Ketogenic diet: electrophysiological effects on the normal human cortex.
Roberto Cantello1, Claudia Varrasi1, Roberto Tarletti1
1Department of Clinical and Experimental Medicine, Section of NeurologySection of Clinical Chemistry, "A. Avogadro" University, Novara, ItalyDepartment of Diet and Nutrition, "Maggiore della Carità" Hospital, Novara, ItalyDepartment of Child Neurology and Psychiatry, IRCCS Fondazione, Istituto Neurologico Casimiro Mondino, University of Pavia, Italy.
Epilepsia
|June 15, 2007
Summary
The ketogenic diet (KD) alters brain activity in healthy individuals, increasing cortical inhibition and beta EEG waves. These neurophysiological changes suggest reduced neural excitation and resolve after diet cessation.
Area of Science:
- Neuroscience
- Human Physiology
Background:
- The ketogenic diet (KD) is recognized for its efficacy in managing refractory epilepsy.
- The precise neurophysiological mechanisms underlying the KD's effects remain incompletely understood.
- Enhanced GABAergic inhibition is a proposed mechanism for KD's anticonvulsant properties.
Purpose of the Study:
- To investigate the impact of a standard ketogenic diet on cortical electrophysiology in healthy humans.
- To explore potential alterations in neural inhibition and excitation patterns.
- To elucidate the electrophysiological correlates of KD in a non-epileptic population.
Main Methods:
- Eight healthy volunteers participated in a 2-week classic ketogenic diet protocol.
- Biochemical markers, including 24-hour ketonuria, were assessed at baseline, 1 week, 2 weeks, and 3 months post-diet.
- Motor cortical excitability was evaluated using transcranial magnetic stimulation (TMS), and EEG signals were analyzed for frequency shifts over rolandic areas.
Main Results:
- Significant neurophysiological changes were observed after 2 weeks of KD (T2).
- A notable increase in short-latency cortical inhibition (SICI), indicative of enhanced GABA-A mediated inhibition, was detected.
- An augmentation of the perirolandic beta EEG band, similar to effects of GABA-A agonists, was also observed.
- These KD-induced changes were reversible, disappearing by the 3-month follow-up (T3).
Conclusions:
- Short-term adherence to a standard ketogenic diet demonstrably alters cortical electrophysiology in healthy individuals.
- The observed increases in SICI and perirolandic beta EEG activity suggest a reduction in cortical neural excitation.
- These findings provide electrophysiological evidence supporting the KD's modulatory effects on cortical excitability.
