The brains of college football players may already display the effects of years of taking hits, according to a new brain imaging study.
Players who had been diagnosed with concussions and those who had been playing for years had smaller hippocampuses - a brain structure critical to memory - compared to those who never played football or played for fewer years, researchers found.
“Boys hear about the long-term effect on guys when they’re retired from football, but this shows that 20-year-olds might be having some kind of effect,” said Patrick Bellgowan, the study’s senior author from the Laureate Institute for Brain Research in Tulsa, Oklahoma.
The researchers write in JAMA that they didn’t find any differences in behavior between players and non-players, but Bellgowan told Reuters Health that a smaller hippocampus is linked to depression, schizophrenia and chronic traumatic encephalopathy (CTE).
There has been growing concern over whether the connection between contact sports - like football - and CTE, which is a brain disease known to affect some athletes who experience repeated hits to the head, may extend to younger players.
“We keep hearing about retired football players having diseases that relate back to smaller hippocampuses,” Bellgowan said. “Maybe this is just the precursor of it.”
The symptoms of CTE, which tend to set in years after the last traumas, often include memory loss, aggression and dementia.
Between June 2011 and August 2013 the researchers recruited 25 college football players who had been diagnosed with a concussion, 25 players without a history of diagnosed concussion and 25 similar young men who had never played.
The participants had magnetic resonance imaging (MRI) of their brains and researchers used the images to measure the volume of certain brain regions. The athletes also took a computerized test to assess their cognitive abilities.
The researchers found that college athletes had hippocampuses between 17 percent and 26 percent smaller than non-athletes. Those who had been diagnosed with concussions also had smaller hippocampuses than the players without past concussions.
The longer the young men had played football, the smaller their hippocampuses were and the slower their reaction time on one of the tests.
“People try to understand why some NFL players have what looks like Alzheimer’s in their forties,” Dr. Jeffrey Bazarian said. “How did they get there? I think this study points out the early stages of that.”
Bazarian was not involved with the new research, but has studied the brains of young athletes at the University of Rochester Medical Center in Rochester, New York.
“Maybe there is something going on early on,” he said. “None of these players were feeling bad but their brain structure isn’t normal.”
Both Bellgowan and Bazarian said it will take longer studies to find out whether a smaller hippocampus may cause problems for these athletes in the future.
For now, Bellgowan suggested that parents and coaches take a conservative approach when dealing with student athletes by taking them to specialists when they walk off the field with a headache.
“The conservative approach is what I’m hoping to get out there,” he said.
Bellgowan is also on the faculty at the University of Tulsa, where, he said, "Participation of the athletic department was essential to this work."