The Immune System Walks Into a Gym
On Eric Topol, inflammation, and the stories we tell ourselves about showing up
Most mornings I walk into a gym that could pass for a senior center with better equipment. The median age in the cardio section hovers somewhere around 68. There are people on the ellipticals who have been coming here longer than some of the staff have been alive. A few are navigating bad knees or replaced hips; one woman I see every Tuesday has been working around a shoulder injury for two years and has simply reorganized her entire routine rather than quit. The place smells like rubber mats and determination, which is not the worst combination.
I've started to wonder, lately, what story each of these people is telling themselves to get here. Not the story they'd give you if you asked — the official version, the responsible answer about cholesterol or the doctor's recommendation. The deeper one. The one that runs underneath, that says this is who I am or this is what I owe myself or, for some of them, perhaps simply I don't know what I'd do with the morning otherwise. Because habits, the durable ones, are almost always stories before they are behaviors. We don't just decide to show up. We decide, at some level, that showing up is the kind of thing a person like us does.
I've been thinking about this in light of something I recently heard from Eric Topol, the cardiologist and genomics researcher at the Scripps Research Institute. Topol has been one of the more rigorous voices in the longevity conversation, which is a space, as anyone knows, crowded with grifters and supplement pushers and people who will sell you a cold plunge tub and call it medicine.
What Topol is arguing — and has been arguing with increasing insistence — is that the key to a longer, healthier life may be less about the genome than we thought, and more about the immune system. In a recent conversation with Kara Swisher, he put it this way:
"But the immune system seems to be the real explanation for many of these people reaching such advanced age — that their immune system has very high integrity. It hasn't lost its protection against cancer, and it also isn't hyperactive, for example, in the artery wall for atherosclerosis or in the brain to promote reaction to these misfolded proteins. So the three big diseases of aging, neurodegenerative, cancers and cardiovascular, the common thread is that we need an intact immune system because if we don't, then we start to see this process of inflammation get unleashed." (Wellness Grifters and the Real Science of Longevity with Eric Topol, Kara Swisher interview, April 9, 2026)
Sit with that for a moment. The three great killers of later life — dementia, cancer, heart disease — sharing a common upstream cause in immune dysregulation and chronic inflammation. The immune system, he's saying, is not just a defense mechanism. It's a kind of narrative coherence that the body maintains about what belongs and what doesn't, what's self and what's threat. When that coherence breaks down — when the system can no longer tell the difference between a real danger and the body's own aging tissues — it starts burning down the house it was built to protect.
And what knocks it off balance? Topol's list is blunt and uncomfortably familiar: poor sleep, chronic stress, sedentary behavior, ultra-processed food, and the low-grade cortisol drip that comes from living in a state of unresolved psychological tension. We are, many of us, marinating in our own stress hormones. And those hormones, over years and decades, appear to be doing real damage to the very system our bodies rely on to fight back.
Which brings me back to the gym, and to the question of stories.
The unhealthy habits — the ones that drive inflammation, that erode sleep, that keep us sedentary and overfed — are not, in most cases, the result of ignorance or moral weakness. They are the result of stories. The story that says I've earned this. The story that says this is the one pleasure I have left. The story that says I'm too far gone to bother, too tired to start, too overwhelmed to change the channel. These are not irrational stories. Many of them are rooted in real exhaustion, real grief, real constraint. The person who reaches for the thing that soothes at 10pm is usually not making a bad decision so much as honoring a story about what the day has cost them and what they are owed in return.
The question is not how to shame those stories out of existence — that never works, and the wellness industry's persistent moralism about self-discipline is one of its least helpful features. The question is what stories we can construct that make the healthier choice feel like an expression of identity rather than a denial of pleasure. I'm someone who moves. I'm someone who protects her sleep. I'm someone who takes the stairs not because I have to, but because the body I want to live in requires it. These sound like affirmations, which makes them slightly embarrassing to say out loud, but they are also just — accurate descriptions of how durable habits work. They require a narrative container.
The people in my gym have built that container, in one form or another. I don't know all their stories. But I know that showing up daily, or nearly daily, at 68 or 74 or 79, requires a self-concept in which this activity belongs. You have to believe you're the kind of person who does this. And believing it, it turns out, is not a personality trait you're born with. It's a story you've chosen to tell — and, crucially, kept choosing to tell, through the bad mornings and the busy weeks and the injuries that required the routine to be renegotiated rather than abandoned.
