Is it truly telomeres that hold the secret to prolonged, vibrant lifespans?
Longer telomeres, the protective caps on our chromosomes, are often associated with living longer and healthier. The idea behind this is that longer telomeres allow a cell to divide multiple times, keeping it vital for longer periods. However, research hints that this might not always be a good thing, as longer telomeres might also increase the risk of chronic health problems. Are longer telomeres indeed the key to an extended, healthy lifespan, or should we seek other ways to live longer and better?
As we grow older, numerous health issues tend to crop up. Despite this, some people seem to age gracefully, remaining active and healthy well into their advanced years. Some attribute their longevity to a healthy lifestyle, good fortune, or genetics. Age-defying secrets often focus on our telomeres, the DNA-protecting lengths located at the ends of each chromosome.
Each cell in our body has 23 pairs of chromosomes, each one made up of DNA twined around proteins. This DNA contains the blueprints for all cellular functions, while telomeres are situated at the terminal region and do not contain genes. Each time a cell divides, the chromosomes replicate, and the telomeres shorten, allowing the cell to divide without shedding essential genes. Eventually, the telomeres become too short to let the cell divide once more, at which point it enters a state of senescence or dies.
Studies have suggested that senescent cells, no longer able to divide, continue to be active, contributing to age-related conditions such as osteoarthritis, atherosclerosis, and cancer. Longer telomeres mean that cells can divide more often before reaching senescence or death, possibly extending their lifespan. Research indicates that telomeres shorten faster in short-lived animals compared to longer-lived ones.
Some patients bred to have extraordinarily long telomeres showcase lean bodies, low cholesterol and LDL levels, and improved glucose and insulin tolerance. They also live longer and have a lower incidence of cancer compared to regular mice. So longer telomeres seem to mean longer, healthier lives. Or do they?
Telomeres and Biological Age
Telomeres are maintained by the enzyme telomerase, which adds to their length, slowing down their shortening rate. While a good idea initially, cancer cells have increased amounts of telomerase, allowing them to continue dividing indefinitely.
Genetic engineer and chief longevity officer at the London Regenerative Institute, Dr. Sebnem Unluisler, informed Medical News Today that, "Studies have demonstrated a correlation between telomere length and biological age. Generally, shorter telomeres are associated with advanced chronological age and increased susceptibility to age-related diseases. Furthermore, individuals with certain genetic variations or lifestyle factors that accelerate telomere shortening tend to exhibit a more rapid aging phenotype."
Telomere length can be compared to a clock, with shorter telomeres indicating greater biological age. There are several lifestyle factors linked to shorter telomeres, such as inactivity and tobacco use. For instance, sedentary women are found to have telomeres that make them appear biologically eight years older compared to women who exercise more, at the same chronological age. Additionally, researchers found that telomere shortening was amplified in the white blood cells of smokers, accelerating biological aging.
In addition to these factors, stress, depression, and specific gene mutations such as the one responsible for progeria, a condition causing premature aging and short lifespan, also decrease telomere length.
Telomere length and brain aging
Recent studies have delved into the link between telomere length in specific cells and a faster pace of brain aging. One study published in Neurology in June 2025 investigated the relationship between leukocyte (white blood cell) telomere length and the risk of brain health problems in aging, focusing on stroke and dementia.
The study's participants, who had an average age of 56, provided data for analysis from the UK Biobank database, including their telomere lengths. Researchers also examined the participants' McCance Brain Care Scores, weighing various risk factors for brain and cardiovascular issues, including blood pressure, blood sugar, cholesterol levels, and lifestyle habits.
The study found that those participants with shorter telomere lengths and lower Brain Care Scores exhibited a higher risk of dementia and stroke as they aged. However, participants with shorter telomeres and higher Brain Care Scores, indicative of healthier lifestyles, didn't seem to have a significantly increased risk for age-related problems affecting the brain.
Based on this result, the study authors concluded that a healthier lifestyle might help offset the impact of shorter telomere lengths, a sign of cellular aging. In a press release, lead study author Dr. Tamara Kimball affirmed that "Reducing risk factors like weight and alcohol consumption, getting enough sleep and exercise, and taking better care of your brain can all help reverse the risk of age-related brain diseases, even for people who are already showing signs of biological aging. In short, it is never too late to start taking better care of your brain."
Maintaining telomere length through diet and exercise
Dr. Joshua Berkowitz, medical director at IV Boost U.K., told Medical News Today that "Recent studies have suggested that telomere length alone may not be a reliable predictor of lifespan or aging. For example, some individuals with shorter telomeres have been found to live longer than those with longer telomeres. Other factors, such as lifestyle, environment, genetics, and stress also play a role in aging and disease."
Shorter telomeres may be associated with a shorter lifespan and a more rapid pace of biological aging. However, studies don't necessarily indicate that longer telomeres equate to longer lives and healthier aging. Many lifestyle factors linked to good health—such as a diet rich in legumes, whole grains, and fresh fruits and vegetables like the Mediterranean diet—are positively associated with telomere length. Evidence suggests that the positive impact of the Mediterranean diet on telomeres can be attributed to its rich array of antioxidants.
