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High-Fat Ketogenic Diet Misunderstood, Underused - 11/18/2010

High-Fat Ketogenic Diet Misunderstood, Underused

Release Date: November 18, 2010

Two Johns Hopkins Children’s Center neurologists say persistent misunderstandings among physicians and patients about the high-fat ketogenic diet may have led to its underuse and are urging both its wider application for seizure disorders and further research into its therapeutic promise for brain cancer, Alzheimer’s and other diseases.

The opinion is contained in a review article in the journal Advances in Pediatrics by pediatric neurologists John Freeman, M.D., and Eric Kossoff, M.D.

 “Several persistent myths and half-truths seem to discourage both doctors and patients from trying a diet that, in many children, is more effective than medication and has fewer cognitive side effects,” says Freeman, professor emeritus of pediatrics and neurology at The Johns Hopkins School of Medicine.

The ketogenic diet has been used since 1921 to successfully treat several forms of epilepsy in patients who don’t respond to anti-seizure medications. Made up of high-fat foods and very few carbohydrates, the diet works by triggering biochemical changes that eliminate seizure-causing short circuits in the brain’s signaling system. Even though it has been used primarily in children, the diet has shown therapeutic promise in adults with epilepsy.

Anecdotal evidence also suggests the diet may be useful in the treatment of brain tumors, Alzheimer’s, stroke and Parkinson’s disease, and several human and animal studies have found tumor reduction after treatment with the ketogenic diet. The suspected mechanism is that cancer cells require glucose for survival, and the ketogenic diet deprives them of this essential fuel. One report described two children with inoperable brain cancer, whose tumors shrank remarkably after treatment with the ketogenic diet, leading to long-term survival of both patients. This evidence indicates that the diet may affect the body’s chemistry on a far more basic level than once believed, with effects far more profound than now thought, and requires further research, the authors say.

What has been well-established is that when it comes to seizures, the diet’s therapeutic effects are often longer lasting than those of medication, and it has resulted in a full cure of seizures in at least some children, the researchers say. Yet, the diet has remained somewhat misunderstood and underused, they say.

The most common misconceptions about the diet are that it causes dangerous biochemical changes, is inappropriate for use in infants and very young children, causes weight gain and fatty build-up in the arteries or that it should be a treatment of last resort. All of these, the authors note, are partly or entirely false.

The diet does require rigorous monitoring by a neurologist and a dietitian, which also may discourage patients and health-care providers from using it.

Several studies have documented the effectiveness of the ketogenic diet in reducing or completely eliminating seizures. In a 2001 Hopkins study, 75 out of 83 children who were on the diet for a year experienced full resolution or partial reduction of seizures. Many of them continued to do well even years after stopping the diet. A 2009 study in the journal Lancet reported nearly 40 percent (28) in a group of 54 children experienced greater than 50 percent reduction in the number of seizures on the diet. Five of the 54 had more than 90 percent fewer seizures after starting the diet. These were all children with drug-resistant epilepsy, whose seizures had not improved with two medications.

The diet is not without side effects, Kossoff and Freeman caution. These include vomiting and constipation, and a temporary moderate spike in cholesterol, which goes down after one to two years on the diet and returns to normal once the diet is stopped. A Hopkins Children’s study showed that one in 20 children on the diet develops kidney stones, but most cases can be prevented or treated with the supplement potassium citrate.

Kossoff and Freeman recommend the diet as a first-line treatment in two rare metabolic conditions — GLUT-1 deficiency and pyruvate dehydrogenase deficiency, both marked by seizures and other neurological problems. The diet, they say, may be a good earlier option for treating infantile spasms, myoclonic seizures, tuberous sclerosis, myoclonic-static epilepsy, Dravet syndrome, Rett syndrome and Lennox-Gastaut syndrome, all of which traditionally do not respond well to anti-seizure medication. In other seizure disorders, the diet should be considered after two medications have failed to resolve the seizures.