November 18, 2020
Heading a football just 20 times may lead to reduced brain function, a new study claims, following increasing concerns that footballers are at a higher risk of dementia.
UK researchers analysed the cognitive function – including memory and mental ability – of footballers before and after 20 headers.
They found working memory, which allows the brain to briefly hold new information while it’s needed in the short term, declined by 20 per cent.
The vast majority of participants who headed the ball (80 per cent) also showed potential signs of concussion – temporary injury to the brain.
Calls for the links between dementia and football to be conclusively investigated have increased following the death of 1966 World Cup hero Nobby Stiles last month, who had advanced dementia.
His England colleague Sir Bobby Charlton was also recently diagnosed with the condition, which is associated with an ongoing decline of brain function.
Sir Geoff Hurst, an England teammate of both players, said this week that a total ban on children in the UK heading footballs would be ‘a sensible suggestion’.
‘Our results are both surprising and concerning,’ said Jake Ashton, a postgraduate research student at Liverpool Hope University, where the new heading experiments was conducted.
‘With the cognitive tests, there was a significant reduction in verbal and spatial working memory.
‘While more research is needed, there may also be a need to put measures in place to limit heading during football training sessions, in all ages.
‘The impacts of using a harder ball should also not be ignored.’
Children under the age of 12 are already banned from heading footballs in training in England, Scotland and Northern Ireland, and under-18s can only head the ball a restricted amount of times in training.
Ashton is now calling for sponge balls to be used during children’s training sessions and for referees at grassroots levels to measure the ball pressure before match kick offs.
To study the immediate effects of heading a ball, Liverpool Hope University researchers recruited 30 recreational male football players aged between 18 and 21 years old who play once a week.
Participants headed one of two different balls – either a soft ball, around 8.8 pounds per square inch (PSI, a unit of pressure) or a ‘hard’ ball, at 16.2 PSI.
’10 of the participants headed balls with a PSI of around 8, while the other 10 headed balls with a PSI of around 16 – pressures at either end of FA guidelines,’ said Ashton.
Researchers performed the King-Devick test, which provides an immediate indicator of head trauma or suspected concussion by measuring ‘saccadic eye speed’ – how quickly one can locate and identify visual targets.
King-Devick is a two-minute rapid number naming assessment in which an in individual quickly reads aloud single digit numbers.
The test revealed an overall increase in both the time and number of errors following heading.
Average saccadic eye speed decreased by around 10 per cent for both soft and hard ball groups on average, compared to the control group who didn’t head a ball.
The time needed to complete the test increased by three seconds when compared to a baseline of the remaining 10 participants who didn’t head a ball at all.
Usually after a knock, if the time needed for an athlete to complete the King-Devick test increases by three seconds from their normal values, it’s considered a possible concussion and they are removed from competition.
The increased times for both the soft ball group (4.32 seconds) and hard ball group (4.57 seconds) were ‘so extreme that it would raise suspicion of a concussion in the case of a head injury’, the research team say.
Two other tests tested the memory recall of the participants.
Spatial span – the recall of objects in space within a particular sequence – reduced by an average of 15 per cent for both ball groups compared with the control group
And ‘digit span’ – the recall of certain numbers within a particular sequence – tailed-off by 20 per cent in the group heading the hard football compared to those heading the soft football.
‘The group with the higher-pressure ball showed greater declines in working memory than the other group,’ said Ashton.
‘And overall both groups showed significant reductions in verbal and spacial working memory.’
Ashton said his study, which has been published in Science and Medicine in Football, doesn’t look at the repercussions of heading a football over a number of years.
But the results showing the effects of just 20 headers suggest the cognitive damage could be even more severe over the typical timeframe of a professional career.
The move to limit heading in training for under-18s this February followed a separate report, published in October last year by the University of Glasgow, which found link between former professional footballers and brain disease.
The study suggested players could be three and a half times more likely to die of dementia and other neurological diseases.
At the time Dr Willie Stewart, the consultant neuropathologist who led the study, said: ‘A lot more research is needed to understand the factors contributing to increased risk of neurodegenerative disease in footballers.
‘Meanwhile it is sensible to act to reduce exposure to the only recognised risk factor so far.’
England manager Gareth Southgate, who headed the ball in a professional career as a defender spanning nearly 20 years, has also expressed his own worries this month after the death of Stiles on October 30.
‘At my age, having headed a lot of footballs, I do have concerns,’ Southgate said.
‘In terms of the link, there is research going on. That’s a little bit inconclusive at the moment, which is a bit frustrating for everybody because we’d love to have a clear solution.
‘Of course it’s a concern for everybody and we have to keep supporting that research. Unfortunately we don’t have all the answers we’d like at the moment.’
Other high profile deaths footballing dementia deaths include Liverpool wing-half Bob Paisley, who died from Alzheimer’s disease, the most common type of dementia in the UK, in 1996, and West Bromwich Albion legend Jeffrey Astle in 2002.
In conjunction with Alzheimer’s Society’s Sport United Against Dementia, the Daily Mail is now calling for meaningful action to battle dementia as part of a new campaign.
The wide-ranging campaign asks for further funding into crucial research around football’s link to the disease and for lawmakers to ratify temporary concussion replacements.