World Cup winner George Cohen and former Manchester United star Pat Crerand have pledged to donate their brains to science after research tentatively linked heading the ball with dementia.

The British sporting heroes, both 77, said they wanted to help improve understanding of how professional players could be at an increased risk of serious health problems in later life.

Cohen and Crerand revealed their intentions following an announcement by University College London experts that they had found signs of chronic traumatic encephalopathy (CTE), a condition that can cause dementia, in the brains of four ex-players.