The problem is, the evidence isn't actually clear for years, if not decades.
The brain damage from sub-concussive impacts may not manifest until older age. The data on incidence isn't great and the causal mechanism isn't 100% clear.
So they have absolutely no idea what a properly safe level is yet.
The worst era would probably have been about 10 years ago, when controls were first introduced.
The players who played from 1995 when professionalism was introduced to 2015 when head injury assessments started to be introduced and concussion started to be taken much more seriously, are now between 30-65. They're still too young for old age impacts to be seen.
A report from the University of Auckland brain bank has found Stage 2 CTE in the brain of the former Blues scrum-half Billy Guyton, who died in 2023
www.theguardian.com
"
The first confirmed diagnosis of chronic traumatic encephalopathy (CTE) in a fully professional rugby union player has been made in New Zealand. Billy Guyton, who represented the New Zealand Māori, played scrum-half in Super Rugby for the Blues and had stints with the Hurricanes and Crusaders, died in May at the age of 33.
Guyton’s brain was donated to the brain bank at the University of Auckland. On Monday, his family received a summary of the results, the first item of which details “changes consistent with chronic traumatic encephalopathy”.
Guyton suffered from multiple concussions and
took the decision to retire because of the symptoms he was experiencing in 2018 at the age of 28.
The summary of the report, seen by the Guardian, also describes the condition of cavum septum pellucidum, a fissure in the middle of the brain associated with traumatic brain injury, and age-related tau deposits, which are not diagnostic of CTE, although often associated, but irregular in a young brain."
So was it the CTE that killed him or he died with CTE? Probably the latter, but the levels of evidence are concerningly low...
