ONE OF MY FIRST MEMORIES is my brother scoring seven touchdowns in a single football game.

I was a little kid on the sidelines shivering in the fall bluster, so close to the field I could hear the crack when helmets collided. One of those cracks left my junior-high brother with a concussion. His doctor didn’t want him alone that night, so when he went to the bathroom Mom made him shout the alphabet through the door.

For the family I grew up in, football is to September what oxygen is to existence. Dad was a Husky halfback who got drafted by the Philadelphia Eagles. His son spent high school making touchdowns. His five grandsons played through high school; one went on to play college ball. Last December I stood shivering on the sidelines once again, as his team won the game that launched them into the National Championship. Then they won that.

I’ve been watching my loved ones play football—glory in football—my whole life. What I can’t remember is when watching it became unbearable.

Maybe it was seven years ago, when a high school sophomore from SeaTac named DeShawn Smith got clobbered in the head, collapsed on the sidelines, and died three days later. Or five years ago, when a 13-year-old kid from Maple Valley named Zackery Lystedt played through a concussion, then suffered a brain hemorrhage that left him partially paralyzed.

In the last few years we’ve learned what concussions actually do to the brain. No mere brain bruises—“bell ringers,” as Dad’s coaches blithely called them, giving the addled player a moment or two on the bench before hustling him back onto the field—concussions shake the brain, flooding it with chemicals and messing with its memory receptors. Confusion, memory loss, blurred vision, and loss of consciousness are short-term effects.

And, we know now, an enhanced chance of neurological damage is the long-term effect. Evidence for this has been mounting conclusively for a decade in studies showing that former pro players who’d had concussions reported significant memory loss, headaches, concentration deficits—even three times the rate of depression—as players who’d never had concussions. It’s called chronic traumatic encephalopathy (CTE) or dementia pugilistica, most of its victims having been boxers (think Muhammad Ali) until football began to rival boxing for bone-jarring hits.

But it’s not only concussion victims who suffer long-term damage. A 2009 study commissioned by the NFL found that its former players, concussed or not, were exponentially more likely than the general population—19 times more likely in some age categories—to get Alzheimer’s.

And that’s what haunts me. Because even as the NFL gets religion on the dangers of the sport, civilizing tackling protocols and improving helmet technology and sidelining concussion victims; and even as we parents of athletes dutifully sign our Lystedt waivers, our state’s educational and regulatory response to young Zackery’s wretchedly preventable brain hemorrhage; and even as my nephews’ generation of players has been meticulously coached away from that deafening helmet-­on-helmet crack; the hard math is that we can no longer credibly pretend that collisions don’t damage us. And football is unavoidably, centrally, a game of collisions.

Knowing this, what kind of monster am I to watch—to cheer—as my loved ones play this game?

It’s a question I ask myself every time I take my seat on a cold metal bleacher under a dark autumn sky and begin to cheer. I think of Dad, who died too young—Alas? Thank God?—to exhibit symptoms of brain damage, but whose awareness of the possibility was one reason he decided not to go pro. I think of Dave Duerson, the former Chicago Bears safety whose final request before shooting himself in the chest earlier this year—“Please see that my brain is given to the NFL’s brain bank”—led to confirmation of his suspicion that CTE was the reason for his inexplicable despair and anger. I think of my nephews, smart young men all, who I hope are smart enough to face down football’s culture of play-through-the-pain machismo.

Then I think of the mothers of the players, the ones wincing and watching through fingers when any young player goes down—breathing again only when he gets up, distracting themselves perhaps with plans for postgame celebrations, where their strapping sons will radiate pure joy for this game they aren’t yet mortal enough to feel even faintly conflicted about.