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Published:16 July 2013

Ketogenic diet affects bone growth in children with epilepsy

Epilepsy treatment with the ketogenic diet for more than six months slowed the long-term skeletal development of 29 children who took part in a study. Children who went on the diet lagged behind children who had normal bone growth, said Dr Mark Mackay at the 30th International Epilepsy Congress in Montreal.

In an interview with Clinical Endocrinology News, Dr Mackay of the Royal Children’s Hospital in Melbourne, Australia, said: 'Put simply, they accrue bone mass at a slower rate than their age-matched peers.'

Children in Dr Mackay’s study were treated with the ketogenic diet for more than six months during 2002-2009. They were an average of six years old when they started the diet, and they followed it for an average of six years.

Risks of ketogenic diet

The findings highlight the risks of a ketogenic diet, which relies on fat metabolism to induce ketoacidosis. A neutral pH is necessary to mobilise calcium from bone, Dr. Mackay said.

Children who are on the diet are also at risk for deficiencies in micronutrients important for health, including vitamin D and calcium. The timing of diet initiation also plays an important role, he said.

'Childhood and adolescence are critical periods for the normal accrual of bone mass. The bone that is laid down needs to last that person for the rest of their life. Therefore any intervention that affects accrual of bone can have long-lasting health consequences for the child.'

Making an informed decision about treatment

While the ketogenic diet is a very effective treatment for some seizure disorders, it’s not risk free, he added. 'Some parents see the ketogenic diet as a "natural" alternative to medications, which it is not. Therefore it is important to be improving our knowledge about potential serious long-term side effects so parents can make an informed decision about treatment.'

The findings should prompt more study of the diet’s potential long-term impact on skeletal health, Dr Mackay said. 'These will inform development of guidelines for bone surveillance in this high-risk group of predominantly children to minimise potential negative health consequences of the ketogenic diet.'