This Helmet Will Save Football. Actually, Probably Not.

PALO ALTO, Calif. — Walk between a colonnade of palm trees and push through a door at Stanford University and find a sorcerer’s apprentice lab where prospective Ph.D. sorts beaver away at bioengineering programs.

This is CamLab, where David Camarillo, a nationally respected bioengineer and former college football tight end, and his students are in pursuit of that American El Dorado: They seek a helmet that will make it safe to play tackle football.

Dr. Camarillo, 40, insisted they could soon crack the case.

He tapped at his keyboard and on the screen, watched a simulation of his new helmet shock absorber, and whispered: “This could reduce concussions by at least 75 percent. Theoretically, this is the holy grail.”

That might be an unintentionally apt metaphor. No one, after all, has found Jesus’ chalice. After years of research, only a few scientists believe they can still make such a helmet. Many who study this field say a more sophisticated helmet may even prove dangerous.

“My fear is that a better helmet will give false reassurance,” said Dr. Lee Goldstein, a psychiatrist and researcher with the C.T.E. Center at Boston University, which has carried out pioneering research on chronic traumatic encephalopathy, the degenerative brain disease linked to repeated hits to the head. “It’s like developing a better cigarette filter. It’s smoother and it might not give you a hacking cough. But you still get lung cancer.”

These are strange and contentious times for football. It remains America’s most popular sport. The National Football League remains a mint, pumping out revenues that have reached $15 billion annually. At the same time, youth and high school football participation has fallen steadily, driven, in part, by broad parental concern about the brutal damage wreaked by hits that shake and rattle the gray mass of mystery that is the human brain.

Their worry is based in fact. When a 310-pound man who runs a 40-yard dash in five seconds flat slams into a running back, that runner’s neck and head accelerate, and the brain and its fibers twist and stretch and tear. A particularly rough hit could jar open the blood-brain barrier, the semipermeable wall that prevents bacterial pathogens from entering the brain.

The danger isn’t limited to the largest and fastest people. In fact, smaller repeated hits — as opposed to spectacular collisions — are the real danger. Football, brain experts say, can represent imminent danger to the brain of a child, a teenager or an adult. No advance in helmet making, they say, is likely to materially change that.

Willy Moss, a physicist at Lawrence Livermore National Laboratory in California, has worked with Dr. Goldstein and the Department of Defense, seeking to develop better helmets for players in contact sports and soldiers in war zones. He has also consulted with Dr. Camarillo.

He is open to a breakthrough in helmet technology, though a thin smile spoke to profound doubt.

“You can make whatever changes you want, but in the end it’s all physics,” he said. “Talking of new and better buffers is like Goldilocks and the three foams.”

Stefan Duma, an engineering professor at Virginia Tech, runs a respected helmet lab that evaluates and rates them, and he has tracked the breadth of the technological leap. More sophisticated helmets and foams have reduced the acceleration of the head by about 50 percent, and all of the companies, he said, are engaged in research to develop new technologies. But he is not convinced that great advances remain.

C.T.E. remains an ever-present danger no matter what a player wears on his head. “Not getting hit in the head at all is the best thing for you,” he said.

“The top five or six pro helmets are interchangeable, well designed and perform well,” he added. “But we have to be clear: This is about risk reduction.”

So the argument is joined, and there’s no doubting the stakes. The N.F.L. recognizes the threat to its future and has shoveled money into helmet and concussion research as fast as a stoker tosses coal into a furnace. It has spent $200 million, and counting, in the past decade, and the Department of Defense has poured in tens of millions of dollars of its own, hoping to find better protection for soldiers. In mid-November, the N.F.L. announced a $2 million grant competition to create a new “top performing helmet.”

Taken on its own, the $140 million football helmet business is dominated by a half-dozen companies and offers a poor profit center, as the market is small and heavily weighted down with insurance liability costs. Dr. Camarillo has applied for a piece of that N.F.L. bounty and has yet to receive money. He is principally underwritten by a grant from the Lucile Packard Foundation for Children’s Health.

Should Dr. Camarillo succeed in creating a radically safer helmet, he hopes his technology would apply to broader and more lucrative sports markets, cycling, lacrosse and hockey. The innovations also are of interest to car manufacturers.

“My goal is not to be a consultant to football,” he said. “Really traumatic brain injury is a much bigger issue.”

And he is convinced that a better helmet can help solve it.

Dr. Camarillo grew up in a seaside agricultural town across the Santa Cruz Mountains from Silicon Valley. He played linebacker and tight end in high school, but at Princeton, in the late 1990s, he concentrated on tight end. All the banging in linebackers practice proved brutal, and he developed fierce migraines. “I was in serious pain,” he said.

He loves the sport and grows poetic as he describes a team camaraderie that cut across race and class. He is loath to see that culture wither. With a background in biomechanics and biophysics, he worked in surgical robotics before launching his own lab at Stanford in 2012; he is focused on understanding and preventing traumatic brain injury. He has worked on developing safer football equipment with a biomechanical approach, using gyroscopes and measuring the rate of rotation of the head upon impact.

He works there with a neuroscientist and neuroradiologist, Dr. Michael Zeineh, and a pediatric neurosurgeon, Dr. Gerald Grant, who has devoted years of work to concussions.

