After an extended break from blogging here on Skeptoid, a recent run of commercials on television offering to check your “cellular age” has inspired my interest enough to bring back a skeptical eye to boutique health claims. The advertisements promote a genetic test, TeloYears, with this claim:
“Go beyond ordinary vital signs to monitor the vitality of your cells with TeloYears. It’s personalized knowledge of your DNA that empowers you with knowledge and inspiration to improve. From a single drop of blood that you collect at home, you can learn your age in TeloYears which can be older or younger than your actual age.”
What does this mean? Can we accurately age ourselves based on a genetic test, and if so what’s the significance?
Genetics, genomics, and its associated testing, as well as disciplined science, is very complicated I am not going to be able to give it a true treatise here in this short blogpost. I’m going to focus on the overall picture.
Let’s begin with what a telomere is.
Like the rest of a chromosome, including its genes, telomeres are sequences of DNA. Like all DNA, the same stuff that comprises your genetic code. Cells normally can divide only about 50 to 70 times, with telomeres getting progressively shorter until the cells become senescent or die. Without telomeres, the main parts of the cells chromosome, the part with genes essential for life would get shorter each time a cell divides.
This is a grand oversimplification, but think of them like placeholders to keep the edges of the DNA strand from being cut off. It allows the cell to make a duplicate copy so that when it divides, a copy is similar to, if not exactly identical to, the original. Like a pre-paid debit card, every time you swipe it takes a little bit of the telomere away. Just like the debit card, it can be depleted to zero. Once the telomere has gone, cellular duplication begins to produce errors; many of those errors are similar to processes we see in aging and cancer, and therefore they are seen as a protective element of chromosomes and their genes.
So lack of telomere in the cellular chromosomes is consistent with cell aging and death. It would seem on the surface that this test would offer great value to help determine what kind of shape our cellular structure is in, our risk of cancer, age-related problems, and other genetic degenerative conditions.
But given that this oversimplification is generally true, does that mean that testing ourselves for our level of telomere health would provide a useful benefit either in predicting or treating health issues? Or, as the advertising promises, does it just give us a better idea of our “true age,” and allow us to better modify our lifestyle in response?
Like all complicated science, the answer is far more nuanced and interesting than the advertising would have us believe. The first question one should always ask is whether the terms used by an advertiser (in this example, “genetic age”) actually have any scientific meaning? To answer this question, we really have to ask another question. Is someone prematurely old because they go bald in their 20s, as opposed to someone who keeps their hair into their 70s? Does more hair on your head mean more genetic vigor? Truthfully, this underlying question has no answer. We know when we see someone who is old, and we know when we see someone who is young, whether they are bald or not. But even a numerical date from birth is not as significant as the overall health of the individual. Does premature graying of hair indicate a risk for early cancer, early heart disease, or early diabetes? The answer is that heart disease, cancer, diabetes, and gray hair are correlated, but not causally related. A statistical analysis of an individual with gray hair provides absolutely zero understanding of their health.
The reason I’m picking on hair in particular is because hair, like our skin, the lining of our gut, plus certain other areas of our body that are continually remaking themselves, are all especially sensitive to telomere loss. Areas of the body where cells do not reproduce, such as cardiac cells, never lose their telomeres, despite the presence of life-threatening cardiac diseases and decline. So checking telomeres from different locations will yield different results and intact telomeres do not, say, imbue immortality on a cardiac structures, making their correlation with long life far less believable.
The company selling these tests wants you to draw the conclusion that these findings are significant predictor of your health, that “TeloYears” (a totally made up term) is representative of your overall health. This, either as a fact or health prognosis, is not at all clear. Although you and your chromosomes do age, shorten, and suffer irreparable damage. But you do eventually have cellular functions that help renew and restructure your telomere and therefore its chromosome protection. These cellular functions, their strengths and weaknesses, are just as individually unique as your other bodily functions are. And although there is some association with telomere loss and cancer, as well as other severe age-related diseases, there has thus far been no way to really determine if old people have bad telomere structures, or if people get old because their telomere structures degenerate—a subtle but very important point.
Age in general places you at higher risk for heart disease, lung disease, cancers, and a host of maladies. Age is also associated with genetic degeneration. The real question is which way the arrows are linked. Does a lack of telomere actively, directly produce the genetic dysfunction of aging? The short answer is that we don’t know.Although genetics is a key part of how we age, it is not clear whether or not monitoring this function of your genetic cellular reproductive system is a significant factor. Experience tells me that it is probably a interplay of many factors, aging causes telomere loss and vice versa. But other obvious and important factors play a role, too, including your lifestyle, activities, and environmental factors.
Another simple analogy is automobiles. By no means are we as simplistic as a mechanical device, but some aspects of our bodies are highly mechanistic. If you purchase a car and in several years you take it to the mechanic and he puts it on a monitor, he may find that one of the pistons in the combustion engine is no longer putting out the full compression strength that it originally did. That finding is indicative of a car that’s been on the road for several years. It is not a reflection of how much life is left in the car, nor is it a reflection of the quality of the manufacturer the car. It may not even be a good indication of how hard you’ve driven the car. You would think that your mechanic is out of his mind if he recommended a complete engine rebuild based on this one small finding. Additionally you would think him equally insane if the car was requiring regular and constant repair but he told you that the compression factor was fine, and therefore you should continue to keep the car on the road.
This is similar to what the advertisers are talking about when trying to give you your “telo-age.” It is one small part of the overall testing that we can offer people to give them an idea of their health. It is by no means the most proven or replicated system of giving you an indication of either your age or your overall health. At this point in the science, it is really no different than taking a picture of your gray hair and saying, “Yup, you have signs of age and therefore need to be concerned,” or, “No, you don’t have gray hairs needn’t have any other concerns about your health.”
The bottom line here is that this testing can be done, but it doesn’t have much value. It is unlikely to be an important factor in the overall picture of your health. Most likely, it is a waste of money. It’s not dangerous unless you place too much value in its findings, whether positive or negative. If you’ve done it and received a concerning finding I wouldn’t spend any sleepless nights worrying about it, though talking to your primary care physician might give you some additional framing for how to think about your health and wellbeing. This test is far less helpful than understanding your cardiac health, cancer risks, family history, and your body mass index or some of the other key factors that your primary care doctor checks regularly.
I would like to stress again: age itself is an arbitrary measurement that we give ourselves. Remember that science is a method; it’s not a tool or an answer or dogma. This test can be perfectly scientifically accurate and still have absolutely no scientific value in evaluating medical health. I recommend everyone go to the doctor regularly, have good conversations with them about your overall health, eat healthy, and get moderate exercise. I don’t see myself recommending anytime soon that people have their telo-age done.