Telomere Shortening: What It Is And How It Contributes To Aging

Written by Ahmed Zayed | Last updated on August 4, 2023

If you’re learning more about the 12 Hallmarks of aging, then you’ll discover just how many processes are really involved in why you age. 

There are a lot of complicated terms that you will come across - and telomere shortening is one of them. 

Telomeres are the protective caps that you have on your chromosomes. Without telomeres, the cellular machinery process would essentially cause serious damage to the chromosome and even cause problems with your genes - this would be disastrous, but thankfully, the telomeres are there to offer protection. 

In this article, we’re going to explore telomere shortening, how it happens, and the effect this process has on your longevity. 

The Science Behind Telomere Shortening

3 telomeres

Let’s start by first looking at what telomere shortening is and how it happens. Telomeres are caps that form at the ends of your chromosomes - and the chromosomes contain your DNA code.

Cells use the DNA code in the chromosome to read data from your genes. The telomeres are there to ensure cellular machinery, as in the byproducts that cells tend to produce, don’t eat away at your genes and your DNA. In time, however, the telomeres become shorter and this causes problems. 

Every time a cell divides to create a new copy of itself, it carries over the chromosome, along with the telomere too.

The repeating sequence in the telomere needs to carry over, but some parts are often lost during this division process. When there are parts of the telomere’s repeating sequence that become lost, it means it’s now shorter than it was before.

At some point, the telomere becomes too short of providing effective protection for the cell - and it is at this point that the cell no longer continues to divide.

It’s also possible for the cell to die when the telomere is no longer able to provide adequate functionality and protect the chromosome in the cell. 

Telomere Length And Longevity 

red and yellow telomere

You already know that your body needs cells to survive and function. Every cell has a role to play and they constantly divide in order to ensure all functions are carried out as they intend to.

As you age, your telomeres become shorter - this is due to the fact that the older we get, the more cellular division processes occur. When telomeres become too short, as we’ve already discussed, the cells stop dividing and eventually end up dying. 

Without a sufficient number of cells, it’s hard for your body to function without problems. A reduction in skin cell division is what we usually observe visually first.

You look in the mirror, and you see some crow’s feet next to your eyes. This already means that some of your cells are not functioning at their full potential anymore.

Over the next decade, the wrinkles become more profound.

Sure, you can go for Botox to make your skin seem less saggy, but the truth is - your telomeres are still shortening. 

In the Proceedings of the National Academy of Sciences [1], there’s an interesting report about a study that looked at how telomere shortening affects lifespan.

To break it down, the researchers found that the length of the telomere is not what truly dictates the lifespan of the organism. Instead, they discovered that the rate at which the telomere shortens is a more accurate indication of the organism’s lifespan. 

That means that how fast your telomeres shorten can be an indication of your expected lifespan. The faster they become short, the shorter their lifespan is expected to be. 

Factors That Contribute To Telomere Shortening

People are always looking for ways to extend the human lifespan, and researchers are already making some progress!

When it comes to extending your lifespan, one area of interest is definitely telomere shortening.

There are many factors that can contribute to the rate at which your telomeres shorten - and as we’ve discussed previously, this has been found to hold a strong link to longevity. 

The question is - what causes telomere shortening? If you’re looking to slow down the rate of these caps shortening, then you’ll have to first understand why it happens.

Age is definitely to blame here.

There are many more cellular divisions that happen throughout a period of 40 years compared to 10 years, for example. The more cells divide, the shorter your telomere becomes, but this is not the only reason. 

You’ve surely seen some people who look much younger than they are - naturally and without the use of Botox and surgeries.

On the other hand, you’ve also seen some who actually look much older than they are. So, why does the rate of telomere shortening differ between these two people?

This is where we need to turn our attention to environmental and lifestyle factors that can affect your telomere length and the shortening rate. 

Environmental Factors That Affect Telomere Length

pollution emmitted by factories

Let’s start with environmental factors. The environment you are exposed to on a regular basis can have a profound effect on your health - in such a way that it could potentially even affect how quickly your telomeres shorten. 

Pollution in the air, along with exposure to environmental chemicals are common in the modern day. If you work in the construction industry, for example, you may be exposed to silica dust consistently.

In a factory setting, perhaps you are tasked to work with chemicals that have harmful substances in them. Constantly inhaling these chemicals can affect your health.

