Researchers have found that players who head the ball with high frequency have brain abnormalities similar to those found in traumatic brain injury patients, stated in a press release from the Radiological Society of North America.
Lionel Messi heading a ball (Sky Sports)
Heading the soccer ball 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,” said Michael L. Lipton from Montefiore Medical Center in New York. “But repetitive heading could set off a cascade of responses that can lead to degeneration of brain cells.”
Dr. Lipton and colleagues conducted diffusion tensor imaging (DTI) on 32 amateur soccer players, all of whom have played the sport since childhood. DTI produces a measurement, called fractional anisotropy, of the movement of water molecules along axons.
The researchers estimated how often each soccer player headed the ball on an annual basis and then ranked the players based on heading frequency. They then compared the brain images of the most frequent headers with those of the remaining players and identified areas of the brain where fractional anisotropy values differed significantly.
“Between the two groups, there were significant differences in fractional anisotropy in brain regions in the frontal lobe and in the temporooccipital region,” said Dr. Lipton. “Soccer players who headed most frequently had significantly lower fractional anisotropy in these brain regions.”
The analysis revealed a threshold level of approximately 1,000 to 1,500 heads per year. Once players in the study surpassed that level, researchers observed a significant decline in their fractional anisotropy in five identified brain regions. These five regions are responsible for attention, memory, executive functioning and higher-order visual functions.
“What we’ve shown here is compelling evidence that there are brain changes that look like traumatic brain injury as a result of heading a soccer ball with high frequency,” said Dr. Lipton. “Given that soccer is the most popular sport worldwide and is played extensively by children, these are findings that should be taken into consideration in order to protect soccer players”.
