What Can Our Telomeres Tell Us?
Buzzy new DNA tests claim to reveal how "old" our bodies really are.
Age has never been a simple matter of birthdays. After all, we all know senior citizens who are spryer and fitter than their driver's licenses would suggest. But what if there was some other, singular measure that let us know how well or badly our bodies were doing, beneath the crow's feet and softening chins? What if there was a scientific way to determine how "old"—and far-gone—we really are?
Enter the new wave of DNA tests. A host of companies now peddle (or are about to start peddling) assessments of the genetic structures that sit at the ends of our chromosomes. These structures, called telomeres, protect DNA from degradation and shorten each time cells divide, so that they are sometimes compared to tiny molecular clocks. Recently, though, some researchers and entrepreneurs have made the leap from cells to selves, arguing that telomere lengths can also signal whether we're at heightened risk for various diseases or whether our bodies have aged faster than the calendar would suggest.
The major players that have jumped into telomere testing in the past few years include Telome Health in California, SpectraCell Laboratories in Texas, and Life Length in Spain. Their results have been touted as, variously, "a wake-up call," letting people know they're on "a rapidly aging path," or something akin to a "check engine light" on a car that warns of hidden trouble. A Life Length adviser has even gone so far as to predict that the company's test results will change people's life plans. "People might say 'If I know I'm going to die in 10 years I'll spend my money now,'" he told the Independent, "or 'If I'm going to live for 40 more years I'll be more conservative in my lifestyle.' "
But to what extent are these new telomere tests biological fortune-tellers? And to what extent do they merely exploit our pervasive fears about aging—our primal urge to know what remains of our allotted time?
Telomeres themselves are not a new discovery. But in 2009, three Americans, including two women, received a Nobel Prize for telomere-related work, and suddenly the field hit primetime. One of these laureates, Elizabeth Blackburn, helped found the company Telome Health and threw her star power behind its marketing, quickly bolstering the tests' credibility. That the new assessments promise self-knowledge through technology—and that they arrive at a moment of intense boomer anxiety about aging—makes their zeitgeisty allure easy to understand. As a scientific consultant to Life Length has put it, explaining his company's appeal: "If you ask people what they worry about, most people would say they are worried about dying."
Amanda Schaffer is a science and medical columnist for Slate.
Photograph of woman looking in a mirror by Guang Niu/Getty Images.