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12 April 2016

Study shows that ketogenic diet may be feasible and effective in adults with epilepsy

A study published in Epilepsy & Behavior has found that ketogenic diet therapies may be feasible and effective in adults with epilepsy.

The ketogenic diet (KD) is a high fat, low carbohydrate, controlled protein diet that has been used since the 1920s for the treatment of epilepsy in children. The diet is a medical treatment and is usually only considered when at least two suitable medications have been tried and not worked. 

The study, undertaken in America five years after the Adult Epilepsy Diet Center was set up , evaluated the efficacy of offering the diet as a treatment for adults with epilepsy.  A group of 168 outpatients at the Johns Hopkins Adult Epilepsy Diet Center in Maryland, USA, were enrolled in the study.  Scientists recorded their medical history, seizure frequency, ketone level and diet type and duration as well as side effects. 

Diet brought seizure reduction

Researchers found that of those patients with reliable follow-up results, after three months of diet therapy, 36 per cent responded with seizure reduction of at least 50 per cent, and 16 per cent of participants were seizure-free.  After a year of diet therapy, 30 per cent had a reduction in seizures of at least 50 per cent and 13 per cent were seizure free.  The study showed that after four years, 21 per cent responded with a reduced seizure rate of at least 50 per cent, and 7 per cent of the patients were seizure-free.

Weight loss and elevated levels of lipids in the blood were the main side-effects of the diet therapy. 

Ketogenic diet may be safe long-term in adults

The study, which is the largest analysis of a series of adults with epilepsy treated with ketogenic diet therapies, concludes: " The study provides evidence that ketogenic diets may be feasible, effective, and safe long-term in adults, although long-term adherence was limited and further adequately controlled studies are necessary to determine the efficacy of ketogenic diets in the treatment of adults with epilepsy."

The science behind the diet

Usually the body uses glucose (a form of sugar) from carbohydrates for its energy source. Chemicals called ketones are made when the body uses fat for energy (this is called ‘ketosis’).  Using the ketogenic diet, the body uses ketones instead of glucose for its energy source. Research in 2015 has shown that another chemical, decanoic acid, is also produced as a result of the diet. These chemicals help to reduce seizures for some people.

Ketogenic diet could starve cancer cells

Scientists believe that the ketogenic diet could also be used to "starve" some forms of cancer, denying the cancer cells the glucose they need to grow.

The  effect of the ketogenic diet on cancer cells has only been examined in animals and only noted anecdotally in humans.  In 2012, a study on mice found that the diet "significantly enhances" the anti-tumour effect of radiation.

Ketogenic research at Epilepsy Society

Here at Epilepsy Society, Professor Sanjay Sisodiya is leading research into why some people with epilepsy respond to the ketogenic diet, while others do not. 

Studies have shown that people with Glut1 deficiency syndrome, which is  caused by a genetic mutation, tend to have a more favourable response to the ketogenic diet.

However,  this gene may not be the only explanation for this positive response.

Working with researchers in the UK, Netherlands and Australia, Professor Sisodiya has shown that there may be other genetic factors that may predict who is likely to benefit from the diet that they hope will  come to light in the Genetics England project that aims to sequence the genetic codes of 75,000 people by 2017.

Read more about the Ketogenic Diet here

Read more articles about the Ketogenic Diet

Research reveals anti-seizure mechanism of ketogenic diet therapy

Ketogenic diet could reduce seizures in adults with epilepsy