WEDNESDAY, Feb. 15, 2017 (HealthDay News) -- For the first time, researchers have confirmed evidence of the devastating brain disease chronic traumatic encephalopathy (CTE) in retired soccer players.
Investigators in the United Kingdom examined the brains of six former soccer players with dementia who had died. All six had signs of Alzheimer's disease and four also had signs of CTE, the degenerative brain condition that has been linked to repetitive head trauma.
"This is the first time CTE has been confirmed in a group of retired" soccer players, said study lead author Dr. Helen Ling, a neurologist at University College London.
The rate of CTE among the former soccer players was higher than the 12 percent found in the general population, the researchers reported.
Other studies have found evidence of CTE in the brains of athletes who compete in such contact sports as boxing and American football.
While the new findings suggest a link between playing soccer and later degenerative brain disease, Ling said only a few retired players were studied. Researchers don't know how common dementia is among soccer players.
"All of the players whose brain autopsies showed signs of CTE also had Alzheimer's pathology, but the relationship between the two diseases remains unclear," Ling said in a university news release.
Study co-lead author Dr. Huw Morris, a neurologist, said researchers don't know exactly what causes CTE in soccer players or how great the risk may be.
"Major head injuries in [soccer] are more commonly caused by player collisions rather than heading the ball," Morris said. He noted that players "head" the ball thousands of times during a career, but this common soccer move seldom causes noticeable neurological symptoms.
More research is "urgently needed" to examine the risks so long-term damage can be prevented, Morris added.
The study was published Feb. 14 in the journal Acta Neuropathologica.
The American Association of Neurological Surgeons has more on sports-related head injury.