The findings are published in the latest issue of the scientific journal British Journal of Sports Medicine.
“Thus far, neuropsychological tests and x-ray examinations have not been able to provide an unequivocal answer to the question of whether heading in soccer can cause permanent brain damage. Our research team has tackled the issue from another angle, monitoring instead various neurochemical markers in the spinal fluid,” says Henrik Zetterberg, associate professor of neurochemistry at the Sahlgrenska Academy.
In the study, some 20 amateur soccer players were asked to head a ball in a manner similar to a common corner kick. A week after the training session, the research team took samples of the soccer players’ spinal fluid for analysis.
“When nerves and support cells in the brain are damaged, they release various protein markers that can be detected in the spinal fluid, but we could not see any signs that these headshots caused brain damage,” says Henrik Zetterberg.
Half of the players performed 10 approved headshots, while the other half headed the ball 20 times. The researchers could not see any difference between the players who headed ten or twenty shots, nor between headshooters and a matched control group that did not head any shots.
“In an average match there are a total of maybe six headshots, so in our study we overdosed the number of headshots. Since we still can’t detect any sign of brain damage, we can say that heading the ball is not dangerous,” says Henrik Zetterberg.
In a previous study, the same research team asked amateur boxers to undergo a similar test. In that study, they found markers in the spinal fluid that indicated that there was damage to the brain.
“The forces that impact the brain in a headshot are considerably more limited than those from a series of blows to the head. This is probably due to a combination of less kinetic energy and a greater ability to stabilize the head in headshot compared with boxing,” says Henrik Zetterberg.
Journal: British Journal of Sports Medicine
Title of article: No neurochemical evidence for brain injury caused by heading in soccer
Authors: Henrik Zetterberg, Michael Jonsson, Abdullah Rasulzada, Cornel Popa, Ewa Styrud, Max Albert Hietala, Lars Rosengren, Anders Wallin, and Kaj Blennow