J

oe Namath takes a deep breath.

He's walking the hallways of Jupiter Medical Center, near his home on the Intracoastal Waterway in Florida. At 72, Namath has a gait that is slightly stooped but determined, his grin craggy but still infectious. He greets the men and women at Jupiter by name, hugs the nurses, asks after family members. He chats with fans who approach, encouraging them to stay healthy.

Namath's eyes sadden a bit as he pauses at a treatment bay where a patient is groaning in distress. "I'll tell you what," he sighs, a familiar dollop of Alabama still sweetening his phrasing five decades after his college days with Bear Bryant, who called him the greatest athlete he ever coached. "You see what some of these folks have to go through and you think, 'There but for the grace of God ...'"

Namath's mission nowadays is to give concussion victims reason for hope beyond divine intervention.

A few years back, he'd begun to think about his own cognitive issues -- they didn't seem serious, but he wasn't sure. He occasionally wondered why he had just walked into a particular room or lost track of his keys. He also struggled with depression. Namath thought about the bone-crunching blows he had taken in his pro career -- knocked cold at least five times, with no treatment except smelling salts. And he pondered the fate of old comrades, struggling through the aftershocks of concussions years after retiring from football, living in fear of losing their minds.

In 2012, he began an experimental hyperbaric oxygen treatment from two doctors at Jupiter. Neither of them was a neurological specialist, but after 120 trips into Jupiter's oxygen chambers, Namath perceived extraordinary improvement in his brain function. And ever since, he's been telling the world -- friends, teammates, reporters -- about the benefits of his therapy. Last September he and Jupiter officials launched the Joe Namath Neurological Research Center. With great fanfare, they announced their goal to a throng of media at the Grand Hyatt Hotel in New York: to raise $10 million for a clinical trial of hyperbaric oxygen on 100 subjects suffering from symptoms of brain damage. Namath would be the lead fundraiser and cheerleader for the project.

The Hall of Fame quarterback has never been conventional, and he knows what he's selling is a leap beyond the fringes of accepted science. To many experts, the endeavor raises serious concerns. But to Namath, the truth is as simple as the air we breathe.

FOR THOSE WHO watched Joe Namath's career up close, it wasn't just his Super Bowl win or his swinging lifestyle that made him a hero but also the staggering pain he endured without complaint. Namath's right knee first gave out while he was still in college. In 1965, the Jets introduced him to the New York media at a news conference at the legendary Toots Shor's. The team orthopedist took Namath into the bathroom to examine him and was horrified at the damage: He thought Namath might never play again even with surgery. Ultimately, Namath had an operation and gritted through more than five seasons without missing a game, but he began seriously breaking down in 1970. Namath battled through torn ligaments and three more knee surgeries, a broken wrist and a separated shoulder, playing a full season just once after the age of 26.

Doctors routinely treated his pain with Percocet and Butazolidin, an anti-inflammatory typically used on horses. They told him to take the medications on a full stomach; concerned about staying in shape, Namath washed them down with Johnnie Walker Red instead. (Later, he switched to vodka.) Many narrative strands are tangled in his tortured relationship with alcohol: a guy out of the steel-mill town of Beaver Falls, Pennsylvania, enjoying the perks of superstardom; a heavy drinker losing his grip on sobriety; a man living like there's no tomorrow because he can't imagine what new hurt the next day will bring.

Throughout two decades of alcohol abuse, Namath was still one of America's most sought-after pitchmen, hawking wares from Noxzema shaving cream and Beauty Mist panty hose to Ovaltine drink mix and Brut cologne. He was ready to tone down his bachelor ways after he married Deborah Mays in 1984, and she helped him stop drinking. Namath says he was sober from 1987 to 1999, a period in which he got both knees replaced and was happy to dote on his young daughters.

But after Mays left him for a Beverly Hills plastic surgeon in 1998, Namath eventually went back to medicating his pain with the hard stuff. He bottomed out on Monday Night Football in December 2003, boozily swooning over sideline reporter Suzy Kolber. While one generation of fans remembers Namath for saying "I guarantee it," its kids are more likely to know him by the humiliating catchphrase "I want to kiss you."

