Ingredient in Blue M&Ms may hold key to treating spinal cord injuries.

A blue dye found in Gatorade and Rocket Pops could play a protective role in the cellular mayhem that follows spinal cord injury. In rats, the dye — known as FD&C Blue No.1 — appears to block a molecule that floods the injury site and kills nerve cells, a team reports in the July 28 Proceedings of the National Academy of Sciences.

Rats dosed with the dye after injury showed greater improvement in motor skills than rats not receiving the dye. And the food colorant’s low toxicity suggests a new approach for treating spinal cord trauma in humans, injuries for which there are few therapies.

“It’s not a cure,” says neuroscientist Maiken Nedergaard of the University of Rochester Medical Center in Rochester, N.Y., who led the new study. “I don’t think that anything can cure this, but for the patient it could be a big improvement.”

The results are impressive and realistic, comments Lynne Weaver, a neuroscientist at the Robarts Research Institute in London, Canada. Weaver notes that the side effects of any new potential therapy must be considered, but “the principle is interesting.”

ATP, for adenosine triphosphate, is known as the energy currency of cells, and the molecule is used like a battery whenever cells need to get stuff done. But a few years ago Nedergaard and her colleagues reported that ATP has a darker side. It wreaks havoc when the central nervous system is injured, flooding the injury site and hitting a receptor that sits on some immune system cells. ATP binds to this receptor, called P2X7, resulting in a cascade of events that leads to cell death.