Researchers reported these findings in the Environmental Toxicology and Pharmacology Journal in 2021 [2].

The research paper notes that exposure to a number of environmental factors seems to modulate not only cellular activity but also the functioning of telomerase. This, in turn, could have a negative effect on cellular division and telomere length.

Apart from chemical exposure, infections obtained from the surrounding environment can induce similar problems within your body.  

Lifestyle Factors That Affect Telomere Length

It is not only the environment that can have added effects on telomere length and the rate of shortening. Some lifestyle factors and habits that you have adopted may also have similar effects, so it’s important to know about them too. 

One of the major factors that we should discuss here is oxidative stress. It’s a term that refers to the damaging effects that free radicals can have - and over your lifetime, there are many things that can cause this type of damage. 

Researchers considered how smoking would affect telomere length in a study published in the International Journal of Dermatology [3].

The primary focus of the study was to see how smoking impacts telomerase in skin cells. They found that smoking causes oxidative modifications to DNA to increase significantly.

The result of this effect is an impact on telomerase reverse transcriptase and telomere dynamics. 

Smoking is only one factor that may contribute to faster telomere shortening.

Other lifestyle factors like drinking excessively, not consuming enough water, and eating a diet that lacks important nutrients are also factors that may impact your cellular function and even cause telomeres to shorten at a rapid rate. 

Measuring Telomere Length

pcr machine

There are a couple of methods that can be used in order to measure the length of telomeres in your cells [4]. It’s important to note that the specific tests largely depend on the reason for these tests. In certain cases, your doctor or a specialist may decide to have more than one test done for more diverse and accurate data to work with. 

The most common methods that you may find doctors use include:

  • Quantitative polymerase chain reaction: Only roughly 50 ng of starting DNA is needed for this test. It’s also called the Q-PCR assay, and it's one of the easier ones that can be done. The telomere signal is referenced to a gene signal that has just a single copy. You’ll get a T/S ratio that helps with determining telomere length.

  • Terminal restriction fragment analysis: Considered the standard for telomere length determination, TRF analysis will essentially consider the TTAGGG sequence. It’s a method that allows researchers to get a reading of how severe telomere smearing is and use this data to get an estimation on telomere length. 

  • Quantitative fluorescence in situ hybridization: A fluorescent peptide nucleic acid telomeric repeat probe is used in this test. It looks at the fluorescence intensity of the telomere under a microscope, although there are a couple of other Q-FISH methods that are also used when measuring the telomere length and shortening rate. 

While these are three of the main methods that laboratories turn to when assessing telomeres, there are other methods too.

Telomere dysfunctional induced foci analysis, for example, can be very helpful in cases where a specialist wants to analyze DNA damage.

When more specific data is needed related to specialized cells in your body, then the appropriate test would be a single telomere length analysis. 

Strategies To Maintain Telomere Length

Imagine being able to extend your lifespan by 10 years. That sounds like something out of a science fiction movie, right? Well, to tell you the truth, researchers are actually making a lot of progress on anti-aging strategies, and one of the key study areas involve telomere shortening. 

While they are still working on this research, some evidence has already emerged that suggests ways you can potentially slow down the telomere shortening rate. By looking at current evidence, we’ll be able to get a better idea about how you can strategize methods to reduce the speed of this particular process. 

  • Diet: “You are what you eat!” - we’ve all heard it before, but we never really pay much attention to this saying. Yet, when you look at how different foods can affect your body, it becomes clear that it's not just a “saying” but rather an actual fact.

    What you eat can affect you at a cellular level. When researchers considered how diet affects telomere length, they made quite an interesting discovery.

    The study, published in the International Journal of Cancer [5], found that those who follow a plant-based diet have longer telomeres compared to age-similar people who do not eat a plant-based diet.

    There was a particular focus placed on plant diets that contained a large amount of antioxidants, such as vitamins E and C

  • Fiber Intake: While on the subject of diet, it’s also important to understand the critical role that fiber plays in your health. Fiber is a type of carbohydrate that is not broken down into sugars. It rather moves throughout your gut and can have a positive effect on your digestive system.

    It seems that eating more fiber may also be linked to improvements in telomere length, according to a study that was published in the American Journal of Clinical Nutrition [6]. 

  • Stress: When you find yourself sitting in front of your computer, biting on your nails, with a mind wondering about everything that stresses you out - remember to take a deep breath.

