Ketogenic Diet
History
It has long been known that fasting can be helpful in seizure control - there is even a reference to it in the New Testament. In 1921 a New York doctor designed a diet which tricks the body into thinking that it is fasting. Despite the successful use of this diet to treat many forms of seizure disorder, it fell out of favour with the development of antiepileptic drugs in the 1940s. It is now becoming rediscovered as an effective treatment for intractable epilepsy in children.
Recent studies have concluded that total control may be achieved by 50% of the children on the diet, and a further 25% are significantly improved.
Principles
The diet is very high in fat, and very low in carbohydrates and protein, which sends the body into a state of ketosis: fat is burned, rather than carbohydrates, and acids called ketones are produced. Fluid intake is also limited, as is the overall calorie intake (about 75% of the norm for their weight and age). It is not yet fully understood how the ketotic state leads to a reduction in seizure activity.
What is involved?
The diet should only be undertaken with the approval of, and under the supervision of, a specialist medical practitioner. The diet begins in hospital, with a 3-5 day fasting period, during which ketone levels in the urine are monitored. Food is gradually reintroduced, according to the childs personalised regime, and the child returns home. The proper ratio of fat to carbohydrate (including sugar) and protein is determined by the childs weight and age, and it is essential that it be maintained at each meal (this is usually approximately 4:1, fat:carbohydrate+protein). Monitoring continues, and careful vitamin and mineral supplementation is required. Antiepileptic medication may be reduced over time.
The diet is generally continued for two to three years, after which many children remain seizure free.
What foods may be eaten?
There are two forms of the diet: in the Classical diet most of the fat comes from dairy products and other naturally occurring fatty foods. In the MCT diet, the child receives some fat from naturally occurring foods, and some from a tasteless medium-chain triglyceride oil (fractionated coconut oil). The ketogenic diet can be modified for children with a milk allergy.
A sample day for a three-year-old:
Breakfast: an egg scrambled with butter; fruit; cream diluted with a little water to drink.
Lunch: a little bowl of popcorn with lots of butter; five strips of bacon.
Dinner: a little steak; broccoli; lettuce with mayonnaise dressing; diluted cream to drink.
A sample day for an 8 year old:
Breakfast: 90g cream, 22g applesauce, 22g bacon, 10g puritan oil.
Lunch: 90g cream, 57g hot dog, 5g potato chips, 21g puritan oil.
Dinner: 90g cream, 44g sausage, 5g cashews, 25g puritan oil.
A diet consisting of 80% fat can be bland and unpalatable. Pure flavouring extracts, such as vanilla, almond, lemon and coconut, plus sugar-free sweeteners, such as saccharine, can help.
Problems and side-effects
In most cases, this diet is well tolerated, and has few, short term side-effects. During the fasting phase, children may experience nausea, vomiting, lethargy and severe acidosis. These may continue as the diet begins, though most children return to their normal activity levels over time. Children do not tend to become over-weight on the diet. Overall development and behaviour are also observed to improve.
The ketogenic diet has been linked with a high rate of kidney stones, and also with pancreatitis.
Both child and parents must be highly motivated. The main problem with the ketogenic diet is that it requires a lot of effort, and is difficult to maintain; it must be rigidly adhered to even the tiny amount of sugar in some medication or toothpaste can bring the body out of ketosis, triggering a seizure.
Who is the diet suitable for?
The diet has proved most effective for children between the ages of 1 and 10. Recent studies on adolescents and adults are promising, but it is thought they may not make or use the ketones so well. They also have difficulty maintaining essential nutrients.
The types of epileptic seizures that the diet is best at supressing are: childhood myoclonic seizures, atonic seizures and tonic-clonic seizures, as well as absence seizures, multi-focal seizures, minor-motor seizures and complex partial seizures. It has also been used to treat structural brain disorders (microcephaly, hypoxic brain damage, prior strokes and developmental abnormalities), and glucose transport protein defects.
It is not effective for petit mal, psychomotor and other types of epilepsy.
Resources
The following institutions are currently leading the field in research into the ketogenic diet:
The Pediatric Epilepsy Center
Johns Hopkins University
600 N. Wolfe Street
Meyer 2-147
Baltimore
MD 21287-8247
USA
Website: http://www.hopkinsmedicine.org/ketodiet.html
Packard Children's Hospital/Stanford University Medical Centre, USA Website: http://www.stanford.edu/group/ketodiet
These organisations may be able to provide further information on the diet and specialist clinics in the UK:
The National Society for Epilepsy
Chalfont St Peter
Gerrards Cross
Buckinghamshire SK9 0RJ
Tel: 01494 601 300
Helpline: 01494 601 400
Website: http://www.epilepsynse.org.uk
British Epilepsy Association
New Anstey House
Gateway Drive
Yeadon
Leeds LS19 7XY
Tel: 0113 210 8800
Helpline: 0808 800 5050 (9am to 4.30pm Mon to Thursday. 9am to 4pm on Friday)
http://www.epilepsy.org.uk
A study to compare the effectiveness of the two types of ketogenic diet will take place at the National Centre for Young People with Epilepsy, Lingfield;
Great Ormond Street Hospital for Children NHS Trust; and the Institute of Child Health, London.
Matthews Friends
P.O. Box 191
Oxted
Surrey
RH8 0WL
Tel:0788 4054811
E-mail: enq@matthewsfriends.org
www.matthewsfriends.org
Books:
- Freeman, J M; Kelly M T; Freeman, J B The Ketogenic Diet: A Treatment for Epilepsy ISBN: 1888799390
- McDonald, L - The Ketogenic Diet: A Complete Guide for the Dieter and Practitioner ISBN: 0967145600
- Brake, D; Brake, C The Ketogenic Cookbook ISBN: 1886559996
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