Keto Diets May Reduce Seizures In Hard-To-Treat Epilepsy

What was studied

This paper was a systematic review of randomized controlled trials on ketogenic diet therapies for people with drug-resistant epilepsy. The authors searched several medical databases and included trials that followed participants for at least 28 days. In total, they found 17 eligible studies out of 1,193 records after removing duplicates.

Eleven studies included children up to age 12, and six studies included adolescents age 13 and older and adults. Follow-up lasted from 6 to 24 months. The review looked at whether ketogenic diet therapies reduced seizure frequency, caused side effects, affected treatment adherence, and changed quality of life or cognitive and behavioral outcomes.

What they found

In children, ketogenic diet therapies may help: about 37% may have their seizure frequency cut by at least half. This was rated as moderate-certainty evidence. About 6 more children out of 100 may have a very large seizure reduction of 90% or more, but that finding was supported by low-certainty evidence.

In adolescents and adults, ketogenic diet therapies may lead to at least a 50% seizure reduction in 16 more people out of 100 compared with usual care. This was also moderate-certainty evidence. It was uncertain whether the diets helped many people reach a 90% or greater seizure reduction because there were too few reported events and the studies were imprecise.

For side effects, the review did not find a significant difference between ketogenic diets and usual care in children, but the evidence was low certainty. In adults, side effects were very uncertain. Sticking with the diet may be a little harder than usual treatment in both age groups, but results were inconsistent. The studies on quality of life, behavior, and thinking were too few, too different from each other, and of very low certainty to give firm answers.

Limits of the evidence

This review can only be as strong as the studies it included. Even though it focused on randomized trials, there were only 17 studies, and some results were based on low- or very low-certainty evidence.

The studies included different age groups and different forms of ketogenic diet therapy, which can make results harder to compare. Some important outcomes, like quality of life, cognition, behavior, and side effects in adults, were not studied well enough to draw strong conclusions.

Because this is a review of trials with varying methods and follow-up times, it cannot show exactly which type of ketogenic diet works best, who is most likely to benefit, or how well these results apply to every person with epilepsy.

For families and caregivers

For families dealing with drug-resistant epilepsy, this review suggests that ketogenic diet therapies may reduce seizures for some children, teens, and adults. The strongest finding was for having seizures reduced by at least half, not for becoming seizure-free.

At the same time, these diets can be hard to follow, and the evidence about side effects, quality of life, and thinking or behavior is still limited. This means ketogenic diets may be a useful option to discuss with an epilepsy care team, but the likely benefits and burdens may differ from person to person.

What to watch next

Larger trials comparing specific ketogenic diet types and tracking side effects, quality of life, and longer-term seizure outcomes more carefully would help strengthen the evidence.

Terms in this summary

drug-resistant epilepsy

Epilepsy in which seizures continue despite treatment with seizure medicines.

ketogenic diet therapy

A medical diet therapy that is typically high in fat and low in carbohydrates and is used as a non-drug treatment option for seizures.

randomized controlled trial

A study where people are assigned by chance to different treatments so researchers can compare results more fairly.

systematic review

A study that collects and summarizes results from many studies on the same question.

moderate-certainty evidence

Researchers think the result is probably close to the truth, but it could change with better studies.

low-certainty evidence

Researchers have limited confidence in the result, and future studies may change it a lot.

usual care

Standard treatment that people would normally receive if they were not in the diet group.