Researchers say they are hard-pressed to find current published medical studies that prove professional football players have a life expectancy of 55 years.
And the author of a 2006 article that startled CFL players last week - citing that a pro football player's life expectancy is 51 to 55 - says he based his medical opinion article on a conversation with an insurance expert, not a medical study.
"I didn't get that age from any study," Michael Arnold Glueck said Thursday from his home in Newport Beach, Calif. "I had an acquaintance who was an insurance writer look up what they had recorded at the time for the average life expectancy for a pro football player for insurance purposes."
The article, which was published on a number of websites in 2006, was among several articles on the future health of football players passed to members of the CFL Players Association last week at their union meetings in Las Vegas.
The byline states it was written by Glueck and a fellow doctor, Robert J. Cihak, but Glueck confirmed Thursday he wrote it alone. Glueck says he is a retired doctor in the areas of diagnostic radiology and nuclear medicine, and has not done any research in the area of the life expectancy of athletes.
"That number of 55 has simply never been proven with any data, it has just floated around and been perpetuated by reporters too lazy to back up the facts," said Chris Nowinski, co-director of the Center for the Study of Traumatic Encephalopathy at Boston University, and founder of Sports Legacy Institute, which educates on concussion in sport.
Nowinski is a former Harvard University football player and professional wrestler who retired in 2003 after multiple concussions. He led the investigation that found 44-year-old former NFL star Andre Waters was suffering from chronic traumatic encephalopathy (CTE), a degenerative brain disease, when he committed suicide in 2006.
"Football players should be concerned about a number of health issues, like heart disease, specifically for linemen. Players should worry about arthritis, chronic pain, or neurological disorders," Nowinski said. "There are certainly anecdotal instances of players dying young from different conditions. But there is no evidence to show football players should expect to die at 55 from some mystery illness."
There has been an documented link between ex-NFL players and increased cases of Alzheimer's disease. A 2005 study at the University of North Carolina at Chapel Hill found dementia-related syndromes may be initiated by concussions in pro football players. Results of that study were also shown to CFL players last week.
The NFL followed with its own study regarding Alzheimer's in 2009, conducted at the University of Michigan, and found a similar result.
University of Montreal researcher Louis De Beaumont has studied the effects of concussions. He says symptoms can persist 30 years after a concussion and cause cognitive and motor function problems when an athlete reaches his or her 50s and 60s.
"I think that life expectancy number of 55 for NFL players would still require more study to be supported, and I wouldn't be surprised if the age is being studied now. Because if doctors have determined a link between NFL players and increased instances of Alzheimer's and memory problems, the next logical step as a researcher would be to find out the expected age of death," De Beaumont said.
"Right now, there are studies to support a relationship between concussed athletes and their quality of life in late years, but life expectancy still doesn't have firm studies."
In 1997, a study was done by the NFL along with the National Institute of Occupational Safety and Health (NIOSH). It found players are not dying younger than the U.S. life expectancy for males of 72. It did, however, conclude that linemen, due to their bulk, had a rate of heart disease much higher than the general population.
That same year, the Atlanta-Journal Constitution did a two-month mail and phone survey of 250 retired NFL veterans and found 60 per cent of respondents believed football would reduce their life by at least 10 years below that of the average American man. It found many players had even taken a reduced pension at 45, instead of a full one at 55, believing they would not live to see it.
Prior to the NIOSH study, there had been only limited research on life expectancy for pro football players.
Len Teeuws, a former NFL offensive lineman, studied 1,800 players who were in the league for at least five seasons between 1921 and 1959, and found an average lifespan of 61 years.