For many epileptics, a spoonful of sugar brings on seizures, but the sugar mimic 2-deoxy-D-glucose (2DG) may actually help prevent them, according to neurobiologist Avtar Roopra at the University of Wisconsin, Madison, and colleagues (Nat. Neurosci., DOI: 10.1038/nn1791). Biomedical researchers have long known that sugar-free diets thwart seizures in epileptics, but the exact mechanism has been something of a mystery. It turns out that, in epileptics, high levels of the cofactor NADH, a by-product of glycolysis, disrupt normal regulation of a neuron's chromatin, the quaternary structure of DNA. This disruption leads to expression of genes that bring on severe seizures. Roopra and his coworkers found that 2DG blocks glycolysis, thereby preventing epileptic seizures in rats without taking away the sweet taste of their food. The ketogenic (low sugar) diet "requires a lot of control and often fails with children, who are fed up of missing out on sweets and cookies," Roopra says. "But 2DG may work as an effective substitute."