Telomeres : the New Cholesterol

Joseph M. Raffaele, MD

On her show one day, Oprah Winfrey listened raptly as her favorite medical guest, Dr. Mehmet Oz, talked about something called telomeres, and how they hold dramatic new information about aging.

A telomere, Dr. Oz explained, is like a protective cap for the ends of chromosomes, which carry the genetic material of cells. He took out a shoelace and held up the two ends—one with its plastic tip, the other without. Just as that tip keeps the threads of a shoelace from fraying, telomeres keep our chromosomes intact and functioning—healthy enough to allow them to reproduce cells. Which is, after all, the key to healthy aging. “When you can’t reproduce cells,” said Dr. Oz, “you’re old and you’re frail.”

It’s the length of a telomere that’s crucial—the longer it is, the healthier you are. And not surprisingly, the older you are, the shorter your telomeres tend to be. What makes this something other than a sad and inevitable fact of life is the same thing that makes the anti-aging field so dynamic. Over the past few years, researchers have been developing methods to measure telomeres—and to evaluate the beneficial effects of therapies to maintain and even increase telomere length. And that makes it one of the most exciting new areas in the entire field.

Oprah, for one, was impressed. She wanted Dr. Oz to measure her telomeres. He did, and found that they measured up. But if having her telomeres measured seemed exotic, it won’t for long.

It’s been a generation since cholesterol levels became known as a marker of cardiovascular health and mortality itself, reliable enough to become a cultural touchstone: People began comparing their cholesterol counts in general conversation, and cholesterol-reducing strategies from eating less fat to taking medications like Lipitor became a mainstay of any discussion of personal health.

But monitoring and intervening in cholesterol levels is now about as cutting edge as a floppy disk.  Though a major advance in its day and still a useful tool, cholesterol counts are hardly sophisticated by today’s standards.  It can give you a snapshot of your heart health, but not much more. Whatever your cholesterol count is today, and whatever it might indicate about your risk of heart disease, it tells you nothing about the cumulative damage your arteries have undergone over the years. History is not written in your cholesterol level. So as an early-warning system, it has its limitations. And it’s by no means a biomarker of aging.

But telomere length is—and its time is fast approaching. It won’t be long before people are talking less about their cholesterol counts than about their telomere lengths.  Indeed, it’s becoming increasingly evident how closely related the two developments are—and how far telomere length may surpass cholesterol as a diagnostic and therapeutic tool. Just as the original Framingham Heart Study demonstrated a link between high cholesterol and heart disease, many studies over the past few years have made a direct association between telomere length, age, and chronic disease.

However, unlike with cholesterol, it’s not just one of the diseases of aging that is associated with telomere length, but many—everything from cancer to dementia. And just as the world changed when a test to inexpensively measure cholesterol came along, it is about to change again with the development of a simple lab test to measure telomere length that will become increasingly available in the coming few years.

What makes all this mean something is that biotech researchers have not only come up with a way of measuring your telomeres. They have also shown that there are ways of maintaining their length as we age—and even making them longer. Just as Lipitor and similar drugs have been shown to lower cholesterol, published studies have demonstrated the beneficial effects of therapies that lengthen telomeres, and some will soon be on the market.

With cholesterol, it is LDL—the so-called “bad cholesterol”—that’s the culprit in cardiovascular risk. Your total cholesterol count is important only to the extent that it is a biomarker for elevated LDL. The corollary for telomeres is that it’s the shortest ones that tell the story, not the average of them all. But as with total cholesterol being a marker of elevated LDL, if your mean telomere length is short, then your cells are likely to be harboring a greater percentage of critically short telomeres—those that trigger the aging or death of cells so that they can no longer replicate, or make normal cells in some tissues susceptible to transforming into cancerous ones.