The ketogenic and the modified Atkins diets, high in fat and low in carbohydrates, could reduce these seizures, suggesting that clinicians bring them into the treatment discussion.
Diets high in fat and low in carbohydrates, such as the ketogenic or modified Atkins diet, may reduce seizures in adults who have refractory epilepsy, according to a research review.
Although a large number of new epilepsy medications have been approved in the past 20 years, “we are still left with about one-third of patients who fail to respond,” said lead author Pavel Klein, MB BChir, of the Mid-Atlantic Epilepsy and Sleep Center in Bethesda, MD. “New medications have helped the side effects profile, but not those epilepsy patients who are refractory from becoming seizure-free.”
The ketogenic diet is often used in epileptic children, Dr Klein noted, and in the past 5 years there has been increasing interest in using the diet in adult patients with refractory epilepsy. Both the ketogenic diet and the modified Atkins diet include bacon, eggs, heavy cream, butter, leafy green vegetables, and fish. The ketogenic diet consists of about 90% fat, with a ratio of fat to protein/carbohydrates of 3 or 4 to 1 by weight. The modified Atkins diet has about 40% to 50% calories from fat and a 1-to-1 fat-to-carbohydrate/protein ratio by weight.
The researchers reviewed all the published studies of the 2 diets among adult patients with refractory epilepsy. They found 5 open-label studies that included a total of 47 patients and 5 studies on the modified Atkins diet that included 85 patients.
“Across all studies, about 30% of those treated with the ketogenic diet and the modified Atkins diet experienced a 50% or better reduction in their seizures,” said Dr Klein. In addition, 9% in the ketogenic treatment group and 5% in the modified Atkins group had a greater than 90% reduction in seizures.
The positive results occurred quickly with both diets, within days to weeks. The effect persisted long-term, but-unlike in children-the results did not continue after patients stopped following the diet.
Adverse effects of both diets were similar and not serious. Weight loss was the most common one.
“Both diets are well-tolerated, with some alterations in metabolism of calcium and magnesium and a risk of kidney stones,” Dr Klein said. “The most significant risk is hyperlipidemia in 20% to 30% of patients, which is transient and reverses upon stopping the diets.”
About half of the patients who used the ketogenic diet and 42% of those who used the modified Atkins diet stopped the diet before the study was completed.
“Unfortunately, long-term use of these diets is low because they are so limited and complicated,” said Dr Klein. “Most people eventually stop the diet because of the culinary and social restrictions. However, these studies show the diets are moderately to very effective as another option for people with epilepsy.”
Dr Klein suggested that clinicians bring diets into the treatment discussion with patients who have refractory epilepsy. However, given the challenges of the diets, he said, “If an epilepsy patient has a medication that works, it’s better than any diet.”
The researchers published their results online in the October 29, 2014 issue of Neurology.