In a study involving more than 600 NCAA college football players, no evidence emerged that those who started playing tackle football at an earlier age took longer to recover from a concussion or had worse performance on thinking and memory tests after sustaining a head injury, the researchers said.
Concussions also did not negatively impact players' balance or put them at increased risk for psychological problems.
"Because football is a very physical game, and concussions can occur, it has been hypothesized that playing at an early age may ... increase a person's vulnerability to neurological problems later in life," study author Thomas A. Buckley said in a press release.
"Our study in NCAA football players, some who started playing tackle football as early as age 5, found no link between playing football earlier in life and worse recovery from concussion," said Buckley, an associate professor of kinesiology and applied physiology at the University of Delaware.
Earlier research into the potential effects of early exposure to tackle football and long-term brain health produced mixed results. While some studies showed worse performance on memory and mental health screening tests or changes in the brain, others showed no effect of playing football at a younger age, Buckley said.
For this study, Buckley assessed 621 NCAA football players from 30 schools as part of the NCAA-Department of Defense Concussion Assessment, Research and Education Consortium.
Athletes in the study reported that they started playing tackle football at an average age of 10, and 46% of them had experienced concussions previously.
All athletes in the study experienced a recent concussion and all had baseline testing before suffering their injuries, Buckley said. All athletes were evaluated within six hours of their latest concussion, he said.
Overall, 294 were evaluated for symptom severity one to two days after their concussions and 327 were evaluated once their symptoms resolved.
Testing included assessments for concussion severity and recovery, including measures of memory, reaction time and speed of eye movements. In addition, the players underwent a balance test, and a survey in which athletes rank the severity of their symptoms, Buckley said.
Still, larger studies are needed to evaluate recovery from multiple concussions as athletes age, he said.
"It's encouraging that our study found no link between earlier exposure to playing tackle football in childhood and adolescence and worse outcomes after concussion while still in college," Buckley said.
"Our results may be reassuring for players and parents, but it is important to note that we were looking at one concussion at one point in time and current testing may not be sensitive enough to detect subtle changes."