Randomized Trial Confirms Efficacy of Ketogenic Diet in Preventing Epileptic Seizures in Children

A randomized controlled trial has confirmed the efficacy of the ketogenic diet in helping control and prevent epileptic seizures in children with drug-resistant epilepsy. These are the conclusions of authors of an article published early online and in the June edition of The Lancet Neurology.

The ketogenic diet has been used widely and successfully to treat children with drug-resistant epilepsy since the 1920s. It is a diet very high in fat, low in carbohydrate, and with controlled protein. Although the exact mechanism of action is still unclear, the high fat and restricted carbohydrate content of the diet is thought to mimic the biochemical response to starvation, when ketone bodies*, rather than sugars, become the main fuel for the brain’s energy demands. While there have been many observational studies of this diet, Professor J. Helen Cross of the Institute of Child Health and Great Ormond Street Hospital for Children NHS Trust at the University College in London and colleagues have done the first randomized controlled trial to test its efficacy.

The trial assessed 145 children aged between 2 and 16 years who had at least daily seizures (or more than seven seizures per week), had failed to respond to at least to antiepileptic drugs, and had not been treated previously with the ketogenic diet. Seventy three children were put on the diet immediately while 72 were assigned to the diet after a delay of three months. The delay group acted as the control group during the three-month delay. Using the baseline figures as 100 percent, they found that the number of seizures in the diet group dropped by more than a third (62 percent of seizures recorded compared with baseline), while the control group saw their seizures rise by more than a third. Twenty-eight of the 54 children who completed the three months in the diet group had greater than 50 percent seizure reduction compared with just four of 49 children in the control group. Five children in the diet group saw a seizure reduction of above 90 percent, compared to none in the control group. The most frequent side-effects reported at three months were constipation, vomiting, lack of energy and hunger.

The authors said, “We have shown that the diet has efficacy and should be included in the management of children who have drug-resistant epilepsy. However, the diet is not without possible side-effects, which should be considered alongside the risk benefit of other treatments when planning the management of such children.” They added, “We stress this is a diet which should only be undertaken on medical advice and under medical and dietetic supervision.”

Dr. Max Wiznitzer of Rainbow Babies and Children’s Hospital in Cleveland said more information is needed about the long-term effects of the ketogenic diet, including changes in blood fat concentrations and persistent ketosis. He added, “Better identification of epilepsies that benefit from starting early on the ketogenic diet and comparisons between the choices of ketogenic diet are needed.”

*Ketone bodies are water soluable compounds that are produced as by-products when fatty acids are broken down for energy in the liver and kidneys. They are used as a source of energy in the heart and brain. In the brain, they are a vital source of energy during fasting.

Source: Adapted from a press release from The Lancet Neurology.