The effect of nutritionally adequate ketogenic diets consistent in protein, fiber and micronutrient content on seizures in EL/Suz mice

The ketogenic diet (KD) is an effective mode of therapy for epilepsy, although the mechanism(s) of action remains unknown. In investigating mechanism(s) of action, controlling for dietary factors, such as protein, fiber, vitamins and minerals, is a critical component of experimental design, particularly as many nutrients modify metabolism and gene regulation. Furthermore, experimental nutrient and energy deficient diets are not readily applicable to humans. Nonetheless, a nutritionally adequate nutrient-controlled KD has not previously been developed and evaluated for utility in an experimental model. In this study, we tested the efficacy of novel ketogenic and calorie restricted diets while maintaining consistent protein, fiber and micronutrient levels across groups in a natural model of epilepsy. Female EL/Suz mice(n=20), 100-200 days old, were randomized into four groups to independently assess the effects of carbohydrate and fat modification as well as calorie restriction.Groups included control (C), calorie-restricted (CR), ketogenic (KD), and ketogenic calorie-restricted (KDCR) diets. Mice were on treatment for 4.5-5.5 weeks. Energy levels for the calorie-restricted groups were reduced to 75% of control levels. The ketogenic groups (KD and KDCR) experienced a trend toward seizure control over the non-ketogenic groups (C and CR) although the differences were not significant. Body weights decreased significantly in the CR and KDCR groups while plasma glucose levels did not differ among groups and plasma beta-hydroxybutyrate (BHB) levels increased in the KD and KDCR groups. Mouse body weight at week 4, as well as the change in body weight at week 4 from baseline, was significantly related to seizure control. Mice that had stable weight or weight loss were more likely to experience seizure control than mice that gained weight.The results from this study suggest that ketosis indicated by elevated BHB levels and energy restriction indicated by weight loss correspond to lower seizure susceptibility in an experimental model of naturally occurring epilepsy. Nutrient-controlled experimental diets can and should be used for investigating KD mechanisms in experimental models.