‘Heading’ a football can cause cognitive impairment and brain injury
By Liz Lockhart
With football players currently in the news, it now emerges that repeatedly heading a football increases the risk of brain injury and cognitive impairment, according to new research.
The research, using advanced imaging techniques and cognitive tests, was conducted by investigators from the Albert Einstein College of Medicine of Yeshiva University and Montefiore Medical Centre, the University Hospital and Academic Medical Centre for Einstein.
The diffusion tensor imaging (DTI) from this study was presented at a recent meeting of the Radiological Society of North America (RSNA) in Chicago.
The researchers used DTI, which is an advanced MRI-based imaging technique, on 38 amateur football players with an average age of 30.8 years who had all played the sport since childhood.
In addition the players were asked to report the number of times which they had headed the ball over the previous year. Brain images of the players who had most frequently headed the ball were compared with those of the remaining players. The researchers found that frequent headers displayed brain injury similar to that found in patients with concussion, which is known as mild traumatic brain injury (TBI).
Given that football is the world’s most popular sport, the findings are particularly concerning. In America 18 million people play football with 78% of them under the age of eighteen.
During recreational play footballs travel at a speed of up to 34 miles per hour whereas in professional play they can reach up to twice that speed.
Having determined the potentially damaging impact of frequent heading, the lead author of the study, Michael Lipton MD., Ph.D., associate director of Einstein’s Gruss Magnetic Resonance Research Centre said ‘ Our goal was to determine if there is a threshold level for heading frequency that, when surpassed, resulted in detectable brain injury.’
Further analysis showed a threshold level of around 1,000 to 1,500 headings per year as a cut-off level, after which the study participants showed significant injury.
‘These two studies present compelling evidence that brain injury and cognitive impairment can result from heading a soccer ball with high frequency. While heading a ball 1,000 or 1,500 times a year may seem high to those who don’t participate in the sport, it only amounts to a few times a day for a regular player,’ said Michael Lipton.
‘Heading a soccer ball is not an impact of a magnitude that ill lacerate nerve fibres in the brain, but repetitive heading may set off a cascade of responses that can lead to degeneration of brain cells,’ Lipton added.
Five areas in the frontal lobe and in the temporo-occipital region of the brain were affected by frequent heading, the researchers found. These areas are responsible for attention, memory, executive functioning and higher-order visual functions.
In a related study Dr Lipton and his colleague Molly Zimmerman, Ph.D., gave the same 38 participant soccer players tests which were designed to assess their neuropsychological function. The players with the highest frequency of annual heading performed worse on tests of verbal memory and psychomotor speed relative to their peers. Psychomotor speed testing involves activities which require mind-body coordination such as throwing a ball.
‘These two studies present compelling evidence that brain injury and cognitive impairment can result from heading a soccer ball with high frequency,’ Dr. Lipton said. These are findings that should be taken into consideration in planning future research to develop approaches to protect soccer players.’
Additional research could help to refine the number in the range for safe heading frequency. This could then be used to establish new heading guidelines and games could be monitored and restricted based on confirmed unsafe exposure thresholds.
‘In the past, pitchers in Little League Baseball sustained shoulder injuries at a rate that was alarming, but ongoing research has helped shape various approaches, including limits on the amount of pitching a child performs, which have substantially reduced the incidence of these injuries,’ noted Lipton.
‘Brain injury due to heading in children, if we confirm that it occurs, may not show up on our radar because the impairment will not be immediate and can easily be attributed to other caused like ADHD or learning disabilities,’ Lipton continued. ‘We, including the agencies that supervise and encourage soccer play, need to do the further research to precisely define the impact of excessive heading on children and adults in order to develop parameters within which soccer play will be safe over the long term.’
