New York, Oct 3 (IANS): The active ingredient in marijuana, tetrahydrocannabinol or THC, may help protect the brain in cases of traumatic brain injury, says a study.

Patients with traumatic brain injuries who tested positive for THC were more likely to survive than those who tested negative for the illicit substance, the findings showed.

"This study was one of the first in a clinical setting to specifically associate THC use as an independent predictor of survival after traumatic brain injury," said lead author David Plurad from the Los Angeles Biomedical Research Institute (LA BioMed) in the US.

Previous studies conducted by other researchers had found certain compounds in marijuana helped protect the brain in animals after a trauma, Plurad added.

The study included 446 patients who suffered traumatic brain injuries and underwent a urine test for the presence of THC in their system.

The researchers found 82 of the patients had THC in their system. Of those, only 2.4 percent died. Of the remaining patients who did not have THC in their system, 11.5 percent died.

The researchers noted that the timing of their study was "pertinent" because of current efforts to decriminalise marijuana and other research that has shown THC can increase appetite, reduce ocular pressure, decrease muscle spasms, relieve pain and alleviate symptoms associated with irritable bowel disease.

The study appeared in the journal The American Surgeon.