The Seizure Control Diet
References to fasting as a treatment for epilepsy go back to Biblical times. But it wasn’t until 1921 when a paediatrician reported using it successfully in severe cases, that interest was reawakened.
In the same year it was proposed that the same metabolic effects created by fasting could be achieved with ketogenesis by utilising a very high fat, low carbohydrate (ketogenic) diet. In this way the benefits of fasting could be extended over time.
Ordinarily the body uses carbohydrates (glucose) as fuel. But if this is not available it will burn fat. Fat does not completely burn but leaves a residue or “ash” called ketones, made up of beta-hydroxybutyric acid and acetoacetate.
The brain can use the former as an energy source. The latter is excreted in the urine and breath. It was theorised that seizures could be prevented if ketones built up in the blood to a certain level.
66% Substantially Benefit
The first study reported in 1925. Of 37 epileptic patients treated over 2½ years, 19 (51%) had over 90% seizure control, and 13 (35%) had 50-90%. Over the next decade or so a number of other studies reported positively. They showed that around one third of children had their seizures largely controlled. Another third saw a substantial improvement, and another third were not substantially benefited.
The ketogenic diet began to be used widely even without any understanding of how it worked. Even today, this is still not known.
As new anticonvulsant medications were developed in the 1940‘s, the ketogenic diet fell out of favour. It was forgotten for decades until the mid 1990’s with the case of Charlie Abraham.
“...after thousands of epileptic seizures, an incredible array of drugs, dozens of blood draws, eight hospitalisations, a mountain of EEG’s, MRI’s, CAT scans, and PET scans, one fruitless brain surgery, five paediatric neurologists in 3 cities...Charlie’s seizures were unchecked, his development “delayed” and he had a prognosis of continued seizures and progressive retardation.”
After 9 months and $100,000 of treatment, Charlie was treated at Johns Hopkins, Baltimore, with the ketogenic diet, after which he was able to discard his medications and became virtually free of seizures.
Some Are Seizure Free
In 1998 Johns Hopkins published the results of 150 consecutive cases. These were all children who averaged over 600 seizures a month and had tried more than 6 medications. Even in this extreme population, after one year 11 (7%) were seizure free, 30 (20%) had over 90% seizure control, 34 (23%) had between 50-90% control, and 8 (5%) had less than 50% control. 83 (55%) remained on the diet at one year, 67 (45%) had discontinued the diet.
Nearly half the children who start the diet will not continue with it because the benefits are not sufficient to make it worthwhile. The diet is extreme and rigid. For some it is too much of a sacrifice if seizures can be largely controlled with drugs.
Others go on the diet even with good control because of the toxicity and side effects of the medication. These can affect the child’s behaviour, mental clarity and alertness. Learning and intellectual development can be impaired. For one in five children, even with the most up to date medications, their epilepsy remains uncontrolled.
The diet can be used for babies only months old, although it is usually reserved for children over one and adolescents. It seems to be equally effective across this age group. It will probably help adults but there is little research or use in older age groups. It seems to be effective regardless of the type or frequency of the seizure.
What Do Children Eat?
It is typically made up of 4 grams of fat for each gram of protein and carbohydrate combined (ketogenic ratio 4:1). So 80% of the diet by weight is fat and it makes up 90% of the calorie intake. A typical breakfast might be mushroom omelette with bacon. Hot chocolate made with 36 per cent cream.
Lunch might include celery stalks filled with peanut butter or cream cheese, lettuce with mayonnaise and a slice of tomato, and a caffeine-free diet soda.
Dinner might be hot dog with ketchup or mustard, lettuce and mayonnaise, a whipped cream sundae with a strawberry, and a diet soda.
Another aspect of the diet is the number of calories consumed. Too many reduces ketogenesis. The diet is based on 75% of the recommended daily allowance for a child of a particular age and weight. Since ketosis decreases appetite, hunger is usually not a problem.
Fluids are also restricted to 20% below normal maintenance, or around 60cc per kilogram of bodyweight to maintain minimal hydration, although it isn’t clear why. In practice it seems to improve seizure control. Ketosis also suppresses thirst.
Carbohydrate is broken down to glucose and is the most severely limited. Over half of ingested protein is also transformed into glucose and must be restricted to between 0.75 and 1.5 grams per kilogram of bodyweight depending on age and growth. Protein needs to be adequate and no more.
The ketogenic diet is not nutritionally complete. A multivitamin and mineral supplement and a calcium supplement is required daily.
The diet is mathematically calculated and must be strictly adhered to. Even small variations can reduce ketosis and bring on seizures.
Starting The Diet
Four days of hopitalisation is required. The child is fasted for a few days to allow the body to use up its stores of glucose and glycogen. Then high fat meals are gradually introduced and the dose of some medications is adjusted.
During this period the dietician teaches the diet to the family and provides them with a number of meal plans specifically calculated for the child.
Over the next few weeks the body learns to adjust to this new way of eating. Parents need to buy a gram scale with one tenth of a gram increments. All food must be carefully weighed. Urine must be tested daily with dipsticks (ketostix) to confirm the required ketone level.
In the weeks ahead the diet will need fine tuning to optimise seizure control and reduce medication to a minimum.
Problems And Mistakes
There are bound to be problems in the early days of the diet and mistakes made. Some of these are as follows.
