Chronic traumatic encephalopathy (CTE) risk among rugby players increases with length of career

In a study of the brains of 31 former players, CTE was present in 21 of the brains (68 percent) donated to research institutes in the US, UK and Australia; Professor Willie Stewart: “Our data shows that risk is linked to the length of the rugby career, with each additional year of playing increasing the risk”

A player’s risk of developing an incurable brain disease uniquely associated with repeated head impacts depends on the length of his playing career, a new study finds.

A study of the brains of 31 former players with an average career length of 18 years found that each additional year of playing increases the risk of chronic traumatic encephalopathy (CTE) by 14 percent.

CTE can only be diagnosed postmortem, and to date the only recognized risk factor for CTE is traumatic brain injury and repeated exposure to head impacts.

The study, published in Acta Neuropathologica the week of the Rugby World Cup final, found that CTE was present in 21 of 31 brains (68 percent) donated to research institutes in the United States, United Kingdom and Australia .

Cases with CTE had an average career length of 21.5 years, while in cases without CTE the average was 12.1 years.

The study’s lead author, Professor Willie Stewart, said: “In this study we combined the experience and expertise of three leading international brain banks to look at CTE in former rugby players.

“These results provide new evidence regarding the association between rugby club participation and CTE. In particular, our data show that the risk is associated with the length of the rugby career, with each additional year of playing increasing the risk.

“Based on this, it is imperative that sport regulators reduce exposure to repetitive head impacts during competition and training to reduce the risk of this otherwise avoidable contact sport-related neurodegenerative disease.”

Twenty-three of the players played exclusively at the amateur level, while eight also played at the elite level. The study found no correlation between the level at which the individual had played and an increased risk of CTE, nor between whether he played as a forward or a defenseman.

World Rugby is investigating ways to reduce the risk of concussion and improve the way diagnosed or suspected concussions are managed.

The governing body’s board has recommended that unions take part in a global trial that will see the height of the tackle in community play reduced below the breastbone – known as a ‘belly tackle’.

World Rugby also promotes a ‘recognize and remove’ approach to managing concussions in the amateur game, while having detailed return-to-play protocols at that level and in the elite game.

A group of former professional and amateur players diagnosed with early-onset dementia are involved in legal action against World Rugby, the Rugby Football Union and the Welsh Rugby Union.

The players claim that the governing bodies have been negligent in that they failed to take reasonable action to protect them from permanent injury caused by repetitive concussion and sub-concussion.

A World Rugby spokesperson said: “World Rugby is aware of the findings of the University of Glasgow research and we strive to always keep abreast of the latest scientific insights.

“Our Independent Concussion Working Group recently met with representatives from Boston University, including Professor Ann McKee, along with other leading brain health experts, to continue our dialogue on how we can make the game safer for the whole rugby family.

“What all the experts told our Independent Concussion Working Group was that we need to continue to reduce the number of head impacts, and that is exactly what we will do.

“World Rugby will never stand still when it comes to protecting players’ brain health. That’s why community players around the world are participating in trials with a lower tackle height this season.

“It’s also why we’ve rolled out the use of industry-leading smart mouthguard technology across WXV, our new elite women’s league, and from 2024, all elite leagues using the Head Injury Assessment will use smart mouthguards, in addition to current independent doctors and in-house game video footage to ensure players receive the best possible care.”