Can heading a football cause brain damage?
A study suggests that people who frequently or repeatedly head a football have changes occur in their brain that are similar to those seen in people who have a form of brain damage. But we don’t know if heading the ball causes these changes.
BMJ Group News
What do we know already?
Research into some contact sports, like rugby, ice hockey, and American football, has shown that head injuries such as concussions are common.
Concussion occurs when the head either accelerates rapidly and then is stopped, or is spun rapidly or shaken violently. This often causes confusion, blurred vision, memory loss, nausea, and sometimes unconsciousness.
To find out if there is a risk that amateur and professional football players could suffer brain injuries through heading the ball, researchers used a technique called diffusion tensor imaging (DTI) to take detailed pictures of the brains of 32 players who had all been playing football since childhood.
Using this technique researchers were able to detect tiny changes in the nerve fibres of the brain, called white matter. These changes within white matter have been associated with impaired brain functions in patients with concussion.
The researchers also asked the players to estimate how often they headed a ball, and ranked the players based on heading frequency. They then compared the brain images of the most frequent headers with those who headed the ball less frequently to see if there were any differences seen in the scans.
What does the new study say?
They found that frequent headers showed changes in the brain similar to that seen in patients with concussion.
The researchers were able to identify five parts of the brain, in the frontal lobe (behind the forehead) and in the temporo-occipital region (the bottom-rear areas) of the brain that were affected by frequent heading - areas that are responsible for things like attention span and memory.
The researchers also compared the changes in each brain region with the frequency of heading in each football player.
They calculated that players would have to head a ball between 1,000 and 1,500 times a year before they were able to see a significant change in the white matter in the five brain regions identified by the scans.
How reliable is the research?
The researchers used advanced brain scanning techniques and so were able to detect very small changes in brain cells. But it is a small study so we can only make limited conclusions because we don’t know if these findings apply more widely.
Also, this type of study can tell us if people who head a football regularly have changes that are the same as those who have brain injuries. But it can’t tell us if heading a ball causes these changes, and if the changes will have any effect on how their brain functions or their health.
This study was presented at a conference, and was not reviewed or published in an academic journal.
What does this mean for me?
The researchers say that heading a football, on its own, is not an impact of a large enough magnitude to damage nerves in the brain. But repetitive heading may trigger responses that can lead to damage to the brain cells over time. But we need more research to be sure that this will have any effect on people’s health.