Absence of increased blood decanoic acid levels in children with epilepsy treated with classic ketogenic diet.

Recently, decanoic acid (C10), a medium-chain fatty acid, was shown to be a direct inhibitor of the AMPA receptor. Accordingly, C10 has been suggested as a potential anticonvulsant factor in the ketogenic diet (KD) or the medium-chain triglyceride KD. Here, we tested whether C10 serum levels correlate with the response to KD in five children (1.5 ± 0.6 years of age) with epilepsy. The serum levels of C10 were measured before and after KD initiation (n=2 at one month, n=3 at three months, and n=1 at six months after initiation) by gas chromatography-mass spectrometry. After three months on KD, two patients were found to be responders. The mean serum level before KD initiation was 63.2 μM. Only one patient, who was a non-responder, showed an increase (5%) in C10 serum level after a month of KD. The remaining four patients (two responders) showed a decrease in the C10 level from -5.3% to -75.5%. Our preliminary data show that KD does not lead to an increase in C10 serum levels, suggesting that increased concentration of C10 might not be directly involved in the anticonvulsant effects of classic KD.