    Turns out, stress can also be something that makes your telomeres become shorter in less time. Researchers found two groups of mothers [7].

    One group had children who were consistently sick, and the other group consisted of mothers to healthy children.

    They were classified as low-stress and high-stress groups. Researchers discovered that those mothers who had less stress also had longer telomeres.

    Remember, stress makes your body release cortisol. It’s not harmful when you are in a stressful situation, but it can be quite a hazard to your body when the stress becomes chronic. 

  • Exercise: It’s a drag getting off the coach to visit the gym, sure. But what if those sessions of the gym could also be a factor that extends your lifespan?

    Researchers created a review paper that used data from various studies that were done in the past [8]. What they found was those who exercise more frequently tend to have longer telomeres than the people who rather have a preference for being sedentary. 

Apart from these, you can also consider taking vitamin D supplements and eating more food that contains omega-3 fatty acids. These are both important nutrients that have been found to impact cellular health and function. 

Frequently Asked Questions

What are telomeres?

Think of telomeres as caps that sit at both sides of each chromosome.

They’re there to protect the chromosomes against damage. In terms of what they are - telomeres are made from both proteins and DNA. You’ll find telomeres in every cell throughout your body, serving as bodyguards for your chromosome. 

Why do telomeres shorten?

Your cells divide many times, but every cell has a finite number of times it can go through this cycle. Every time your cell divides, the telomere shortens.

At some point, this results in the apoptosis of the cell - where it marks itself for destruction. Once apoptosis happens, your immune system will remove the cell from your body. 

How does telomere shortening affect aging and disease risk?

To continue functioning, your cells will divide over time. As telomeres shorten, the risk of errors in the code copied during cellular division becomes more likely.

Plus, at some point, the cell can’t divide correctly anymore. This leads to poor cell function and raises the risk of cancer and other age-related diseases. 

Can you reverse telomere shortening?

You’re already aware of the fact that there are different types of cells in your body.

Some of these cells can use telomerase to reverse some of the shortenings that have happened to the telomere. It’s not something that every cell can do, however. 

Is there a way to lengthen telomeres?

This is still an emerging topic, but in one report, scientists explained that they could potentially lengthen the telomere of some human cells by about 1000 nucleotides. This would essentially turn back the internal “aging” clock in the human body. 

What age do telomeres start shortening?

There isn’t really a specific age. While you’re young, your cells haven’t gone through too many divisions. That means telomerase can add TTAGGG to the end of chromosomes as your cells divide, but this becomes less effective with old age. 

Can telomere length be measured?

It’s possible to use some methods to measure the length of telomeres, but you should know that variability is often found between different chromosomes and cells. A study in the Journal of Nursing Research also explains that this measurement could be used as a biomarker in diseases. 

Does exercise slow telomere shortening?

It might, but the topic is rather complex. You see, when you exercise, it may help to slow down the rate at which your telomeres become shorter. On the other hand, some evidence shows that extreme forms of exercise could actually speed up this shortening process. 


Think of telomeres as bodyguards that protect your genes against damage. They’re essential to ensure your chromosomes can be accessed when your cells have to divide.

Over time, these caps on the ends of chromosomes become shorter, raising the risk of errors in cell coding and contributing to age. It’s not just about the wrinkles that frighten you when you look in the mirror, but also the impact that poor cellular division has inside your body.

All hope is not lost, though, as there are many studies looking into ways to slow down telomere shortening or to even potentially reverse it. 


  1. Telomere shortening rate predicts species life span. Retrieved from

  2. External environmental agents influence telomere length and telomerase activity by modulating internal cellular processes: implications in human aging. Retrieved from 

  3. Effects of smoking on human telomerase reverse transcriptase expression in the skin. Retrieved from 

  4. Comparison of telomere length measurement methods. Retrieved from

  5. Telomere length, oxidative damage, antioxidants and breast cancer risk. Retrieved from 

  6. Associations between diet, lifestyle factors, and telomere length in women. Retrieved from 

  7. Accelerated telomere shortening in response to life stress. Retrieved from 

  8. Physical activity and telomere length in U.S. men and women: An NHANES Investigation. Retrieved from 

About the author 

Dr Ahmed Zayed is a medical resident specializing in plastic surgery with years of experience in the field. He is also a writer for top-rated websites including Washington Post, Chicago Tribune, ConsumerHealthDigest, and Huffington Post

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