John York (MD ’75) is making Sundays safer in the NFL

“We started putting pressure on the helmet manufacturers,” York says, gesturing at the poster, which shows the safest NFL-approved helmets in green, approved but less preferred options in yellow, and prohibited helmets in red. “They told us that players wore the same helmets as they had in college and they would never change. But if you’ve got the numbers and start to show [players and coaches] what happens with decreasing concussions when you have a better helmet…they do change.”

The facts bear this out. Jay Brunetti, the team’s equipment director, says in the past year the number of players who selected either a Guardian Cap–optional or a position-specific helmet, the two safest helmet categories, rose from 20 to 46 percent. In another notable sign of change, many marquee players — including Philadelphia Eagles quarterback Jalen Hurts and San Francisco 49ers’ tight end George Kittle—now wear the Riddell Axiom 3D, a top-ranked model sized from player head scans, says Erin Griffin, a senior vice president at the company.

York, though scrupulously self-effacing and reluctant to admit it, is at least partially responsible for much of the helmet innovation that has taken place in recent years—and the NFL’s willingness to embrace it. His career, though following a nonlinear path, traces its roots to the scientific research methods and ethical values he cultivated as a student at the Stritch School of Medicine and resident in the Loyola University Medical Center (formerly the Loyola University Health System).

The York family owns a controlling interest in the $8.6 billion 49ers franchise. John York, together with his son Jed York, the 49ers’ principal owner; his wife of nearly 50 years, cochair Denise DeBartolo York; and their twin daughters Jenna York and Mara York, the organization’s chief impact officers, oversees operations of the five-time Super Bowl–winning team. He never envisioned himself at the helm of an NFL team, but in 1978, when he married Denise, he married into the early makings of a football dynasty. Colleagues close to York say he has made immense contributions to the franchise. For instance, he invested heavily in the design of the $1.2 billion Levi’s® Stadium, which includes four educational classrooms; a museum; a natural grass field; and a handsome, wood-grained Owners Club. In partnership with local California vintners, he built an extensive wine program called Appellation 49, using a portion of the proceeds to fund philanthropic causes. Perhaps most notably, as cochair of the 49ers Foundation board since 2000, York has increased annual contributions from roughly $500,000 to more than $10 million, partnering with companies like AT&T, BlackRock, Chevron, and Google to advance STEAM-based education programs in schools and sponsor education and social justice programs throughout the Bay Area.

“Seventeen to 22 days a year we focus on football, and we want to be champions on the field. The other 340-plus days we focus on being the best stewards of the community,” said Justin Prettyman, the executive vice president of philanthropy for the 49ers Foundation, echoing one of York’s animating refrains. All these accomplishments will undoubtedly become part of York’s legacy. But years from now he may be remembered, above all, for his commitment to harness science to make a beloved but punishing game safer. At a time when concussions have raised growing concerns and cut prominent NFL careers short, such as that of 49ers’ quarterback Steve Young, York has been a tenacious champion for change, embodying the Ignatian value of magis—striving for excellence to serve the greater good—in actions with profound human impact.

“He sees himself as a physician, as a scientist, and as a public health advocate, which I think is just really unique in his role as an NFL team owner,” said Allen Sills, MD, the NFL’s chief medical officer, who founded and codirects Vanderbilt University’s Sports Concussion Center. “When he became chair of the NFL Owners Health and Safety Advisory Committee in 2011, he really framed the committee’s focus around important questions of injury reduction and prevention. And I’d say we’ve had a real sea change—from counting injuries and talking about how many we have and how we treat them to looking upstream to determine how we can actually prevent them.”

Building bridges with data and design thinking

The NFL Health and Safety Committee’s efforts are showing real results. In 2024, according to data compiled by the health research company IQVIA, total concussions in the preseason and regular season decreased to a historic low of 182, a 17 percent reduction from the 219 concussions experienced in 2023 and a 34 percent reduction from the 275 experienced in 2015. The NFL also has seen a sustained reduction in lower-extremity injuries and a substantial increase in the number of players self-reporting symptoms, says Christina Mack, PhD, the chief scientific officer at IQVIA.

But it has taken the relentless determination of York and the committee, working in collaboration with the NFL Players Association and medical experts, to develop and advance a comprehensive multiyear roadmap for injury reduction. Over the past decade, these efforts have prompted equipment upgrades, rule changes, medical staffing and intervention improvements, practice and training modifications, and enhanced data collection protocols that have fundamentally reshaped the game.

