Saturday, October 15, 2016

Telomere Length: Biomarker of Health

Photo by NHGRI.
Everyone agrees that good health is vital.

However, not everyone agrees on how to achieve good health.

There are a lot of ideas on how to be healthy and how to postpone the ravages of aging.

Similarly, there are a lot of ideas about what biological factors are correlated with healthy aging.

Since the mid 1970s, scientists have isolated a genetic feature called telomeres and argue that their length is correlated with health and longevity.

I don't believe there is one single genetic factor that humans can manipulate in order to ward off all aspects of aging.  However, telomere length is viewed by many as the chief marker for longevity and health.

I'm looking more closely at telomeres length as just one out of eighteen important biomarkers of health and longevity. But I do concede that it's an important one, in part because it's a genetic. Also, it's one of the newer biomarkers on the list. We still have a lot to learn.

This post is part of a series on biomarkers of health and longevity.


What are telomeres?

Telomeres are caps located at the ends of chromosomes--as illustrated in the diagram above.

Specific patterns of DNA sequencing that occur at the ends of the chromosomes help secure the code from unraveling or from connecting to neighboring chromosomes.

When we are born, we have a lot of these sequences to protect the chromosomes structure. As we age--or more specifically each time cells divide--these caps or tips shorten, weakening the chromosome and making it more easily susceptible to damage.

Getting a lab for telomere length is more difficult and expensive to measure than waist-to-hip ratiomean arterial pressure or even HbA1c, so most readers will never know the length of their telomeres. (There are businesses that will do this for a fee, but I don't want to link to any of them.)

Correlations 

By reading through a half dozen popular articles and scholarly articles on telomere length, researchers are finding a correlation between smoking, stress, inactivity, and the shortening of telomere length.  Some cancers are more prevalent among those with shorter telomeres.

Because scientists have seen a correlation between telomere length and health, more studies are underway that are doing more than measuring the correlation. Here is a 2010 scientific journal article that summarizes an array of telomere research published chiefly in the first decade of the 21st Century.

Today, many are exploring methods for lengthening telomeres.

Here is a basic explanation of telomeres by Calvin Harley, Ph.D.--in the first half of this video. For a discussion of telomere length as a biomarker of health and longevity, start the video below at the 4 minute mark.




The second presenter, Alyssa Epel, a psychology researcher, discusses the effects of stress on telomeres length.

Too Good to Be True?

Others find the correlation between telomere length and longevity to be just slightly more common "than a coin flip."  US News and World Report, summarizing an academic journal, notes that chronological age and self-reported health were cheaper and easier than measuring telomere length.

So is this biomarker going to fall out of favor in the same way that reading the life line on one's palm has fallen out of favor?

Genetic research probably holds more information than skin wrinkles.  Nevertheless, a single marker for longevity--the elusive "Aging Gene"--will probably never materialize--given the complexity of the human body and how many variables exist for how biology interacts with behavior, psychology and the environment.

Want to learn more?  See this link at Your Genome for a longer discussion of telomere length that is more detailed without being too technical.

Related

Biomarkers of Longevity and Health





10 comments:

  1. Whew! I'll have to come back to this another day! It was like being back in University listening to him!

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    1. He could work a bit on voice inflection, but he covers some basics for those who would rather watch a video than read through some of the links.

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  2. I'm back...it's worth taking the time!

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    1. I admire your persistence. I tried to write plainly about the topic, but it's genetics, and it's being dicussed quite broadly. I don't claim to be an expert. I'm just mainly raising awareness and directing readers to others' work on telomeres.

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  3. But ... we don't know how long our telomeres are, do we? I'm sure a lot of it has to do with the accident of birth (how long our parents lived); but in the meantime, I'll just keep moving and try to eat a decent diet.

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    1. We can get a test for a fee, but I am not going to bother. Like you, I already know what behaviors to adopt. My money would be better spent on elements that support healthy lifestyle choices.

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  4. It is fascinating. I think it is a good indicator but not the end all on longevity answers. I don't think it will go the way of a palm reader but be another tool used to promote better health.

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    1. I'm interested enough that I want to read popular science articles on telomere length and evidence-based research journal articles. But I'm not interested enough to pay for a lab to learn the length of my telomeres. I'm tapping my fingers on the table waiting for more longitudinal studies to roll in.

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  5. This is fascinating! One day, maybe this telomere testing will be part of our yearly physicals.

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    1. That would be interesting. Or I don't know if insurance companies would first start with a once in every 5 year test (like a colonoscopy).

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