Retired ruby players suffer "no significant effects on daily life" despite several concussions during their career, a study has found.

A Glasgow University study of 52 former Scotland rugby stars found they displayed only "some mild memory effects" in the long-term.

The research sought to gather more evidence about the health and well-being consequences later in life for athletes who suffered multiple concussions during their playing career.

The 52 men, who had an average of 14 concussions each, were analysed alongside 29 control volunteers.

Researchers found they "only displayed some mild memory effects" in contrast to the volunteers. They also reported no significant effects on daily life overall.

There continues to be concern about the long-term effects of concussion and repeated concussion in athletes, including boxers and rugby players who may suffer several concussive injuries throughout their career.

Health concerns about effects of concussion on athletes later in life include neurodegenerative disease and chronic traumatic encephalopathy, a progressive degenerative disease of the brain found in athletes.

Evidence on the long-term health and well-being of athletes and retired athletes is limited.

This study, however, found "despite a high number of repeat concussions in the retired rugby players, effects on mental health, social or work function were not evident some 20 years after they had stopped playing".

The study, published on Friday in the Journal of Neurology, Neurosurgery and Psychiatry, found cognitive test results in the retired rugby players and the volunteers found few differences.

The retired players performed less well on a test of verbal learning and on another test of fine coordination of the dominant hand but the effects were mild.

The research also found there were no "significant associations" between the number of concussions and the participants' performances on cognitive tests.

The authors assessed all study participants on a history of playing rugby and traumatic brain injury, general and mental health, life stress, concussion symptoms, cognitive function, disability and markers of chronic stress.

Professor Tom McMillan, professor of clinical neuropsychology from the Institute of Health and Wellbeing, said: "Despite a high number of repeat concussions in the retired rugby players, effects on mental health, social or work function were not evident some twenty years after they had stopped playing.

"Overall there is not a suggestion of widespread decline in daily function in ex-rugby internationalists who had a high number of repeat concussions.

"Although some differences in memory were found, these were mild overall and their cause uncertain."

New guidelines for dealing with concussion were published in Scotland in May last year. The guidelines, said to be a global first, cover concussion management across all Scottish sports.

They were drawn up by the Scottish Government's chief medical officer along with the Royal College of Physicians and Surgeons of Glasgow, universities of Edinburgh and Glasgow, Scottish Football Association, Scottish Rugby Union and the sportscotland institute of sport.

Details of the latest study were published a day after the issue of head injuries in sport was raised during First Minister's Questions at Holyrood.

Conservative MSP Liz Smith asked if there should be a standardised approach to serious concussion injuries across all sports, highlighting that suspension from the ring for such cases in boxing is at least 28 days, but just seven days in rugby.

First Minister Nicola Sturgeon told her: "We do need to make sure that we keep this under review and that as we do so we are informed of the best medical opinion."

A spokesman for governing body Scottish Rugby said: "Scottish Rugby welcomes the University of Glasgow's study into the effects of concussion in retired players.

"Our support in actively encouraging former Scotland internationalists to take part in the study once again demonstrates the proactive approach the sport is taking to better understand concussion in both current and former players.

"While the results in this study show no evident effects on general long-term health, Scottish Rugby believes it is important knowledge of concussion continues to grow and we will contribute to relevant future studies whenever possible.

"The study also appeared to demonstrate the wider benefits of being active and playing sport, with the former players recording good cardio-vascular results and nearly all reporting being in good or excellent health."