How Can a High-Fat Diet Treat Epilepsy? Dr. Besser Reports

April 21, 2011— -- Imagine treating childhood epilepsy with bacon, heavy cream and hot dogs. This may sound like an unlikely approach, but the extremely high-fat and low-carb ketogenic diet has been shockingly effective in treating kids with drug-resistant epilepsy. ABC News' senior health and medical editor Dr. Richard Besser sat down with the director of pediatric epilepsy at Massachusetts General Hospital, Dr. Elizabeth Thiele, to discuss this unusual approach to fighting epilepsy.

For more information on the ketogenic diet and pediatric epilepsy, watch 'World News With Diane Sawyer' Thursday at 6:30 p.m. ET on ABC

Dr. Richard Besser: So what is the ketogenic diet?

Dr.Elizabeth Thiele: The ketogenic diet is a high-fat, low carbohydrate diet, and it was developed in the 1920s after people noticed that when epileptics fasted, for various reasons, seizures would be markedly reduced.

Besser: So the ketogenic diet mimics what you'd see in someone who's fasting?

Thiele: Right. When this was noticed, this observation was made in the 1920s, people started thinking, "Gee, what happens when someone fasts?" And when a person fasts, your body starts breaking down your fat stores. Obviously, fasting is not great for a treatment for epilepsy or other conditions because it doesn't provide adequate nutrition, so the thought was, "Gee, how could we mimic starvation and trick our bodies into thinking we're starving by using fats as the main energy source?"

Besser: So this treatment is solely based on diet?

Thiele: This treatment is solely based on diet.

Besser: No medicines, nothing else?

Thiele: We do supplement vitamins, because with the high-fat, kids can become deficient in some vitamins -- so while on the diet, all children are supplemented with vitamins and also calcium.

Besser: So on this diet, some children, who are having dozens of seizures a day, will become seizure-free?

Thiele: We've had several children having hundreds of seizures per day become completely seizure-free, oftentimes within a few weeks.

Besser: So this is a treatment based solely on diet and vitamins?

Thiele: Absolutely. While on this treatment, hopefully, the children are taken off all of their medications if the diet successfully controls their seizures, and then they just continue on the diet for a period of time and supplement it with vitamins and calcium.

Besser: So on this you've seen children who've been having dozens of seizures a day become seizure-free?

Thiele: We've seen many children who are having hundred of seizures a day become seizure-free oftentimes within just a few weeks of being on the diet.

Besser: That's miraculous.

Thiele: It's miraculous. No, it's a miracle. And many children who go on this diet have already been on six or eight or 10 anti-convulsion medications without effective seizure control or with side effects that can't be tolerated. And they go on this diet and become seizure-free. About a third of children who go on this diet become completely seizure-free.

Besser: I would imagine for some of these families, they've completely given up hope that their child will be seizure-free.

Thiele: That's true. By the time a lot families learn about the diet or come to talk to us about the diet, their children have been on numerous medications, the children are continuing to have seizures, they're having side effects from the medication and many people view this diet as their last chance at controlling their child's seizures. Now with increasing awareness of the diet and the fact that more and more people are learning about it and hearing about it, many people come to consider the diet earlier in the treatment of their epilepsy, oftentimes after only one or two medications instead of after eight to 10 medications.

Besser: How effective is this treatment?

Thiele: It's very effective. And this has been looked at. The ketogenic diet has been used for more than 80 years, and every time anyone has looked at the efficacy of the diet in study form, about a third of children who go on the diet become seizure-free, about a third of children have a great than 50 percent reduction in seizures. and for the other third, the diet doesn't work and that's often because the children have trouble tolerating the restrictions.

Besser: When you think about seizures and the complexity of seizures, and then you think about treating this with diet, you have to wonder how does this work?

Thiele: How the diet works is a very big question, because when children are on this diet, they're restricted from having birthday cake, from having French fries, from having potato chips, from having Halloween candy. So you're taking a child who's already living with epilepsy, and you're further restricting their world. So it would be much easier if we could figure out how this diet works and put it in a pill form so people could take it that way. Because it's so extremely effective, and it continues to be more effective than any medicine we have, there's an increasing amount of interest in the basic science community about what the mechanism of the diet is. It would help us understand epilepsy. And the diet is also expanding in other areas, especially neurologic disease, and there's increasing interest of using a similar diet in cancer. So obviously, understanding the mechanisms of the diet would help further help its utility in these other areas.