Teens who reported having a traumatic brain injury in the past year were seven times more likely to have consumed at least five energy drinks in the past week than those teens with no history of traumatic brain injury, according to a new study.
The study, published Wednesday in the journal PLOS ONE, also found that teens who reported sustaining a traumatic brain injury (TBI) in the last year were at least twice as likely to have consumed energy drinks mixed with alcohol, compared with teens who reported sustaining a TBI more than a year ago.
Dr. Michael Cusimano, a neurosurgeon from Toronto's St. Michael's Hospital and co-author of the study, said the findings are significant because energy drinks have not previously been associated with brain injuries.
"We've found a link between increased brain injuries and the consumption of energy drinks or energy drinks mixed with alcohol," Cusimano said in a statement. "This is significant because energy drinks have previously been associated with general injuries, but not specifically with TBI."
TBI in adolescents is concerning, as it can lead to cognitive, emotional and psychosocial consequences, the study said. According to a separate 2013 study, about one in five teens from a 2011 Canadian sample reported a TBI in their lifetime.
Cusimano said energy drinks that are laden with caffeine could potentially interfere with the recovery of teens with TBI.
"Brain injuries among adolescents are particularly concerning because their brains are still developing," he said in a statement.
Dr. Robert Mann, a senior scientist from the Centre for Addiction and Mental Health, said the results of the study raise several concerns.
"It is particularly concerning to see that teens who report a recent TBI are also twice as likely to report consuming energy drinks mixed with alcohol," Mann said in the statement. "While we cannot say this link is causal, it's a behaviour that could cause further injury and so we should be looking at this relationship closely in future research."
The study also found that teens who suffered from TBI in the past year while playing sports were twice as likely to consume energy drinks compared to teens who reported a TBI sustained from other injuries.
It notes that past research on energy drinks and adolescent behaviour support the idea that consuming these drinks may "compound" the natural tendency to engage in risky behaviour.
The study's authors write that future research should investigate the context in which energy drinks are used, and to what extent they are a "contributor," a "consequence" or a "result" of common underlying factors.
The Canadian Beverage Association issued a statement in response to the study, noting that it does not show a causal link between energy drinks and adverse health outcomes.
"Energy drinks are non-alcoholic beverages which, in Canada, contain approximately half the caffeine of an equivalent-sized cup of drip coffee," the statement said.
The association reiterated that it supports responsible marketing of its products, noting that energy drinks are not to be promoted to be mixed with alcohol.
The statement pointed to a risk assessment from the European Food Safety Authority, conducted earlier this year, which outlined the daily amounts of caffeine that are safe for adults, teens and children to consume.
The data from the study came from the 2013 Ontario Student Drug Use and Health Survey from the Centre for Addiction and Mental Health. More than 10,000 Ontario students between the ages of 11 to 20 participated in the self-administered survey.
In the survey, TBI was defined as an injury resulting in the loss of consciousness for at least five minutes or being hospitalized for at least one night. About 22 per cent of all of the students surveyed reported that they'd sustained a TBI in the past year, with sports injuries accounting for almost half of the cases, the study found.
