Effect of modified Atkins diet in adults with drug-resistant focal epilepsy: A randomized clinical trial.

Objective: Ketogenic diets reduce seizures in children with drug-resistant epilepsy. Whether adults benefit from similar treatment has not been clarified. We therefore examined the efficacy of the modified Atkins diet in adults with drug-resistant focal epilepsy.

Methods: We performed a randomized clinical trial (RCT) with patients >16 years who had at least 3 seizures per month despite having tried at least 3 antiepileptic drugs. They were randomized to either 12 weeks on the modified Atkins diet (diet group) or habitual diet (control group). Primary endpoint was a change in seizure frequency from baseline to the intervention period, comparing those on diet with controls.

Results: We assigned 37 patients to the diet group and 38 to the control group. Nine of the patients in the diet group and 4 controls were excluded. Of those who completed the dietary intervention (n = 24), median seizure change was -1.0 (interquartile range [IQR] -13.7-8.8), while in the control group (n = 32) the median change was 4.5 (IQR -4.8-33.5). The median difference between the groups was -7.0 (95% confidence interval [CI] -37.0-3.0; P = .21). In the intention-to-treat analysis, the relative risk (RR) for achieving >50% seizure reduction was 1.8 (95% CI 0.3-10.2; P = .65), while for achieving >25% seizure reduction RR was 2.43 (95% CI 0.94-6.28; P = .06). We observed no serious adverse events.

Significance: In this RCT investigating the effect of an adjunctive modified Atkins diet on seizure frequency in adults with difficult-to-treat focal epilepsy, we found a significant reduction in seizure frequency in the diet group compared to the controls, but only for moderate benefit (>25% seizure reduction) among those who completed the intervention. However, seizure response varied considerably between individuals, perhaps negatively influenced by a drop in serum concentrations of antiepileptic drugs.