Last Updated: 2007-10-04 19:01:04 -0400 (Reuters Health)

NEW YORK (Reuters Health) – The results from a systematic review of observational studies suggest that amateur boxing does not cause chronic traumatic brain injury.

"Amateur boxing is becoming an increasingly popular participation sport, especially within universities and for both sexes," Dr. Mike Loosemore, from Northwick Park Hospital in Harrow, UK, and colleagues note in the October 5th Online First issue of the British Medical Journal. The present findings suggest that, at least from a brain injury standpoint, the sport is safe.

The researchers identified 36 observational studies, which looked at chronic traumatic brain injury related to amateur boxing. The definition of chronic traumatic injury included any abnormality on clinical neurologic examination, neuroimaging studies, electroencephalography, or psychometric testing.

The investigators found that the quality of evidence either supporting or refuting amateur boxing as a cause of brain injury was generally poor. Studies with the best methodology included those with a cohort design and those with psychometric testing.

Just 4 of the 17 highest quality studies found any evidence of a link between boxing and brain injury; the others yielded negative results.

In a related editorial, Dr. Paul McCrory, from the University of Melbourne in Victoria, Australia, comments that "given the quality of the published literature, it is not surprising that Loosemore and colleagues find little conclusive evidence for chronic traumatic brain injury in amateur boxing."

Still, given the short careers that most boxers have today and their limited exposure to repetitive head trauma, it is unlikely that chronic traumatic brain injury will develop in many participants, he adds.

BMJ Online First 2007.