“We have to know the mechanisms of injury, biologically, and what are the tolerance levels,” he said. “How much is too much?”

He developed a computerized mouth guard. It was hoped that mouth guards might lessen the impact of hits and lead to fewer concussions. That has not panned out, but the high-tech mouth guards have helped scientists chart the nature of damaging blows. “Every person reacts different to taking a traumatic physical hit,” he said.

Dr. Camarillo’s hope for the future of helmets, which other scientists at other institutions are pursuing as well, relies on two of the oldest earthly substances: water and oil. His team inserts one of these fluids into helmet columns and uses its nearly unmatched ability to absorb the massive energy load of a football hit, and thus reduce the effect of the hit on the head and brain.

In a soon-to-be-published academic paper, he and his team forecast a 75 percent reduction in concussions compared with the best helmet now on the market. “Think of this as a hydraulic shock absorber,” he said.

Challenges remain, not the least of which is that water is heavy, even in small quantities; no player wants to carry a water bed on his head.

Dr. Camarillo said that his team seemed to have found a way to engineer around that challenge, that it could produce something no heavier than a bike helmet.

“It is predicting less than one concussion per football season for a team,” he said. “Maybe it’s too good to be true and maybe it is, but theoretically? It looks possible.”

His findings so far are drawn from computer simulations, and no matter how sophisticated they are, that’s not the same as a good field test.

In the battle over football and brain health, Dr. Camarillo portrays himself as occupying the sensible center, an agnostic caught between ravening ideologues. There are those who deny that football damages the brain, and, in his telling, there is the C.T.E., sky-is-falling camp, which sees no choice other than to end football.

“It has become so charged it’s almost political,” he said.

He raised a doubting eyebrow about aspects of the expansive C.T.E. research of those at Boston University and Carnegie Mellon. He argued those groundbreaking experiments — the ones that have shown that repeated and less powerful hits can produce C.T.E. in mice — were less conclusive than they appeared. “What is a concussion in a rodent?” he said. “Can we so clearly define it in a human? No.”

I spoke to a half-dozen neuroscientists from four universities, and all said that the science of using mice as analogues for humans is robust and that evidence that shows repeated hits damage the brain keeps accumulating.

I shared Dr. Camarillo’s views on the drawbacks of experimenting on mice with Dr. Goldstein of Boston University. He sighed and fell silent on the phone line before speaking.

“He can believe whatever he wants, but it’s a misinformed reading of the science,” he said. “We get identical neuropathology in our animal models that we have seen in humans.”

The two sides in this debate as often seem to speak different languages. The N.F.L. and the N.C.A.A. and Dr. Camarillo talk of an overarching goal: preventing concussions, which they regard as synonymous with the brain damage caused by football. Camarillo works independently for now of the helmet manufacturers, although he hopes that one day soon that might be different.

Researchers at Boston University and Carnegie Mellon and elsewhere focus on C.T.E. as the greatest threat and insist the culprit is not the concussion — as terrible as that injury can be. Rather, it’s thousands of cumulative hits over many years. So yes, taking a freight train hit from a pro linebacker is dangerous — but being repeatedly whacked and knocked to the ground thousands of times by players in Pop Warner, middle school and high school puts you at more risk for C.T.E.

The average college and professional player undergoes 700 to 1,000 hits each year, rattling and twisting and tearing at the brain inside the skull. “I can say with great certainty that there is no correlation between a single concussion and C.T.E.,” Dr. Goldstein said. “It’s the accumulation of hits.”

Researchers at Carnegie Mellon and the University of Rochester collaborated on a recent study in which they put sensors in the helmets of 38 Division III college players and measured hits in practices and games. Only two players sustained concussions that season. But season-ending tests found evidence of structural damage and change in the brains of two-thirds of the players.

“It’s woven into every play,” said Bradford Mahon, a cognitive neuroscientist at Carnegie Mellon.

His partner, Adnan Hirad of the University of Rochester, held out the possibility that a better helmet might help in the margins. But that’s it. “It’s a dangerous sport, and we can’t mince words about a technology. There’s no El Dorado.”

I asked Dr. Goldstein what sort of technological breakthrough would protect a player against C.T.E.? He peered at me. “A force field that keeps a player from blocking or tackling you,” he said.

He did not smile.

I mentioned to Dr. Camarillo this upwelling of skepticism. He nodded with the confidence of a true believer. He and several of these scientists know each other and plan to collaborate on research. If his proposed helmet reduces concussions, he said, logically it might reduce the force of subconcussive hits that cause long-term damage to the brain. In this way, he said, it’s analogous less to a cigarette filter than to technological changes that have made surviving car crashes progressively safer.

I mentioned that claim to Dr. Goldstein and his head started to wag. He insisted the evidence on C.T.E. and the toll taken by even small hits did not support Dr. Camarillo’s optimism. “This is hope-and-a-prayer science,” he said.

Evidence could take years, at the very least, to accumulate. For now, there is no way to diagnose C.T.E. in the living; it can be found only with an autopsy.

And yet Dr. Camarillo is not deterred. “I hope this is like the seatbelt,” he said of his new helmet design, with a jauntiness that would warm the heart of an N.F.L. executive. “And the day will come when you think it’s just crazy we didn’t have it sooner.”