Football players routinely suffer teeth-rattling tackles on the field. Even when these hits don’t result in a concussion, a type of traumatic brain injury, they can still cause harm.
Recently, scientists at the University of Rochester in New York installed accelerometers in 38 college football players’ helmets. The devices measured every blow the players received during a single season.
Only 2 of the 19,128 hits resulted in a diagnosed concussion. Scans, though, revealed that two-thirds of the players had a decrease in white matter—the tissue that carries messages in the brain. The researchers’ conclusion: “The more hits, the more brain damage,” says psychologist Brad Mahon, who led the study.