Doctors routinely urge their patients to quit smoking and exercise regularly. But what if there were a blood test that could show smokers and couch potatoes the damage their lifestyle was actually wreak­ing on their chromosomes?

Two groups of prominent researchers have started companies to provide just such a test, which would measure the length of one’s telomeres. Telomeres are caps on the ends of chromosomes, protecting them much as plastic tips on the ends of shoelaces keep the laces from fraying. Whenever chromosomes—the store­houses of our genes—are replicated in preparation for cell division, their telomeres shorten. That shrinking has led many scientists to view telomere length as a marker of biological aging, a “molecular” clock ticking off the cell’s life span, as well as an indicator of overall health. Studies comparing the telomere length of white blood cells among groups of volunteers show distinct correlations between telomere length and lifestyle. Those who exercise regularly have longer telomeres than those who do not. Folks who perceive themselves as the most stressed have shorter telomeres than those who see themselves as the least. Certain diseases, too, correlate with shorter telomeres, including cardiovascular, obesity and Alzheimer’s.

“Knowing whether our telomeres are a normal length or not for a given chronological age will give us an indication of our health status and of our physiological ‘age’ even before diseases appear,” says María A. Blasco, who heads the Telomeres and Telomerase Group at the Spanish National Cancer Research Center and who co-founded the company Life Length in September. Telomere research pioneer Calvin B. Harley, who co-founded Telome Health last spring with Nobel laureate Elizabeth H. Blackburn, considers telomere length “probably the best single measure of our integrated genetics, previous lifestyle and environmental exposures.” Beginning as early as this spring, the companies will offer telomere-measurement tests to research centers and companies studying the role of telomeres in aging and disease; the general public may have access by the fall through doctors and laboratories, perhaps even directly.

Although enthusiasm for the research services runs high, some telomere experts question the tests’ current value for individuals. “We haven’t defined what we consider to be a norm and what we consider to be abnormal, either long or short,” says Nilesh J. Samani, head of cardiovascular services at the University of Leicester in England. But telo­mere length is not a diagnosis or a prognosis, Harley says. The data, he insists, are sufficient to help people make “personal lifestyle decisions,” regarding, say, diet, exercise and stress.

This article was originally published with the title My, What Long Telomeres You Have.

5 Comments

1. 1. Qev55 11:52 PM 3/27/11

   The biggest question of all is how to keep this information out of the hands of health/life insurance companies.

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2. 2. lamorpa in reply to Qev55 12:06 PM 4/7/11

   "The biggest question of all is how to keep this information out of the hands of health/life insurance companies."
   or better yet, in their hands, so people with more healthy lifestyles get better rates!

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3. 3. rshoff in reply to lamorpa 12:36 PM 4/7/11

   If you segregate the risk pool too greatly in order to manipulate insurance rates in your favor, then you may as well revert to a completely private pay health care system where everyone pays all of their bills with no insurance. Insurance is based on spreading risk across large populations. Instead of rate based incentives, we should care enough to make the effort and spend the money on health educating programs.

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4. 4. ConcernedCitizen 01:55 PM 4/7/11

   Very cool. Thanks for the info, SciAm. ;)

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5. 5. jime23 11:47 PM 9/21/11

   It's an unfortunate side of telomeres science, that of insurance companies, pharmaceutical corporations, or other business interests trying to own the field and reshape it for their own financial benefit. But tt's an exciting time for telomeres science; I definitely feel a growing buzz, so I think now is really the time to start looking at the big picture and ask ourselves how valuable this branch of science can be, and what it means if its in the wrong hands.
   
   Jaime A.
   Writer, AgeMarker.com

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