The study followed 38 amateur soccer players who had been playing the sport since their childhood, an average of 22 years. Results founds that using your head more than 1,000 to 1,500 times within a year could cause symptoms of cognitive dysfunction, said study lead Dr. Michael Lipton, director of radiology research at Albert Einstein College of Medicine of Yeshiva University in New York.
The study, which used advanced imaging techniques and cognitive tests that assessed memory, was published online June 11 in the journal Radiology.
“We studied soccer players because soccer is the world’s most popular sport,” Lipton said. “Soccer is widely played by people of all ages and there is concern that heading the ball — a key component of the sport — might damage the brain.”
On average, soccer players head the ball six to 12 times during games, where balls can travel at speeds of more than 80 kilometers per hour. During practice drills, players commonly head the ball 30 or more times, the researchers said. The impact from a single heading is unlikely to cause traumatic brain damage, they said, but scientists have worried about cumulative damage.
“Repetitive heading could set off a cascade of responses that leads to degeneration of brain cells over time,” Lipton added.
In a separate study published in Plos One earlier this year, high school soccer players who had just completed a practice session involving heading soccer balls performed worse on an iPad cognitive test than students who didn’t play soccer.