Epilepsy is a disorder that causes recurring seizures. Before epilepsy drugs came on the market, it was common to treat epileptics through dietary changes. Many epileptics became seizure-free on a ketogenic diet. The modified Atkins diet is a modern version of the standard ketogenic diet used by epileptics. The modified Atkins diet resembles the ketogenic diet in that it limits carbohydrates and results in a ketogenic state, but allows higher protein and calorie consumption.
Seizures
Glutamate and γ-Aminobutyric acid, or GABA, are two important neurotransmitters in the brain. Glutamate helps store memories for the long term and it is also the brain's main excitatory neurotransmitter. GABA is the brain's main depressive neurotransmitter. In a neurotypical brain these two neurotransmitters together prevent over-excitation and neuronal depression. When an imbalance occurs and localized neurons become over-excited, a seizure occurs. In a grand mal seizure, the excitation spreads to the whole brain, which results in convulsions and loss of consciousness, according to Mayo Clinic.
The Ketogenic Diet
As early as in the 1920s, researchers discovered that a diet high in fats and low in protein and carbohydrates could reduce or prevent seizures. At the beginning phases of a starvation, the body turns carbohydrates into glucose, which can be used as fuel, stored as glycogen in the liver and muscle tissue, or be converted into fat tissue. When carbohydrates are restricted, the body is forced to burn up stored glycogen and then fat. Muscle tissue is important for survival, so when no glucose is available, the main source of energy is fat tissue. Fats cannot cross the blood-brain barrier. But ketone bodies, a byproduct of fat breakdown, can enter the brain and serve as brain fuel.
Mechanism of Action
No one knows exactly how ketosis, the metabolism of ketone bodies, prevents or reduces seizures. Neuroscientists Kristopher J. Bough and Jong M. RhoOne, reporting in the January 2007 issue of "Epilepsy," suggest that ketone bodies are more efficient as an energy source than glucose. It is possible that this heightened efficiency requires more cell mitochondria to regulate cellular metabolism. Mitochondria are structures within the cell that act like a digestive system that breaks down glucose or ketone bodies to create energy. An increase of mitochondria in the neurons can make neurons more stable. As a result, neurons may develop resistance to excitability that they would not otherwise have, making seizures less likely to occur and to spread through the brain.
The Modified Atkins Diet
The modified Atkins diet is a variation on the Atkins weight loss diet. The original Atkins diet reduces both calories and carbohydrates. The modified diet is not intended as a means to lose weight, so it only reduces carbohydrates. Epilepsy.com notes that the modified Atkins diet allows more protein and calories than the ketogenic diet. It has proven quite effective as a treatment for epilepsy. Consensus is that, despite the differences between the ketogenic diet and the modified Atkins diet, the mechanism of action is the same.
References
- Mayo Clinic: Epilepsy
- Epilepsy: Ketogenic Diet
- Glutamate and GABA systems as targets for novel antidepressant and mood-stabilizing treatments
- "Epilepsia"; Anticonvulsant Mechanisms of the Ketogenic Diet; Kristopher J. Bough and Jong M. Rho; January 2007
- Epilepsy: Modified Atkins Diet
- "Journal of Neuroscience"; Mitochondrial Ca2 Uptake Regulates the Excitability of Myenteric Neurons; P.V. Berghe, et al.; August 2002
