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.
Efficacy and safety of the ketogenic diet for intractable childhood epilepsy: Korean multicentric experience.
We wished to evaluate the efficacy and safety of the ketogenic diet (KD), and we also evaluated the prognosis of the patients after successful discontinuation of the diet in infants, children, and adolescents with refractory epilepsy.
                This was a retrospective study of epilepsy patients treated with the KD during 1995 through 2003 at the Korean multicenters. Outcome measures included seizure frequency, electroencephalography (EEG), adverse reactions, and antiepileptic drug (AED) number. The variables related to the efficacy and prognosis also were analyzed.
                The outcomes of the 199 patients enrolled in this study at 6 and 12 months after the diet were revealed; 68% and 46% of patients remained on the diet, 58% and 41% showed a reduction of seizure frequency of >50%, including 33% and 25% who became seizure free, respectively. Finally, 66 (34%) of 199 patients successfully completed or maintained the diet. EEGs showed an improvement in background in 40 (72.7%) of 55 patients and a reduction in generalized and focal discharges in 41 (57.7%) of 71 and 15 (33.3%) of 45 patients. Most complications were mild, but five patients died during the KD. No significant variables were related to the efficacy, but those with symptomatic (p=0.047) and partial epilepsies (p=0.073) showed more frequent relapse after completion of the diet.
                The KD is a safe and effective alternative therapy for intractable childhood epilepsy in Korea, although the customary diet contains substantially less fat than traditional Western diets, but life-threatening complications should be monitored closely during follow-up.