The level of 4+ needs to be reached on the ketostix. This is the highest level they measure. While this confirms ketosis, a much higher level may be required for optimal control. It is the level of ketones in the brain which determines seizure control, not urine. So reaching the required level may not supply enough seizure control. It is hoped a finger prick blood test may become available. This should prove more accurate.
The most common mistake made is the measure of calories. Basal metabolic rates and activity levels can differ markedly from one child to the next. An overestimate of as little as 25-100 grams a day can upset ketosis. Restricting calories for those that are gaining weight can result in better ketosis and seizure control.
Some may lose weight and will require a very carefully controlled increase in the calorie level over several weeks so as not to provoke seizures.
Because ketosis suppresses the appetite, this brings about an interesting paradox. Reducing calories leads to better ketosis and thus reduced appetite. And vice versa. So the answer to children who complain of hunger may be to give them less to eat.
Many other adjustments may need to be made. This might involve fine tuning the meal plans, the carbohydrate level, the proportion of saturated to unsaturated fats, the ketogenic ratio, the time that foods are eaten (too long a period between meals will reduce ketosis), the fluid level, and the medication levels.
The Diet Is Challenging
“I would not wish this diet on my worst enemy, but I would wish it on every child with uncontrolled seizures.”
Such a diet is not for the faint hearted. It requires an absolute commitment on the part of parents. They need to be very positive and persuasive in order to get and keep the child’s cooperation.
Pastas, pizzas, chips, sweets, biscuits, cakes and ice cream are out. Most children will not only be deprived of their favourite foods, but will be ‘different’ from the rest of their family and friends.
Every scrap of food has to be eaten, every last drop drunk, otherwise the precise calculations of the diet will be invalid. Every food label has to be scrutinised, even on branded goods in case the recipe has changed.
Every food item must be carefully weighed. Eating away from home, at school and on trips must be planned with vigilance. Well meaning members of the wider family, and friends must be persuaded not to give treats.
Even after control is established there may still be unexpected seizures. It may take a good deal of detective work to establish how this happened.
The child could have contracted an infection. This can reduce ketosis. A seizure could be triggered from carbohydrate in toothpaste, or even sorbitol in sun tan lotion! The diet presents a great challenge to families especially in the first few weeks and months.
Because of this, at Johns Hopkins, they have a “ketoteam” consisting of a doctor, nurse, dietician and counsellor. They also have a “ketocoach”, a volunteer parent who has been through it successfully. They estimate the average family will need 40 hours of telephone counselling alone in the first year.
In spite of all this, children appear to tolerate the diet well, especially when the benefits are apparent, and parents find ways to overcome difficulties. The diet today is actually far more palatable, appealing and varied than in the early days.
Isn’t The Diet Dangerous?
A typical meal of chicken, carrots, double cream and butter might not seem healthy, but look again at what children are not allowed to eat. Children grow normally. Weight remains stable so long as calories are controlled. Supplements provide for nutritional shortfalls.
It’s true that blood lipid levels are raised. This may be a problem but probably isn’t, as I’ll shortly explain. Dietary fibre intake is low, so constipation can be a problem, but adjustments to the type of vegetables eaten can usually get around this.
The most common serious problem is kidney stones. Because of this, parents must use a urine dipstick to test for blood and specific gravity once a week.
The Diet Can Be A Cure
The diet is effective for the majority of children who try it. Their seizures are eliminated or greatly reduced. They are able to reduce or discard their medications. As if that wasn’t enough, there is another amazing benefit.
After a few years, children can be weaned off the diet and return to eating normally. For children who became seizure and medication free on the diet, it means they are effectively cured. That is why higher blood lipids is not a problem. The diet is short term for most children.
For those who are not seizure free, the diet can be continued if seizures increase once the diet is stopped, or if increased medication is needed.
A recent study published in Pediatrics (Vol. 108 No. 4 898-905 October, 2001) followed up the 83 children from the earlier study who had remained on the diet for one year. After 3-6 years, 20 (24%) were free of all seizures. An additional 21 (25%) had a 90%-99% decrease. 29 (35%) were free of all medications. 28 (34%) were on only 1 medication. 15 (18%) remained on the diet.
The lead researcher said “we have got exceedingly impressive results.” And the British Epilepsy Association commented: “the study has shown there are significant beneficial and long standing improvements in seizure control.”
Treatment in the UK
The ketogenic diet is a proven method of controlling epilepsy. It substantially helps the majority of children with difficult-to-control seizures. Every paediatric physician should be aware of it, although they may not have the facilities to administer it. Hospitals that will oversee the diet are Glasgow’s Royal Hospital, Great Ormond Street, Chelsea & Westminster, Manchester Children’s Hospital, Birmingham Children’s Hospital, Leeds General Infirmary and Leicester Royal Infirmary.
The Central Middlesex Hospital in West London, together with Great Ormond Street and St Piers, Lingfield, Surrey, are conducting a study with 90 children, looking at two different versions of the diet.
For Further information read The Ketogenic Diet - A Treatment For Epilepsy by John M Freeman MD Demos Medical Publishing ISBN: 1-888799-39-0
This article was first published in Enzyme Digest No. 55, New Year 2002
High-Fat Ketogenic Diet Effectively Treats Persistent Childhood Seizures, Study Finds
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