KEY POINTS:
NEW YORK - University-age soccer players may show some degree of brain-tissue shrinkage, a small study has found - adding to evidence that the sport carries a risk of long-term brain injury.
Using high-resolution MRI brain scans, researchers found evidence of reduced gray matter in the brains of 10 male college soccer players, compared with 10 young men who had never played the sport.
Grey matter refers to the brain tissue that controls thinking and memory. The significance of the relatively smaller gray matter volume and density seen in these players is not yet clear, the researchers say.
However, some past studies have found that professional and even college-age soccer players are more likely to show problems with memory and attention than non-players.
Among players in the present study, reduced grey matter was seen in a part of the brain called the anterior temporal cortex - which was consistent with effects from repeated knocks to the front of the head, John Adams and colleagues at the University of Cincinnati College of Medicine in Ohio report in the Clinical Journal of Sports Medicine.
Like many other sports, soccer carries some risk of concussion, from players colliding with each other or with the ground, for instance. Multiple concussions over time can cause brain damage.
It's still a matter of debate, though, whether the ordinary knocks involved in "heading" the soccer ball raise the risk of brain injury.
Of the 10 soccer players in the current study, only two said they'd suffered a mild concussion in the past, while none reported a history of serious head injury. It's impossible to tell exactly why the players showed relatively less gray matter than the comparison group.
"I'd be very reluctant to ascribe this purely to heading," said study co-author Dr Caleb Adler, an assistant professor of psychiatry and neuroscience at the University of Cincinnati College of Medicine.
The bottom line, he said, was that while these findings were preliminary, they added to evidence that soccer was "not an entirely benign sport".
"Any activity is a balance of risk and benefits," Dr Adler said.
Some youth soccer leagues banned heading before a certain age, he noted.
- REUTERS
