Evidence is mounting that football is potentially even more damaging to the brain than it is to the body. According to an NFL-commissioned study, retired football players aged 50 and above are 5 times more likely to suffer from Alzheimer's or other dementia-related disorders. For players aged 30-49, the rate is 19 times higher than the national average.
While the mechanisms behind these statistics are not precisely known, leading neuroscientists and neurologists discussed this apparent link between head trauma and brain disorders during a Big Think panel on Alzheimer's disease last December.
Head trauma appears to create havoc in the brain that tears synapses, says Dr. Ottavio Arancio of the Taub Institute for Research in Alzheimer's disease at Columbia University. Within hours of a head trauma, a brain plaque called beta amyloid—one of the well-studied hallmarks of Alzheimer’s disease—is seen to build up in patients. This material, the beta amyloid, exists in small amounts in the brain since birth, and largely without effect. "However," says Dr. Arancio, "something happens in the disease and this balance, the communication within cells, is broken and there is an accumulation of this material.”
A single severe incident of head trauma—as could result from a concussive explosion, during war for instance—can increase the risk for Alzheimer’s disease, says Dr. Samuel Gandy, Associate Director of the Mount Sinai Alzheimer's Disease Research Center. But repeated blows to the head, as experienced by football players and boxers, can also lead to a similar disorder called chronic traumatic encephalopathy, which Dr. Gandy explains in the clip below:
Knowing this, it's hard to watch the game in quite the same way.
—Recent New Yorker feature article about "the concussion crisis" in the NFL.
—New York Times topic page on head injury in sports.
—More information about the brain disorder from Big Think's Breakthroughs: Alzheimer's Disease series.