The Professional Fighters Brain Health Study released new data this week about how repeated blows to the head impact brain structure and performance. According to the results, processing speed slows and regions of the brain shrink among many professional martial arts fighters.
The results are cumulative over a five-year period during which researchers evaluated 224 professional fighters between the ages of 18 and 44. Not surprisingly, while fighters in all forms of martial arts evaluated experienced some shrinkage and/or cognitive slowing, those who were professional boxers fared the worst.
“Perhaps the most obvious explanation is that boxers get hit in the head more,” the authors suggest in their report. “In addition to trying to concuss (i.e., knockout) their opponent, martial arts fighters can utilize other combat skills such as wrestling and jiu-jitsu to win their match by submission, without causing a concussion.”
What kind of fighting is the worst for brain shrinkage
Among those athletes evaluated, each was given a fight exposure score, or FES, based on total number of career matches, the average number of professional fights each year, and the type of marital art involved. Based on individual risk factors, fighters were given scores from 0 to 4.
By the end of the study, experts had found for every jump in FES there was a volume shrinkage of 0.8 percent in the caudate and thalamus regions of the brain, as well as a reduction in processing speed of 2.1 percent, or an estimated 0.19 percent reduction per fight.
Overall, fighters with an FES of 4 were 8.8 percent slower in processing speed than those with an FES of 0.
“The most common measurable relationship between smaller brain volumes and performance is in tasks that involve speed of processing information. Keep in mind, we are studying young active fighters, so the slower processing speed may be difficult for someone to notice on a day-to-day basis,” study author, Dr. Charles Bernick, told MNT. “However, the regions that show a correlation between fight exposure, volume and speed of processing are deep in the brain and receive input, connections, from a wide range of other areas that converge.”
Brain shrinkage isn’t unique to sports where head trauma is likely–or even just to sports in general. A handful of things that are known to cause brain shrinkage, including lack of sleep, obesity, cigarette smoking, diabetes and high blood pressure. According to a study from University of California, Davis, it all has to do with damage to vessels in the head. Once these vessels become damaged, they can no longer support the brain tissue around them and it begins to atrophy.
Fighting sports complicate brain vessel damage not only through direct impact, but through the violent twisting motion of the head that often accompanies it.
There are a few things fighters can do to avoid brain shrinkage and cognitive slowing, states Bernick, the primary of which is simply not to lose, therefore typically coming out of the fight with the fewest injuries. Training and proper recovery time was also critical.
“From what we know of the relationship between exposure to head trauma and either imaging or performance on clinical testing,” he added, “it seems most prudent to try and avoid significant head trauma in training (that is, limit the amount of hard sparring that is done in training), and allow enough rest time between competitions, particularly if it was a hard fight or if the fighter was KO’d or TKO’d.”