Stewart said: “Of particular concern are the data on motor neurone disease risk among our rugby players, which is even higher than that for former professional footballers.
“The finding requires immediate research attention to explore the specific association between rugby and the devastating condition of motor neurone disease.
“This should be a stimulus to them [rugby’s authorities] to really pick up their heels and start making pretty dramatic changes as quickly as possible to try and reduce risk.
“Instead of talking about extending seasons and introducing new competitions and global seasons, they should be talking about restricting it as much as possible.
“So, cutting back on the amount of rugby we’re seeing, getting rid of as much training as possible. Things like that have to be addressed pretty, pretty rapidly.”
