Telomere testing is all the rage. Is it ready for prime time?

May 20th, 2011 | By | Category: Health

From a whole range of news sources this week there was coverage of a new “longevity” test. It revolves around telomeres. Telomeres are a fascinating biological discovery–and their identification and analysis was the foundation for the award of a Nobel Prize in 2009:

The Nobel Prize in Physiology or Medicine 2009 was awarded jointly to Elizabeth H. Blackburn, Carol W. Greider and Jack W. Szostak “for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase”.

The best description of telomeres that I have heard for non-scientists is this: you know that little plastic bit on the end of your shoelaces–that keeps the lace from fraying? Telomeres are kinda like that, but for the ends of your chromosomes.

There’s certainly some intriguing science about the features and roles of telomeres, and the mechanisms of their maintenance. But is it really ready for prime time testing–to indicate for you something about your lifespan? Here’s what one of the co-winners of the Nobel Prize said this week in the New York Times:

Dr. Greider acknowledged that solid evidence showed that the 1 percent of people with the shortest telomeres were at an increased risk of certain diseases, particularly bone marrow failure and pulmonary fibrosis, a fatal scarring of the lungs. But outside of that 1 percent, she said, “The science really isn’t there to tell us what the consequences are of your telomere length.”

Dr. Greider said that there was great variability in telomere length. “A given telomere length can be from a 20-year-old or a 70-year-old,” she said. “You could send me a DNA sample and I couldn’t tell you how old that person is.”

So yes, we have some leads on some situations. But it is generalizable to everyone’s telomeres right now? What can you do if you find your telomeres are sub-par (whatever par is)? It goes back to one of my earlier posts: ask yourself if it is actionable. I wouldn’t spend the money on it at this point.

Is it risky? Probably not, because there’s so little you could really conclude from this right now that it’s likely not possible to damage yourself physically. The worst consequence right now is probably financial: people are going to try to sell you longevity potions that are likely to be snake oil. Genomic snake oil, but snake oil nonetheless. In none of these testing stories have I seen a suggestion about what you can definitely do if you found your telomeres were shorter than other peoples’. Although some people want to sell supplements and claim that it has effects….

Look at the design of this study:

One of Telome Health’s first clients is Shaklee Corp., a health-supplement maker in Pleasanton, Calif., with $500 million in annual revenue, said Les Wong, its vice president of health sciences. Shaklee is looking to prove that taking its supplements, such as protein powders, as part of a healthy lifestyle can result in longer telomeres, Mr. Wong said.

Shaklee recently submitted blood samples from more than 100 individuals who use its products to Telome Health and is awaiting results.

What’s might not be kosher about the outcome of such a study? A company that wants to prove their supplements work gave samples for testing. People who use their products are the sample group. Are these people already pursuing a healthy lifestyle in other ways? Does the demographic profile of their customers mean that this subset of people may not be representative of the general public? Is this properly controlled? Do you need to consider who is funding this study and providing samples? Does the telomere testing company have a stake in the outcome? Think about it.

But if you have this kind of money and you are so anxious about your health that you must know what your telomeres look like, well, then–I think your money might be better spent on something to help with your anxiety.

A subset of companies is aiming genetic testing at the “worried well”. People with disposable income, who are worried that they aren’t doing everything possible for the best health. For these folks, if they are tested and find their telomeres are short–the stress alone might make it worse….

Some companies are using people’s fears against them. I think that’s unfortunate. It is also profitable. Just something to consider when you are deciding on the value of a test: Who benefits from it: them, or you?  Sometimes it will be you, and it’s worth it. But at least ask yourself the question.

Maybe it will turn out to be true that telomeres predict your longevity. What does this mean for your health insurance? Or long-term care insurance? Will you still be able to get it? Will it cost more? As much as we support the GINA legislation, keep in mind that it does not protect you from discrimination about long-term care insurance. And if you had long telomeres, would you want to consider some of that?

If you want to learn more about the pitches that are being made, here are several news sources that reported on telomere testing this week, and other telomere research as well. Some of them breathlessly uncritical. Some a bit better. You can evaluate them for yourself. Think about the sources, who benefits, and what you would do with this information. Evaluate critically.

NY Times:  A Blood Test Offers Clues to Longevity

The Independent: The £400 test that tells you how long you’ll live

Wall Street Journal: Scientists Bank on Stress-Health Link

Nature News: Stress can shorten telomeres in childhood

EDIT: here’s another I just found for your perusal: To Measure Longevity, Common Sense Trumps Genetic Test

UPDATE: Elizabeth Blackburn, one of the co-founders  of a teleomere testing company and also on that Nobel Prize, says (emphasis mine):

Can a telomere test predict how long you will live?

That’s just silly, isn’t it? It is statistical. Yes, there are mortality connections, but it’s silly to say this will tell you your life length. You need to take it in context with other information.

 

UPDATE 2: @paulblaser finds a helpful tidbit from the new CDC Genomics blog:

Testing for telomeres

Research on telomeres is still at an early stage but some entrepreneurs see human curiosity as an untapped market. Last week, a company in the UK announced that it would soon be offering a test of “biological age” based on telomere length to the public for approximately $700 (US). Given the state of the science, it doesn’t sound like a good deal.
Most of the 2,000 or so genetic tests currently available for clinical use are for diagnosing rare disorders, like cystic fibrosis. Many other tests are being developed and marketed directly to the public via the Internet and other media. Tests that are based on very limited scientific information may not be valid or useful. Let the buyer beware!

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