“I played college football at Stanford in the late eighties, early nineties,” said John Lynch, the general manager of the 49ers. “First of all, we only called it a concussion when you were knocked out. And we never had protocols, really. We had a doctor who would say, ‘How many fingers do I have up?’ And if you could come close or get it right, you’re back in the game to help your team try to win. I don’t think that was out of being cavalier…We didn’t know as much then.”

Now much more is known, not only about the health risks of concussions, but also about how to mitigate and manage them, and York has played a key role in the league’s progress by acting as a sort of medically informed maestro who can bring the right people into the right rooms to evaluate research, build consensus across divergent viewpoints, and advance change.

“He’s a master at amplifying voices,” Mack said. “He will listen to the person in the room who has knowledge, experience, and perspective, and he spots that and draws it out, so there is that crisp message and amplification.

”By many accounts, the NFL needed an effective bridge builder. When Sills was hired as the league’s first chief medical officer in 2017, the NFL had recorded the highest number of diagnosed concussions in a single season—281, a 16 percent increase over the 243 in 2016—and just a few years earlier, the league had agreed to a $765 million legal settlement earmarked to cover medical assistance for more than 18,000 retired players, including retired players diagnosed with Alzheimer’s and ALS. Within the league, there was consensus that something needed to be done, and quickly, but high-level stakeholders had differing views about the best way forward.

As the only NFL owner trained as a physician, York became a close advisor to Sills, and the two led the charge to bring technology and design thinking to the forefront of the league’s decision-making process. York’s status as an owner provided validation to trainers, coaches, and sports scientists that the NFL was taking impact risks seriously and that their work had value, said Biocore CEO Jeff Crandall, PhD, an NFL engineering consultant who also directs the University of Virginia’s Center for Applied Biomechanics.

One of the most meaningful tools the NFL Health and Safety Committee helped implement is an electronic health record system, which incorporates historical injury data, on-field video surveillance, sensor readings, and up-to-the-minute medical reports in an AI-enabled database, so “that we under-stand what injuries are happening and how they’re impacting players,” Mack said.

Helmet technology has also advanced tremendously. Many helmets are now 3D printed, with honeycomb-like lattice structures custom fitted to the topography of players’ skulls. Quarterbacks, for instance, have added cushioning in the rear of the shell, as they tend to get knocked backwards. Linebackers have more coverage near the forehead to dampen the impact of head-on collisions. And crucially, all NFL helmets are tested by bio mechanical experts in Biocore’s simulation laboratory in Charlottesville, Virginia, where their force-reduction potential is assessed in trials with crash test dummies.

York played a crucial role in these efforts. After attending an additive manufacturing conference in Detroit, he became enthralled by the possibilities of computer modeling and 3D printing. With the support of the National Additive Manufacturing Innovation Institute (now America Makes), are search and training network based in Youngstown, Ohio, he organized the NFL Helmet Challenge.

A kick-off symposium held in November 2019 brought together product designers and helmet manufacturers from across the country to create 3D-printed prototypes of force-mitigating helmets. With a $1 million prize for the best design, it proved a watershed moment in the league’s testing and adoption of high-performing helmets. “The concepts that came out of [the NFL Helmet Challenge] very much laid the groundwork for the innovations that exist on the field today,” Crandall said.

All these breakthroughs can be seen as career-defining achievements. But perhaps the biggest change York and the NFL Health and Safety Committee have brought to the league has been cultural, a shift from the smash mouth swagger and bone-crushing bravado celebrated in years past, to a recognition long espoused in Catholic tradition that the human brain and body are fragile vessels deserving care and respect.

“Occasionally you see a big hit, and instead of everybody ‘Hurrahing,’ everybody now goes ‘Ooh,’” York said. “You can see it in the stands; you can hear it with the announcers—a totally different way of looking at a big hit.”

Growing up quickly

Apart from his deep compassion and medical curiosity, York’s commitment to player safety reflects an ethically minded response to the lessons he learned about life’s fragility at a young age.

His father, John York Sr., was a dentist and part-time investor who took John and his younger brother, Tom, fishing for trout and catfish in creeks near their home in Little Rock, Arkansas. On weekends and at least one instance in which he pulled John from school for the day, his father drove John to Hot Springs to place bets on horses. Too young to enter the Oaklawn Park racetrack through the front gates, John, at 8 years old, snuck in the back, learning the ins and outs of horse racing from trainers and jockeys roaming the grounds.

