LONDON - The debate over the damage inflicted by heading a soccer ball took another turn on Wednesday as a leading expert on brain injuries said children under the age of 18 should not be allowed to do it.

Dr Bennett Omalu, who was the first specialist to discover how American football players were affected by chronic traumatic encephalopathy (CTE), told the BBC he realized his remarks might jar with some people, but that society was evolving.

"No child under the age of 18 should be heading the ball in soccer," said the 49-year-old Nigeria-born naturalized American.

"Kids under the age of 12 to 14 should play a less contact form of soccer which we should develop for them.

"Kids between 12 and 18 can play, but should not head the ball. I know this is difficult for many people but science evolves.

"We change with time. Society changes. It is time for us to change some of our ways when it comes to young people and sports."

Omalu, whose discovery of the impact of CTE on NFL players arose from his autopsy of former Pittsburgh Steeler Mike Webster in 2002, said heading a ball is dangerous and that it should be restricted, even at the professional level.

"It does not make sense to control an object traveling at a high velocity with your head," he said.

"I believe, eventually, at the professional level we need to restrict heading the ball. It is dangerous."

The side effects of heading has been a burning issue since an inquest into the death of former England and West Bromwich Albion striker Jeff Astle ruled he died from brain trauma caused by heading old heavy leather soccer balls.

He died in 2004, aged 72, after suffering with Alzheimer's for almost 10 years following his 16-year career.

A second former professional player, Rod Taylor, was also recently diagnosed with a similar form of dementia linked to heading the ball, after his family donated his brain to scientists for analysis following his death at age 74 earlier this year.

Several other high-profile players, including a trio from England's 1966 World Cupwinning team - Martin Peters, Nobby Stiles and the late Ray Wilson - have also been diagnosed with dementia.

"The human brain floats like a balloon inside your skull so when you head the ball you suffer brain damage," said Omalu.

"You damage your brain when you head the ball. And over time, the damage only gets worse.

"Playing soccer will increase your risk of suffering brain damage when you are much older and developing dementia and CTE."

Agence France - Presse