A link between early onset dementia and playing rugby has been established by a brain injuries expert in the United Kingdom.
Dr Willie Stewart says high impact sports such as American football, ice hockey and rugby are starting to lead to problems later in life usually associated with former boxers.
In an interview with BBC Radio Scotland the neurologist discussed his research of the brain with a former rugby player where he examined sections of tissue and found abnormal proteins associated with head injuries and dementia.
The former player who took part in the study was found to have higher levels of the protein than a retired amateur boxer who has dementia pugilistica, also known as punch drunk syndrome.
Symptoms usually appear around 15 years after the boxer's career begins and include memory, speech and personality problems and a lack of coordination.
Until recently it had been thought to only affect boxers who suffered repeated concussive injuries through blows to the head, Dr Stewart said.
The percentage of rugby players affected is likely to be lower than other high impact sports
where concussion is common, but it remains a concern.
Dr Stewart, who is based at the Southern General Hospital in Glasgow, believes better precautions have to be taken by players and organisers.