But when York was a freshman in high school, his father died of a heart attack. His father’s death and John’s newfound realization that he would need to work and earn a scholarship to pay for college sharpened his already zealous entrepreneurial spirit. After all, this was a child who, in third grade, read an issue of Boy’s Life featuring an advertisement urging readers to sell holiday greeting cards, and quickly started knocking on doors. One neighbor promptly slammed the door in his face. Undeterred, York went home and wrote a sales speech: “I believe that at that age,” he said, “90 percent of the kids would’ve gone home, and that would’ve been the last Christmas card they sold.” Not York. He resumed his door-knocking campaign soon thereafter and sold cards to nearly a quarter of the houses on his street and many more in the surrounding blocks.

Years later, he rode the tailwinds of his ambition to Notre Dame, where, as a pre-med student, he met Denise DeBartolo, the love of his life. They first locked eyes in 1968 at a group blind date, arranged by Ron Mastriana, who was York’s roommate and Denise’s cousin. That weekend, Denise, who was a first-year student at nearby Saint Mary’s College, had invited several girlfriends from her hometown of Youngstown, Ohio, to visit. The ladies paired off with York, Mastriana, and several of their friends to attend an off-campus party. Almost immediately, York set his sights on Denise. She wasn’t blown off her feet—at least not at first—but, as always, York was persistent.

For the next 10 years, they continued to date, flying back and forth to see each other when living in separate cities. But the couple spent the first years of their courtship in the Great Lakes region. After graduating magna cum laude from Notre Dame in 1971, York enrolled at the Stritch School of Medicine to pursue a medical degree. The decision meant he could stay close to Denise, who was a year behind him in school, and pursue a career that would allow him to apply his innate curiosity and love of science to solve problems and improve the lives of patients.

The Loyola Years

Beyond its proximity to Saint Mary’s College, Loyola’s Stritch School of Medicine was attractive to York because of its pragmatic, hands-on approach to physician training and focus on holistic, team-based care. In a competitive field where pedigree is often measured by the quantity and esteem of one’s academic publications, the school’s philosophical underpinnings, rooted in the Jesuit idea of cura personalis, or care for the whole person, stood out as a refreshing outlier.

“I’ve never been around any other group of trained physicians that are better than those at Loyola,” York said. “Being around practicing physicians where their first love is taking care of patients, not writing papers, is unbelievably influential for the average medical student. And that’s what you had at Loyola.”

After earning his medical degree in 1975, York spent several years in a postdoctoral program at Vanderbilt University, specializing in the diagnosis of leukemia and lymphoma, before returning to Loyola to begin a two-year residency in blood pathology. He found a willing mentor in the late Ralph Leischner (MD ’68), an attending physician at Loyola University Medical Center, who admired York’s work ethic and obsessive attention to detail. On Saturday mornings, the two attended morbidity and mortality conferences, where they reviewed complex or adverse cases, including autopsies indicating patients’ speculated causes of death. Often on the same side of heated medical debates, they quickly became close friends.

Leischner went on to chair the pathology department and became senior associate dean at Stritch. He is credited with revolutionizing the school’s medical curriculum by shifting its emphasis from large lectures to a problem-based, small-group format. The Ralph P. Leischner, Jr., MD, Institute for Medical Education, established in 2004 with York’s seed funding, grew out of Leischner’s vision to train world-class doctors and educators. It has since evolved into the Ralph P. Leischner, Jr., MD, Department of Medical Education, a nexus for research and education programs that fuse pedagogical scholarship and clinical practice.

York remembers Leischner fondly as “one of the greatest teachers I’ve ever had,” and it is apparent that Leischner’s compassion and iterative approach to improve care delivery systems left a lasting impression on York, whose leadership of the NFL Owners Health and Safety Advisory Committee bears its imprint. More broadly, York remembers Stritch as a welcome environment to test fresh, cutting-edge ideas.

After his residency, however, York struggled to find a position at a Midwest academic medical center or hospital aligned with his goals as a forward-thinking pathologist interested in using emerging biomarker-based approaches, such as the Lukes-Collins classification of lymphomas, to diagnose blood diseases. In the absence of a clear alternative, he approached Denise’s father, Edward DeBartolo Sr. with a modest proposal. “I said, ‘I want too pen a lab’…And I told him that if he could support me for two years, I’d figure out how to make it work. He wanted to know why he should do that. And I said, ‘because if you don’t, your daughter is going someplace that isn’t going to be Youngstown, Ohio.’”

DeBartolo Sr. acquiesced, and in 1982 York launched DeYor Laboratories, a Youngstown-based blood pathology and hematology lab that grew from a lean, four-person operation to 500-person regional enterprise active in three states. Anthony Nasrallah, PhD, an immunologist who served as the laboratory’s director throughout its lifespan, recalls York asa leader who had high expectations for his staff and insisted on impeccable accuracy and responsiveness.

