You’re Older Than You Think You Are

As much as we try to fight it, we’re aging faster than we’d like, and we can blame our own bad habits for some of that. Researchers at the University of North Carolina (UNC) have developed a way to test for our molecular, or physiologic age, which, it turns out, may have little to do with the number that appears on our driver’s licenses.

This age reflects the various assaults on our bodies that come from things such as smoking, tanning, and stress, as well as exposure to ultraviolet light (every time we step outdoors). Led by senior author Dr. Norman Sharpless, director of the Lineberger Comprehensive Cancer Center at UNC, the scientists developed a litmus test for how quickly a group of immune cells known as T cells aged. As cells near the end of their natural life, they start dividing more slowly and accumulate more DNA damage, and that triggers a certain gene to become more active. Using that gene’s activity as a signal of such cellular senescence, Sharpless and his team started to test how different factors affected this gene.

So far, they report in the journal Trends in Molecular Medicine, cigarette smoke and ultraviolent light drove both mouse and human cells to age faster. No surprise there. Chemotherapy drugs use to treat breast cancer also stressed the cells to wear out sooner.

More surprising, however, was that a high fat diet, which Sharpless assumed would also contribute to aging, didn’t make the mice get much older. “Why we got that unexpected answer is unclear—it may be that the mice are different enough from humans, or it may be that the dose [of the high fat diet] wasn’t sufficient,” he says.

The things he and his team tested have involved agents or behaviors that damage DNA. But Sharpless knows that’s not the only thing that turns young cells old. He’s also aware that cellular senescence isn’t the only marker of a person’s physiologic age. But it does provide a good way to put all of our favorite anti-aging remedies to the test—like green tea, exercise and that glass of red wine with dinner. He also hopes that it can be used to predict which cancer patients may experience faster aging from chemotherapy and guide them toward less damaging drugs.

You won’t be able to do that on your own, since harvesting T cells isn’t something that’s available in a DIY kit, but Sharpless has founded a company that is creating a more user-friendly (and commercial) way to track how quickly we are barreling toward our golden years.