Kids with epilepsy may find that fasting helps lessen their seizures when drugs fail, according to new research from a Johns Hopkins University-led team of researchers.

Fasting as an epilepsy cure is hardly a new idea. Ancient Greek doctors often recommended dietary cures for patients who had seizures.

“One inclining to epilepsy should be made to fast without mercy and be put on short rations,” Erasistratus, a court physician to the ruler of Syria in the third century B.C., is quoted as saying by the Roman physician Galen.

In the modern era, children with seizures who do not respond to drugs are often treated with what's called a "ketogenic" diet -- high on fats, low on carbs. In a new paper published in the journal Epilepsy Research, Johns Hopkins researcher Adam Hartman and his team claim that fasting can complement the ketogenic diet.

Hartman and his colleagues examined six children between the ages of 2 and 7, all of whom were on the ketogenic diet and still experiencing seizures. They asked the children to fast every other day. Four out of the six children saw a reduction of between 50 and 99 percent of their total number of seizures. Half of the subjects kept up the fasting regimen for two months or more.

“Our findings suggest that fasting does not merely intensify the therapeutic effects of the ketogenic diet but may actually represent an entirely new way to change the metabolism of children with epilepsy,” Hartman, a pediatric neurologist, said in a statement Thursday.

Of course, the current study is with a very small group of children, and larger studies must be done to evaluate the benefits of fasting for young epileptics further.

Fasting also should only be done under the watchful eye of a pediatric neurologist, the researchers caution.

The ketogenic diet is thought to work by influencing the signaling pathways in the brain that lead to seizures. The diet was developed specifically to force patients to burn fats instead of carbs, mimicking the physiological processes in starving people. When a person is eating very few carbohydrates, the fat in their diet is broken down into fatty acids and compounds called ketone bodies. After a while, the person enters a state called ketosis, where ketone bodies become elevated in the blood and replace glucose as an energy source for the brain.

A controlled trial published in The Lancet in 2008 found that a ketogenic diet is effective in reducing seizures in children. In that study, which examined 54 children on the ketogenic diet and 49 controls, 28 children in the diet group saw their seizures reduced by half or more, compared with only four of the children in the control group. Five of the children who were treated with the ketogenic diet saw seizure reductions greater than 90 percent, a result that did not surface in the control group.

The ketogenic diet isn't always pleasant, with some children experiencing constipation, vomiting, listlessness and hunger.

Many researchers think that ketogenic diets and fasting work in the same way, but Hartman and his team suspect that fasting affects nerve cells in a completely different way.

The team conducted a previous study that examined epileptic mice, which was published in the journal Epilepsia in 2010. One group of mice was put on a ketogenic diet, and the other was treated with fasting. The different groups responded differently to certain seizure triggers -- the fasting mice had seizures in response to mild electric shocks, but they tolerated injections of the nervous system stimulant kainic acid. The researchers observed the opposite phenomenon in ketogenic mice; they could tolerate electricity, but were triggered by the kainic acid.

“We don’t fully understand the reasons for these marked differences, but unraveling the mechanisms behind them will help pave the way toward new therapies for epilepsy, and is the focus of our ongoing work,” coauthor Eric Kossoff said in a statement Thursday.

SOURCE: Hartman et al. “Intermittent fasting: A 'new' historical strategy for controlling seizures?” Epilepsy Research published online ahead of print 1 December 2012.

Medicine