“John’s diagnoses might as well have been a hundred percent,” Nasrallah said. “Even though we were just a little lab and Pittsburgh and Cleveland had very well-known hematologists and immunologists, our lab was producing results that nobody refuted.”

The lab’s regional reputation and track record of growth and profitability eventually attracted the attention of the material science conglomerate Corning Inc., which purchased the business in 1993. Having made good on his promise to DeBartolo Sr. and shown his business acumen to be on par with his medical talents, his father-in-law appointed him as senior vice president and director of racing operations for the DeBartolo Corporation. York managed the role well, drawing on his boyhood experience at Oaklawn Park to oversee the company’s portfolio of thoroughbred racetracks. His success in the executive role set the stage for an even larger responsibility: taking ownership of the San Francisco 49ers with his wife Denise.

Training his protege

Denise’s father, Edward DeBartolo Sr., was a shopping mall magnate whose success led to other ventures, including the purchase of the San Francisco 49ers. In 1977, Eddie DeBartolo Jr.became the club’s principal owner, ushering the team through five Super bowl victories. But when he became implicated in a gambling fraud case (he has since been pardoned), he relinquished control of the team. Denise and York took over ownership in April 2000, and York felt a sense of filial duty to run the team.

In some ways, it was a dream come true. As a child, York had grown up rooting for the San Francisco 49ers, whose prized Million Dollar Backfield—quarterback Y. A. Tittle, halfbacks Hugh McElhenny and John Henry Johnson, and fullback Joe Perry—were his boyhood heroes. But he had no experience running an NFL franchise.

He quickly committed himself to developing a budget for a team that by some accounts didn’t have one. However, as York was working to rein in front-office spending, the team’s performance on the field was flagging. Between 2003 and 2008, the team suffered a string of losing seasons, and fans and players grew impatient. So, too, did York, who ultimately wanted to win and had a plan to make that happen.

From the day he took over the team, York had seen his son, Jed, as the team’s rightful heir. Not only was Jed a lifelong fan—as a child, he had walked the sidelines of Candlestick Park with Eddie DeBartolo Jr. and coach Bill Walsh—he also was blessed with the kind of brisk, panoramic mind York believed could reestablish the team as a Super Bowl contender. In 2008, at just 28 years old, Jed took over as president and was promoted to CEO four years later, but not before York had rotated his son through nearly every role in the organization: food service, public relations, accounting, scouting, even a humbling stint prepping ice packs and sewing nameplates on players’ jerseys in the laundry room. It was emblematic of the type of skill- and character-building exercises York practiced with his children when they were younger.

More than that, it was York’s way of orienting Jed to the organization and its employees, winning their approval by working with them side by side. For the former New York financial analyst, paying dues was table stakes for acceptance—and for developing empathy as a leader.

“I think we have a very good rapport and have figured out how, collectively, to have a very, very strong organization,” Jed said. “I just have a different approach to day-to-day business than my father. But there’s a reason why you would never come to me for medical advice or advice on a science project. That’s where Dr. York comes in.

Leveraging football to educate and empower youth

In York’s own telling, his medical contributions to improve NFL health and safety are important, but his support for education—and the many ways in which profits from, and interest in, football can animate philanthropic efforts to train future thinkers and leaders—is just as consequential. Through their service on the 49ers Foundation board, York, Denise, Jenna, and Mara have played a pivotal role in supporting STEAM education and social outreach efforts that have empowered young lives and strengthened communities.

“Before we got involved in 2000, the 49ers Foundation was a very small organization giving out small contributions to a lot of different entities,” York said. “And while all that was good, I did not see it as being particularly impactful. So we started to decrease the number of entities that we impacted and raised how much we were giving. The first year we gave out $500,000. Today, we raise over $10 million a year.”

One of the most visible manifestations of the foundation’s work is the inclusion of four educational classrooms inside Levi’s® Stadium. The idea for the classrooms—initially posed by Denise—gained momentum when Jed’s wife, Danielle York, a former teacher in the San Francisco Unified School District, found herself unable to take her class on a field trip to a local science museum because the district lacked the money to pay for busing.

It was a striking example of educational inequity, and John and Denise, via the foundation, set out to address it by providing interactive spaces for football-themed lessons on topics such as the stadium’s engineering, the aerodynamic design of footballs, and statistical decision-making. The program was a success and grew quickly.

