Many of us are looking for ways to stay healthier, live longer, and make the most of our later years.

We already know we can improve our health and encourage longevity by eating the right foods, staying active, and visiting our doctor if we have any health concerns. But research suggests that the length of our telomeres also plays a key role.

So what are telomeres and could we have more control over ageing than we think?

What are telomeres?

Telomeres are protective caps found at the end of chromosomes (which are long strands of DNA that contain our genetic information).

Telomeres are often compared to the plastic tips at the end of shoelaces, which prevent the laces from fraying and unravelling. In a similar way, telomeres protect the genetic information in our chromosomes from being lost or damaged during cell division and other processes.

What are telomeres

Why does telomere length matter?

The length of our telomeres dictates how well they protect our chromosomes.

Researchers estimate that when we’re born, our telomeres are about 10,000-20,000 nucleotides long, but are gradually worn down by the process of cell division and DNA replication.

This cell division and DNA replication process happens constantly throughout our lives as our body grows and repairs itself – and each time our telomeres become shorter.

As telomeres become shorter, they become less able to protect chromosomes from damage or from fusing with nearby chromosomes.

Eventually, after multiple rounds of cell division, the telomeres become so short that they can no longer do their job, and cells can no longer divide. When a cell can no longer divide, it dies or becomes inactive.

Therefore, telomere length is a key factor in determining how many times a cell can divide before it reaches the end of its lifespan – the shorter it is, the fewer divisions it will have left and the closer to the end of its life it will be. Telomeres essentially act as the ageing clock in every cell.

However, while telomeres shorten naturally with age, research suggests that oxidative stress can also speed up telomere shortening. Oxidative stress describes the imbalance between antioxidants and harmful molecules known as free radicals, which can damage cells and cause chronic inflammation.

The impact of short telomeres

More research is needed to fully understand the impact that telomere shortening has on overall health, but multiple studies have linked short telomeres to an increased risk of age-related diseases, such as cancer, heart disease, and dementia.

Some people are also born with abnormally short telomeres – and research suggests that these individuals may have weaker immune systems because their immune cells age and die much quicker.

We’ll take a closer look at some of this research below…


Research has shown that short telomeres are associated with increased cancer risk – specifically lung, bladder, kidney, gastrointestinal, head, and neck – though it’s not yet understood why.

What’s also confusing is that cancer cells grow and divide rapidly compared to other cells. So, in theory, they should rapidly shorten their telomeres and die off. However, the reason they don’t is because of an enzyme called telomerase, which can reduce the process of telomere shortening in certain cells.

Telomerase isn’t found in most normal cells, but science has shown that 90% of cancer cells contain it and they use it to protect their telomeres and delay cell ageing.

This information has been helpful in developing new cancer treatments, which target telomerase so that cancer cells die faster.

Heart disease

meta-analysis of 24 studies involving 43,725 participants and 8,400 patients with heart disease found telomere length to be an independent risk factor for coronary heart disease.

Further research has also found that people with a form of heart disease known as cardiomyopathy have abnormally short telomeres in the heart muscles that are responsible for contraction. However, it’s not yet understood whether these short telomeres affect heart muscle function – or whether it’s the reverse, with heart disease being the cause of the short telomeres.


In an analysis of MRI and electronic health records from over 31,000 people, it was revealed that patients with longer telomeres tended to have better brain health. Overall, they had a larger volume of grey matter and a larger hippocampus, both of which are known to shrink in patients with Alzheimer’s disease.

The cerebral cortex also tends to get thinner as Alzheimer’s disease progresses – but in the analysis was notably thicker in people with longer telomeres.

Compromised immune system

study of 28 people under 60 who had abnormally short telomeres and were unable to regulate telomere length, found that nine of them developed infections most commonly seen in people with damaged immune systems. Seventeen people also had abnormally low numbers of T-cells, which play a significant role in immunity.

The study compared these T cells with those of 12 short-telomere older adults and 18 normal-telomere young adults. It showed that all adults with short telomeres pumped out half the amount of telomeres of the young adults with normal telomeres.

These findings suggest that short telomeres may contribute to immune system ageing.

Compromised immune system

Can telomeres tell us more about our biological age?

Research has suggested that telomere length can reveal more about our biological age and life expectancy than our chronological age.

Our chronological age refers to the number of years we’ve been alive, while our biological age refers to the age of our cells and tissues based on physiological evidence – and the two might not be the same.

Depending on how fit and healthy we are, our biological age may be lower or higher than our chronological age. So, if you’ve ever thought that someone looked or seemed older or younger than their age, their biological age may be significantly different from their chronological one.

Studies generally suggest that longer telomeres indicate a lower biological age, while shorter telomeres indicate a higher biological age.

Are there any problems with using telomere length to determine someone’s biological age?

Since it’s become more widely understood that telomeres are one of the keys to ageing, several companies have started offering telomere tests. These tests measure the length of your telomeres to predict your biological age.

