers met with a dietician at the beginning of the study and every two weeks after. For five days a week, participants followed the modified Adkins diet. This involved carbohydrate restriction along with high amounts of fat. The program also called for participants to fast twice weekly, eating only 20% or less of their recommended daily calories.

Scientists wanted to see if the participants could adhere to the diet without significant side effects. Of the group, 21 people completed the study, with 48% following the diet to a T. However, urine tests revealed that 80% of the volunteers had elevated ketones. Their body relied primarily on fats and protein rather than carbohydrates for energy.

Most participants with brain tumor growth did well on the keto diet. Only two people experienced significant side effects during the study period. Scientists found that one wasn’t related to the diet, while the other could’ve been related.

Scientists noted significant metabolic changes in the body and brains of participants near the end of the study. Specifically, hemoglobin A1c levels, insulin levels, and fat body mass all decreased. On the other hand, their lean body mass increased.

Scientists took specialized brain scans of participants to measure brain metabolites as well. They discovered increased ketone concentrations and metabolic changes in brain tumor growth.

The results are encouraging, but future studies are necessary

“Of course, more studies are needed to determine whether this diet can prevent the growth of brain tumors and help people live longer, but these results show that the diet can be safe for people with brain tumors and successfully produce changes in the metabolism of the body and the brain,” Strowd said.

Overall, the keto diet shows promise for those with brain tumor growth. While scientists can’t say conclusively that it slows tumor growth or increases survival, it does benefit health in the short term. Hopefully, follow-up studies will be done to determine the diet’s long-term benefits on brain tumor growth.

Researchers also stress that the study participants had a high level of contact with researchers.  They say this isn’t possible in a more extensive study or routine doctor visits. Therefore, the results of this study may not be replicated in other settings.

The study was supported by the philanthropy of Dr. John and Elaine Freeman, Dr. Jon Weingart, the Martz, Redwood, and Dalos families, the National Center for Advancing Translational Sciences, National Institutes of Health and National Cancer Institutes.

Other benefits of the ketogenic diet

Doctors have prescribed the keto diet for decades to treat epilepsy and even mental health conditions. Today, people follow the diet for other reasons, such as the following:

  • Weight loss. Many people eat a keto diet to burn more fat and induce weight loss. One longitudinal study found that obese patients who followed the diet for six months dropped a significant amount of weight. Other health markers such as cholesterol, blood triglycerides, and blood glucose levels also improved. The risk for heart disease also decreased.
  • Reduces brain fog and improves cognition. Some people on a ketogenic diet report having more mental clarity after eating less sugar and carbs. One study found that this diet leads to better cognition and biochemical effects in the prefrontal cortex. Scientists believe this may have important implications for treating neurodegenerative diseases like Alzheimer’s and Parkinson’s.

brain tumor growth
Final thoughts on a study showing effects of the keto diet on brain tumor growth

A small study revealed that the keto diet could help patients with brain tumors. The study found that patients had more ketones and improved metabolism after the eight weeks. They also had more lean body mass and lower insulin levels. However, they’re still unsure how the diet could impact brain tumors in the long term. More studies are needed to determine these effects, but the results from this study are promising indeed.