Researchers at the Mayo Clinic say they are "surprised" at the rate of chronic traumatic encephalopathy (CTE) they found in a recent study of adult men who participated in amateur contact sports in their youth.
Their report, which was published Tuesday, suggests that boys who participate in amateur contact sports such as youth and high school football, hockey and rugby, are at increased risk of developing CTE, a degenerative brain disorder that often leads to memory loss and dementia.
The condition is caused by repeated head trauma, and there's growing evidence of CTE among professional football players, the Rochester Post-Bulletin reports.
'Surprisingly high' rate of CTE
Mayo researchers in Jacksonville, Florida, examined the clinical records of 1,721 people whose brains had been donated to the Mayo Clinic Brain Bank. They found 66 men who had documented participation in contact sports during their youth and teenage years. Of those men, one-third of them had evidence of CTE.
By comparison, none of the 198 brains of people who had not participated in contact sports during their youth showed any sign of CTE. That includes all 66 women who were examined.
CTE only can be diagnosed posthumously, so the study used brains donated for research.
“The 32 percent of CTE we found in our brain bank is surprisingly high" compared to the general population, said the study's lead author Kevin Bieniek in a news release from Mayo. “If one in three individuals who participate in a contact sport goes on to develop CTE pathology, this could present a real challenge down the road."
It's the first study that looks at the incidence of CTE in non-professional athletes in line with criteria recently established by the National Institute of Neurological Disorders and Stroke, according to the news release.
The study's senior author, Dr. Dennis Dickson, calls the findings "groundbreaking."
“The frequency with which [Bieniek] found CTE pathology in former athletes exposed to contact sports was surprising. It is pathology that had gone previously unrecognized," Dickson added.
Other questions raised
This study is just the latest to raise questions about the safety of contact sports for youth and teenagers.
Last month two physicians from the University of Minnesota made headlines when they recommended schools drop their tackle football programs because of the high number of players who get concussions.
The U.S. Soccer Association issued new recommendations last month to limit headers for players younger than 10 years old, the Post-Bulletin notes.
And a new movie coming out soon, called "Concussion," that looks at brain injuries among NFL football players, will no doubt raise more questions about the safety of the game.
The Mayo reseachers said they're not trying to discourage people from participating in sports. But "it is vital that people use caution when it comes to protecting the head," Bieniek said.
The study was published in the December issue of Acta Neuropathalogica.