Former NFL players found to be at greater risk for brain diseases

As the National Football League kicks off a new season, a study appearing in a leading medical journal underscores the long-term costs of the game on those who play it.

A study tracking 3,439 retired players with five or more seasons in the NFL found these athletes four times as likely as other men their age to die of Alzheimer’s disease or amyotrophic lateral sclerosis, better known as Lou Gehrig’s disease. Among the league’s “speed players” — those who build up substantial speed before they make a tackle or are brought down by one — the odds of dying of those causes were even greater.

The heightened risk of death from these neurodegenerative disorders was in sharp contrast to an overall picture of remarkable health among the former players. Compared with men in the general population, the NFL veterans were about half as likely to die at any given age.

The study, published Wednesday by the journal Neurology, is the most extensive survey of former athletes since concern about the long-term consequences of repeated blows to the head has become a major safety issue among NFL players.

The NFL has found itself in a precarious legal position amid claims by former players that they were not properly warned of the dangers of head injuries. The players say the blows to the head have contributed to depression, memory loss and other neurological disorders.

Most recently, a postmortem investigation found that former NFL safety Dave Duerson was suffering advanced neurodegenerative disease at the time of his suicide at the age of 50 in February 2011.

About 3,400 former players have sued the NFL over these claims, according to an analysis by the Associated Press. The NFL has asked the courts to throw out some of these suits on the grounds that it’s a matter for collective bargaining.

The league denies withholding information about the dangers of concussions, noting that medical experts are still trying to determine the long-term effects of them.

The authors of the new study — a team from the National Institute for Occupational Safety and Health, which is part of the Centers for Disease Control and Prevention — cited recent research on chronic traumatic encephalopathy, or CTE, a buildup in proteins seen in the autopsied brains of former athletes who played a wide range of contact sports. That research, the authors wrote, “now suggests that CTE may have been the true primary or secondary factor in some of these deaths.”

Dr. Ann McKee, a pathologist and co-director of the Center for the Study of Traumatic Encephalopathy at Boston University, called the new research “groundbreaking.”

The study “opens new avenues for research and validates our neuropathological findings,” said McKee, whose autopsies of 15 former NFL athletes have turned up substantial evidence that repeated brain trauma has detrimental effects. “It raises our concern about the risk of CTE, dementia and ALS and the way these conditions overlap.”

McKee, whose brain bank has drawn donations from a growing number of former athletes, added that research into the long-term effects of brain trauma “is an issue not just for football players, but also other sports, the military and accidents involving head trauma.”

There is little doubt that the claims by former players has forced the NFL to change some of its rules and procedures. Players who suffer concussion-like symptoms must now be cleared by an independent neurologist before returning to either practice or a game. This process often takes several days before a player can rejoin his team.

The league also moved its kickoffs five yards closer to the opponent’s end zone last season in the hope of having more touchbacks — the ball being downed without contact and placed at the 20-yard line — to avoid the dangers associated with runbacks, in which players often collide at full speed.

“Well before this study was released, the NFL took significant steps to address head injuries in football, provide medical and financial assistance to our retired players, and raise awareness of the most effective ways to prevent, manage and treat concussions,” league spokesman Brian McCarthy said in a statement.

“The study underscores the continuing need to invest in research, education and advocacy, strengthen and enforce our rules on player safety, and do all we can to make our game safer,” the statement said.

To that end, the NFL announced Wednesday a $30-million contribution to the Foundation for the National Institutes of Health to support “research on serious medical conditions prominent in athletes and relevant to the general population.” It was the largest philanthropic donation ever made by the NFL in its 92-year history to any single organization.

“We hope this grant will help accelerate the medical community’s pursuit of pioneering research to enhance the health of athletes past, present and future,” said NFL Commissioner Roger Goodell. “This research will extend beyond the NFL playing field and benefit athletes at all levels and others, including members of our military.”

A 2005 study found that compared with former NFL players with fewer than three concussions, those who had sustained three or more showed a fivefold increase in mild cognitive impairment — a condition that often precedes a diagnosis of Alzheimer’s disease — and a threefold increase in significant memory problems.

The new study did not, in fact, find substantial numbers of former players with neurodegenerative disease. Among the 3,439 players the researchers tracked, 1,116 died during the study period. Of those, only 27 were found to have a neurodegenerative disease as an underlying or contributing cause of death.

In nine of the cases, death certificates listed dementia or Alzheimer’s disease as a contributing factor to death, and 13 noted a diagnosis of ALS. Five of those who died had had a diagnosis of Parkinson’s disease as an underlying or contributing factor.

Although those numbers were much higher than is typically seen in the general population, experts cautioned that they were a slim statistical base upon which to draw sweeping conclusions.

“We need to view the findings with a little caution,” said Kevin Guskiewicz, a brain trauma researcher at the University of North Carolina.

At the same time, those small numbers may not reflect the reality of contemporary football play and its consequences for players, said UNC epidemiologist Steve Marshall. The majority of the study’s NFL veterans played during the 1960s, ‘70s and ‘80s, when players were not as big or as fast as they are today.

“The game’s changed a lot since then in ways that are potentially worse for players’ outcomes,” Marshall said. If further research were to reflect the health of players after 1988, the last year of play for those in the current study, “it might be worse,” he added.

Guskiewicz said one of the study’s findings should prompt further research on which players were at greatest risk of developing long-term cognitive effects from play. Of the 17 for whom neurodegenerative disease “contributed” to death, 14 were classified by the study’s authors as “speed” players — offensive ball carriers and the defenders who pursue them. Only three such cases were diagnosed among “nonspeed” players — offensive and defensive linemen, who sustain more blows to the head in a given game while moving at lower velocity.

“It’s a little counterintuitive,” Guskiewicz said. “Maybe it’s not the high number of repetitive impacts that creates the problem, as the scientific community has come to think. Maybe it’s the high-magnitude impacts.”

A league-commissioned study in 2009 determined that Alzheimer’s disease or similar memory-related afflictions seemed to have been diagnosed in former NFL players at a vastly higher rate than among the national population. The study was conducted by the University of Michigan’s Institute for Social Research and was based on information gathered in phone interviews with 1,063 retired players, each of whom had played at least four seasons in the NFL.

“None of this was ever told to us,” former NFL offensive lineman Kyle Turley told The Times in 2010, in reference to the findings of that study. “The NFL never talked about it. The general public never talked about it. It’s just because of neglect and ignorance. There could have been so much study and research done on this issue. And now we’ve finally got doctors who are getting their voice heard.

“They have knocked on the NFL’s door many times. It’s just never been opened for them before.”

melissa.healy@latimes.com

Times staff writer Sam Farmer contributed to this report from East Rutherford, N.J.