Ketogenic diets for drug-resistant epilepsy
Do you have any clients with epilepsy who continue to have seizures in spite of taking anti-epileptic medication? Have you asked the neurologist about trialling them on a ketogenic diet?
What is a ketogenic diet?
Ketogenic diets contain very high amounts of fat, adequate amounts of protein, and extremely low amounts of carbohydrates. This means these diets greatly restrict a person’s intake of foods such as bread, potatoes, pasta, rice, biscuits, milk, fruit, some vegetables and sugar. There are a few different options for ketogenic diets – the classical ketogenic diet (where the amount of fat is in a strict ratio to the amount of protein + carbohydrate such as 4:1), medium-chain triglyceride ketogenic diet, low glycaemic index treatment and modified-Atkins diet. Each one varies in how strict they are when it comes to carbohydrate intake. In general, ketogenic diets are meant to mimic the metabolic processes which occur during starvation or fasting. When the body doesn’t have enough glucose available for fuel, it will compensate by breaking down fat instead. The breakdown of fat results in chemicals called ketone bodies which the body and brain then use as an alternate source of energy.
In spite of all of the research done on these diets, we actually don’t know the exact mechanism for how these diets reduce seizures.1 However, we do know that they can be effective in some individuals.
What is the evidence?
The NICE guidelines CG137 on Epilepsies: diagnosis and management (point 1.12) recommend that children and young people who have not responded to anti-epileptic drugs consider the ketogenic diet as a treatment option. The most recent Cochrane review on Ketogenic Diets in Drug-resistant Epilepsy (2018) considers ketogenic diets a valid option. Research into this area is still quite limited though, and the Cochrane review only included 11 studies (10 of which were on children).
The number of people who become completely seizure free as a result of the diet after three months ranges from 16%-55% depending on which diet is used (the strict 4:1 diet tends to get the best results).1, 2 Up to eighty-five percent of children tend to see reductions in their seizure activity while 35-53% of adults see a reduction.1,3 Two studies also found improvements in alertness, concentration and global cognition as a result of the diet.4
What does a ketogenic diet look like? (modified-atkins)5
2 eggs scrambled with butter and cream
Chicken breast with butter or mayonnaise
150 grams of steamed broccoli with olive oil
2 tablespoons cheddar cheese
125 grams steamed cauliflower
2 Tablespoons cheddar cheese
113 grams steamed spinach cooked in butter or oil
Sugar-free gelatin topped with double cream
Whole milk string cheese
1 slice deli turkey with 1 slice cheese and mayonnaise
A ketogenic diet for drug-resistant epilepsy must be medically supervised and the team must include (at a minimum) a neurologist or GP and a specialist dietitian. Since ketogenic diets severely restrict or eliminate most dietary sources of carbohydrate – including grain products, potatoes, fruit, milk, some vegetables and sugar – it is impossible for someone to meet all of their nutrient needs unless they take vitamin and mineral supplements as well.
Ketogenic diets require blood tests before starting on the diet and again after 3, 6 and 12 months to check cholesterol levels, kidney and liver function and to screen for nutrient deficiencies.2 The person will need to self-monitor blood (or urine) ketone levels twice daily (at least initially) to make sure they are staying in a ketogenic state.2 Certain food and drink must be weighed and measured to the gram and “cheating” (by eating a high carbohydrate food even for one meal or snack) isn’t allowed because it would take the person out of ketosis and could cause seizures to return.6 Most food will need to be prepared from scratch at home. For these reasons, many people find it difficult to follow a ketogenic diet and this is something which must be considered before pursuing this option. Diarrhoea, constipation, vomiting, weight loss and increased cholesterol levels are common side effects of the diet.1,7 The diet is generally trialled for a minimum of three months and usually followed for two years.2 For children who become seizure-free from following the diet, the benefits generally continue even after the diet is stopped.2
Where can you refer?
Your client’s neurologist or epilepsy consultant would be the one to decide whether trialling a ketogenic diet is appropriate or not. It’s certainly worth asking them about it, especially if all medication options have been unsuccessful.
Paediatric clients can usually be referred to their local children’s hospital where dietitians will be trained on implementing the ketogenic diet for children. Adult clients will need to be referred to one of the following clinics by their GP or neurologist:
- The National Hospital for Neurology & Neurosurgery in London (NHS)
- Matthews Friends Clinics, in Lingfield, Surrey.
- The Complex Epilepsy Clinic, University Hospitals Birmingham (NHS)
Due to the complexities involved, advising clients on ketogenic diets requires specialist training. I haven’t taken the training yet, but this is something I would be happy to do if it would benefit your clients. Please get in touch at firstname.lastname@example.org.