A new study led by the School of Medicine and co-authored by School of Public Health researchers points to a possible increased risk of cognitive impairment from playing youth football.
The National Institutes of Health-funded study, published online in the January 28, 2015, edition of the journal Neurology, finds that former National Football League players who participated in tackle football before the age of 12 are more likely to have memory and thinking problems as adults.
The study contradicts conventional wisdom that children’s more plastic brains might recover from injury better than those of adults, and suggests that they may actually be more vulnerable to repeated head impacts, especially if injuries occur during a critical period of growth and development.
Contributing to the study from the SPH were: Yorghos Tripodis, assistant professor of biostatistics; Michael McClean, associate professor of environmental health; and Brett Martin, statistical manager of the Data Coordinating Center.
The study’s lead author, Julie Stamm, a PhD candidate in anatomy and neurobiology, said sports offer “huge benefits to kids, as far as work ethic, leadership, and fitness, and we think kids should participate.” But, she added, “There’s increasing evidence that children respond differently to head trauma than adults. Kids who are hitting their heads over and over during this important time of brain development may have consequences later in life.”
“This is one study, with limitations,” added study senior author Robert Stern, a MED professor of neurology, neurosurgery, and anatomy and neurobiology and director of the Alzheimer’s Disease Center’s Clinical Core. “But the findings support the idea that it may not make sense to allow children—at a time when their brain is rapidly developing—to be exposed to repetitive hits to the head. If larger studies confirm this one, we may need to consider safety changes in youth sports.”
In the study, researchers reexamined data from BU’s ongoing DETECT (Diagnosing and Evaluating Traumatic Encephalopathy Using Clinical Tests) study, which aims to develop methods of diagnosing chronic traumatic encephalopathy (CTE) during life. CTE is a neurodegenerative disease often found in professional football players, boxers, and other athletes who have a history of repetitive brain trauma. It can currently be diagnosed only by autopsy.
For the study, researchers examined test scores of 42 former NFL players, with an average age of 52, all of whom had experienced memory and thinking problems for at least six months. Half the players had played tackle football before age 12, and half had not. Significantly, the total number of concussions was similar between the two groups.
Researchers found that the players exposed to tackle football before age 12 had greater impairment in mental flexibility, memory, and intelligence—a 20 percent difference in some cases. These findings held up even after statistically removing the effects of the total number of years the participants played football. Both groups scored below average on many of the tests.
With approximately 4.8 million athletes playing youth football in the United States, the long-term consequences of brain injury represent a growing public health concern. The study comes at a time of increasing awareness of the dangers of concussions—and sub-concussive hits—in youth sports like football, hockey, and soccer.