A potential cause of dementia thought to arise from blows to the head has been confirmed in a group of retired footballers for the first time, prompting Dawn Astle to ask authorities to stop pushing the issue 'under the carpet'.
The findings, from a study of 14 former players, suggest a possible link between playing football and developing conditions such as dementia in later in life.
Former West Brom and England striker Astle died in 2002, aged 59, suffering from early on-set dementia, which a coroner found was caused by heading heavy footballs and gave the cause of death as 'industrial disease'.
A subsequent re-examination of Astle's brain found he was suffering from the neuro-degenerative brain disease Chronic Traumatic Encephalopathy (CTE).
CTE can only be established following death and it has also been found in deceased American footballers, boxers and rugby players.
Today's results provide a platform for a "pressing research question" on whether dementia is more common in footballers than the general population, Dr Helen Ling, lead author of the UCL Queen Square Brain Bank study said.
The Astle family have campaigned for the Football Association to recognise the impact of heading footballs and take action to protect players since the death of the former striker.
Ms Astle said: "We know what happened to dad and the evidence is mounting and mounting. What we need is for football to do something.
"This isn't a broken leg, people are dying, these former players are dying. They have to take responsibility. It is too late for older players, it is about today's players and the footballers of the future."
"It has been 15 years since dad died. This could have been done. It is time for the authorities to pull their fingers out and stop pushing it under the carpet."
The brains of six of the 14 retired players involved in the research underwent post-mortem examinations and four were found to have CTE pathology, while all six had signs of Alzheimer's disease.
CTE can cause dementia and, like Alzheimer's, is characterised by a build-up of abnormal tau protein in the brain.
The rate of CTE detected in the footballers' brains was greater than the 12 per cent average found in a previous study which looked at 268 brains from the general population.
The ex-players involved in the study, 12 of whom eventually died of advanced dementia, all began playing football and heading the ball when they were children or teenagers and continued for an average of 26 years.
They were all referred to the Old Age Psychiatry Service in Swansea, Wales between 1980 and 2010.
Consultant psychiatrist Dr Don Williams, who ran the study from the Swansea service, said he was motivated to do so after being approached by a man whose footballer father had been diagnosed with dementia, and who wanted to know if headers could be the cause.
He said: "As a result I looked out for men with dementia and a significant history of playing soccer, followed them up and where possible arranged for post-mortem studies to be carried out.
"The results suggest that heading the ball over many years, a form of repetitive sub-concussive head injury, can result in the development of CTE and dementia.
"Thus the original suggestion has been shown to be of merit and worthy of further investigation."
The scientists acknowledged the size of the study was small, and appealed to people to remain open-minded when it comes to presenting themselves for research.
Prof Morris said: "I think people being involved in research is a good thing and would encourage people to consider that."
Dr Ling said the research, published in the journal Acta Neuropathologica and funded by The Drake Foundation is important, but added more is needed for definitive results.
"Previous studies have shown that the risk of Alzheimer's disease is increased in people with previous head injuries.
"On the other hand, the risk of dementia is also increased with age and we don't know if these footballers would have developed Alzheimer's disease anyway if they hadn't played football.
"The most pressing research question is therefore to find out if dementia is more common in footballers than in the normal population."