Key points from article :
After just one season of rugby players at a professional team saw a decline in both blood flow to the brain and cognitive function.
Researchers followed a team in the United Rugby Championship.
Some former players have been diagnosed with early onset dementia.
It may not be concussions alone that could impact the brain, but the cumulative effect and volume of contact events too.
Recorded six concussion incidents among all the players over the course of the year.
Damian Bailey, one of the study authors, "Even over a short period we're seeing...a greater rate of decline in brain function."
Findings include a correlation between an increase in contact amount, playing position and rate of decline on the main measures tested.
More research is needed on the long term effects of such a decline.
World Rugby recently committed to double the investment in player welfare and new concussion research and initiatives.
Study by University of South Wales published in Journal of Experimental Physiology.