Beauty may be only skin-deep, but aging goes all the way down into our very cells. That, at least, has been the consensus of scientists studying the reasons we all grow older. But now two groundbreaking studies hint at radical new ways in which we might slow down and even stop the march of time.
The problem begins with the fact that our cells, like our selves, have a finite life span. After dividing about 50 times, many types of cells reach what’s called the Hayflick limit, where they simply run out of gas and quit multiplying. This, it’s long been thought, is why we lose our youthful ability to regenerate and heal: Things sag, bag, and go kaput.
But more recently scientists have realized that the real problem is what those cells do after they’re done dividing. At that point, they can enter a so-called senescent state, where they’re basically retired but not dead. Rather than just sit there quietly, however, senescent cells can spew out a toxic brew of inflammatory factors that poisons the cells around them, like the ultimate bad neighbors. Some researchers believe they could be partly responsible for some of the worst aspects of aging—everything from cataracts to cancer.
“Senescent cells are clearly bad and clearly contribute to the aging process,” says Laura Niedernhofer, a DNA researcher at the Scripps Institute in Jupiter, Florida. “So there’s been a race to find drugs that can target them.”