PARIS • Suffering a traumatic brain injury from a blow to the head boosted dementia risk by 24 per cent in a Danish study group of nearly three million people, researchers have said yesterday.
The survey of 36 years' worth of data - collected from the Danish national patient register - found that the risk of dementia rose with the number and severity of brain injuries, a team wrote in The Lancet Psychiatry, a medical journal.
"Individuals with a history of traumatic brain injury (TBI)... have an increased risk of developing dementia, even decades after the injury," said study leader Jesse Fann of the University of Washington School of Medicine in Seattle. This included "less severe" injuries like concussion. But the team said the absolute risk to an individual remained low.
In the study group, 5.3 per cent of dementia sufferers had experienced a brain injury when younger, compared to 4.7 per cent of people without dementia.
"Our findings do not suggest that everyone who suffers a traumatic brain injury will go on to develop dementia later in life," Dr Fann said.
But it would be advisable for people who had had a severe knock to the head to take extra precautions, he added. This could include exercise and avoiding risk-boosting behaviour like smoking, or eating and drinking too much. "Importantly, a person who has sustained a TBI should do what they can to prevent further TBIs as the risk of dementia increases with the number of TBIs."
Previous studies on a link between brain injury and dementia yielded contradictory results.
According to the World Health Organisation, about 50 million people worldwide suffer from dementia, including Alzheimer's Disease. There are about 10 million new dementia cases each year.
According to the study authors, more than 50 million people every year experience a traumatic brain injury.