Bad news about a bump
Just one blow to the head ‘increases risk of dementia by nearly two-thirds’
A SINGLE blow to the head early in life can raise dementia risk by nearly two-thirds, a major study reveals.
Experts warn it can cause brain injury that triggers the incurable disease decades later.
Young adults are most at risk, scientists found. If they suffer a head impact from falls, car crashes or fights in their twenties, they are 63 per cent more at risk of the brain-wasting illness later in life.
While for victims in their 30s, the likelihood went up by 37 per cent.
Across all ages, a traumatic brain injury was found to increase dementia risk by a quarter.
The dangers also increased with the number and severity of head bangs.
And even a mild concussion raised dementia risk by 17 per cent.
The findings, from a study of 2.8 million adults, suggest measures to curb brain injuries – such as wearing cycling helmets – could help slash the number of cases.
There is currently no cure for dementia but some drugs can control the symptoms.
Some previous studies have hinted at a link between the disease and blows to the head but others found no connection.
The latest probe provides the strongest evidence yet.
Researchers from the University of Washington School of Medicine, in Seattle, US, tracked millions of adults for 36 years.
They compared dementia rates among head blow victims with those free of injury. The results, in The Lancet
Psychiatry, revealed nearly one in 20 participants – more than 132,000 – had suffered a mostly mild head injury.
If it was a single blow they were 22 per cent more likely to get dementia after the age of 50.
This rose to 33 per cent with two blows and 61 per cent with four or more.
Scientists said the earlier the blow the greater the risk.
Dr Doug Brown, of the Alzheimer’s Society, said smoking and couch potato lifestyles were much bigger problems.
He said: “And these are risk factors that are much easier for all of us to do something about.”