A new study suggests that, among former National Football League (NFL) players, there may be a link between the age they began playing tackle football and their brain development later in life.

The study, from Boston University School of Medicine (BUSM) and Brigham and Women’s Hospital (BWH), appears online in the Journal of Neurotrauma.

It suggests, according to a news release from Boston University Medical Center, that among former NFL players, those who began playing tackle football before the age of 12 had a higher risk of altered brain development compared to those who began playing at a later age.

This study was conducted as part of the Diagnosing and Evaluating Chronic Traumatic Encephalopathy using Clinical Tests (DETECT) project, funded by the National Institutes of Health (NIH), under the leadership of Robert Stern, PhD, professor and director of the Boston University Alzheimer’s Disease and CTE Center’s Clinical Core, according to the release.

During the study, the release explains, the research team examined 40 former NFL players between the ages of 40 and 65 who had participated in organized football play for more than 12 years, with at least 2 years at the NFL level. Half of the players began playing tackle football before the age of 12, and half began playing at age 12 or later. The number of concussions sustained was similar between the two groups. All of these players experienced at least 6 months of memory and thinking problems.

“To examine brain development in these players, we used an advanced technique called diffusor tensor imaging (DTI), a type of magnetic resonance imaging that specifically looks at the movement of water molecules along white matter tracts, which are the super-highways within the brain for relaying commands and information,” explained study co-author, Inga Koerte, MD, professor of neurobiological research at the University of Munich and visiting professor at BWH, Harvard Medical School, in the release.

The results suggest that the research participants who started playing football before age 12 were more likely to have alterations of the white matter tracts of the corpus callosum, the largest structure of the brain that connects the two cerebral hemispheres, per the release.

According to the researchers, there is growing evidence that there is a “critical window” of brain development between the ages of 10 and 12, when the brain may be especially susceptible to injury. “Therefore, this development process may be disrupted by repeated head impacts in childhood possibly leading to lasting changes in brain structure,” explained lead author Julie Stamm, PhD, currently a post-doctoral fellow at the University of Wisconsin School of Medicine and Public Health, who conducted this study as part of her doctoral dissertation at BUSM, and who was funded by the NIH, the release states.

While the study shows there may be a neurodevelopmental window susceptible to repeated head impacts, such as those experienced playing tackle football, the authors underscore the fact that this is a small study with just 40 individuals, and results cannot be generalized to individuals who did not go on to play professional football.

“The results of this study do not confirm a cause and effect relationship, only that there is an association between younger age of first exposure to tackle football and abnormal brain imaging patterns later in life,” said senior author Martha Shenton, PhD, professor and director, Psychiatry Neuroimaging Laboratory, Department of Psychiatry, BWH, Harvard Medical School, in the release.

Stern cautions in the release that their findings are not necessarily indicative of chronic traumatic encephalopathy, or CTE. “While this study adds to the growing concern that exposing children to repetitive hits to the head in tackle football may have long-lasting consequences, there are likely other contributing factors that contribute to overall risk for CTE,” he adds.

[Source(s): Boston University Medical Center]