Of all the sports activities a young person may engage in, American football is probably the most controversial. Increasing attention to the risk of brain damage from the sport—from the movie Concussion to a series of articles in The New York Times in 2017 on chronic traumatic encephalopathy (CTE) suffered by NFL players—has led some parents (even ones who are diehard football fans) to think twice about letting their children play football competitively.
Brain imaging studies consistently show that a large amount of brain maturation happens during the school-age years (usually defined as ages 6 to 11 or 12), which scientists worry could make head impacts especially detrimental to children. Now research is lending additional support to that concern—finding that even among players with similar exposure to head impacts in high school, college, or professional football, those who took up the sport the earliest are significantly more likely to later experience cognitive deficits. In a study of former male football players (played in high school, college, or professionally) published in the journal Translational Psychology, for example, researchers found that those who had started playing football early in life—particularly before age 12—were more likely to experience impaired executive function (the ability to solve problems, set and meet goals, and exert self-control) and unwanted mood changes in adulthood compared with those who took up the sport later.
Similarly, a study of 42 former NFL players published in Neurology found that those who took up football before age 12 had a higher likelihood of cognitive impairment later in life. The researchers concluded that “these findings suggest that incurring repeated head impacts during a critical neurodevelopmental period may increase the risk of later-life cognitive impairment.”
There are limitations to these studies. First, such observational studies can only find associations, and association is not always equal to causation; other variables may account for the link between early football playing and brain problems down the line. And these studies are relatively small; additional studies with larger samples and longer follow-up periods are needed to help confirm the findings. Even for CTE—which has become the poster child for long-term brain damage from repetitive head injury, especially in football players—a 2017 review article in JAMA highlighted the need for a clearer definition of the condition and more human studies on it. And there are currently no blood tests or brain imaging that can tell us clearly whether or not someone is cognitively impaired from sports.
Some experts have called for policy changes to help reduce the risk of permanent brain damage from football head impacts, such as prohibiting football teams in school for children younger than 12, or allowing only touch football; setting clear, evidence-based national standards for protective gear; and establishing a federal task force to investigate the phenomenon of CTE in former professional athletes. But it’s not clear that any of those will be implemented any time soon, especially in light of what a staple of American society (and huge business) competitive football is.
What parents can do
There is no established safe age a child can start playing football, but studies seem to point to 12 as the age before which it’s definitely prudent to avoid any kind of contact football (and, by extension, other sports with a high risk for head impact injuries). We don’t know whether the same finding extends to female athletes, since the research has all been done in males; future research will ideally include both genders, as well as other sports than football that can entail impacts to the head. In the meantime, it’s wise for parents to encourage younger children to take up other, lower-impact sports and make them wait until at least the teenage years (if ever) to begin tackle football.
Also see Spotting and Treating Concussions.