The quest to slow and ultimately stop aging is as old as human culture. Infinite youth is, quite literally, the Holy Grail. However, according to a recent paper, aging is inevitable and there is nothing that can be done to stop it.
Aging is natural — it happens to every human, beaver, axolotl, fruit fly, and newt alike. But that doesn't mean that we have to like it. In fact, aging is roundly considered undesirable.
Scientists have worked for many centuries on methods that might interfere with the process of aging, and somehow keep us youthful for longer.
Our desire to stay young has seen humans make some odd decisions: from Egyptians bathing in donkey's milk to soccer moms having regular coffee enemas, it seems that we'll try anything to stave off old Father Time.
To investigate this ancient and intractable problem, Joanna Masel — a professor of ecology and evolutionary biology at the University of Arizona in Tucscon — recently teamed up with postdoctoral researcher Paul Nelson.
They put their mathematical minds to work, and their paper — titled "Intercellular Competition and Inevitability of Multicellular Aging" — is published in the journal Proceedings of the National Academy of Sciences. In it, they ask, "Is it mathematically possible to prevent aging?"
The conundrum of cellular aging
As far as our current understanding of the aging process goes, there is hope that we can, one day, slow the negative cellular effects of time. One theoretical method would be to somehow eliminate "sluggish" cells that are linked with aging while keeping normal cells ticking along.
In theory, this sounds good. But as Prof. Masel and Nelson explain, it's not as simple as that (it never is). As we age, some cells give up the ghost and stop working — hair cells stop making pigment, for example.
But at the other end of the activity scale, some cells start to work overtime. These unnecessarily busy cells can go on to develop into cancer. And almost everyone, at some point, will develop cancer cells as they age — even if they do not cause any problems.
Nelson spells out the conundrum, saying, "As you age, most of your cells are ratcheting down and losing function, and they stop growing, as well. But some of your cells are growing like crazy."
"What we show is that this forms a double bind — a catch-22," he continues. "If you get rid of those poorly functioning, sluggish cells, then that allows cancer cells to proliferate, and if you get rid of, or slow down, those cancer cells, then that allows sluggish cells to accumulate."
"So," he explains, "you're stuck between allowing these sluggish cells to accumulate or allowing cancer cells to proliferate, and if you do one, you can't do the other. You can't do them both at the same time."
The researchers claim that their findings prove that aging is an "incontrovertible truth" and "an intrinsic property of being multicellular."
Why hasn't evolution solved aging yet?
Natural selection has come up with a dizzying array of solutions to the problems of life on earth, but aging appears to have it stumped. This question has plagued scientists for decades.
However, Prof. Masel and Nelson believe that evolution hasn't managed to defeat aging for the same reason that humans don't have laser beams shooting from their eyeballs and the ability to walk through walls: it's simply not possible.
"We're saying it's not just a question of evolution not doing it; it can't be done by natural selection or by anything else."
Prof. Joanna Masel
Sadly, the slow crumbling of our bodies over time is inescapable; according to the math, you can end up making the issues worse if you try to fix them. "We have a mathematical demonstration of why it's impossible to fix both problems. You can fix one problem, but you're stuck with the other one," says Prof. Masel.
"Things will get worse over time," she adds, "in one of these two ways or both: either all of your cells will continue to get more sluggish, or you'll get cancer. And the basic reason is that things break. It doesn't matter how much you try and stop them from breaking, you can't."
So the upshot is that science may be able to slow aging, but it cannot be stopped. As Nelson says, "It's just something you have to deal with if you want to be a multicellular organism." And I, for one, certainly do want to continue to be multicellular.