The problem with this is that the individual tests available can produce a lot of inaccuracies.

Most tests are based on a blood sample, which looks at the average length of telomeres found in those cells. But telomere length can vary considerably from tissue to tissue – so someone in their 80s will still have some chromosomes with long telomeres. This variation in telomere length can make the results somewhat random, as they’ll depend on which collection of telomeres you get in that particular sample.

Plus, the range of what’s considered to be a ‘normal’ telomere length is huge, which makes it difficult to use as a measure of biological age.

Research has also found that test results can differ on different days depending on the measuring methods used and what our body is going through.

Speaking about telomere test results Elissa Epel, co-director of the Aging, Metabolism, and Emotions Center at the University of California, said “Some of it is measurement error but some [changes to telomere length] may be true biological regulation [or] periods of shortening and compensatory periods of lengthening.”

Is it possible to increase telomere length?

Some companies sell products alongside telomere tests that claim to increase telomere length. But, research in this area is still new and there’s currently not enough evidence to confirm whether telomere lengthening is actually possible.

To look at an example of a small pilot study where telomere lengthening looked promising, let’s take this one from 2013. It looked at the telomere length of 10 men with low-risk prostate cancer who made several lifestyle changes, including eating healthily, getting regular exercise, and managing stress.

The telomeres of these men were compared to those of 25 other men with low-risk prostate cancer who didn’t make the lifestyle changes – and the 10 men who did had longer telomeres five years on.

Although telomere lengthening could be a positive thing, there’s also conflicting evidence over whether telomeres that are too long could cause problems. For example, this study on mice found that those with hyper-long telomeres had less metabolic ageing and lived longer.

Meanwhile, other research that looks at the human body’s evolved mechanism of trimming elongated telomeres suggests that having telomeres that are too long may not be of benefit. Some studies have even linked long telomeres to an increased risk of cancer.

However, while we don’t yet fully understand whether we can lengthen short telomeres or what the specific impact of having long telomeres is – what experts are more confident about is that telomeres gradually shorten as part of the natural progression of age and that oxidative stress can speed this process up.

While natural ageing is a normal and inevitable by-product of the telomere shortening process, the good news is that oxidative stress can be prevented – and doing so may help to preserve telomere length and help us age healthily.

3 ways to potentially slow down telomere shortening

1. Eat a diet rich in antioxidants

Oxidative stress is caused by an imbalance of antioxidants and free radicals. And studies suggest that a key step in preventing it (and therefore reducing inflammation and helping to preserve telomere length) is to make sure that you’re eating foods that are rich in antioxidants, such as vitamins C, D, and E, and selenium.

Fruits and vegetables, nuts and seeds, whole grains, and green tea are all high in antioxidants, as are spices like turmeric, cinnamon, and ginger.

It’s also important to limit your intake of processed foods and sugary drinks, which can be low in antioxidants, high in calories, and may cause inflammation.

To read more about antioxidant foods and get some ideas for recipes, check out our articles; Superfoods – what are they and what are the benefits? and 14 anti-inflammatory foods.

2. Explore ways to reduce stress

The release of stress hormones, such as cortisol, causes an increase in oxidative stress, which research suggests can cause telomeres to shorten at a faster rate.

In addition, stress can also lead to unhealthy behaviours, such as poor diet, lack of exercise, and smoking, which can also contribute to telomere shortening.

We understand that sometimes combatting stress is easier said than done, but taking steps to explore ways to cope can help. Our article, 7 tips for coping with stress and anxiety, has some things you might like to try, such as learning how to focus on the present moment and challenge negative thoughts.

3. Get regular exercise

Research has shown that getting regular exercise can increase antioxidant activities in vital organs and prevent oxidative damage. This study also found a link between longer telomeres and high levels of physical activity.

Increasing your exercise levels is something that you can do gradually – for example, by taking the stairs instead of the lift or walking to get your groceries rather than driving. Check out our list of 17 creative ways to increase your daily step count for more ideas.

Or, for more fitness and exercise ideas, head over to the relevant section of our website, where you’ll find everything from running and dance to yoga and swimming.

Final thoughts…

Although research generally suggests that shorter telomeres are linked to an increased risk of age-specific diseases, more studies are needed to better understand the connection between telomeres and longevity.

However, what experts are confident about is that telomeres will naturally shorten throughout our lives and that this is a normal part of the ageing process.

With that said, research suggests that how quickly this process happens can be down to certain lifestyle factors, such as what we eat, how much we move, and how stressed we are. So, by taking steps to look after our health in these areas as best as possible, we may be able to preserve telomere length for longer and potentially increase our lifespan as a result.

Meanwhile, research into other ways to preserve telomere length is ongoing. In fact, one man is even spending 100 days underwater in a bid to understand whether atmospheric pressure holds the key to a longer life! This includes looking at the effect it has on telomere length.

For more content on healthy ageing, check out our article; 7 diet tips that may boost longevity.