Diets serve more than just one purpose besides weight loss. What we eat, how much we consume, and even the timing of our meals all have an impact on how well our brains function. Diet can play a role in reducing the frequency of seizures in people who have epilepsy. Mackenzie Cervenka, a neurologist at Johns Hopkins Hospital and the director of the Adult Epilepsy Diet Center, describes what people with epilepsy are and how the ketogenic diet can be beneficial to those with the condition.
What is a keto diet?
A diet that is very rich in fat and very low in carbohydrates is called a ketogenic diet. This type of diet is intended to stimulate fat metabolism. When all of the body's glucose reserves are used up, it switches to the metabolism of fat and fatty acids, which results in the production of substances known as ketones. Ketones can penetrate the blood-brain barrier and make their way into the brain, where they are put to use as an alternate fuel.
A ratio of four grams of fat to one gram of carbs and one gram of protein is characteristic of the traditional ketogenic diet, which dates back to the 1920s. This means that fat accounts for around 90 percent of the total calories. Our patients are often instructed to follow a modified version of the Atkins diet, which restricts the number of net carbohydrates they can consume to 20 grams per day but places no limits on the amount of protein or fat they can consume. In most cases, fat makes up 60 and 70 percent of their calorie consumption on a daily basis.
Why do doctors do it?
This diet reduces the number of seizures in clinical trials involving people with treatment-resistant epilepsy by an average of fifty percent or more in fifty percent of patients. This means that the individuals have tried a number of antiepileptic medications but continued to experience seizures despite these treatments. It is estimated that only a tiny percentage of patients will go on to become seizure-free after following a ketogenic diet; some studies claim that the percentage is as low as 0% of patients, while others estimate that it is closer to 20% of patients.
How does it reduce seizures?
Networks of neurons in the brain spontaneously activate when they are not meant to, which is what causes seizures. This is a possibility because the cells in the brain are more excitable and release a lot of excitatory neurotransmitters, such as glutamate. Alternately, it is possible that nearby brain cells are unable to limit the spread of excitability as they typically would by making use of inhibitory neurotransmitters such as gamma-aminobutyric acid or GABA.
By lowering the amount of glutamate in the brain and increasing the production of GABA, the ketogenic diet makes it less likely that an individual would experience an epileptic seizure. Additionally, the diet can lower inflammation in the brain, which is important because inflammation in the brain caused by illnesses such as meningitis, encephalitis, or autoimmune disorders can cause seizures.
In the recent past, there have also been a few highly intriguing studies that investigated how the ketogenic diet can affect the gut microbiome. The gut microbiome is comprised of trillions of bacteria that are found in the digestive tract. According to the findings of these studies, following a ketogenic diet can lead to an increase in the population of particular species of bacteria that encourage a higher ratio of GABA to glutamate in the brain.