If time travelers from a past era ever visited our time, they would be astonished at the amount of planning we put into our future well-being.
We take vitamins in the morning and make sure to get enough fiber though the day, even though it doesn’t seem to have any instantaneous benefit.
We go to the gym and avoid too many sweets because we want to be healthy, live long and look well, not just immediately, but years ahead.
A hundred years ago, sobriety was a matter of social order — now, we do “Dry January” to give our bodies a detox.
But it might be that even things we do on shorter timescales leave an imprint on the body, much in the same way as individual experiences can leave a lasting memory in the brain. The gap between your lunch and your dinner. The number of times you repeated your squats yesterday. The frequency with which you watch horror movies. All of those could, theoretically, have effects on the body that we cannot yet predict or anticipate.
Does this mean that in the future, as we understand our bodies better, our health planning will become even more obsessive than it is today?
Medicine of the future will deal with vastly more information than medicine of the past
Source: Midjourney / Midjourney, Inc.
I study cellular cognition. It is an exciting new field of biology focused on the ways in which living cells process information — how they analyze their environment, detect patterns, form memories, and communicate with each other.
In a recent study, which I co-led with Tom Carew, we showed that non-brain cells — including cells derived from a kidney — can learn from patterns of chemicals they are exposed to, in much the same ways as brain cells learn when we learn to play a piano, or study for class.
This learning happens surprisingly fast, on the scale of minutes, even though non-brain cells are generally considered relatively “slow”. But the changes that occur in these cells — the cellular memories — can last for days, and maybe longer.
What does the existence of such cellular memories mean for everyday life?
We don’t know yet. One thing it might mean is that our conscious, emotional memories — for example, trauma — reside in part outside the brain. This is the main thesis of The Body Keeps the Score, a controversial but influential book about trauma by the Dutch psychiatrist Bessel van der Kolk.
Published in 2014, the book was criticized for leaping ahead of the evidence. But today, the idea that memory is spread throughout the brain and the body no longer sounds as risqué as it did ten years ago. We know that the brain and the body have mutual effects on each other: a thought or an emotion can modify a cell in the gut or the liver, and that, in turn, could modify thoughts and emotions. Our study shows that non-brain cells have memory, and this memory could potentially store such changes.
Non-brain cells can process information and learn from patterns
Source: Midjourney / Midjourney, Inc.
So there’s nothing spooky about trauma being stored in the body.
But our bodies probably retain a lot more than such imprints of conscious experiences.
There have been studies in the past, coming from different fields of medical science, showing memory-like properties in various organs and tissues: a quick input causes a lasting change.
But until recently, no one thought of these isolated cases as literal memory — and no one considered the possibility that they might operate similarly to each other, and to the canonical, brain-based memory.
For example, cells in the pancreas respond to sugar in the blood by releasing the hormone insulin, which causes sugar to be absorbed. If you expose those cells to a large amount of sugar at once, then wait twenty minutes and do it again, the second time they will release twice as much insulin as the first time.
This makes biological sense: if you maxed out your insulin-releasing (and therefore, sugar-absorbing) capacity, you would want to ramp it up in case more sugar arrives, but you wouldn’t want it permanently elevated, or you would get hungry and fatigued too easily.
Another example: bone cells detect mechanical load, and respond to it with more bone formation. The bone becomes stronger if you repeatedly bend it.
What’s more, the bone cells respond not just to the load, but to its frequency: if you apply pressure to a rat leg once every two seconds, the bone is unaffected, but if you do it a rate of twice per second, bone growth increases as much as four-fold. So in this case, a time pattern on the scale of seconds is what makes a difference lasting months, if not years.
There are many other examples: in the immune system, in embryonic development, in cancer. Maybe the most obvious example, hiding in plain sight, is muscles growing in response to exercise.
This list is probably just scratching the surface. But already two things are clear about cellular memory.
One, it exists.
Two, it can depend on precise timing, sometimes down to minutes, and even seconds.
As we continue to uncover the rules of this cellular memory in the future, I suspect it might lead us to be even more sensitive to the experiences of our body than we are now, with all our fiber and vitamins.
We might develop sophisticated, ornate rules: no dumbbells for three days after eating smoked salmon, unless supplemented by mustard; five dabs of vitamin B at fifteen-second intervals before going out, but only in the summer.
What will that future world be like — a world in which we are hyper-cognizant of our “body memory”? Will it make us better, healthier versions of ourselves? Or will it just feed into our growing anxiety about the future, a compulsion to control every cell of the body to maximize success?
Will health become our obsession?
Source: Midjourney / Midjourney, Inc.
Time will tell — but for now, there’s no reason to do anything drastic. Until science refines the timeline, we are safe with “an apple a day keeps the doctor away”.