A little alcohol in the blood may actually help the survival of those entering hospitals with traumatic brain injury, according to a study by Canadian researchers.

"Low concentrations of alcohol may have the ability to reduce secondary brain injury and may therefore improve brain injury survival," Dr. Homer Tien, a trauma surgeon at Toronto's Sunnybrook Health Sciences Centre, said in a press release.

"However, the study only describes the effect of alcohol on the brain after injury occurs and I'd like to stress that alcohol remains the leading cause of preventable trauma deaths and dramatically increases the likelihood of injury and fatal injury."

In fact, researchers said that up to half of all trauma patients are intoxicated before suffering their injuries.

"I'm a trauma surgeon, so I don't want people to drink and drive," Tien told CTV News.

The study was published Monday in the Archives of Surgery journal. Doctors at Sunnybrook looked at 1,158 patients admitted with traumatic brain injury (TBI) between Jan. 1 1988 and Dec. 31, 2003.

All of the patients suffered TBI from blunt head trauma.

Tien and his team then divided the patients up into three groups, depending on their blood-alcohol content: zero; low to moderate (less than 230 milligrams per deciliter); and high (greater than 230 mg/dL).

Those with TBI who had a high blood-alcohol reading actually had a higher risk of dying, because the alcohol made their injuries less manageable.

But patients with a low to moderate level were 24 per cent less likely to die from their injuries than those with no alcohol in their blood.

That could be because alcohol depresses brain activity, which can be beneficial if the brain is trying to heal itself, according to Dr. Tarek Razek, director of trauma at the McGill University Health Centre in Montreal.

But like the authors of the study, Razek told The Canadian Press that alcohol greatly increases the risk of being injured in the first place.

"The number one cause of death for people under the age of 49 is injury, and your risk of having an injury is humongously increased if you're drinking alcohol," he said.

"There may be a small chance that there's an improvement in your outcome after you have a major brain injury. The problem is, if you're using alcohol and driving, you have a higher risk of having that injury in the first place."

Other doctors, like Charles Tator of Toronto Western Hospital, said the research contradicted basic medical knowledge.

"It flies in the face of what we have learned over the past 50 years, that alcohol is damaging to nerve tissue," Tator told CTV News.

"Nerve tissue does not survive with a little bit of alcohol on board."

Tien and the other researchers wanted to see if alcohol could protect brains against severe trauma to the head, after seeing similar evidence in animals.

But because they drew their data from hospital records, it meant they couldn't keep track of patients after they were released. Tien's team also had no idea whether patients retained any brain function after suffering head trauma, or if alcohol played a role in such retention.

Further research would be limited because of the ethics involved in testing alcohol on head trauma patients. But if doctors persist, Razek said they could find a new way of helping the brain recover from injury.

"We may find a chemical derivative of alcohol that is a good way to put you into a coma after you've had a brain injury to sort of sedate your brain and let it heal. (But) you'd rather not be in that situation in the first place," he told CP.

"If you put brain injury on a scale from one to 10, with one being a mild brain injury like a hockey player concussion and 10 being you're dead, maybe you can drop your injury from an eight to a seven.

"But if you didn't drink, you wouldn't have had one."

With a report from CTV's Avis Favaro and Elizabeth St. Philip and files from The Canadian Press