The first clinical trial of a ketogenic diet -- high in fats and low in carbohydrates and protein -- for epilepsy has shown that it sharply curtails seizures and is an effective tool for managing children who are resistant to anti-epilepsy drugs.
The diet mimics the effects of starvation and induces the body to produce chemicals called ketone bodies rather than glucose as an energy source for the brain. Researchers are not sure why ketone bodies appear to reduce seizures.
The diet, which has four times as many calories from fats as from carbohydrates and protein, was developed in the early 1900s when the only treatments available for seizures were harsh, ineffective drugs such as phenobarbital and potassium bromide.
The diet fell out of use with the development of gentler, more effective epilepsy drugs, but interest was renewed in the 1990s with publicity surrounding Hollywood producer Jim Abrahams' son, whose severe epilepsy was effectively controlled by the diet.
There have been many observational and retrospective studies of the procedure but never a randomized, double blind trial, which is considered the gold standard for assessing efficacy.
In the new study, Dr. J. Helen Cross of Great Ormond Street Hospital in London and her colleagues enrolled 145 children, ages 2 to 16, who were having at least seven seizures per week and who were not responding to anti-epileptic drugs. They were randomly assigned to receive the ketogenic diet or a normal diet for three months, after which those on the normal diet were switched to the treatment diet.
After several children dropped out for various reasons, there were 54 children in the diet group and 49 in the control group.
The team reported Friday in the online edition of the journal Lancet Neurology that the number of seizures dropped by more than a third in the group receiving the ketogenic diet, while the seizures rose by more than a third in the control group.
Twenty-eight of the 54 children in the diet group had more than a 50% reduction in seizures, compared with four of the 49 children in the control group.
The most frequent side effects were constipation, vomiting, lack of energy, and hunger.
The researchers concluded that "the diet should be more widely available as a treatment," but cautioned that it "should only be undertaken on medical advice and under medical and dietetic supervision."