Research found a possibly high rate of mild cognitive impairment, or "pre-Alzheimer's," in some retired pro-football players, who take many hits to the head in their careers.
The study was reported Monday at the Alzheimer's Association International Conference in France.
The study is follow-up work on nearly 4,000 retired National Football League players surveyed in 2001. New surveys were sent in 2008 to 905 of them who were over 50. Of those who responded, 513 had spouses who could complete the part assessing the players' memory.
"We were surprised that 35 percent of them appeared to have significant cognitive problems," said lead researcher Dr. Christopher Randolph of Loyola University Medical Center in Chicago.
Researchers sent 41 of them to the Center for the Study of Retired Athletes at the University of North Carolina in Chapel Hill. Tests showed they had mild cognitive impairment that resembled a comparison group of much older patients from the general population.
The results are preliminary, and suggest the players have higher rates of impairment than would be expected for their age, but they also have more dementia risk factors, such as obesity, high blood pressure and diabetes, Randolph said.