THREE mild concussions over a lifetime is all it takes to significantly impede brain function later in life and triple the risk of dementia.
The UK-based research analysed data from over 15,000 participants of the online PROTECT study, which is dedicated to better understanding who the brain ages and why people develop dementia.
Participants were asked to report the severity and frequency of concussions they had experienced throughout their lives using a detailed questionnaire and completed annual, computerised tests over four years to measure any changes in cognitive functions.
The study found that three episodes of even mild concussions lead to significantly worse concentration and ability to complete complex tasks. Those with four or more episodes also showed worse processing speed and working memory. Furthermore, just one moderate-to-severe concussion was associated with worse concentration, ability to complete complex tasks and processing speed.
On average, participants reported suffering their last head injury an average of 29 years prior to the study and their first an average of 39 years earlier.
“We know that head injuries are a major risk factor for dementia, and this large-scale study gives the greatest detail to date on a stark finding – the more times you injure your brain in life, the worse your brain function could be as you age,” says Dr Vanessa Raymont, senior author of the study from the University of Oxford.
Helen Brooker, a study co-author from the University of Exeter says that “cognitive rehabilitation should focus on key functions such as concentration span and completion of complex tasks, which we found to be especially susceptible to long-term damage.”
The study’s authors acknowledge that the factors like socioeconomic status and other covariates may affect these findings.
People with a history of concussions should be wary of the potential dangers of continuing activities that have a potential risk of head trauma.