If scientists ever discover the elusive fountain of youth, that fountain will have to rejuvenate one particular group of cells that will make us all ageless.
These cells are the body’s workhorses with the potential to maintain your organs in the pristine condition of a teenager. They may also keep your muscles as toned as those of a young athlete and fine-tune your brain cells so they’re as rapid-fire smart as those of a chess prodigy. Keep reading and I’ll disclose the identity of these wonders.
The cells I’m talking about are stem cells.
Research shows that the changing nature of stem cells, as you grow older, is a key factor in the destructive forces that old age lets loose.
They’ve Got Rhythm
In the past, researchers thought the actions of aging stem cells begin to deteriorate because their daily circadian rhythms became disrupted more every year as we grow older. Young stem cells follow daily routines that prevent damage to the body. Early studies of these cells seemed to indicate that their daily routines devolved into a stem cell permanent vacation in older people.
But scientists in Spain have now shown that even aged stem cells still follow a daily pattern. Irregular patterns are not the reason their protection of the body proves inadequate.
The real reason your stem cells falter, say the Spanish researchers, is because the cells get reprogrammed in their tasks, not because they fail to stick to a 24-hour clock.
According to researcher Salvador Aznar Benitah, “The problem is that as they age, stem cells lose the rhythmic functions necessary for tissue protection and maintenance, which become replaced by functions aimed at coping with stress. Loss of the previous circadian functions of stem cells during natural aging contributes in some way to greater damage and greater aging.”
Half-Hearted Fix-Ups Instead of Brand-New Parts
In other words, young stem cells are great at preventive maintenance of the body. Like a conscientious car owner who keeps replacing tires before the treads wear down, young stem cells put “new tires” on organs before they show too much wear.
But older cells are apparently reprogrammed to mostly do mop-up work – repairing damage after it’s already appeared. It’s as though instead of putting on new tires, they’re only capable of patching holes when the treads on the old ones start to wear out.
So just as tires that have been patched way too many times become dilapidated and start falling apart, your aging organs, patched by stem cells but not rejuvenated, become tattered and decrepit.
The researchers believe this stem cell reprogramming occurs when an older body harbors a growing amount of DNA damage, inflammation and cellular debris.
Reincarnating Younger Stem Cells
So far lab studies have only found one dependable way to restore stem cells in the body to a younger state – eat fewer calories.
“Eating less appears to prevent tissue aging and therefore prevents stem cells from reprogramming their circadian activities,” according to Professor Benitah.
But before you decide to tighten your belt and start eating a meager diet, be warned that the Spaniards — and other researchers — aren’t sure it’s practical for us humans to cut our calories by the drastic 30 percent it takes to change our stem cells’ behavior.
That kind of diet “entails constant hunger and so requires a lot of willpower,” says Prof. Benitah. “They provide the body with the minimum energy to perform its basic functions, which in the long term may have negative effects on people’s everyday lives.”
There May Be Another Path to Healthy Stem Cells
However, other scientists are working to produce stem cells that can be manufactured on a larger scale than currently available and which can be injected into people to turn back the effects of aging.
A study at the University of Pennsylvania Medical school shows that stem cells taken from human fat tissue are more stable and more usable than the kind of stem cells being used now in some situations to treat people. And they say this is true even when the stem cells are extracted from the fat tissues of older folks.
“Unlike other adult human stem cells, the rate at which these (stem cells) multiply stays consistent with age,” says researcher Ivonah Percec. “That means these cells could be far more stable and helpful as we continue to study natural aging.”
All of this research makes me hopeful that we are on the verge of breakthroughs in fighting off aging. As these studies tell us more about these remarkable cells, a growing number of anti-aging therapies should become common.