Just who among us needs our heads examined?

Football players? Last week’s revelations of the late Giants star Frank Gifford’s positive test for the degenerative brain disease chronic traumatic encephalopathy, or CTE, came days after St. Louis Rams quarterback Case Keenum, attempting to rise after a tackle, was all rubbery and disoriented, while  little imaginary birds twirled around his helmet.

Football fans? There certainly are some who have begun to wonder about the ethics of supporting a sport faced with increasing evidence of its participants’ cognitive impairment. Gifford was the 88th of 92 deceased former NFL players examined who was found to have had CTE.

Parents of potential football players? At the Boston University center that studies CTE, the percentage of positive tests on former players from all levels is a whopping 90-plus percent, and pre-collegiate players have been sustaining some 90,000 concussions per year. Among the public figures who have said that, if they had sons, they would not allow them to play football, is Football-Fan-In-Chief Barack Obama.

How about anyone who thinks these headache-inducing reports signal the imminent demise of our most popular sport? It has been almost 14 years since the first case of CTE was diagnosed in a deceased football player, yet Harris Polls continue to find football to be the nation’s overwhelmingly favorite spectator sport—37 percent of the population lists the NFL as No. 1 and another 11 percent prefer college football. (Only 16 percent of the citizenry list Major League Baseball as top choice and no other sport breaks into double figures.)

In 2009, in a New Yorker magazine piece, Malcolm Gladwell considered football’s future extinction, and a stream of thoughtful reports since then have considered how the ramifications of head injuries might play out: Liability suits that could subject coaches, team doctors and referees to financial exposure. Parental concerns. Skyrocketing Insurance costs. The drying up of advertising and television commitments. Congressional action.

Last year, a self-described NFL fan wrote to New York Times ethics columnist Chuck Klosterman pondering the morality of supporting a league apparently aware that its sport is detrimental to the health of its participants. Klosterman concluded that, as long as everyone is enlightened about the peril that could visit football players, he “can live with” the public loving something that is dangerous.

Me, too. And, after all, football isn’t boxing or—worse—mixed martial arts, in which the primary purpose is to separate an opponent from his or her senses. But we should persist in furthering our education about the potential hazards, and hope that football authorities do the same. Early-onset dementia among players is real gray matter, something to consider in all its shades and consequences.

A crack neurologist once explained to me the brain’s vulnerabilities, and it goes something like this:

The brain isn’t much more than a blob of Jello, about three pounds net weight, floating in a fluid, held in place by a scaffolding of fibers. It is as well-housed as any other internal human gadget—the skull, after all, doesn’t crack easily. But with a blow to the head, whether encased in a helmet or not, the brain easily can rattle off the inside walls of the skull or, worse, twist violently, causing a tear.

A simple concussion brings temporary alteration of consciousness, often so brief as to go unnoticed, yet short-circuits the part of the brain controlling awareness, alertness and focus of attention. A stronger bop on the head can create a contusion, a bruise caused by the brain ricocheting off the opposite wall of the skull and then back again. Even more damage results if the torque force wrenches the Jello mass.

Later this month, the movie Concussion will be released, and director Peter Landesman has said the film can’t help being “a shot between the eyes of the NFL,” because it portrays how forensic neuropathologist Bennet Omalu (played by Will Smith) had to battle NFL efforts to suppress his research on players’ brain damage.

Omalu was the man who, in a 2002 autopsy of former Pittsburgh Steelers lineman Mike Webster, first recognized CTE in a football player. Each of the first nine deceased NFL players’ brains Omalu examined, in fact, had CTE, and he told me during a telephone interview in 2010 that the root cause was not “just concussions. It’s repeated blows to the head. Helmets do not prevent concussions or [undiagnosed] sub-concussions, because they don’t stop the brain from bumping around in the skull.

“We have to take the head out of the game.”

And good luck with that. Though the NFL and other football authorities belatedly are implementing rules and protocols to limit head trauma, there is this Gordian knot: With both Frank Gifford’s conspicuous 1960 concussion, suffered on what often has been described as a “brutal, blindside” tackle by Philadelphia’s Chuck Bednarik, and Case Keenum’s recent injury, the damage in fact was not a result of an opponent’s contact with the head.

The Gifford injury, which precipitated his one-year sabbatical from football, was sustained when the back of Gifford’s head struck the ground as he went down. He had attempted to sidestep the charging Bednarick and the two essentially were facing each other at the instant of the tackle. On impact, Bednarick caught the off-balance Gifford with an arm and shoulder across Gifford’s chest, rocking Gifford backward.

Keenum was tackled waist-high but, like Gifford 55 years earlier, bounced his noggin off the turf as he fell backward. Jello surprise. So how to safeguard against that?

I don’t have a son. So that’s settled. And I will continue to be a football spectator. But I will make sure to check out Concussion as well.