Tipping point for contact sport? US health body rules collision sports cause CTE in landmark change

Leeds United's Polish midfielder Mateusz Klich is treated for a head injury during the English Premier League football match between Wolverhampton Wanderers and Leeds United. (Photo by GEOFF CADDICK/AFP via Getty Images)

In a move that will have ramifications for collision sports, the US National Institutes of Health has formally acknowledged a causal link between repeated blows to the head and the neurodegenerative disease chronic traumatic encephalopathy (CTE).

The NIH is the largest biomedical research agency in the world, and the decision to rewrite their official guidance on CTE has been described by campaign groups as a tipping point in the debate about the risks of playing collision sports. In the NIH’s view, research to date suggests the causal link between repeated traumatic brain injury and CTE is clear and unequivocal.