Dr. Bennet Omalu is a forensic neuropathologist by training. He grew up in Nigeria and admits that for years after arriving in the United States, he knew nothing about football. He used to be the assistant medical examiner for the city of Pittsburgh. And what Omalu first saw in 2002 while performing an autopsy on retired Steelers lineman Mike Webster, what he saw after he put some slides of Webster's brain under a microscope for a routine examination, eventually led to Omalu's being discredited by NFL officials for some controversial conclusions that the league wouldn't publicly embrace for another five years.
What if football is as dangerous to your brain as boxing?
Would that change the way you regard the long-term risks of the game, or the way you parent your kids?
Before Omalu studied the brains of Webster and a handful of other NFL players whose lives had met sudden ends, the NFL never really looked at itself that way. Omalu was the first person to contend those players had been afflicted with pugilistic dementia or "punch-drunk syndrome" -- a layman's term for a disease called chronic traumatic encephalopathy. CTE's only known cause is repeated blows to the head. Omalu says all of the first nine NFL players he examined posthumously showed the sort of brain damage that doctors usually only see in older patients suffering from Alzheimer's or dementia.
On Monday, Omalu and a colleague, Dr. Julian Bailes, found themselves back in the news as they presented the findings on their latest subject, Cincinnati Bengals wide receiver Chris Henry, who died at the age of 26 in December. Until Henry, no active NFL player had been diagnosed with CTE. And none with the diagnosis had been as young.
The diagnosis, for an athlete who played just five NFL seasons, was a surprise to Omalu and Bailes. The idea that Henry was playing with brain damage that can only be diagnosed using brain tissue samples (which can't be culled until a person dies) ramped up concerns over how quickly athletes start to suffer from CTE -- and why they do.
Researchers say concussions aren't the only danger. Even the accumulation of lesser blows to the head -- the sort of contact that's intrinsic in football -- could be enough to eventually cause serious long-term brain damage. The threshold could be far lower than anyone previously thought.
That's a confounding dilemma for people trying to make organized football safe. If that's possible.
"I am still a persona non grata to the NFL," Omalu said in a phone interview Monday after he and Bailes, his co-director at the Brain Injury Research Institute at West Virginia University, presented the Henry findings at a campus news conference.
"I wouldn't expect what we have found to be accepted happily. The first person to diagnose pugilistic dementia in boxers was also a forensic pathologist and that was in 1928. Here I was 80 years later, finding the same thing in football."
Still, you rarely find anyone screaming that football should be abolished, and few consider it as dangerous as boxing.
It's time that changed.
"I think people are in still denial," Omalu said, "because the public loves football so much."
Maybe the perception gap also exists because boxers are so explicitly up front about their intent to separate opponents from their senses. Fight fans aren't riven with guilt over the violence in the sport because they cling to the consoling idea that boxers make "informed" decisions about the risks, the same as cigarette smokers or Indy car drivers or skydivers do.
Football fans used to say the same thing.
But the Henry findings change all that. Football just became a bit harder to love unconditionally on Monday. The brain trauma caused by a lot of sports -- not just football -- just became a lot harder to rate for risks.
That's why Bailes, a former team physician for the Pittsburgh Steelers and current team doctor for the WVU football team, confessed that he was initially "sad" about Henry's diagnosis and struggled to find something positive because the red flags were so "profound."
Bailes noted Monday that as a wide receiver, Henry was usually far away from the play-after-play collisions in the trenches. He wasn't a kamikaze hitter.
Bailes said Henry had never even been diagnosed with a concussion during his college career at WVU or in his five NFL seasons with Cincinnati.
And, Bailes added, the usual tools that team doctors use, such as MRIs and CT scans, don't show the presence of CTE, anyway.
So again, how does an athlete assess the danger he or she faces?
More than ever, it's clear no one really knows.
Bailes says the Henry discovery may force us to rethink everything.
No wonder the Bengals' Andrew Whitworth, a teammate of Henry's last year, told the Cincinnati Enquirer on Monday, "It's kind of fearful. It's shocking that a guy you played with and didn't really play that long could be diagnosed [with CTE]."
"It's very emotional to hear -- it rattles me," the Seattle Seahawks' Sean Morey, a special-teams player, told The New York Times. "You have to ask how many are playing the game today that have this and don't even know about it."
Like many of the other former football players found to have CTE after their deaths, Henry had behavioral problems that Omalu and Bailes strongly suspect were at least partly a result of the disease, which Bailes said is linked to depression, substance abuse, erratic behavior and even suicide.
Webster, the former Steelers center, was sleeping in train stations and sometimes at odds with his family just before he died. Lineman Terry Long, the second NFL player Omalu studied, committed suicide by drinking antifreeze in 2005. Former Philadelphia Eagles safety Andre Waters shot himself after inconsolably telling a family member he needed to get help. Henry was arrested five times early in his NFL career for incidents ranging from assault to marijuana possession to drunken driving. He died December after either jumping or falling out of the back of a moving pickup truck being driven by his fiancée in Charlotte, N.C., as they were having an argument.
"It was a big shock when I first learned [Chris was playing football with brain damage]," Henry's mother, Carolyn Henry Glaspy, told reporters on Monday after watching Omalu and Bailes present their findings about her son.
Glaspy sighed and said, "Some things make so much sense."
Johnette Howard is a contributing columnist to ESPN.com and ESPNNewYork.com, and is the author of "The Rivals: Chris Evert vs. Martina Navratilova, Their Epic Duels and Extraordinary Friendship." She can be reached at firstname.lastname@example.org.