A single season of professional rugby could be enough to cause a decline in a player’s blood flow to the brain and cognitive function, según un estudio.
Researchers from the University of South Gales followed a professional team playing in the United Rugby Championship over the course of a season, testing the players pre-season, mid-season and post-season.
The peer-reviewed study, which will be published on Wednesday in the Journal of Experimental Physiology, found that over the season the squad experienced reduced blood flow to the brain and cognitive function – the ability to reason, remember, formulate ideas and perform mental gymnastics.
And while previous research has focused predominantly on the incidence of concussion, there has been little investigation of the physiological toll of repetitive contact on the field.
Some studies suggest professional rugby players could be exposed to thousands of contact events each season. Increasingly, further research is beginning to show that it may not be concussions alone that may affect the brain, but the cumulative effect and volume of contact events as well.
The team behind the study said further research was needed on the long-term effects.
The issue of brain injury in the sport came under the spotlight last year when a group of former players sued the game’s authorities after being diagnosed with early-onset dementia, which they believe was caused during their rugby careers.
In a statement responding to the University of South Wales study, the sport’s governing body, World Rugby, said it welcomed further research. It added: “World Rugby recently committed to double our investment in player welfare and new concussion research and initiatives.”
Funded by the Royal Society Wolfson Research Fellowship, the research recorded six concussion incidents among the players that took part over the course of the year. Every player involved in the study recorded a decline in blood flow to the brain and cognitive function between pre- and post-season results.
Prof Damian Bailey, one of the authors of the study, said that even over a short period there was a greater decline in brain function. “And we’re assuming our baseline is a normal healthy baseline but many of these players have already had many years playing the game, so that baseline is probably still impaired,” he told the BBC.
The study also found a correlation between an increase in contact amount, playing position and rate of decline on the main measures tested. In forwards, who are involved in more contact, a greater degree of impairment was noticed, relative to backs.
Asked whether any comparison could be made between professional and grassroots level, Bailey told the BBC: “It’s difficult to say, but we don’t think why it would be terribly different,” adding that while professional players have less opportunity to recover, bigger physiques, and potentially bigger impacts as a result of contact, amateurs could have arguably poorer technique and be at risk as a result.
“We have every reason to believe that the damaging effects could be cumulative over time,” Bailey added. The team is also working on a similar study, comparing both current and retired players against a control group to determine whether there is a faster rate of decline in brain function in rugby players. They said further research was needed on the long-term effects of such a decline.