Epilepsy Diet Has Lasting Anti-Seizure Effect
Kids have fewer attacks, even after going off high-fat, low-carb diet

By Nicolle Charbonneau
HealthScoutNews Reporter

MONDAY, Oct. 1 2001 (HealthScoutNews) -- The longest-ever follow-up of 
children who consume a special diet known to reduce epileptic 
seizures has produced some surprising results that may shed some 
light on this mysterious brain disorder. 

The study reports that the ketogenic diet, a strict food regimen that 
involves high-fat, low-carbohydrate meals, not only reduces the 
frequency of seizures in about half the children who try it, but it 
also appears to reduce the number of seizures even after the kids 
have stopped the diet. 

According to one pediatric neurology expert, the study could lead to 
a better understanding of why the diet works, which could ultimately 
help all patients with epilepsy. 

Epilepsy is a neurological disorder affecting more than 2 million 
Americans. People with this condition are prone to seizures -- bursts 
of uncontrolled, abnormal brain activity that can cause strange 
sensations, bizarre behavior, and, sometimes, convulsions. Unless 
brain surgery can correct an underlying cause of the seizures, there 
is no known cure for this disorder. Patients can achieve varying 
degrees of control over their seizures with medications, an 
implanted "brain pacemaker" called a vagus nerve stimulator, or the 
ketogenic diet. 

Neurologists at Johns Hopkins Medical Institutions followed 150 
children with difficult-to-treat epilepsy for between three and six 
years after the kids started the ketogenic diet. 

The children's ages ranged between 1 and 16 when the study started 
and they had at least two seizures per week, with an average of 410 
seizures per month. They hadn't responded to an average of 6.2 
different seizure medications. 

Of those children, 83 stayed on the diet for at least a full year, 58 
stuck with it for two years, 30 stayed for three years and 19 lasted 
on it four years. Fifteen children stayed with the diet for more than 
four years, and one child has remained on it for 6.5 years. Most 
families discontinued the diet because they felt it was ineffective 
or too restrictive, or because of another illness. 

In 1999, three years after enrolling the last child, the researchers 
asked about the child's current health, seizure frequency, and 
current epilepsy medications. The survey also looked for information 
on a child's experience with the diet and why it was discontinued. 

Three to six years later, 13 percent of the original 150 children 
were seizure-free, 14 percent saw their seizure frequency drop by 
between 90 and 99 percent. Another 17 percent had their seizures 
reduced by between 50 and 99 percent, and the remainder had their 
seizures decline by less than 50 percent. 

Of the 83 children who remained on the diet for one year, 59 percent 
had originally been taking two or more medications and 27 percent had 
been taking three or more drugs. Three to six years later, 34 percent 
of that group no longer needed anticonvulsant drugs, 37 percent were 
down to one drug, and only 30 percent were taking two or more 
medications. 

The research appears in the October issue of Pediatrics. 

Senior investigator Dr. John Freeman, the director of the Pediatric 
Epilepsy Center at Johns Hopkins Hospital, says that this is the 
first time anyone has looked at the effect of stopping the ketogenic 
diet. 

It may be possible that the children grew out of their seizures, says 
Freeman. "But if you look at the literature, these children who were 
having 400 seizures a month when they started [the diet] and who had 
failed on six drugs, had a 10 percent chance of getting their 
seizures under control with any medication. So you wouldn't expect 
them to have their seizures under control, let alone to outgrow the 
seizures." 

But Freeman simply doesn't know why the effect appears to 
persist. "Unfortunately, we don't even know why the effect exists to 
begin with," he says. Some studies have suggested that the diet 
forces the body to generate compounds called ketones (hence the name 
of the diet), which somehow reduce seizure activity when metabolized 
by the brain. 

Right now, there are more questions than answers about how the diet 
works. And, he adds, "nobody has even begun to approach the question 
of why its effect persists after you stop." 

Freeman says the diet may somehow cause a fundamental shift in the 
metabolism or physiology of the person's brain. "The diet clearly 
works different than any of the anticonvulsant medications, but we 
don't know how any of them work either," he says. 

Dr. James Wheless, the director of the Texas Comprehensive Epilepsy 
Program at the University of Texas Houston Health Science Center in 
Houston, and a specialist in pediatric epilepsy, agrees that there's 
little solid evidence about how the diet works. 

"Clearly, we know it works, and it obviously works in people where 
the medicines don't work, and we believe it works very differently," 
says Wheless, who's familiar with the new study. "If it's helping 
epilepsy in a totally different manner from how we think our 
medicines help, then obviously there's a whole other system there 
that we don't understand. If we did understand that, it could impact 
the treatment of epilepsy in general." 

"The other important point that they address is the safety issue," he 
notes. "From a safety standpoint, it reinforces what we thought 
about . . . the safety of the diet." 

Wheless says that the biggest dilemma that doctors face when putting 
children on the ketogenic diet is whether the required high-fat 
intake puts the child at risk of future heart disease or stroke. 
However, he says that other studies suggest that the children burn 
the fats for nourishment, and that despite the seemingly unhealthy 
nature of the diet, the children's cholesterol levels are only 
marginally higher than normal. 

There were no reported cardiac complications among the children in 
this study. 

Freeman says, "The most outstanding thing about the study was that so 
many children continued to do well after the diet was stopped, after 
they had come off medication. That's what exciting and meaningful." 

What To Do 

Find out more about the ketogenic diet from the Epilepsy Foundation 
or Stanford University. 

For a more comprehensive view of epilepsy, visit the National 
Institute of Neurological Disorders and Stroke Web site.