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.

Typical Meal, Drawbacks and More on the Ketogenic Diet

Besser: What kinds of things are being looked at for treatment with a ketogenic diet?

Thiele: Right now there's some preliminary evidence in Parkinson's disease and Alzheimer's disease that a diet similar to the ketogenic diet may be very effective. And there's actually a critical trial, ongoing, in ALS, or Lou Gehrig's, disease of using a similar diet and there's a lot of evidence, mainly animal model evidence, that similar diets may be very effective in helping to treat cancer.

Besser: Treating cancer?

Thiele: Treating cancer. There's evidence in prostate cancer and there's a lot of evidence in some brain cancers, like neuroblastoma. And I think that's because cancer cells are rapidly dividing so they have a very high metabolic rate and they use a lot of energy.

And so the ketogenic diet basically shuts down the cell's energy production and makes the cells rely more heavily on fat metabolism, and cancer cells, I think, are not thought to do that as effectively.

. Besser: Is this diet used to treat adults with seizures as well?

Thiele: There is less experience using the ketogenic diet with adults. When it was first described in the 1920s, it was described both in children and adults, and it is effective in adults, but it's honestly harder for adults to maintain and tolerate the restrictiveness. Since I've been at the Mass General we have started several adults on it, and it can be extremely effective, but again, the restrictiveness. The diet is kind of like the Atkins diet, so it really has a limit to 10 grams of carbohydrates a day -- which isn't a lot.

That's why there's medications on the classic ketogenic diet now, a modified Atkins diet that's being used at Hopkins, and the modified diet we developed here, called the low glycemic index treatment, and both of those diets are less restrictive, and both of those diets appear to be probably almost as effective as the classic ketogenic diet. So there is increasing interest in using those diets in the adult population because it's thought that adults can tolerate those better because they are so much less restrictive.

Besser: What are some of the downsides of being on this diet?

Thiele: For a kid, a big downside is not being able to eat your own birthday cake, going to other kid's birthdays and not being able to eat the cake or other things the child's having. For the family, a big downside is not being able to go to restaurants. The family can go to a restaurant, but if their child is on the classic ketogenic diet, they have to take that child's meal because on the classic ketogenic diet, the meals are composed by grams of each food substance and the family weighs each component out on a gram scale, and that's not possible to do in a restaurant setting. Another advantage of the modified diets, our low glycemic and the modified Atkins, are, because they are less restrictive, the families can go to restaurants and children can order off menus. Children can eat school lunches that their school provides, just have an understanding that what's on the menu would be compatible with their diet and what would not be. But I think for most kids it's really not being able to eat candy, not being able to eat ice cream, not being able to eat French fries and that's a lot of other things that children enjoy doing.

Besser: Being different from other children.

,Thiele: Being different from other children, and these are children who already feel different from other children because they have epilepsy. And it's a group of kids who are, really to me, superheroes, because they try to be normal kids even though some of them are dealing with 50,100 seizures a day.

Besser: Describe a typical meal for someone on a ketogenic diet.

Thiele: The diet is composed of what is called the ketogenic diet ratio. And that ratio means the grams of fat in a meal to the grams of carbohydrates plus protein.

And many children get started on a 4:1 ratio, meaning they get 4 grams of fat to every gram of carbohydrate plus protein. So a typical meal would be bacon, and often lots of it, with sometimes a small amount of carbohydrate in the form of vegetable or fruit. What many children on the diet, really children on the classic ketogenic diet, don't get, is breads, they don't get grains, they don't get rice because all of those foods are high carbohydrate foods.

Besser: So it really reverses totally the food pyramid for these kids?

Thiele: Pretty much. We have a graph that we show that shows the typical American diet, and I think the typical American diet is close to 60 percent carbohydrates, which I'm not sure is great, and then on the ketogenic diet about 90 percent of the calories come from fat. And so many people are concerned. "Gee, high fat. What does that do for risk of heart disease in later years?" And that has never been looked at, unfortunately, but the diet's been used for over 80 years in this country, and at least as far as I'm aware, there isn't really an increased cardiovascular risk. We do follow children extremely carefully when they're on this diet, since they're growing children and we're changing their nutrition and what we do see is that the lipids, the cholesterol will increase slightly when children start the diet but that tends to normalize over time.