Playing Tackle Football Before Age 12 May Be Bad for the Brain
A 2017 study found that men who began playing American tackle football before age 12 were more likely to have depression, apathy, problems with executive functioning, and behavioral issues in adulthood than their peers who began playing football after age 12. Duration of football play did not seem to matter—those men who stopped playing football after high school were just as likely to be affected in adulthood as those who went on to play football in college or professionally.
The study by Michael L. Alosco and colleagues was published in the journal Translational Psychiatry. It included 214 men (average age 51) who had played football in their youth, but not other contact sports. The men reported their own experiences with depression, apathy, cognitive function, and behavioral regulation. Those who began football before age 12 were twice as likely to report impairment in behavioral regulation, apathy, and executive function than those who began playing later. Those who started younger were also three times more likely to have clinical depression in adulthood than those who started older.
According to Alosco and colleagues, between ages 9 and 12, the brain reaches peak maturation of gray and white matter volume, and synapse and neurotransmitter density also increases. The repeated head injuries that can occur during youth football play during this time may disrupt neurodevelopment, with lasting negative effects.
One drawback to the study was that recruitment was not random—men who volunteered for the study might have done so due to a recognition of their own cognitive problems. However, the results suggest more study is needed, and caution is encouraged when making decisions about youth football participation. Some youth football leagues have begun placing greater limits on the type of contact allowed during play.
Following Collisions, High School Football Players with No Signs of Concussion May Still Have Neurological Impairment
In a small 2014 study in the Journal of Neurotrauma, researcher Thomas M. Talavaga and colleagues reported that repeated head trauma that did not produce concussion symptoms was still associated with neurocognitive and neurophysiological changes to the brain in high school football players.
The longitudinal study tracked ‘collision events’ experienced by 11 teens who played football at the same high school. The young men also completed neurocognitive testing and magnetic resonance imaging (MRI) scans of their brains over time.
The researchers expected to see the participants fall into two categories: those who had no concussions and normal neurological function, and those who had at least one concussion and subsequent neurological changes. They ended up observing a third group: young men who had not exhibited concussion symptoms, but nonetheless had measurable changes to their neurological functioning, including impairments to visual working memory and altered activation of the dorsolateral prefrontal cortex. Young men in this last group had had more collisions that impacted the top front of the head, directly above the dorsolateral prefrontal cortex.
The authors suggest that the discovery of this third category mean that some neurological injuries are going undetected in high school football players. The players who are injured in this way are not likely to seek treatment, and may continue playing football, risking more neurological brain injury or brain damage with subsequent collisions.
Repeated Sports Injuries Linked to Brain Inflammation
Professional football players face repeated mild traumatic brain injuries throughout their careers, and may face a variety of brain impairments, from depression to dementia, as a result.
A recent study by researcher Jennifer Coughlin and colleagues clarified how these impairments may be caused by repeated brain impacts. The researchers used positron emission tomography (PET) scans to observe the volume of translocator protein, a marker of brain injury and repair, in the brains of seven active or recently retired National Football League (NFL) players. Compared to healthy, athletic volunteers who were age-matched to the NFL players, the NFL players showed greater volume of translocator protein in several brain regions, including the left and right thalamus, the left and right temporal poles, and the brainstem.
It is not yet clear whether the increased volume of translocator protein is a sign of the brain’s attempts to repair itself, or whether it shows deterioration toward chronic traumatic encephalopathy. Translocator protein is also considered a marker of microglial activation, which occurs with inflammation.
High levels of translocator protein have also been seen in patients with depression and schizophrenia.
