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The Power And Pitfalls Of The Popular Ketogenic Diet For Patients05:16
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To manage her seizures, 9-year-old Gloria Johnson uses the ketogenic diet, which she says includes "lots of avocados." (Matthew Mead/AP)MoreCloseclosemore
To manage her seizures, 9-year-old Gloria Johnson uses the ketogenic diet, which she says includes "lots of avocados." (Matthew Mead/AP)

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Gloria Johnson was born missing part of the right side of her brain. Now a talkative, bubbly fourth-grader, she has daily seizures. But not nearly as many as the 50 or 60 electrical storms that used to course through her brain every day.

“So, is that why you eat special foods?” her mom, April Johnson, prompts her during a recent dinner at their home in Stratham, New Hampshire.

“Yeah,” she says, squirming in her high chair.

“Can you tell me what they are? Use your words,” her father, Josh, adds.

“Avocado,” she responds.

Gloria Johnson with her father, Joshua (Karen Weintraub for WBUR)
Gloria Johnson with her father, Joshua (Karen Weintraub for WBUR)

“And what else?”

"And mayonnaise."

Gloria eats an unusual diet for a 9-year-old — very heavy on fats, with virtually no carbs. And none of the typical childhood treats like French fries, candies or chips. She can only have a slice or two of her current favorite food: apples.

That restrictive menu is called a ketogenic diet, and these days it's widely considered one of the hottest food fads in America.

But a century before the ketogenic diet became fodder for celebrities like the Kardashians and LeBron James, doctors began using it as medicine for patients like Gloria. And it clearly works. But as her family's experience shows, and many casual keto dieters are finding out, it is extraordinarily challenging to follow.

"The ketogenic diet is probably the best treatment we have for epilepsy," says Dr. Elizabeth Thiele, Gloria's neurologist and the director of the Pediatric Epilepsy Program at Massachusetts General Hospital.

Most kids who try the ketogenic diet have already been on four to six medications — and are still seizing, Thiele says. They also may have side effects from the drugs, including liver damage, weight changes or behavior shifts. Some turn into zombies.

In about one-third of them, eating a ketogenic diet ends their seizures entirely.

"The diet for them can be a game changer,” she says.

"The ketogenic diet is probably the best treatment we have for epilepsy."

Dr. Elizabeth Thiele, of MGH

But it presents tremendous difficulties for those who try to follow it — from families like the Johnsons to everyday dieters.

How The Diet Works

The point of the ketogenic diet is to shift your body from burning glucose as fuel to burning compounds called ketone bodies. From an evolutionary perspective, this ability to shift fuel was a hedge against starvation, for when food wasn't available and the body needed to burn its own fat.

Essentially, though, to make the switch, you have to trick the body into thinking it’s starving. If the body perceives more than a tiny amount of carbohydrates, it will stick with burning glucose.

That's why people on the diet, including Gloria, have to eat almost no carbs  — the equivalent of a few saltines per day — and only a moderate amount of protein, because the body can convert larger amounts to glucose. (In that way it differs from the Atkins diet, in which people are told to indulge in bacon cheeseburgers, hold the bun.)

Eating a ketogenic diet can generally be safe, says Harvard's Dr. David Ludwig, a leading nutrition expert. There are entire populations of people — like the Inuit and Laplanders — who naturally ate a ketogenic diet most of their lives, he says.

And he thinks the processed carbohydrates that fill the typical American plate are a disaster. Eating tons of processed carbs programs the body to gain fat, he says.

“It's just a battle between mind and metabolism that we're destined to lose because metabolism is stronger,” he says. A ketogenic diet may help restore a healthy metabolism, he adds: “Lower carbohydrate diets, and especially ketogenic diets, may put metabolism back on our side.”

But, Ludwig says, it can be tough for people used to American diets to make the shift. He’s tried it himself a few times.

“I love how I feel on a ketogenic diet," he says, "especially the mental clarity and the sense of stability of energy. But it is restrictive and especially during the summer,” when there are sweet peaches, plums and cherries to enjoy.

