MINNEAPOLIS, Minn. — Modifying the popular ketogenic diet may have a surprising benefit for patients dealing with brain tumors. Researchers with the American Academy of Neurology say this dieting trend, which is high in fat and low in carbohydrates, may help to starve cancerous tumors of the fuel they need to grow.
The study finds a keto diet is both safe and practical for patients who have a certain type of brain tumor called astrocytomas. Scientists believe brain tumors use sugar coming from a patient’s diet to survive and grow. The keto diet however, changes what the body uses for fuel, which may be less appetizing for cancer cells.
“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,” says study author Roy E. Strowd, MD, MS, MEd, of Wake Forest School of Medicine in a media release.
“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 what are called ketones. Normal brain cells can survive on ketones, but the theory is that cancer cells cannot use ketones for energy.”
What’s so different about the keto diet?
Researchers recruited 25 patients with astrocytomas who had all completed radiation treatment and chemotherapy. Each participant followed a modified ketogenic diet which included intermittent fasting two days a week.
The group followed the normal ketogenic menu for the other five days of the week for eight weeks. This includes eating foods like bacon, eggs, heavy cream, butter, leafy green vegetables, and oily fish. On fasting days, the brain cancer patients only ate up to 20 percent of their normally recommended calorie limit.
Study authors say their goal was to see if the patients could tolerate such a diet without suffering any side-effects. Results show 21 of the 25 patients finished the eight-week trial, with about half following the diet plan completely.
Despite not everyone sticking to the keto diet strictly, study authors find 80 percent of participants still reached a level where their bodies were using fats and protein as fuel instead of sugar and carbohydrates. Moreover, only two people experienced serious side-effects, with one of them dealing with issues not related to the diet.
By the end of eight weeks, researchers discovered both metabolism and brain changes among the cancer patients. The team found hemoglobin A1c levels, insulin levels, and fat body mass all decreased. Meanwhile, lean body mass increased. Additionally, brain scans revealed an increase in the concentration of ketones and metabolic changes in brain tumors.
“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 concludes.
The study appears in the journal Neurology.