mountaineer summiting a peak mountaineer summiting a peak mountaineer summiting a peak

The Science Behind Telomeres and Aging

There’s no way around it—we all age. Aging is an expected, regular part of life. But some people seem to enter their older years with more energy and vitality than others. Why?

Questions like this have long interested scientists, and the answer is complex. It’s impossible to pinpoint exactly why we all age differently. Still, research published in Cell documents the nine hallmarks of aging, or what scientists believe are the common denominators that contribute to the aging process.

One of these hallmarks involves the microscopic structures we all have inside our cells called telomeres. Telomeres are closely linked to cellular aging and division.  As a result, they are believed to play a significant role in how quickly we age.

What are telomeres?

The word telomere stems from Greek roots, telos for “end” and meros for “part.”  Telomeres are found on the ends of your chromosomes, the threadlike structures of DNA inside the nucleus of the cell.

Telomeres don’t code for any genes. Their function is to keep DNA from unraveling and are often compared to the plastic caps at the ends of your shoelace. A review paper in Physiological Reviews explains that telomeres are critical for keeping your chromosomes healthy and protecting your cells from damage that can accelerate the aging process.

Your cells are constantly copying themselves, but your telomeres don’t replicate. Instead, these end pieces get a little bit shorter with each replication. 

Ultimately, telomeres get so short and worn down that they can no longer function, so the cell stops dividing or dies. Shortened telomeres are associated with lifespan and age-related health concerns. As described in Pflugers Archiv European Journal of Physiology, they act as a cellular biological clock in your body.

What is the connection between telomeres and aging?

The World Health Organization defines aging as “the accumulation of a wide variety of molecular and cellular damage over time.”  Eventually, this damage contributes to decreases in physical and mental capacity, increases in health complications, and ultimately death.

Shortened telomeres are closely linked to cellular aging. As your cells age, it impacts your health and the aging process. In fact, according to a review paper from Clinical Nutrition and Metabolic Care, shortened telomeres are considered a primary reason your cells break down with age.

Research published in the Proceedings of the National Academy of Sciences found that it’s not necessarily the initial telomere length but how quickly they shorten that may predict lifespan. So two people born in the same year can age differently depending on the rate their telomeres shorten, highlighting a possible difference between biological and chronological age.

How does lifestyle impact telomere length?

It appears that certain behaviors may extend the length of telomeres, or at the very least, slow the rate of shortening.

On the other hand, other lifestyle factors may accelerate the shortening process. Understanding how your daily choices can impact your cellular health may help you age successfully.

You may not be surprised to learn that most behaviors that can impact telomere length and shortening rate are the same health factors associated with general health. These include stress, smoking, weight, exercise, and diet.

A small study published in The Lancet Oncology found that a comprehensive lifestyle program increased relative telomere length.  And even further, the more participants in the study adhered to the program guidelines, the more likely their relative telomere length improved.

The program included dietary modifications, stress management with peer support, and physical activity.

Physical activity may increase your telomeres.

It appears that one way physical activity impacts the health of your telomeres is by increasing levels of telomerase. Telomerase is an enzyme that helps telomeres maintain their length.  

A German study on healthy, inactive volunteers found that people randomized to participate in endurance training or high-intensity interval training had increased telomerase activity and telomere length after six months. Those who did not exercise or people who only did resistance training without aerobic activity did not see the same benefits.

Another study from Preventative Medicine found that people who exercised more had significantly longer telomeres and reduced cellular aging. Researchers referred to this finding as an “aging advantage” that active people have over sedentary adults.


Your response to stress can impact telomere length.

Both physical and mental stress is closely associated with telomere health. As described in a study from PNAS, people with higher levels of perceived stress and those who experienced long-term stress had shorter telomere length and signs of cellular aging.

This study indicates the importance of stress management. Since perceived stress negatively impacted telomere length regardless of the actual stress levels, your stress response may matter even more than the actual event itself. Sometimes we can’t control stress levels in our lives, but we can work on how we react and adapt.

The relationship between stress and telomeres may be related to the release of the body’s primary stress hormone cortisol. A study from The Journal of Clinical Endocrinology and Metabolism found a potential association between people with greater cortisol responses to stress and accelerated telomere shortening.

Researchers even suggest that early life stress and trauma as a child may permanently impact the length of telomeres well into adulthood.


Diet and weight are closely tied to telomere health.

The Mediterranean diet, rich in healthy fat, fiber from fresh produce, and unprocessed ingredients, is one of the most well-studied patterns for longevity and health. It may impact healthy aging due to its influence on telomeres.

A study from PLoS One found that older adults who closely followed the Mediterranean diet had longer telomeres and increased telomerase activity. Additionally, boosting your fiber intake with those fresh fruits and veggies is linked to healthy telomeres. 

And since what you eat is a primary influencer on how much you weigh, telomere length may be another reason to watch what you eat. More research is needed, but several studies suggest a relationship between obesity and shortened telomeres and health conditions typically associated with unhealthy diet patterns.

Do supplements have any effect on telomeres?

As with anything that has to do with your health, your diet, mental health, and physical fitness are foundational elements. But supplementing with nicotinamide adenine dinucleotide (NAD+) precursors may be an additional way to support your cellular health.  Precursors are smaller nutrients used to make a bigger molecule, so NAD+ precursors help make more NAD+.

NAD+ is a molecule found in all living cells. It’s essential for energy production and cellular health. It also decreases with age, but NAD+ precursors, especially nicotinamide riboside (NR), can increase levels in your body.

Preclinical research suggests improvements in NAD+ levels are associated with increases in telomere length. An animal study from The EMBO Journal found that supplementing with nicotinamide riboside improved NAD+ balance in animals and primary human cells with conditions affecting the function of telomeres.

One of the benefits of supporting NAD+ levels may be due to the effect on sirtuin activity. Sirtuins are a group of proteins that regulate cellular health and balance.

A review paper from npj Aging and Mechanisms of Disease illustrates the interconnected relationship between NAD+, sirtuins, and longevity. As noted in Cell Metabolism, sirtuins also may stabilize telomeres and help reduce age-related shortening.

Healthy aging begins with cellular health.

A comprehensive plan that includes big picture health habits—moving your body, following a nutrient-dense diet pattern, managing your stress—in combination with appropriate supplementation can help support aging all the way down to a cellular level.

While some people will always search for the fountain of youth, most of us realize that we can’t stop time. Instead of assuming that increased age equals less enjoyment in life, taking these smart steps to protect your telomeres can be a way you can take control and truly enjoy those happy golden years.

Related Posts

senior couple doing yoga senior couple doing yoga senior couple doing yoga

The 9 Hallmarks of Aging

There are nine hallmarks of aging that contribute to the aging process. We break down each of them in plain English.
mitochondria under the microscope mitochondria under the microscope mitochondria under the microscope

Mitochondria and Aging

Microscopic power plants in your cells, known as the mitochondria, may be the key to why we age.
woman looking for signs of aging in the mirror woman looking for signs of aging in the mirror woman looking for signs of aging in the mirror

NAD+ Benefits: The Key to Anti-Aging

Discover the potential of NAD+ therapy for anti-aging and healthy aging. Learn about the benefits, mechanism of action, and recommended use.