“Football is played with the head. Your feet are just the tools” – Andrea Pirlo
From the paper, “MRI-defined White Matter Microstructural Alteration Associated with Soccer Heading Is More Extensive in Women than Men.”
An essential element in playing football is the ability to header the ball. The majority of players will header the ball multiple times in every game. It has already been shown that consistent heading over a 1-year period can result in cognitive dysfunction and changes to the brain structure (1). In general, repetitive head injury will lead to a decline in brain function and cause behavioural changes within someone. However, does gender determine the levels of damage to the brain that heading causes. Using diffusion-tensor imaging (DTI), researchers have looked into the relationship between repetitive heading of a football and the brain structure of football players, both male and female to see if there is a difference.
DTI is an MRI neuroimaging technique that accurately details the white matter of the brain (2). The white matter of the brain contains nerve fibres (3), so is very important in cognitive function and other functions. DTI allows for the measurement of water flow through the brain, tracking the neural pathways in the brain. If there is no water flow where there would be flow expected, then it can be said that there is damage to that area of the brain. DTI looks at white matter fractional anisotropy (FA) (looks at the size of pathways from different directions). It looks at whether there is flow from all sides of the brain or whether there is only flow from one side. This can determine whether or not there is damage to the brain due to the presence of neuronal connections in these areas. A low FA means that there is no damage and a high FA means there is damage.
It was determined that some areas of the brain are not affected by heading. In men, there were four regions that were not changed by heading and there were eight regions in women. However, there are numerous regions in the female brain that are affected by heading and had a significantly high FA value particularly in the left frontal matter. In men, there was only one location that had a high FA after heading which was in the left temporal hemisphere. Both men and women do have a relationship between heading a ball and brain damage, except these relationships are different. In some cases, one brain damage relationship in women would have the opposite relationship in men. Importantly, the amount of brain damage in women was five times greater than in men, meaning that women are more susceptible to brain damage after heading a football than a man.
It has been shown that using white matter FA is a good long-term indicator for brain injury and concussion. A high FA could be an indicator of recent injury that changes the structure of the brain, resulting in neuronal inflammation. A low FA could still indicate brain damage but the damage is chronic over a long period of time. Either way, the FA is an indicator of traumatic injury to the axons (transports nerve information) of the brain.
The study has shown that heading a football can lead to brain damage in both men and women. It has also shown that brain damage to women can be more severe than in men. Why is this? Simply, no one really knows. The reason could be evolutionary-based, where the female brain is more susceptible to damage after repetitive injury. The female brain has been shown to be larger than men’s. Does a larger brain result in a greater amount of injury if hit with the same force of a ball? Could the reason be that women head the ball differently to men, resulting in increased injury? Biomechanical differences of the head and neck between genders could cause the differences, meaning that the way the female head and neck operate are different to males. What we do know is that further research needs to be conducted to determine the reason for the brain injury differences between males and females.
No matter what the reason/s for the difference is, it is clear that repetitive heading of a football can result in cognitive damage. Therefore, more steps need to be taken to protect football players from brain injury. Further research should also be conducted in how to treat brain injuries that have risen from heading footballs. Already, current and former football players have spoken about the detrimental effects of heading footballs. However, given the nature of football, would the sport change its ways to prevent such injuries?
— by Daniel Baird
(1) Lipton, Michael L., Namhee Kim, Molly E. Zimmerman, Mimi Kim, Walter F. Stewart, Craig A. Branch, and Richard B. Lipton. “Soccer Heading Is Associated with White Matter Microstructural and Cognitive Abnormalities.” Radiology 268, no. 3 (September 2013): 850–57. https://doi.org/10.1148/radiol.13130545.
(2) Imagilys. (2018). Diffusion Tensor Imaging (DTI) – Fiber Tracking. [online] Available at: https://www.imagilys.com/diffusion-tensor-imaging-dti/ [Accessed 6 Aug. 2018].
(3) Merriam-webster.com. (2018). Definition of WHITE MATTER. [online] Available at: https://www.merriam-webster.com/dictionary/white%20matter [Accessed 6 Aug. 2018].
Blog post based on research paper of: