Our review update included data from four new randomised studies of the ketogenic diet. Although none were blinded, some were of good quality. These studies suggest that in children, the ketogenic diet results in short to medium term benefits in seizure control, the effects of which are comparable to modern antiepileptic drugs. However, one study of long term outcome reports a high attrition rate for the diet. This would suggest that many children find the diet difficult to tolerate. The main reasons for drop-outs in the included studies included gastrointestinal side effects and dislike for the diet.
We found just three studies on the use of the diet in adults and none of these were randomised. There has been less research involving other diets. We found one randomised study of reasonable quality of the Atkins diet. This study showed similar benefits in seizure control with a less restrictive diet.
For those with medically intractable epilepsy or those in whom surgery is unsuitable, a ketogenic diet could improve seizure control, but tolerability is poor. One observational study suggested that the Atkins diet may have a similar effect on seizure control, but this requires more investigation.
Modified Atkins diet to children and adolescents with medical intractable epilepsy.
The aim of the present study was to evaluate the tolerability and efficacy of the modified Atkins diet given to children and adolescents with antiepileptic drug (AED) treatment resistant epilepsy. 15 children with medically intractable epilepsy were enrolled in the study. Inclusion criteria were at least one seizure a week and a trial of at least two AEDs without obtaining seizure freedom documented in a seizure calendar. At baseline subjects initiated a diet with carbohydrates restricted to make up 10 energy percent. If seizures were reduced by less than 50% after 7-14 days carbohydrates were further restricted to 10g per day. No change in AED treatment was allowed. The diet was well tolerated. After 3 months six out of the fifteen children (40%) had a seizure reduction of more than 50%, which was seen in different epileptic syndromes and different age groups. The responders reported an increase in quality of life and cognition. At 12 months follow-up 3 (20%) continued the diet with an unchanged marked seizure reduction. The present study confirms the high tolerability and effect of the modified Atkins diet on seizure control in AED treatment resistant epilepsy. Further larger prospective studies are however needed to confirm these results.