Headers have always been an integral and aesthetically pleasing part of soccer (or football if you’re not from the United States of America), but new research has found that the common action actually negatively affects the user’s brain.
A team of researchers has recently discovered that a single session of heading practice results in temporary impairment in memory as well as a disruption of the chemical balance in the brain. These findings were published online in EBioMedicine and have raised questions about the future of headers in soccer.
Image Source: Martin Rose
In the experiment, nineteen amateur soccer players, mostly aged in their early twenties, were asked to head machine-projected soccer balls in a procedure that attempted to imitate a typical soccer practice. The brain inhibition of each player was tested before and after the practice using transcranial magnetic stimulation, a laboratory technique that uses a coil over the subject’s head to generate a brief magnetic pulse to stimulate an area of the brain. Through this, researchers measured neural signals going from the brain to the muscle to test the levels of inhibitory chemicals. Inhibitory chemicals are those that interrupt or block certain brain activities. In particular, the researchers looked at the chemical GABA, the most powerful inhibitor in the brain’s motor system. In addition, memory was also tested through simple memory tests.
In their data, the researchers discovered immediate changes in the brain’s composition due to heading. After just a single session of heading, the brain was found to have increased inhibition. Memory test performance was also reduced by an average of 41-67% after training. However, the good news is that the effects seemed temporary. By 24 hours, inhibition levels normalized and memory test performance returned to normal. Despite this news, it is still unclear whether long-term heading, such as during daily or weekly practices, has a permanent effect on the brain’s composition, especially for younger players.
The human brain is not fully developed until the early twenties, with the frontal lobe maturing extremely late. Therefore, this part of the brain, which absorbs the most impact of the ball during a typical header, is most affected whenever the ball makes contact with the head. Soccer is the most popular sport in the entire world, and more than four million of America’s youth are registered in a U.S. soccer league. More research needs to be done in order to ensure that heading, and soccer in general, won’t harm kids’ brain composition they mature into adults.
Feature Image Source: Soccer by Michael Neel