(CBS) Retired football players are at heightened risk for mild cognitive impairment (MCI), a subtle form of dementia that is considered a prelude to Alzheimer's disease.
That's the word from Dr. Christopher Randolph, a Loyola University neurologist whose preliminary study of 513 retired NFL players, average age 61, and their wives was presented at the Alzheimer's Association International Conference 2011 in Paris.
"It appears there may be a very high rate of cognitive impairment in these retired football players, compared to the general population in that age range," he said in a written statement. Thirty-five percent of the players who participated in the survey had scores suggestive of MCI. In other words, more than one in three retired players may be suffering from MCI.
MCI causes problems with memory, language, and/or another mental function. The impairment is obvious to sufferers and those around them but is not severe enough to interfere with daily living.
The increased risk presumably is the result of repeated blows to the head that pro footballers sustain. Animal studies have shown that blows to the head can kill brain cells even when they are not severe enough to cause a concussion, according the statement.
Previous research on college football players has shown that, on average, players receive more than 1,000 10-g or higher blows to the head each season. More than 250 of these blows are greater than 30 g-force. One G is equal to the force of gravity.