The ketogenic diet and treatment of epilepsy in children

Nowadays, epilepsy is one of the most common neurological diseases. According to the European Union’s Written declaration on epilepsy, 6 million people suffer from epilepsy, from which 40.000 live in Croatia.

There are various causes and symptoms of epilepsy. The disease is characterized by epileptic seizures, which vary in length and form. Epilepsy is a chronic disorder of the brain cortex cells that develop excessive excitability, leading to the repetitive firing of electric impulses and resulting in epileptic seizures.

Treatment of epilepsy includes medications, installing neurostimulating electrodes, or neurosurgical procedures. Medications sometimes cannot control the disease and this is when a ketogenic diet may be indicated.

Use of the ketogenic diet for the epilepsy treatment was first reported in the 1920-ies. It was encouraged by the study from 1911., suggesting that fasting reduced epileptic seizures.

The ketogenic diet is based on the foods rich in proteins and fats, and poor in carbohydrates. Due to the low intake of carbohydrates during the ketogenic diet, substances called ketones are used as an alternative source of energy. They use the energy stored in fats (lipids) and create the state of ketosis in our body. In short, instead of using carbohydrates as the primary source of energy, our body switches to the use of lipids. This leads to the rapid loss of body weight achieved mainly by reducing stores of fat tissue, since the intake of proteins is relatively high in ketogenic diet.

Ketones also seem to prevent epileptic seizures, although the exact mechanism is still unknown. A number of studies have confirmed the successful treatment of epilepsy using the ketogenic diet. However, it should be executed following the menus developed by experts and supervised by medical doctors.

There are various types of ketogenic diets and they can be divided into 2 main categories: the classical ketogenic diet and the one with the medium-chain triglycerides.

The classical ketogenic diet uses 3:1 or 4:1 ratio of fats to proteins and carbohydrates combined. The main source of lipids comes from the long-chained triglycerides, intake of proteins is reduced to the amounts necessary for the normal body functioning/development, while the carbohydrate intake is very limited. Contraindications for this diet include hyperlipidemia (high amount of lipids in blood), kidney stones, and organic acids deficiency syndrome. Complications include hunger, vomiting, diarrhea, abdominal pain, and malaise, but they are usually resolved with modifications in implementation of the ketogenic diet. This type of diet has provided good results in children suffering from epilepsy, especially in those having the mutation of SLC2A1 gene.

Medium-chain triglycerides (MCT) ketogenic diet uses the medium-chain instead of the long-chain triglycerides. Since MCTs provide more ketones per kilocalorie, it allows for the higher intake of proteins and carbohydrates. MCTs represent 30-60% of the total energy intake, depending on whether it is the traditional or modified MCT diet. Compared to the classical ketogenic diet, the MCT diet has produced similar results in epilepsy treatment, but allows for the increased intake of carbohydrates and proteins, and for the supplements of vitamins and minerals.

The modified ketogenic diet is a lighter version of the ketogenic diet. The intake of carbohydrates is limited to 10 grams per day, while the protein intake is unlimited. Complications include constipation, and in rare cases anorexia, lethargy and vomiting. It is recommended for the elderly.

Another dietary treatment approach to epilepsy is Low Glycemic Index Treatment (LGIT). The intake of carbohydrates in LGIT is limited to 40-60 grams daily (or to 10% of total daily energy requirements), while the intake of fats and proteins fulfills the remaining portion of energy needs. Fats participate with 50-60% and proteins with 20% of daily energy needs. Complications include mild fatigue, lethargy and diarrhea. This type of diet proved efficacy in children, but randomized clinical studies have not yet been reported.

Several studies have compared results of the classical versus medium-chain ketogenic diet in the treatment of epilepsy, but all the studies had some limits. A larger study published in 1989. compared clinical and metabolic parameters after implementation of the classical or the MCT ketogenic diets. The MCT diets involved both 30% and 60% of the fat-based daily energy intakes. Results showed no significant differences between those three types of ketogenic diet interventions in children under 15 years of age. But this study has also not been randomly controlled.

In 2009., the first randomized clinical trial comparing the effects of the classical versus MCT ketogenic diet in treatment of epilepsy was published by the group of scientists from London. The children included in the treatment groups where 2-16 years of age, with the minimum of 7 epileptic seizures per week, previous negative response to at least 2 anticonvulsive medications, and should not be on the ketogenic diet prior to inclusion, also without history of hyperlipidemia, kidney stones, or organic acids deficiency syndrome. 145 children met the inclusion criteria and were divided into one of the age groups: 2-6, 7-11, or 12-16 years. They were further randomized either to the group following the classical ketogenic diet, or to the group on MCT diet. Study results revealed no significant differences between the groups in the treatment of epileptic seizures, but both groups showed encouraging treatment results in case of unresponsiveness to medication treatment.