Amateur Boxers at Risk of Brain Injury
Even Mild Blows Can Cause Brain Damage, Study Shows
May 2, 2007 (Boston) -- A new study gives added scientific meaning to the
term punch drunk.
Researchers report that even the relatively mild blows to the head incurred
by amateur boxers appear to cause brain damage.
The researchers analyzed the cerebrospinal fluid of 14 amateur boxers for
protein markers of brain injury. Levels of one particular marker for brain
damage, known as neurofilament light (NFL) protein, were four times higher in
boxers within 10 days of the fight than in healthy nonboxers.
In the study, the boxers were tested both after a fight and then again three
months after their last match. NFL levels were still elevated three months
Researcher Max Hietala, MD, PhD, of Sahlgrenska University Hospital in
Goteborg, Sweden, tells WebMD that the Swedish boxers studied were wearing
helmets that were much better padded than those generally used in U.S. amateur
“Regardless of the gear, if they got hit more than 15 times, it was like
having a mini-stroke,” he says.
NFL levels were up to eight times higher in amateur boxers who received more
than 15 high-impact hits to the head after a match than after the three-month
“Given that amateur fights are much shorter and generally involve milder
head blows than pro fights, you can just imagine what’s happening to
professional boxers,” James Kelly, MD, visiting professor of neurosurgery at
the University of Colorado in Denver, tells WebMD. Kelly was not involved with
The study was presented at the American Academy of Neurology’s annual
Repeated Hits Cause Brain Cells to Die
Hietala says a well-thrown punch carries more than a half-ton of force.
He says that the hits cause brain cells to die. Then they leak proteins into
the cerebrospinal fluid.
“If you get a concussion, you’ll also have elevated NFL levels, but there’s
nothing you can do,” Hietala says. “With boxing, you can.”
“We’ve seen some studies [on this topic before], but this is much more
scientifically detailed, with finer testing,” Kelly says. “This is truly
Not all the news is distressing: The researchers found that no evidence of
increased levels of NFL or other markers of brain injury in medical students
who volunteered to repeatedly hit a soccer ball with their heads.
“Our conclusion is that hitting a soccer ball with your head is not
dangerous,” Hietala says.