22 April 2011

Health at Telomere's Length

A health checkup could soon incorporate a telomere measurement to estimate a person's biological age as a superior indicator of age-related degeneration and vulnerability to disease than chronological age, reports Mitch Leslie in an article entitled, "Are Telomere Tests Ready for Prime Time," published in Science magazine today.

The article reports that two companies have announced plans to start performing tests for the general public this year: Life Length of Madrid has already began offering the tests to patients and Telome Health, of Menlo Park, Calif., will begin to make them available to clinicians sometime later this year.

Already, medical researchers have employed telomere measurement for predicting illness and tailoring treatments to save lives, yet the article reports that skepticism exists about how effective telomere tests will be in predicting disease or determining lifespan in a clinical setting.

"By curtailing self-renewal, worn-down telomeres might promote the senescence of our bodies—although how much has been controversial," writes Leslie.

On one side of the issue is Telome Health co-founder Elizabeth H. Blackburn, a cell biologist at University of California, San Francisco (UCSF), who is quoted as saying "Telomeres are an integrative indicator of health."

Carol W. Greider, a former graduate student in Blackburn's lab and a molecular biologist at Johns Hopkins University School of Medicine in Baltimore, Maryland, disagrees saying, “Do I think it’s useful to have a bunch of companies offering to measure telomere length so people can find out how old they are? No.”

In 2009, Blackburn and Greider were awarded the Nobel Prize in Physiology or Medicine, along with Jack W. Szostack, for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase.

Telomeres are comprised of non-coding, repetitive sequences of coiled DNA that serve as protective caps at the end of chromosomes, preserving their integrity and keeping them from fraying and sticking to each other.

Shortened telomeres are linked with a greater chance of developing cardiovascular disease, diabetes, Alzheimer's disease, and other chronic diseases. In the last few years, studies have also showed that the rate of telomere shortening can be strongly affected by diet and lifestyle.

According to the article, among factors that affect telomeres harshly are smoking, drinking heavily, obesity, and chronic psychological stress. On the other hand, meditation, exercise, a healthy diet, and higher blood levels in omega-3 fatty acids offer a buffer to help maintain longer telomeres.

The enzyme telomerase, which plays a role in helping to maintain telomere length, is a recognized target of pharmaceutical-nutraceutical companies for producing possible therapies in the future.

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