Heading in Soccer Linked to Brain Changes

In amateur soccer players, more frequent heading, or using the head to control or pass the ball, is linked to alterations within the folds of the brain, according to a study published in Neurology. The study does not prove that soccer heading causes brain changes, it only shows an association.

"While taking part in sports has many benefits, including possibly reducing the risk of cognitive decline, repetitive head impacts from contact sports like soccer may offset those potential benefits," said study author Michael L. Lipton, MD, Ph.D., of Columbia University in New York City.

"Our study found that people who experienced more impacts from headers had more disruptions within a specific layer in the folds of the brain, and that these disruptions were also linked to poorer performance on thinking and memory tests."

The study included 352 amateur soccer players with an average age of 26 and 77 athletes in non-collision sports with an average age of 23.

Athletes' soccer activity was surveyed to estimate the number of head impacts over one year. Soccer players were divided into four groups, with the highest group having an average of 3,152 headers per year compared to 105 headers in the lowest group.

Athletes had brain scans. Researchers used the scans to examine the microstructure of the juxtacortical white matter within the folds of the brain. This layer of white matter lies alongside the gray matter of the cerebral cortex, the outer layer of the brain.

When analyzing scans, researchers looked at how water molecules moved in the folds of this brain layer.

They found that soccer players in the highest group had much greater disruption in the microstructure of this area of the brain compared to soccer players in the lowest group and non-collision sport athletes. As the number of headers increased, the organization of water molecule movement deteriorated, indicating more disruptions and suggesting worsening of the brain's microstructure.

Athletes took tests to examine thinking and memory skills. Researchers found that players with worse performance on tests had more disorganized movement of water molecules in this area of the brain.

Researchers found that disruptions in the folds of the orbitofrontal brain region, just above the eye sockets, partially affected the relationship between repeated head impacts and thinking and memory performance.

"Our findings suggest that this layer of white matter in the folds of the brain is vulnerable to repeated trauma from heading and may be an important place to detect brain injury," said Lipton. "More research is needed to further explore this relationship and develop approaches that could lead to early detection of sports-related head trauma."

A limitation of the study was that the number of headers over the previous year was estimated based on athlete responses and may be influenced by their ability to remember this information accurately.