Injury study calls for tackling bans in junior sport after finding 'conclusive evidence' of brain disease risk

Newly published research has revealed "conclusive evidence" that the brain disease chronic traumatic encephalopathy (CTE) can be caused by repetitive head impacts during sports with tackling and ball heading.

The study, conducted by researchers from nine academic institutions in six countries, including University of Melbourne and University of Sydney, collated independent CTE studies from around the world, and across different sports.

As a result of the findings, published in the journal Frontiers in Neurology, the researchers are calling for repetitive head impacts and CTE among children to be treated like exposure to lead, mercury, smoking and sunburn.

Newly published research has revealed "conclusive evidence" that the brain disease chronic traumatic encephalopathy (CTE) can be caused by repetitive head impacts during sports with tackling and ball heading.

The study, conducted by researchers from nine academic institutions in six countries, including University of Melbourne and University of Sydney, collated independent CTE studies from around the world, and across different sports.

As a result of the findings, published in the journal Frontiers in Neurology, the researchers are calling for repetitive head impacts and CTE among children to be treated like exposure to lead, mercury, smoking and sunburn.

Neurodegeneration in sportspeople's brains revealed
Over half of brains donated to the Australian Sports Brain Bank have signs of a degenerative brain disease associated with repeated blows to the head, researchers find.

They then checked this evidence against an established set of criteria designed to test whether there was a causal relationship between an environmental exposure (i.e. repetitive head impacts) and an adverse health outcome (CTE).

This method, known as the Bradford Hill Criteria, has previously been used to establish the causal relationship between smoking and lung cancer.

In the case of CTE, said Dr Pearce, a neuroscientist at La Trobe University, advised that the researchers were able to satisfy each of the nine criteria.

Dr Pearce, a co-author of the report, advised “each institution took a section of the criteria and collated the evidence to meet the criteria.

"It was essentially a very structured review of the existing research."

The nine criteria included showing there was a consistent association between repetitive head impacts and CTE, that it occurred after the head impact, that there was a plausible mechanism between the cause and the effect, and that greater exposure led to greater incidence.

Dr Pearce added “we looked at different sports with different characteristics, and they were all showing a similar thing.

"Anyone who engages in repetitive head trauma ... they get CTE where you don't see it in random populations of people."

Lead author Chris Nowinski, Chief Executive of the Concussion Legacy Foundation, said the analysis "gives us the highest scientific confidence that repeated head impacts cause CTE".

Calls for heading, tackling bans until high school
The  Australian Institute of Sport's most recent position statement on concussion in sport, last updated in February 2019, states that, "the link between sport-related concussion and CTE remains tenuous."

However, Dr Pearce feels this is now out of date, suggesting “we're hoping that the sports will take notice and hoping they will now acknowledge more seriously the risks.”

This could include changing the rules of contact sports, enforcing the existing safety rules more consistently, and restricting tackling and heading in junior sports.