Dr. Michael L. Lipton, associate director of the Gruss Magnetic Resonance Research Center at the Albert Einstein College of Medicine and medical director of magnetic resonance imaging service at Montefiore Medical Center in New York, said "heading," in which players field the soccer ball with their head, is an essential part of the game and the focus of many training drills.
"Heading a soccer ball is not an impact of a magnitude that will lacerate nerve fibers in the brain," Lipton said in a statement.
"But repetitive heading could set off a cascade of responses that can lead to degeneration of brain cells."
DTI, an advanced magnetic resonance technique, allows researchers to assess microscopic changes in the brain's white matter, which is composed of millions of nerve fibers called axons that act like communication cables connecting various regions of the brain.
Lipton and colleagues conducted DTI on 32 amateur soccer players -- average age: 30.8 years -- all of whom have played the sport since childhood.
"Between the two groups, there were significant differences in five brain regions in the frontal lobe and in the temporooccipital region -- responsible for attention, memory, executive functioning and higher-order visual functions," Lipton said. "Soccer players who headed most frequently had significantly lower FA in these brain regions."
The findings were presented at the annual meeting of the Radiological Society of North America.