After that, Namath sought help: He checked into rehab, and he stopped drinking on Jan. 12, 2004, the 35th anniversary of Super Bowl III. He emerged ready to attend Alcoholics Anonymous meetings and battle through his depression. And it was as if he found himself blinking in unexpected sunlight after a long winter's night. It turned out that Namath's daughters still adored him. His old teammates still wanted to see him. Fans still loved him. The endorsements had dried up, but for the first time in years, Namath could flash his famous smile at himself in the mirror and feel great, so great that it was hard for him to believe he deserved his good fortune. Maybe there was something to the St. Jude medal he had worn for decades, dedicated to the patron of lost causes. There but for the grace of God indeed.

After his physical rejuvenation, Namath began to hear about athletes who couldn't shake the mental effects of their playing days. It's often said that NFL Nation wasn't aware of the dangers of brain injury until recently, but that's not true. Plenty of players, teams and league executives -- and fans too -- suspected for a long time that terrible things could happen to athletes who repeatedly got smashed in the head. In more careless times, however, football shrugged off concussions as a casual inevitability.

In 1979, for example, when Namath was the man of the hour on The Dean Martin Celebrity Roast, comedian Charlie Callas staggered to the podium pretending to be "O.J. Simpleton," a former Jets lineman. "He gets all the glory while we get all the injuries," Callas cracked, referring to Namath. "Look!" he added, taking off his helmet to reveal a giant bandage wrapped around his head. "I've had the same concussion for 15 years. My vision is blurred, my speech is sl-sl-slurred, I g-get dizzy spells and I can't walk straight."

"I've had that for years," the oft-plastered Martin quipped. The crowd roared with laughter.

Three decades on, jokes like those hit Namath disturbingly close to home. There was the death of Mike Webster, then the suicide of Dave Duerson, then the sad decline of a real-life O.J. Simpleton named Dave Herman. A Pro Bowl guard for the Jets, Herman blocked for Namath for nine seasons, but toward the end of his career he couldn't remember details of games the next day. His short-term memory problems worsened, and he worried that he might have Alzheimer's disease. Herman had been a regular at Namath's football camp in Connecticut since the 1970s, and a few years ago, he shared his concerns with his old teammate, wondering if he would even be able to return the following summer. "You could just see the fear in his eyes," Namath says.

A lifetime of concussions can lead to a feedback loop of anxiety: If you feel your reasoning power or memory or emotional grip slipping, you begin to worry about what's going on inside your head -- and then worry further about whether you still have enough presence of mind to recognize the changes you're going through. For Namath, the loudest warning bell came in May 2012, when Junior Seau shot himself dead in the chest. Shortly after that, Namath reached out to Lee Fox, a golfing pal from Jupiter Medical Center, where Namath and his family had been treated for minor injuries, to get himself checked out.

As Namath puts it: "It behooved me to find out what's going on with my brain."

FOX, A 47-YEAR-OLD Duke- and Washington University-trained radiologist, is the director of imaging at Jupiter, a 327-bed nonprofit hospital in a town booming with retirees and wealthy golfers. (Jack Nicklaus is one of its major donors.) Fox had been thinking for a while about how the medical center might develop new ways to treat brain injury. He knew it made extensive use of hyperbaric oxygen therapy (HBOT), a process in which patients climb inside small chambers to breathe pure, compressed oxygen, flushing cells with extra energy. The Food and Drug Administration has approved HBOT to treat 13 conditions, including burns and carbon monoxide poisoning, but not brain injury. Indeed, while various celebrities, most notoriously Michael Jackson, have sought additional therapeutic benefits from HBOT, the FDA recently issued a consumer update that warned: "Do a quick search on the Internet, and you'll see all kinds of claims ... for which the device has not been cleared or approved."

It behooved me to find out what's going on with my brain. - Joe Namath

Still, Fox wondered if the treatment could help the brain recover from long-term trauma. "A head injury is really just a wound of the brain," Fox says. "I said to myself, 'Why wouldn't it work on a different type of wound?' That's when I became interested in it."

