What is a telomere test?
A telomere test is a blood test that measures the length of telomeres, the protective structures located at the tips of chromosomes. The test is intended to reveal a person's biological age, the age a person shares with most people of similar physiology.
Whereas chronological age measures the number of years since birth, biological age measures changes in the physical structures of the body (such as organs and bones), sensory perception, and motor skills. A person's chronological age and biological age aren't always the same. Telomeres are considered a good indication of a person's biological age.
Most chromosomes have telomeres that normally shorten as a person gets older. By analyzing telomere length individuals may gain insights into their health, lifespan and susceptibility to diseases, such as cancer and Alzheimer's.
For example, a 70-year-old man with relatively long telomeres may be considered to have a young biological age and, therefore, have better health and longer to live than a 70-year-old man with shorter telomeres.
Conversely, a 35-year-old woman with relatively short telomeres may be considered to have a biological age of 45, meaning she is aging faster than normal and has the telomere length of an average 45-year-old. She may also be at higher risk for cancer, heart disease and early death.
Generally speaking, in a group of people of the same chronological age, those with longer telomeres are more likely to outlive those with shorter telomeres.
Benefits of Telomere Testing
The primary benefit of a telomere test may be the information it provides to an individual regarding their biological age. This information may enable a person to make adjustments to his/her lifestyle that can lead to better health and a longer life.
Telomeres are known to respond well to a healthy lifestyle. A person who maintains a good diet, exercises regularly, and is free from constant heavy stress, is not likely to endure accelerated telomere shortening.
In contrast, people who, for example, care full-time for elderly or sick relatives (such as a daughter caring alone for a mother with Alzheimer's and a brother with autism) carry a tremendous burden of stress and are more likely to have shorter telomeres.
In particular, mother's who care for sick children—enduring long-periods of high emotional stress—are known to have shorter telomeres.
Telomere Tests are Not Definitive
The science of telomeres as it relates to aging and disease is in its early stages of discovery. Although the measurements taken of telomere length may be accurate, these measurements in relation to aging and health yield no definitive interpretation. Therefore, the results of a telomere test should not be considered conclusive.
No reputable scientist, doctor or laboratory claims that telomere testing can predict the time a person has left to live.
Regardless, recent advances in telomere science have opened the door to commercial ventures hoping to exploit the theoretical potential of telomere testing for all its worth. These companies believe that telomere testing will soon provide reliable (and marketable) data regarding human health and longevity.
Should telomere science advance to such a degree the effect on human life could be far-reaching:
- People may be able to know how long they will live until their natural death;
- People may be able to know their risk for cancer and other diseases;
- Insurance companies may require telomere testing before providing life, health or disability coverage;
- Employers may require telomere testing results before hiring.
Criticism, Controversy & Ethical Questions
If the assumption is made that telomere testing will one day be accurate, reliable and accessible to the general public, many legal, ethical and personal questions may arise.
First, reactions to the test itself will depend on the information it yields. Will it pinpoint how many years remain in a lifetime? Will it reveal the likely onset of a disease? Will it be a useful evaluation of overall health, which gives the person a valuable lifestyle guide going forward?
When it comes to the most important question—"How many years do I have left?"—it's reasonable to assume that many people will not take the test because they don't want to know the results. The knowledge of lifetime remaining has a limited upside because most people already hope or expect to live a long life ("Okay, I have another 30 years. Cool. I need to get back to the office now."). However, it has a potentially catastrophic downside ("The test reveals you have 2 years left in your life."). With so much downside risk, many are likely to avoid the test altogether.
For those who do take the test, they may see the results and ask themselves:
"Now that I know I'm going to die in 9 years..."
- "Do I tell my wife? Do I tell my kids? Do I tell my employer?"
- "Do I quit my job and start tackling my bucket list?"
- "Do I spend all my money over the next 9 years?"
- "Do I start exercising and eating right and try to turn this thing around?"
Telomere testing may also give rise to significant legal and ethical issues:
- Insurance companies may require a telomere test before providing coverage, and may deny coverage or adjust premium rates based on the results.
- Telomere testing may become a pre-condition for employment;
- All sorts of companies may emerge offering unproven telomere-lengthening elixirs, telomere-arresting potions, and other supposed anti-aging therapies.
Telomere Testing Companies
NOTE: The companies listed below are included on this page for informational purposes only. Their inclusion herein does not constitute a recommendation or an endorsement by us of any products or services.
- The £400 Test That Tells You How Long You'll Live, The Independent
- A Blood Test Offers Clues to Longevity, The New York Times
- Can a Blood Test Determine How Long People Will Live?, ABC News
- Decoding Immortality (video - 47 minutes), Smithsonian Channel
- How and Why We Age: The Power of Telomeres and Telomerase, HuffPost, Dennis Kravetz
- Are Telomeres the Key to Aging and Cancer?, Genetic Science Learning Center, The University of Utah