Repeated blows to the head during boxing and martial arts fights can result in shrinkage of brain structures as well as a loss of cognitive performance, according to a study published in the British Journal of Sports Medicine.
Those with a higher fight exposure score (FES) had reduction in volumes in several brain regions and poorer cognitive performance compared to those with a lower FES score and controls.
The researchers used MRI and tests of verbal memory, processing speed, fine motor skills, and reaction times to assess 224 professional fighters over 5 years. Fighters participated in up to 101 fights, with an average of 10 matches and careers that lasted for as long as 24 years.
Those with more extensive fight histories, and presumed elevated number of blows to the head, had lower volumes in the caudate and thalamus regions and lower processing speeds. For each increase in FES score, there was a 0.8% volume shrinkage in brain structures and a 2.1% reduction in processing speed, or 0.19% per fight. Those with an FES score of 4 were had 8.8% slower processing speeds than those with an FES score of 0.
Overall, boxers showed greater loss of brain structure volume and slower processing speeds compared to martial arts fighters, likely due to the fact that the sport centers around “knocking out” an opponent, or in clinical terms, giving them a concussion.
Certain parts of the brain lost their volume as a result of repeated appearances in boxing and martial arts tournaments, in a study that monitored brain structures with magnetic resonance imaging and tracked the brainpower performance of 224 fighters over 5 years of their combat careers.
As well as shrinkage in parts of the brain, the fighters in the study suffered losses in brain processing speeds in comparison with controls who had never taken part in any type of sport that could lead to head injury.