According to their findings, one single head injury could have lasting impacts on cognitive functioning. They explained that though many people may think they’re fully healed from a childhood or young adulthood accident, their risk of dementia is actually higher.
“Head injury is a significant risk factor for dementia,” said researcher Dr. Andrea L. Schneider. “Our findings show that the number of head injuries matter -- more head injuries are associated with greater risk for dementia.
“The dose-dependence of this association suggests that prevention of head injury could mitigate some risk of dementia in later life. While head injury is not the only risk factor for dementia, it is one risk factor for dementia that is modifiable by behavior changes such as wearing helmets and seat belts.”
How head injuries impact long-term cognitive function
To see how head injuries can increase the risk for dementia, the researchers analyzed data from the Atherosclerosis Risk in Communities (ARIC) Study. For nearly three decades, this study tracked the long-term effects of head injuries across the country. The team also looked at hospital records to determine the scope and severity of these injuries.
The researchers learned that head injuries were associated with a higher risk of dementia later in life, and repeated head injuries increased that risk even further. Experiencing several head injuries made dementia two times more likely among the participants while one head injury increased the dementia risk by 1.25 times.
Because the data included participants from diverse backgrounds, the researchers were able to break down the findings by various demographic groups. They learned that white participants were at a higher risk for dementia than black participants, regardless of the number of head injuries incurred, while women were more likely than men to struggle cognitively following head injuries.
Promoting safety tips
While dementia isn’t entirely avoidable by working to prevent head injuries, these findings highlight the need for more comprehensive prevention strategies. The researchers explained that working to reduce the frequency of head injuries is a good place to start to protect consumers’ long-term cognitive health.
“Given the strong association of head injury with dementia, there is an important need for future research focused on prevention and intervention strategies aimed at reducing dementia after head injury,” said Dr. Schenider.
“The results of this study have already led to several ongoing research projects, including efforts to uncover the causes of head injury-related dementia as well as investigations into reasons underlying the observed sex and race differences in the risk of dementia associated with head injury.”