Retired pro football players seem to have higher-than-average risks of dying from Alzheimer's or Lou Gehrig's disease, U.S. governement researchers reported Wednesday.
In a study of more then 3,400 retired National Football League (NFL) players, the researchers found that death rates from the two brain diseases were four times higher than those in the general U.S. population. The researchers, from the National Institute for Occupational Safety and Health (NIOSH), cannot be sure of the reasons.
But they suspect they could be looking at the long-term consequences of repeat concussions during players' careers. "This study cannot establish cause-and-effect," said lead researcher Everett J. Lehman.
"We did not have data on concussions." But, Lehman said, other studies have found links between repeat concussion and an increased risk of neurologic disorders, including memory impairment.
Lab research has specificially linked concussions in athletes to a distinct disorder known as chronic traumatic encephalopathy (CTE) -- a progressive decline in brain cell function that eventually causes problems with memory, movement and balance.
Dr. Ann C. McKee, co-director of Boston University's Center for the Study of Traumatic Encephalopathy, has analyzed autopsied brain tissue from athletes, including football players, to find the damage that marks CTE.