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Stories: High-fat diet puts Ashley back on the ice

Diet that chemically mimics starvation controls or reduces seizures in most kids who don't respond to drugs

Three years ago, Debbie May felt like she was losing her child.

Ashley - then 11 - had complex seizures, as many as 10 a day despite taking regular cocktails of anti-seizure medication. Bursts of electrical activity in her brain - combined with medication that made her groggy - made it difficult for her to focus and learn. At the same time, “she was rapidly losing her motor skills, making it hard for her to do the one thing she loved - skate,” Debbie says. “She cried a lot and said: ‘My legs don’t work anymore.’”

Today, Ashley rarely has more than one seizure a week, has jumped three grade levels in two-and-a-half years, and just earned a spot to compete in figure skating at the National Special Olympic Games in Prince Edward Island next year.

Her mother attributes her improvement to her ketogenic diet - a high-fat, low-carbohydrate diet that’s offered at Bloorview to children with intractable seizures. “The first thing we noticed with the diet was her ability to focus, which allowed her to move from an early grade 1 level at school to an early grade 4 level in two-and-a-half years,” Debbie says. “She also gained back her motor skills, which allowed her to accomplish her skating. And there was a huge leap in her confidence.”

That kind of success with the diet is common, says Dr. Rosalind Curtis, a pediatric neurologist who runs the complex epilepsy clinic at Bloorview. “About 25 to 30 per cent of children become totally seizure-free while on the diet, while another 40 per cent will have a 50 to 90 per cent reduction in seizures.” The remainder don’t respond at all.

“The ketogenic diet was invented by a chap in the 1920s who noticed that when his child was sick and not eating, the seizures reduced,” Rosalind says. “So he developed a diet that would mimic starvation in terms of its chemical results.”

The ketogenic diet does this by replacing carbohydrates with fat. On the classic ketogenic diet, children receive 90 per cent of their calories from fat, about 5 to 7 per cent from protein, and 3 to 5 per cent from carbohydrates. “Just as carbohydrates are broken down into glucose, fat is broken down into chemicals called ketones, and those ketones are used in place of glucose for metabolic energy,” Rosalind says.

For some reason, which has not yet been determined, one or more of the ketones control seizures in many children.

“It’s very effective and better than medication when a child has reached that stage of epilepsy,” Rosalind says. However, it’s also “a very difficult, restrictive diet,” she says, because of the lack of carbohydrates permitted. “The children can’t have bread, potatoes, pasta, candy or sugar,” she says. Instead, two-to-three times the amount of fat a child would typically eat is provided through butter, oil and whipping cream. For example, a child’s breakfast might consist of two tablespoons of whipping cream, one egg, one teaspoon of sugar-free applesauce and three tablespoons of butter, says Christiana Liu, a dietician in the complex epilepsy clinic.

If the diet is effective, children typically stay on it for two years, and then are slowly weaned off it to a regular diet. While on the ketogenic diet, they may be medication-free, or use a much lower dose of seizure medication than before.

“When effective, the diet gives the brain a chance to mature and stop seizing,” Rosalind says. “If we can keep a brain seizure-free, the chances of the child outgrowing it are higher.”

Children who become seizure-free on the diet often have no recurrence after going off it, while those who see a significant reduction in seizures will usually maintain that status after the diet.

In Ashley’s case, she was seizure-free for the first year on the diet, but then experienced occasional seizures during her second year. When she came off the diet last fall, she required a much lower dose of seizure medication than she had in the past.

Although the diet has a high rate of efficacy for children with intractable seizures, “there’s always concern among some health professionals and parents because it’s so imbalanced,” notes Christiana. The children receive vitamin and mineral supplements and are closely monitored, but there are questions about the impact of the diet on their growth, nutritional status and heart health.

About eight per cent of treated children develop kidney stones, and a pilot study by Rosalind and her team at Bloorview - published in the Journal of the American Dietetic Association last year - found that 85 per cent of children who had been on the diet for an average of 14 months experienced a slowing in their height growth. “That’s because they’re not getting the typical amount of protein,” Rosalind says. “However, when we look at children who have been off the diet for two years, they tend to catch up in growth.”

Rosalind and her colleagues hope to demonstrate that with proper supplementation and monitoring, children can remain healthy while on the diet. They’ve begun an ongoing study that will monitor nutrient intake and growth and biochemical indexes of children with intractable epilepsy at six, 12, 18 and 24 months on the diet. A pilot of the study - which looked at these variables in 30 children who had been on the diet for four months - was published last month in the Journal of the American Dietetic Association. “It showed that there were no changes that one would be concerned about in terms of growth, vitamin levels or nutritional status, and we’re going to use that as a baseline for our long-term study,” Christiana says.

Some children do see their cholesterol levels rise during the first year on the diet, but these levels are monitored, so the diet can be adjusted if necessary.

Debbie May is confident her family made the right choice in putting Ashley on the diet. “It gave her brain the long rest that it needed, and that had a huge impact on her learning, skating and self-confidence.”

To be connected with expert sources, contact:

Louise Kinross, Manager, Communications
Tel: 416-424-3866
Pager: 416-589-8826
E-mail: media at bloorview dot ca

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