Epilepsy and a Ketogenic Diet: Facts and Research
Epilepsy and Diet
Epilepsy is a disorder involving periods of abnormal electrical activity in the brain. The neurons in the brain transmit an electrical signal in order to perform their job. They're often said to "fire" as they do this. During a seizure, the neurons in a particular area fire at the same time, resulting in an intense burst of electrical activity. The disturbance causes a person to experience unusual sensory, motor (movement), or mental events.
Epilepsy can sometimes seriously interfere with life. Drugs, surgical techniques, and special diets are used to control the disorder. The ketogenic diet is very helpful for some people. The diet is high in fat and low in carbohydrates. It's described as potentially beneficial for patients by both medical organizations and epilepsy associations. Recent research supports the idea that the diet can be beneficial.
What Is Epilepsy?
Please note that this article is intended for general interest only. Anyone who has questions about epilepsy treatment or who wants to follow a non-traditional diet in an attempt to help a medical condition should seek a doctor's advice.
Treatment With Medication or Vagus Nerve Stimulation
Epilepsy can be a relatively minor condition involving seizures that are successfully controlled with medication. My father had the condition. Once he was diagnosed, his medication worked well. There are many drugs available for a patient to try. If one drug doesn't work, another may.
Some patients have a severe form of epilepsy that involves frequent seizures and doesn't respond to medication. Surgery may be used as a treatment for these patients. One type of epilepsy surgery is known as vagus nerve stimulation, or VNS.
The vagus nerve travels from the brain to the abdomen. Branches extend from the nerve to various parts of the body. In VNS, a small device resembling a pacemaker is placed under the skin in the upper part of the chest. A wire extends from the device to the vagus nerve in the neck. The device sends regular electrical pulses through the wire and nerve to the brain, which interferes with the creation of a seizure. The patient can use a magnet to trigger a burst of pulses when they sense that a seizure is approaching.
VNS helps some patients, but it isn't effective for everyone who tries it. Scientists don't know how the process prevents seizures. It may disrupt the abnormal electrical signals in the brain in some way. Another theory is that it stimulates the creation of chemicals that interfere with the signals.
Nerves consist of neurons, or nerve cells. The signal that's transmitted along a neuron is sometimes known as a nerve impulse.
Treatment With a Corpus Callostomy
The cerebrum is the largest part of the brain. It has a convoluted surface and consists of the right and left cerebral hemisphere. The hemispheres are separated by a groove known as the longitudinal fissure. The separation isn't complete, however. The corpus callosum is a band of nerve fibres that connects the two cerebral hemispheres. It passes messages from one side of the cerebrum to the other. A much smaller band of nerve fibres called the anterior commissure also connects one hemisphere to the other.
One type of surgery used to control severe epilepsy is known as a corpus callostomy. The corpus callosum is partially or completely cut during the surgery. This prevents electrical disturbances from travelling from one side of the cerebrum to the other. As a result, the severity of the patient's seizures is reduced. The seizures aren't eliminated, however, because an electrical disturbance can be generated in a single hemisphere.
Although separating the two hemispheres of the brain shouldn't be taken lightly, it may have fewer consequences than some people imagine. It's sometimes hard to tell that a major connection between the hemispheres has been severed unless special tests are performed. In other cases, it may be more obvious that certain brain functions have been lost.
The corpus callosum is coloured green in the illustration above. The anterior commissure is represented by the white oval structure just underneath the corpus callosum.
The Ketogenic Diet for Epilepsy
Ever since the 1920s, the ketogenic diet has been recognized as a helpful treatment for some people with epilepsy. The idea is mainstream today. The diet is also used to help people with diabetes. It's high in fat, low in carbohydrates, and adequate in protein. It's described in terms of the ratio of fat to carbohydrate plus protein. A 3:1 diet contains three grams of fat for every one gram of carbohydrate plus protein, for example. A 4:1 diet contains four grams of fat for every gram of carbohydrate plus protein.
Although slightly different forms of the diet exists, it generally includes:
- hard cheese and plain yogurt
- most vegetables
- a few legumes or products made from them (including tofu)
- berries and a few other fruits
- large amounts of animal fat and plant oil
All grains, the starchiest vegetables and legumes, and the sweetest fruits are prohibited.
Anyone following a ketogenic diet in an effort to relieve epilepsy must be under a doctor’s supervision. There are several reasons for this, as described below:
- The diet is challenging to follow correctly. A large amount of fat must be eaten on a regular basis in order to prevent seizures.
- Food must be weighed before it's consumed. Training and practice may be needed in order to do this correctly.
- The diet lacks certain nutrients, as least in the version used to treat epilepsy. The missing nutrients must be provided by supplementation.
- Doctors must discover the proportion of fat to other nutrients that is most beneficial for the patient.
- The introduction and initial effects of the diet must be monitored. The diet is generally started while the patient is in hospital.
Patients may experience side effects from the ketogenic diet, especially if they follow it for a long time. These effects may include constipation, acidosis (excessively acidic body fluids), kidney stones, and an increased risk of bone fractures. Some of the side effects may require medical treatment.
Another potential problem with the diet is it often contains a high level of saturated fats. Many health experts and agencies consider these to be unhealthy when eaten in excess. This fact is probably unimportant for someone who has been experiencing many seizures a day and finds that the diet reduces their frequency, though. In addition, since researchers don't completely understand why the diet can be helpful, it's possible that the saturated fats—or specific fatty acids found in the fats—are responsible for the benefit.
Dietary Therapy for Epilepsy
Ketone Bodies and Ketosis
The body's preferred source of energy is carbohydrate molecules. When these are unavailable during fasting or in a diet low in carbohydrate, the body obtains energy by breaking down fatty acids. These are obtained from the fat molecules stored in the body or from the food that's eaten. Ketone bodies are produced during the process. These molecules include beta-hydroxybutyrate, acetoacetate, and acetone. The production of ketone bodies is known as ketosis.
