What are telomeres?

Your DNA is located within the nuclei of your cells, where it’s bundled within structures called chromosomes. Each chromosome carries specific genetic information in the form of genes. As the cells in your body divide, your chromosomes need to replicate so that each cell contains a complete set of chromosomes in its nucleus.

At the ends of each of your chromosomes are stretches of DNA called telomeres. Telomeres help protect the ends of your chromosomes from damage or fusing with nearby chromosomes.

Keep reading to learn more about these tiny but important structures and why they could unlock the door to preventing disease and reducing the effects of aging.

Your DNA strands become slightly shorter each time a chromosome replicates itself. Telomeres help prevent genes from being lost in this process. But this means that as your chromosomes replicate, your telomeres shorten.

That’s where an enzyme called telomerase comes in. It’s found in certain cells and helps prevent too much wear and tear. This includes shortening of your telomeres. Telomerase does this by adding additional telomere sequences to the ends of your chromosomes.

Most of the cell types in your body don’t have telomerase. This means that most of your telomeres continue to get shorter over time.

Some people claim that telomere shortening is a major contributor to the aging process and development of disease. But no one fully understands the impact that telomere shortening has on our overall health.

Mortality rates

A 2011 review suggests that markers indicating DNA damage and decreased telomere function increase with age. This could be significant: A 2003 study found a link between shorter telomeres and an increased rate of death from heart disease and infectious diseases.

But this study is nearly 20 years old and only involved 143 participants. More recent meta-analyses also suggest connections between shorter telomeres and coronary heart disease or certain types of cancer. Research into the link between telomere shortening and death is ongoing.

Oxidative stress

While it’s known that chromosome replication shortens telomeres, some experts believe oxidative stress can also shorten them. Oxidative stress refers to damage to DNA and other biomolecules from reactive oxygen species.

Reactive oxygen species are created by both natural cellular processes within your body and inflammation. You can also acquire them from your environment through things such as pollution, smoking, or alcohol consumption.

Over time, the damage to DNA and other biomolecules caused by oxidative stress may contribute to health problems associated with aging. Again, this is a fairly new area of research, so there’s not much definitive evidence.

Read our primer on oxidative stress.

Shorter telomeres are associated with an increased risk of cancer, though no one’s sure why. The specific cancers associated with shorter telomeres are:

  • bladder
  • lung
  • kidney
  • gastrointestinal
  • neck
  • head

In addition, one of the hallmarks of cancer cells is that they grow and divide rapidly compared to other cells. So, how do cancer cells not aggressively shorten their telomeres and die off?

Telomerase, the enzyme that reduces telomere shortening in certain cells, is reactivated or increased in more than 90 percent of cancers, found a 2016 study. Remember, this enzyme isn’t found in most cell types. But it seems that cancer cells are able to use telomerase to protect their telomeres, delaying their deterioration.

Based on this information, some new cancer treatments target telomerase to help destroy cancer cells faster.

Given the links between telomere shortening and disease, some people are now interested in finding ways to lengthen their telomeres. But is this even possible?

Research surrounding telomere lengthening is still very new. But so far, the results do show some promise. While it’s unclear if you can actually lengthen your telomeres, there are likely ways to slow down the shortening process.

For example, a small pilot study from 2013 looked at the telomere length of 10 men with low-risk prostate cancer. They were asked to make several lifestyle changes, including:

  • following a healthy diet
  • getting regular exercise
  • managing stress through yoga and support groups

Compared to the 25 participants with low-risk prostate cancer who didn’t make the lifestyle changes, the 10 who did had longer telomeres five years later. Again, this was a very small study, and it only involved men.

However, this small study provides a foundation for more recent research surrounding the effects of diet, exercise, and stress management on telomere length.


Your diet may play a role in determining the length of your telomeres. A 2016 journal article suggests following a Mediterranean-style diet rich in antioxidants. Curious to try it yourself? Start with our ultimate guide to the Mediterranean diet.

A 2018 study involving more than 5,000 adults found that eating more fiber was linked to longer telomere length. This could be due to fiber’s ability to help control blood glucose levels. The investigators noted that higher blood glucose is associated with inflammation and oxidative stress. Both of these may cause additional telomere shortening. Try adding these 22 fiber-rich foods to your diet.

On the other hand, another 2018 study looked at the diet quality of older adults in Australia and telomere length. The investigators found that those who followed a healthy diet didn’t appear to have longer telomeres. Instead, they suggest that genetics and other non-dietary factors play a role.

Stress management

When you’re stressed, your body releases hormones that can cause oxidative stress. This could result in more DNA damage and telomere shortening. Based on this information, reducing stress should help to reduce oxidative stress — and studies show that it does.

A 2004 study followed women who were caring for a chronically ill child, something that can greatly increase your stress level. These women had shorter telomeres, reduced telomerase activity, and more oxidative stress when compared to a group of women caring for healthy children.

A 2016 study evaluated men and women who were exposed to stressors. Those who responded with an increase in cortisol, the main stress hormone, had increased telomere shortening for several years.

Regardless of whether it reduces telomere shortening, stress management is a crucial part of feeling your best. Not convinced? See how stress affects your body.


Exercise has a range of health benefits, including reducing inflammation and oxidative stress.

A 2017 study involving thousands of men and women in the United States looked at the connection between exercise and telomere length. Those who participated in high levels of activity had significantly longer telomeres than those who did low or medium levels of activity. There wasn’t a noticeable difference between those with low physical activity and those with medium levels.

Another 2017 study involving a group of young adults found that those who participated in high levels of aerobic fitness and had more muscle endurance had longer telomeres. Here are 10 aerobic exercises to add to your workout.

Suggested reads

  • The Telomere Effect”: Co-authored by a Nobel Prize-winning scientist who first discovered the link between telomeres, telomerase, and aging, this book explores how different habits affect telomeres.
  • Deep Nutrition”: A physician and biochemist takes clues from our ancestors to recommend a new way of eating that can potentially alter DNA.
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Telomeres help protect your chromosomes from damage. In the process, your telomeres shorten, which is associated with aging and disease development. But recent research suggests that there may be ways to hack this process through diet, stress management, and exercise.

While these findings are all very preliminary, we already know that an active lifestyle, along with a nutritious diet and stress management techniques, provide a multitude of other health benefits as well.