The researchers found that permanent brain damage can result from repeated blows to the head, even if they do not knock an athlete unconscious.
Football players are most likely to sustain a brain injury, according to the researchers.
But they found that wrestlers and female soccer players are also at risk. Brain damage can occur any time a player suffers a concussion, which is a blow to the head severe enough to cause disorientation or to slow reaction time, says Mark Lovell, PhD, a researcher at the Henry Ford Health System in Detroit. Lovell was part of a group that studied the mental functioning of 393 college football players. He says about a third of the players had sustained one concussion and a fifth had sustained two or more. A battery of mental functioning tests showed that players who'd had at least two concussions were less able to remember things and took longer than other players to process information.