He also warns against trying the ketogenic diet without first checking with a doctor and getting some expert guidance on how to follow it. The diet has some side effects, he says, and “you also want to really commit to doing it consistently, because if you pop in and out of ketosis,” you might not have enough energy to fuel your brain cells. “And that's not a place that people typically feel good.” (As celebrity dieters confirm, describing headaches and low energy, particularly when they started the diet.)

Mostly, Ludwig thinks more research is needed to show whether sticking to a ketogenic diet is really worth the effort, and for whom.

His group at Boston Children’s is eager for volunteers for a clinical trial to begin this fall: They’re going to bring 125 overweight people to a residential center in western Massachusetts for three months, feed them different diets — including the ketogenic diet — and see what happens.

Diet As A Way Of Life

For the Johnson family, the ketogenic diet means there’s no such thing as spontaneity. No weekend trips without hours of grocery shopping, food prep and packing Tupperware.

“There are so many parents who just don't want to cook every once in a while and it's like I can't be lazy," says April Johnson, sitting with her husband Josh after dinner. "I just want one time when I can be lazy."

"And you can't give her a bowl of Cheerios in the morning too," Josh adds.

"Right. I can't say to her older brother: 'Hey, just pour some cereal,' like before she was on the diet.”

And because Gloria has to eat the same number of calories every day, her parents spoon-feed her to be sure, though she’s perfectly capable of feeding herself.

Gloria has already suffered from a typical side effect: kidney stones. A high-fat diet can be very constipating, so she has to take medication for that, too. And she’s developed reflux.

But there’s no question that the keto diet works for her.

Once, at their wits’ end, the Johnsons tried stopping it. Within a few days, Gloria had a huge, minute-long seizure at a birthday party and then another at home.

“Those two episodes were enough for me to be like, ‘The diet works, and it works really well,’ ” April Johnson says. “It’s really unfortunate — but fortunate that we have something we can turn to, because medication has failed time and time and time again.”

Why Does It Work? 

The biggest mystery about the ketogenic diet is why it works.

Dr. Thiele’s husband, Dr. Gary Yellen, was so intrigued by the benefits he saw in his wife’s patients that he transformed his research at Harvard Medical School and now focuses on the biochemistry of the ketogenic diet.

Yellen says that once kids’ brains get into the habit of seizing, it’s very hard to break the pattern. “The brain is really good at learning to do seizures," he says. Yet the ketogenic diet can sometimes succeed at breaking that cycle where medications fail.

“We think it might be this change in fuel source that puts the neurons of the brain in a different physiologic state that allows them to resist seizures better,” Yellen says.

He believes that when brain cells burn less glucose, that activates an anti-seizure mechanism that is meant to turn on when someone is drowning or oxygen-deprived. But the ketogenic diet turns it on at a lower threshold, thereby stopping the seizures.

Although the research is still very preliminary, Yellen says the ketogenic diet could also help some cancer patients by depriving their fast-growing cancer cells of glucose, making it easier for the body to suppress them. Theoretically, it could help Parkinson's disease patients as well, by providing their brain cells with an alternative energy source.

But because the diet is so hard to stick to, Yellen focuses his research on finding alternative ways to trigger the same benefits. He's hoping to find a way to manipulate the body's metabolism to burn less glucose and more ketone bodies while still eating carbs.

April Johnson says she’d love to give Gloria a pill every day instead of struggling with scales, plastic containers and spoon feeding.

She admits that she gets annoyed with the current popular enthusiasm for the ketogenic diet — knowing what she knows about its hassles and side effects.

“Honestly that bothers me a little bit,” she says.

Her husband, Josh, says he couldn’t stick to the limited diet that his daughter follows — mostly without complaint.

“I watch what she eats. I have no desire,” he says. “I would have given up a long time ago and voted for seizures.”

This segment aired on September 10, 2018.

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Karen Weintraub Contributor, CommonHealth
Karen Weintraub spent 20 years in newsrooms before becoming a freelance writer. She's a contributor to WBUR's CommonHealth.

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