The effects of physical activity on telomere length are not uniform, as exercise is thought to have benefits, yet the optimal dose remains unclear. Some studies found that physical activity helps maintain telomere length, yet the positive effects are thought to diminish with excessive exercise. Other research has shown that tobacco, stress, and depression can help preserve telomere length.
Challenging conventional views about telomeres
"While previous research has suggested that longer telomeres may be associated with longevity, most of this research has been done in cells, and it is not yet clear whether longer telomeres in humans are a cause or a consequence of healthy aging," said Dr. Unluisler.
Even studies have shown that telomeres at both extremes—much longer or shorter than average—are associated with susceptibility to diseases. Short telomeres are linked to organ failure, while long telomeres are associated with a variety of cancers.
A later study suggested that longer telomeres might not be the key to healthy aging. Instead, it posits that long telomeres let cells with age-related mutations live longer, increasing the potential for tumors and other chronic health conditions.
The study, which focused on individuals with a mutation (POT1) causing longer telomeres, discovered that, while some exhibited signs of youthfulness, such as no gray hair in their 70s, those with the mutation had a higher incidence of benign and cancerous tumors, as well as the age-related blood condition anemia, which boosts the risk of multiple cancers.
One of the researchers, Dr. Mary Armanios, suggested an explanation. According to her, "Cells with very long telomeres accumulate mutations and appear to promote tumors and other types of growths that would otherwise be put in check by normal telomere shortening processes."
Dr. Unluisler comments that "This study suggests that there may not be a simple relationship between telomere length and aging."
"While longer telomeres may be associated with increased cancer risk, they may also be associated with decreased risk of other age-related diseases and improved overall health," she noted.
Are telomere length differences set at birth?
Telomere length might not solely hinge on external factors, as growing evidence suggests. A study published in Science in April 2024 used an innovative method called "Telomere Profiling" to examine telomere lengths in 147 subjects. The study found that the telomeres at each chromosome's ends were consistently longer or shorter, and that these differences in telomere length across various chromosomes appeared in newborn cord blood as well.
This finding contradicts previous beliefs about telomeres, which maintained that they had fairly consistent average lengths that didn't vary across all chromosomes.
The good news, according to the study's authors, is that other researchers and clinicians can utilize Telomere Profiling to improve diagnostics and develop new, superior drugs.
Pushing aging research further
Telomere length is just one aspect of aging and longevity, and research is exploring many other possible factors.
"The genetic basis of aging is complex, and it is likely that both cellular and whole organism factors contribute to aging. While telomeres are one important factor, other genetic and epigenetic factors may also play a role in determining how quickly a person ages," said Dr. Unluisler.
Dr. Berkowitz agreed that there are numerous avenues for further research. He proposed that future studies would concentrate on:
- Identifying genetic and epigenetic factors that contribute to aging and longevity
- Understanding the role of the microbiome in aging and longevity
- Investigating the effects of senescent cells on aging and age-related diseases
Maximizing your healthy life years
Though longer telomeres might have some influence on lifespan, it is a factor that cannot be controlled, and the evidence for their benefits isn't conclusive. However, a healthy diet and lifestyle can increase lifespan and even predisposition, regardless of telomere length.
The National Institutes of Health (NIH) recommend taking the following steps to promote healthy aging:
- Set yourself in motion—according to research, taking approximately 8,000 steps a day reduces mortality from any cause by 51% compared to taking 4,000 steps.
- Opt for a healthy diet, like the Mediterranean diet, which is loaded with fresh fruits, vegetables, and legumes
- Maintain a healthy weight—exercise and a balanced diet will aid in achieving this
- Enjoy good rest—aim for seven to nine hours of sleep nightly
- Say no to smoking, or quit smoking if you're a smoker
- Limit your alcohol consumption
- Regularly check your health
- Take care of your mental health by maintaining connections and managing stress
"While genetics play a role in determining lifespan, environmental and lifestyle factors also play a significant role in an individual's health and longevity. By making healthy choices and adopting a healthy lifestyle, individuals can reduce their risk of age-related diseases and improve their chances of living a long, healthy life," said Dr. Berkowitz.
Longer telomeres may offer some bearing on your lifespan, but their influence is not definitive. However, a healthy diet and lifestyle can extend lifespan and even influence the genetically predisposed.
While discovering what's happening in our cells can give us clues, the tools for healthy aging are primarily in our own hands.
- The biological age of individuals can be partly determined by their telomere length, with shorter telomeres indicative of advanced chronological age and increased susceptibility to age-related diseases.
- Some studies suggest that telomere length can be maintained or even increased through lifestyle factors such as a healthy diet, regular exercise, and avoiding tobacco use.
- While longer telomeres might contribute to certain health benefits, they could also increase the risk of chronic health problems, such as cancer, due to cells with age-related mutations living longer.
- A healthy lifestyle, regardless of telomere length, can help offset the impact of biological aging on the risk of age-related diseases like dementia and stroke.
