Plasma phospholipid fatty acids are influenced by a ketogenic diet enriched with n-3 fatty acids in children with epilepsy.

The ketogenic diet (KD) is used to treat medically refractory epilepsy in children. Alterations of fatty acid (FA) levels may reflect one mechanism of action. We examined the influence of the KD on FA levels and seizure control. The levels of 17 FAs in plasma phospholipids were determined before and 1, 3, 6, and 12 months after initiation of the KD in 25 children (mean age 6.3 years) with intractable epilepsy. Fluid omega-3 FA was supplemented in the diet after one month. Highly significant changes of the levels of several FAs were found. Linoleic acid (LA) and eicosapentaenoic acid (EPA) increased, whereas arachidonic acid (AA) and Mead acid (20:3 n-9) decreased. Docosahexaenoic acid (DHA) increased insignificantly. However, no correlation of changes in FA levels with seizure response was found. The ratio of omega-6 to omega-3 gradually decreased from 7.0 before to 4.9 at 12 months after starting the diet, presumably a cardiovascular benefit. The composition of the KD differs as to FA content and type between different treating centers but, still, the efficacy reports are very similar. This study demonstrates the possibility of composing the KD in such a way that the FA profile is kept within a normal range, which may reduce cardiovascular risks.