Fasting helps to improve epilepsy in some people, as even people in Ancient Greece noticed. It's obviously not practical to fast for a long time, since we need food to survive. Since both fasting and the ketogenic diet increase the level of ketone bodies in the blood, scientists have assumed that both methods help epilepsy by the same method. This may not be the case, however. Research in mice suggests that fasting and the ketogenic diet work by different mechanisms.
Researchers don't know whether the ketone bodies produced in the ketogenic diet, the low carbohydrate intake, or another factor is responsible for the benefit observed in epilepsy. The ketone bodies alter the way in which the brain obtains energy, but this isn't necessarily the reason for the diet's benefit. It's wonderful that the eating plan is helpful for some people, but it would even better to help more people and to help patients to a larger extent. Hopefully researchers will soon discover how the diet works as well as how to improve its effectiveness.
A Ketogenic Diet Plus Fasting
In 2012, researchers at the John Hopkins Children's Center discovered that children who were benefitting from a ketogenic diet experienced even fewer seizures when they fasted every other day for a short period of time. Four of the six children involved in the study experienced between fifty and ninety-nine percent fewer seizures after fasting was added to their regimen. Further research is necessary, however, due to the small number of children in the study. It's vital that a doctor is consulted before any form of fasting is started in a person with epilepsy.
Effects of Diet on Seizures: Some Recent Research
Research confirms observations about the benefits of the ketogenic diet for epilepsy. Two recent projects support the idea. The first was led by a doctor at Dell Children's Medical Center of Central Texas. It involved 210 children whose epilepsy was resistant to drug treatment. The children were divided into groups as follows:
- 150 children were treated with vagus nerve stimulation.
- 44 had corpus callostomy surgery.
- 98 followed a ketogenic diet.
A "successful" treatment was defined as one that caused a 50% or greater reduction in seizures. The percentages of children who experienced success after receiving a specific treatment were as follows:
- 52% of the children given VNS
- 54% of those who underwent a corpus callostomy
- 63% of those who followed the ketogenic diet
Although it would be nice if the percentages were higher, the results of the study are significant and impressive.
Another Research Project
The second study was performed by a researcher at McMaster University in Canada. Like the first one, it was described at a meeting of the American Epilepsy Society in December, 2017. The results of the study haven't yet been published in a scientific journal.
The study involved forty children and teens up to the age of seventeen. The goal of the research was to discover whether a ketogenic diet that was more lenient than usual could still be helpful for patients.
The initial diet contained a lower percentage of fat than the traditional ketogenic one and was started when the subjects were outpatients at a hospital. If seizures weren't controlled, the ratio of fat in the diet was increased at two to three week intervals. Unfortunately, more specific details about the different fat ratios and the timing of their introduction aren't yet available to the general public.
As a result of the study, the researcher found that "about half" of the children had a greater than fifty percent reduction in seizures even while following a lower fat content than usual. In seven children, seizures completely stopped.
Variations of the Ketogenic Diet
Research exploring the link between the ketogenic diet and epilepsy is usually performed in children. Adults with epilepsy may also benefit from a high fat diet. In the case of adults, the diet that's explored is generally the modified Atkins diet. The Atkins diet is a low-carbohydrate eating plan created by a cardiologist. The modified diet is high in fat as well as low in carbohydrate. It's easier to follow than the ketogenic diet and doesn't require a hospital stay at the start.
As the quote below shows, the modified Atkins diet has about a fifty percent success rate in adults, with "success" meaning a significantly lowered rate of seizures. John Hopkins Medicine has also explored the use of the ketogenic diet in adults with a severe form of drug-resistant epilepsy. The researchers say that about a third of the patients benefitted from the diet.
The MCT oil diet (or MCT diet) is another variation of the ketogenic diet that has been used to help people with epilepsy. MCT stands for medium-chain triglycerides. Coconut oil is a good source of these chemicals and is the main fat in the diet. According to the University of Toronto's Hospital for Sick Kids, the diet has about the same percentage of success as a classic ketogenic diet.
Recent studies have shown that the modified Atkins diet lowers seizure rates in nearly half of adults that try it, usually within a few months.— John Hopkins Medicine
Food and Epilepsy
It's certainly seems worthwhile for people without adequate control of their epilepsy symptoms to try dietary therapy (with a doctor's recommendation and guidance). There is some concern about health problems that may result from the intake of foods high in fat over a long period. Researchers are also investigating whether a high-fat diet must be a permanent or long-term eating plan or whether it can be eventually dropped. Hopefully these questions will be answered in the future. In the present, though, the ketogenic diet or a similar eating plan may be very helpful for some people with epilepsy.
- Epilepsy facts from the Mayo Clinic
- Facts about vagus nerve stimulation from the AANS (American Association of Neurological Surgeons)
- Corpus callostomy information from WebMD
- Information about the ketogenic diet for epilepsy from WebMD
- Diet may help epilepsy in children when medications fail from the Medical Xpress news site
- Ketogenic diet information from the Epilepsy Foundation (This website also has information about the modified Atkins diet.)
- Information about the MCT diet for epilepsy from The Hospital for Sick Children (This hospital is affiliated with the University of Toronto Faculty of Medicine.)
- Adult epilepsy and facts about the modified Atkins diet from John Hopkins Medicine
- Johns Hopkins Medicine. "Fasting may benefit patients with epilepsy." ScienceDaily. www.sciencedaily.com/releases/2012/12/121206203122.htm (accessed December 12, 2017).
Questions & Answers
© 2017 Linda Crampton