The body, meanwhile, is quietly keeping its own account. Sustained moderate aerobic exercise — the kind that fills a gym like this one — reduces circulating inflammatory markers like C-reactive protein and interleukin-6. It promotes immune surveillance, the body's capacity to detect and neutralize aberrant cells before they become tumors. It lowers visceral fat, which is itself an inflammatory organ. It reduces resting cortisol. It improves sleep quality, giving the brain its nightly chance to clear the metabolic debris — including the amyloid plaques associated with Alzheimer's — that accumulates during waking hours.
In other words: the gym, for all its humble, fluorescent reality, may be one of the most effective anti-inflammatory interventions available to most people. Not because it's glamorous, but because it works on precisely the mechanisms Topol is pointing at. The wellness industry would like you to believe that the road to healthy aging runs through a $4,000 continuous glucose monitor and a weekly IV drip of NAD+. What the evidence actually supports is stubbornly ordinary: regular movement, genuine stress reduction, restorative sleep, a diet that doesn't come in a package. The frustrating thing about this list is that it requires consistency rather than purchase. It asks something of us that money can't quite substitute for.
It asks us, specifically, to be the protagonist of a particular kind of story. One in which we are active agents in our own biological future, not passive recipients of whatever the genome or the insurance system or the food environment hands us.
But here is where I want to push the conversation a little, because I think there's something the longevity researchers sometimes miss when they talk about stress reduction as a path to immune health.
They tend to mean stress reduction as an individual practice. Meditation. Sleep hygiene. Breathwork. And these things are real. But the stresses that quietly shred the immune system in later life are not only internal. They are relational, economic, social, existential. The person lying awake at 3am is often not doing so because they haven't discovered the right app. They're doing so because they are caregiving without support, navigating a healthcare system designed for people with more time and money, sitting with grief that has nowhere to go. The story they're living doesn't have space in it for the gym. It barely has space in it for rest.
Community, it turns out, is also anti-inflammatory. This is not a metaphor — social isolation activates the same physiological stress-response pathways as physical threat. Loneliness is, in Topol's framework, a form of chronic inflammation by another name. And shared story — the sense of being witnessed, of belonging to a group with a common practice — is one of the mechanisms by which community does its biological work on us.
Which is perhaps why that gym, with its aging regulars and its particular morning rhythms, is doing more than its equipment would suggest. The person on the elliptical who nods when you walk in is part of the medicine. The instructor who remembers your name. The low-stakes social fabric of a shared physical practice, repeated enough times to become a kind of infrastructure. These people are not just exercising together. They are, in a modest and daily way, co-authoring a story about what it looks like to age with intention — and each of their bodies is, apparently, taking notes.
I'm not in the business of telling people what to do with their bodies or their mornings. And I'm aware that gym access is unevenly distributed, that the frictionless daily workout is a function of privilege as much as discipline.
But the picture Topol is painting — and that I find myself returning to — is one in which the health of our later years is less a matter of genetic luck than of accumulated daily choices. The genome turned out to be surprisingly unhelpful in explaining who lives to 90 in good health. The immune system, shaped by decades of stress, sleep, movement, and connection, turned out to matter more. And the immune system, it turns out, takes its cues — in part — from the stories we are living. Whether those stories include rest. Whether they include movement. Whether they include other people who give a damn whether you showed up today.
The woman working around her shoulder injury has, whether she'd use this language or not, written herself into a story where quitting is not really an option. Not because she's heroic — she'd probably laugh at that — but because somewhere along the way the daily practice became part of who she is. Her immune system, I'd like to think, has registered this.
There's a particular kind of knowledge that only arrives through sustained practice, that the body carries in its tendons and its resting heart rate and its improved capacity for sleep. It doesn't fit neatly into a longevity protocol. It's closer to what craftspeople and farmers in earlier generations understood intuitively: that the body is not a problem to be solved but a practice to be maintained.
The gym is not a cure. But it might be, for many of us, one of the more honest stories we're telling ourselves about how we want to age.
