What are Telomeres?
Telomeres are distinctive structures, regionized in DNA strands which are located at each end. They are caps to prevent the chromosome from deteriorating, somewhat like the plastic shells of a shoelace. They have a repetitive, short DNA sequence and are many kilobases in length.
The Telomeres also prevent fusing with neighbouring chromosomes. Telomeres derives from the two Greek words “telos” which means “end” and ”meros” which means “part”.
The sequence in human Telomeres is TTAGGG, which is repeated around 2,500 times. There are 194 Telomeres in a human cell, 4 for each of the 46 chromosomes.
What are Telomere tests
As cells age, its Telomeres gradually become shorter. The average cell will divide around 60 times before it dies. As the cell divides, the Telomeres of course get shorter and shorter each time. Eventually, it will become too short to allow the cells to replicate, meaning the cells cannot divide and will die.
This branch of DNA testing is similar to Microbiome testing – new, innovative, but still not fully proven.
So, what does this tell us and why are home DNA test kit companies so interested in it?
Well, given the Telomeres are related to the cell’s age, the length of our Telomeres could possibly give us an indication of the person’s age.
The analysis is performed on a large selection of peripheral whole blood cells. The average Telomere length is calculated and compared to the average of a population sample in the same age range as the customer. This produces a percentile score, which is usually placed on a graph with a downward sloping linear line (Telomere length to Age).
Regardless of how it is presented, the customer will essentially be hoping for a high percentile, which would represent having younger cells than the average person of your age, which is presumably one (of many) signs of good health.
Which companies are doing Telomere analysis? What they do claim they can tell you?
Companies claim that there is nutritional implications of the Telomere length findings. For example, it is claimed that a diet that increases oxidative stress or is generally inflammatory, will shorten Telomeres more quickly. Foods that this refers to is fast food, carbohydrates, artificial sweeteners, trans & saturated fats as well as sodas.
To combat this, a significant variety and high quantity of antioxidants should be consumed as they help improve oxidative dense and suppress oxidative stress, meaning that the Telomere shortening process will be slowed down.
The lengths of Telomeres can be preserved also by consuming certain foods and micronutrients (we wrote extensively about health and genetics here). This includes: omega-3, fish, vegetable proteins, mixed fiber, monounsaturated fats (which help counter saturated fats!) and 10 servings of fruit and vegetables per day. One DNA company even suggests a 12 hour fast most nights.
Is this scientifically credible?
The Telomere tests are marketed as a way to “stay younger for longer” by gaining insight on if you need to take action by getting a low percentile score.
A problem here is if there is a high risk of type II error, that is, if a customer has poor health for their age but receives test results stating that they are healthy because their Telomeres are long. So, are the tests accurate and are they a good indicator of health?
Telomere tests are great at finding patients with short telomere syndromes, which has been around for years, but the marketing of these tests are exaggerating slightly.
The problem is that when dealing with the mean, you forget the distribution. This leads to the “absurdity of reporting any value that is below the median for a white blood cell count as abnormal,” according to Mary Armanios, from the Telomere Center at the John Hopkins University School.
It seems that whilst these tests are useful for those who lie on the extreme low-end, there are too many variables within both the population and individual to offer solid information.
It isn’t that they are not worth the money. There may be people who do discover something of value, particularly if they are on the extreme end. The commercialization of science is also garnering up a more health-centric lifestyle that is hitting the mainstream. Reading about the best DNA test kits is also a great way to find the ones who aren’t looking to scare you into buying products.
What should be of concern is the Telomere Support Supplements which are being sold by some sites. Selling supplements and such through using semi-reliable science to scare you into sales is certainly an exploitative marketing tool.
If paying for a test, it is worth bearing in mind the limitations, not being scared into paying the same company for things that will coincidentally “fix” your poor result, and lastly to get a professional to help interpret and explain the results (because there still may be something of concern there).