Footballers who repeatedly head the ball can end up suffering from dementia, new findings have suggested, prompting calls for more research into a long-suspected issue in the sport.
A potential cause of dementia thought to arise from blows to the head has, for the first time, been confirmed in a group of retired footballers following a small study.
The results provide a platform for a "pressing research question" on whether dementia is more common in footballers than the general population, the authors said.
The brains of six of the 14 retired players involved in the research - none of whom have been identified - underwent post-mortem examinations and four were found to have chronic traumatic encephalopathy (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.