Cedars-Sinai Blog
What Do We Know About the Keto Diet?
By now you’ve likely heard of the ketogenic—or keto—diet.
It’s become a trend in recent years, but the keto diet has been used by doctors for nearly a century—and researchers are still exploring ways it can help patients.
"A ketogenic diet has been known as a true medical metabolic therapy for decades."
What is the keto diet?
A keto diet follows a strict low carb, moderate protein, high fat regimen.
The goal of a keto diet is to drive the body into ketosis, a metabolic state that forces the body to produce ketones from fat. The body uses these ketones for energy, so fat—rather than carbs—becomes a main source of fuel for the body.
"By increasing the amount of fat and decreasing the amount of carbohydrates, circulating blood sugar goes down," says Cedars-Sinai neuro-oncologist Dr. Jethro Hu.
"This triggers the liver to produce molecules called ketones that the brain then uses as an alternate source of energy when sugar isn’t readily available."
This can result in significant weight loss as well as lowered blood sugar.
"What seems to be unhealthy is eating fat with a lot of carbohydrates."
Health benefits of a keto diet
The keto diet was around long before its recent rise in popularity. Its original purpose was actually medical.
"A ketogenic diet has been known as a true medical metabolic therapy for decades," says Dr. Hu.
"It was developed as a treatment for children with epilepsy almost 100 years ago."
Children who were prescribed a keto diet saw significant reduction in epileptic seizures. Some patients even got rid of seizures altogether.
But as other medical treatments were developed for epilepsy, the keto diet became less prescribed.
Read: Q&A: Metabolism
Patients with type 2 diabetes have also reported benefits from being on a keto diet.
The diet can help the body maintain healthy glucose levels, which in turn helps patients manage their diabetes.
"Many diabetic patients can greatly reduce or even eliminate their need for insulin by going on a keto diet," says to Dr. Stephen Freedland, director of the Center for Integrated Research in Cancer and Lifestyle.
The biggest concern for many people is the high fat intake, which is contrary to a lot of nutritional advice.
"Patients are understandably concerned that a ketogenic diet would raise LDL (bad cholesterol) levels, but that’s often not the case," says Dr. Hu.
"What seems to be unhealthy is eating fat with a lot of carbohydrates."
In the Newsroom: Cedars-Sinai Investigators Develop More Accurate Measure of Body Fat
Researching keto further
With all the renewed interest in the keto diet, scientists and patients alike are eager to better understand its full potential.
Dr. Hu is currently looking at how keto could be used to help patients diagnosed with glioblastoma, an aggressive form of brain cancer.
Cancer cells are dependent on glucose as an energy source so researchers want to know if limiting the amount of glucose in the blood could stop or slow tumor growth.
His phase 1 clinical trial is working to determine the safety and feasibility of a keto diet for patients undergoing treatments such as chemotherapy. While in treatment, patients will adopt the keto diet for 4 months.
"A lot of what makes this study so exciting is the fact that we’re collecting so much data to better understand exactly what’s happening in these patients with a ketogenic diet," says Dr. Hu.
"We’re also looking at the tumor tissue itself to see if there are potential changes in the DNA of the tumor that may potentially correspond to benefit from the ketogenic diet or a lack of benefit from the diet."
The idea for the study came from patients who were looking for ways to improve their own quality of life. Patients started expressing interest in trying the keto diet, so with the help of a dietitian, patients began informally testing the diet.
"Many patients reported feeling better on a ketogenic diet, which is an uncommon thing to hear from patients dealing with the types of cancers that we treat," says Dr. Hu.
"From there, we decided we have to study this more formally, so that’s why we started this clinical trial."
