As awareness of concussion-related brain damage among professional football players grows, researchers say they have developed a way to predict who will develop cognitive problems even long after the player retires.

Sports-related injuries account for as many as 3.8 million traumatic brain injuries per year in the U.S., according to researchers. Young men, aged 10-19 years, tend to have the highest rates of sports concussions, and five-to-10 percent of high school and college American football players are at risk of suffering a concussion each year, researchers say.

A research team led by LA BioMed studied the severity and frequency of game-related concussions among 40 former professional football players, many of whom who had suffered cognitive deficits. The researchers combined this data with the estimates of each player's cognitive reserve, a mechanism that helps protect the brain from injury.

To determine cognitive reserve, the researchers utilized test, questionnaire and interview data. The researchers also surveyed other studies, which have found cognitive reserve is protective in other forms of brain injury and disease, including Alzheimer's disease.

Cognitive reserve is developed through mentally enriching experiences, such as education and reading. The researchers concluded that a unique combination of the harmful and the protective factors could predict cognitive outcomes in players who had suffered concussions during their football careers and have been retired from American professional football for an average of 20 years.

According to the researchers, the most important factor in determining potential cognitive problems from sports-related concussions was the football players' cognitive reserve.  In term of harmful factors, they also found that experiencing post-traumatic amnesia after a concussion was a more significant predictor of later cognitive deficits than the loss of consciousness.

They are also hoping this tool can be used to also determine which players should be allowed to return to the field after suffering a concussion, the researchers said of their study, which appears in the Journal of Clinical and Experimental Neuropsychology.