FA chairman Greg Clarke calls for concussions subs "as quickly as possible"

This phase of the report has not looked into why the incidence of these conditions is higher among footballers than the control group, but Clarke said on Monday that the game needed to understand whether repeated heading of the ball, or a failure to treat concussion properly, were contributory factors.

"One of the things we're pushing on, and I've spoken to FIFA and UEFA about this, is to introduce concussion substitutes as quickly as possible," he told the Digital Culture Media and Sport committee.

"If anyone has a head injury you don't just want to have a doctor looking at them quickly and saying 'you're OK' or 'you're not OK' – you can send someone else on to play while that player is assessed to make sure we move away from time pressure on doctors to make really important health decisions."

Football's lawmaking body, the International Football Association Board (IFAB), will discuss concussion at the meeting of its football and technical advisory panels in Zurich on Wednesday.

Within that, the PA news agency understands there will be a discussion on the use of concussion substitutes in the event of head injuries.

Jeff Astle's daughter was "staggered" to learn of the FIELD study findings.

Former England and West Brom striker Astle died 17 years ago from chronic traumatic encephalopathy (CTE), which the coroner described as an "industrial injury".

Dawn Astle, who has been campaigning since her father's death for football to research into this area, said: "My overall feeling is that I am staggered even though my own research and instinct was always that there was a serious problem.

"There will be no celebrations. It doesn't bring my dad back, it won't bring any other dads and husbands back. We knew dad could not be the only one. We just wanted that question answered.

"We just wanted to see that football cared enough to find out the scale of the problem, to do the right thing and be there for these people when they need them most. Whatever they do, it must be across all parts of the game.

"You can't assume it is not in grassroots and there is no evidence it is generational or that it was the old leather ball. And these players who have suffered dementia must not be a statistic – they must never be forgotten. They remain in the consciousness of the game."

The study assessed the medical records of 7,676 men who played professional football in Scotland and were born between 1900 and 1976. Their records were matched against more than 23,000 individuals from the general population.

It found that there was a five-fold risk of Alzheimer's disease, a four-fold increase in motor neurone disease and a two-fold increase in Parkinson's disease in former professional footballers compared to population controls.

Former Blackburn, Norwich and Celtic forward Chris Sutton, whose father Mike suffers from dementia, criticised the PFA for its handling of the issue.

Sutton said on Twitter: "If Gordon Taylor had anything about him he would apologise to all his union members and their families who he has failed... his own members dying in the most horrible and humiliating way... he failed my dad and hundreds more."