LONDON - England's soccer authorities on Thursday invited applications for independent research into whether playing the sport heightens the risk of degenerative brain disease in later life.

It follows a campaign by the family of former West Bromwich Albion striker Jeff Astle, whose 2002 death from chronic traumatic encephalopathy (CTE) was linked to repeatedly heading heavy leather soccer balls.

The Football Association and players' union the Professional Footballers' Association (PFA) made the call for research following 18 months of consultation and analysis.

"This is a crucial issue for the FA and one that we feel passionately about addressing," the FA's head of medicine, Charlotte Cowie, said in a statement.

"Dementia is a debilitating disease, which places extraordinary emotional and physical burdens on both sufferers and those close to them.

"Player welfare is paramount and it is increasingly important that the football authorities investigate further whether there are any potential risks associated with heading the ball, as this is a unique feature of our game."

The focus of the independent study will be the question: "Is the incidence of degenerative neurocognitive disease more common in ex-professional footballers than in the normal population?"

The FA and PFA will jointly fund the project. The closing date for the submission of research proposals is May this year.

Later on Thursday, Gordon Taylor, the long-serving chief executive of the PFA, insisted his organization had done more to look into possible links between heading the ball and brain injuries than any other in world soccer.

Taylor, who played over 500 league games in his 18-year career, and the PFA have been heavily criticised for allegedly failing to take the matter seriously.

Astle's daughter Dawn walked out of a meeting with Taylor because she felt he was evasive when she repeatedly asked him why the PFA had not made more advances regarding the issue over the past 15 years. The exchange was filmed by the BBC.

However, Taylor vigorously defended himself and the PFA.

"I don't know of another football organization anywhere in the world that has done more than us? If you do, please tell me," the 72-year-old told Press Association Sport.

"The rest of the world has struggled to get to grips with this, not just us. There is no magic key.

"I feel very offended when people accuse us of a cover-up and say we don't want to know about the health risks. We do."

Research into links between soccer and brain damage in later life is thin on the ground.

A recent British study published in the Acta Neuropathologica journal found the brains of four out of six former players with dementia showed signs of CTE, far in excess of the average rate of 12 percent.

Agence France-Presse