“Year one, we hit 25,000 students served,” said Prettyman, noting that the project started with a single classroom. “We went to the Yorks and said, ‘Hey, first-world problem on our hands: We reached 25,000 students in year one, but we have about 35,000 students on the wait list.’ The family basically said, ‘Well, if you can find another place for classrooms, we’ll build them.’”

Prettyman found the space, and the Yorks delivered.

The breadth of the foundation’s work, reflecting more than $70 million invested in historically under resourced communities since 1991, is nothing short of staggering. In addition to sponsoring STEAM learning inside Levi’s® Stadium, the foundation has raised funds to support girls’ flag football leagues; a mentorship program called Fresh Lifelines for Youth that supports young, nonviolent offenders; acclaimed beneficiary programs, including writer Dave Eggers’s 826 Valencia and AmeriCorps’s City Year; and far-flung social and educational outreach efforts in the United Kingdom, Mexico, and the United Arab Emirates.

In early February, when Super Bowl LX brought the Seattle Seahawks and New England Patriots (not to mention Puerto Rican rapper and singer Bad Bunny) to Levi’s® Stadium for an event that saw the highest peak viewership of any broadcast in U.S. television history, the 49ers Foundation hosted 70 community activations across the Bay Area, engaging more than 4,000 young people. Together with the NFL Foundation and the Bay Area Host Committee Foundation, the foundation also invested $3.7 million to revitalize Townsend Field at Buchser Middle School in Santa Clara, creating a physical legacy designed to serve students and the community far into the future.

“Education and learning have always been [my father’s] number one focus and number one passion,” Jed said. “And I think the more you can give back to kids, the more you can give them great educational opportunities to learn and to overcome hardships—that’s what brings people out of poverty.”

All these efforts speak to York’s deeply ingrained civic interests and a culture of family—natural and adopted—whose influence is felt not only in disadvantaged communities, but also among retired players and their relatives. Through alumni weekends, public recognitions, and seed funding of programs like the Golden Heart Fund, which supports players and families undergoing hardship, York and his family have helped bring many former players back into the fold.

Lynch points out that few owners are as deeply connected to players as York, a familiar face in the 49ers’ locker room who also communicates regularly with many former players. Among them is retired San Francisco 49ers running back and five-time Pro Bowler Frank Gore, who credits York with signing him to the team in 2005 when other owners, scared off by the specter of the two ACL injuries Gore suffered to his left knee as a player at the University of Miami, cowed at the prospect.

“I love him,” Gore said. “I love the family. I love everything about the organization, man. We family: Dr. York, Mama York. They all my family.”

Doing well and doing good

As York walked onto the field to pass out 49ers’ pins and field passes shortly before the team’s early season game against the Jacksonville Jaguars, fans in scarlet and gold regalia leaned over the risers, shouting “Dr. York!” with obvious admiration. He had just spoken with Head Coach Kyle Shannahan and dropped in on a meeting of paramedics to discuss an emergency action plan. Sixty minutes before kickoff he would attend a pregame, 30-person medical meeting led by the team’s head physician and including athletic trainers, an intubation expert, game officials, as well as unaffiliated neurotrauma consultants who observe the game from the sidelines and booth.

York isn’t required to go to these meetings, but he does, nearly every time the team plays, because he feels they’re important to player safety. “When you see a player concussed, when you see somebody come off with an ACL or Achilles injury, all of that is devastating. You have to be moved by that,” he said. “We are a part of one another as the owners, players, and coaches. It’s a different kind of family, but just like you would feel for one of your own kids or for your brother or sister or mom or dad, those are the feelings there.”

When it comes to player safety, York acknowledges there is a long way to go. The day of the game, 14 San Francisco players were listed on the pregame injured report, with conditions ranging from minor ankle sprains to more serious knee and shoulder injuries. Meanwhile, concussions remain a concern among league executives, and diagnoses of chronic traumatic encephalopathy, a neurodegenerative disease associated with memory loss and mental illness, continue to emerge in former NFL players.

But what is clear is that York’s insatiable curiosity and commitment to accomplish more—both for the long-term health and well-being of current and retired players and for the surrounding community—is making a difference. He has lived a professional life where tiny details matter. Microscopic differences in cells viewed on pathology slides. Discrepancies of millimeters in the dimensions of helmet shells and liners. Details that are easily overlooked but that have profound implications for human welfare, especially when one considers the visibility and influence of a $23 billion league that captivates hundreds of millions of fans and fuels medical research and technological innovations whose impact is felt far beyond the football field. York is doing well. But, above all, he is doing good.

Read more stories from Stritch School of Medicine.