The NFL season kicked off September 5. The same day, the U.S. Centers for Disease Control and Prevention (CDC) issued a special report about NFL players’ deaths from brain diseases.

The CDC study found that NFL players died from brain diseases at three times the rate as the general population.

The study, led by Everett J. Lehman, MS, of the CDC, looked at all the neurodegenerative causes of death among professional football players.

“Neurodegenerative” means the disease involved a breakdown of the brain. This study especially looked for deaths caused by Alzheimer’s, Parkinson’s and amyotrophic lateral sclerosis (ALS) among the players.

ALS is also referred to as “Lou Gehrig’s disease” and involves a deterioration of the muscles, which eventually leads to an inability to speak and difficulty swallowing and breathing.

Lehman and his colleagues looked at 3,439 NFL players who played at least five seasons from 1959 to 1988. They were divided into two categories: linemen and all other players (“speed players”) except kickers.

A total of 334 players in that group have died, and 17 of them have died from a neurodegenerative disease.

The researchers compared this group to the U.S. population to see if the rate of degenerative diseases among the players matched what would be expected of any subset of the general population.

They found that football players died of a neurodegenerative disease at about three times the rate of similar individuals in the general population.

They were more than four times likely to have ALS and nearly four times more likely to have Alzheimer’s disease.

The players most at risk are those who play in “speed positions,” not the linemen. The speed players’ risk of dying from a neurodegenerative disease was three times that of the linemen.

Further, the average lifespan of the football players combined was considerably shorter than that what would be expected compared to the general population — about 50 percent shorter.

Meanwhile, the Associated Press announced on the same day that the NFL has pledged $30 million to go toward the National Institutes of Health for medical research.

The study was published September 5 in the journal Neurology. It was funded at the CDC, and the authors had no disclosures.