As it turned out, Barry Miskin, Jupiter's director of hyperbarics, had believed in the healing powers of the chambers for a long time. Miskin grew up outside Philadelphia and went to medical school at the Universidad del Noreste in Tampico, Mexico. ("I didn't have the test-taking gene, so I had to leave the country," he says.) A surgeon, he had a long career as a wound-care specialist and in trauma wards, until his life took a sudden detour when his daughter Talya suffered an intrauterine stroke and was born with a seizure disorder. Searching through medical literature and looking into cutting-edge experiments for ways to help her, Miskin hit upon hyperbaric oxygen as a possible method to stimulate damaged areas of the brain. At a local hospital, his wife would hold little Talya as she breathed compressed, purified oxygen through a hood inside a chamber that would typically be used to help divers recover from the bends. Once his daughter started receiving treatments, Miskin says, her condition improved. A decade later, he still believes it has helped. "I believe that after injury, there are areas of the brain that aren't functioning, and the oxygen wakes up those areas," says Miskin, now 61.

Miskin went so far as to install a hyperbaric chamber in his home to continue the treatments. He borrowed money to buy a device from a research outfit in Canada, tracked down a supplier to deliver liquid oxygen to his house and, with the help of a plumber, installed the necessary pipes. "I was going to put it in the garage, but my wife insisted we use the den," Miskin says. "I know that if you look at it from the outside, people think I'm insane. But I'm a surgeon. I can't sit around and wait and see what happens. I need to fix things."

When Fox asked Miskin about treating brain injuries with oxygen, Miskin replied: "I've been waiting for years for somebody to ask me that question." And when Namath called Fox, the two doctors had a test case. "It was a perfect storm," Fox says. "We all kind of came together at the same time for the same purpose."

To evaluate Namath, Fox used a SPECT scan, a nuclear-imaging test that shows blood flow in the brain. The results were shocking: Red, orange and yellow images lit up on the right side of Namath's brain, showing normal activity, but the left side was largely dark.

"Well, something's wrong there," Namath thought, but the scans seemed to make awful sense: As a player, he had been hit everywhere, but the hardest shots came from his blind side.

"As a right-handed quarterback getting hit from the left side, [Namath] would typically be hit in the left temporal lobe," Fox says. "When he gets sacked, he falls onto the ground and hits the back of his head. Those are the areas of the brain that we saw had decreased function."

From August 2012 to March 2013, Namath overcame his tendency toward claustrophobia and breathed hyperbaric oxygen for an hour a day, five days a week, following a protocol devised by Miskin. The treatment seemed intuitive to the former quarterback; Namath had learned how to retrain his breathing back in 1977, his last year in the NFL, when his wheels were so bad that he worked out in a swimming pool. "To this day, I stay with it, oxygen in and out, in and out, whatever exercise I'm doing," he says. "A lot of us can go without water for a while and we can fast for a while. But how long can we go without oxygen?"

After 40 dives in Jupiter's chambers, there was a dramatic change in Namath's SPECT scans: They looked bright and symmetrical. He underwent 120 treatments, and a year later there was still renewed blood flow on both sides of his brain. His cognitive tests improved too. And he felt generally stronger. "The areas of the brain which had decreased activity on the pre-scan now are actually functioning normally," Fox says. "And you can see the results are durable."

"It signals to me that I've been helped," Namath says, looking at his brain scans one afternoon. "I know I'm thankful." So thankful that he decided to give his name to the Joe Namath Neurological Research Center, which launched in September 2014 with Fox and Miskin as co-directors.

At the moment, the center is basically made up of the equipment and staff needed to support Fox and Miskin, who plan to test the effects of hyperbaric oxygen on 100 people suffering prolonged symptoms of brain injury. With Namath's help, they're trying to raise $10 million, largely to offset costs for patients who can't afford treatments, which can reach $75,000 -- and aren't covered by insurance. "The big drawback for all these guys is paying for it," Namath says.

Namath once made a second career from selling almost anything with a wink and a smile, but about hyperbaric oxygen, he is a true believer. He has energetically promoted the Jupiter study, which has a waiting list of nearly 400 volunteers. (Five have been cleared for therapy so far.) And he has recruited donors, helping raise almost $1 million. Jupiter didn't pay Namath for naming rights, nor has he partnered financially with the center, though he has reserved the right to invest if Fox and Miskin someday commercialize their therapy.

"He was basically patient zero," Miskin says. "And because somebody like him came to us, people took notice."

Namath's advocacy has led to glowing publicity, including favorable coverage everywhere from local TV to Good Morning America. Seeing the colors on Namath's post-treatment brain images, one West Palm Beach TV reporter gushed, "The scans say it all!"

Except they don't, not by a long shot.