Telomeres are the caps at the end of chromosomes made up of nucleotide sequences that protect our genetic info through many cell divisions. Vital for growth, replication and life of an organism, they are key to understanding aging.
Telomeres were first discovered in 1933 by Barbara McClintock and have been studied for their role in chromosome stability. Their importance was further recognized when Elizabeth Blackburn, Carol Greider and Jack Szostak won the Nobel Prize in 2009 for figuring out how telomeres protect chromosomes.
What Are Telomeres and Why Are They Important?
Telomeres are nucleotide sequences at the ends of each chromosome that function as protective caps against deterioration. They protect our genetic data during cell division. Telomeres prevent our chromosomes from degrading which is essential for growth, replication and overall health of an organism.
Telomere Dynamics and Cellular Aging
Every time a cell divides, telomeres get shorter and eventually the cell dies. This is a natural part of the aging process and affects the immune system and increases cancer risk. Telomere length which declines from birth to old age is a biomarker for aging, not chronological age.
To maintain the living organism, chromosomes are always making copies of themselves and mending DNA. Each round of chromosome duplication leads to a shortening of telomeres as the enzymes that duplicate DNA fail to carry the job to the chromosome ends.
Therefore telomeres are essential protective bodies that should not be damaged in the process. They’re disposable, i.e…. Telomere shortening inhibits cells from making copies of themselves by limiting the number of cell divisions.
Short telomeres also compromise the immune system and predispose to cancer. Many age-associated diseases are associated with shortened telomeres] . Long telomeres are associated with a longer lifespan than short telomeres. It’s unclear if short telomeres are merely a marker of cellular aging or the prime movers of the aging process. Probably both. Human telomeres on average shorten from approximately 11 kilobases as a newborn to less than 4 kilobases in late age.
You lose more than half of your telomeres once you are older than a child. However, your biological age can vary from your chronologic age as your telomeres can shorten or lengthen depending on lifestyle factors
How Do Telomeres Affect Aging and Longevity?
Telomerase: The Enzyme That Replenishes Telomeres
Each time a cell divides, its telomeres get shorter. Eventually the telomeres get too short to protect the chromosomes and the cell dies. This natural process is linked to the aging of the whole organism and increases the risk of age related diseases like cancer.
Telomerase reverse transcriptase (TERT) adds sequences to the ends of chromosomes and counteracts the natural shortening and potentially extends cellular life. Telomerase is active in stem cells and helps them live longer, but is limited in other cells which contributes to aging.
Balancing Telomere Length: Health and Disease
While necessary to prevent premature aging, too much telomerase can cause cancer as it can also prolong the life of cancer cells. So we need to balance the telomere activity.
Can Lifestyle Choices Affect Telomere Length and Health?
Yes, lifestyle choices can affect the length and health of your telomeres. A stressful life can shorten telomeres and aging while meditation, intermittent fasting and resistance training can stabilize or even lengthen telomeres. These activities reduce oxidative stress and overall cell health.
Lifestyle and Telomere Health
Excessive stress shorten telomeres but it also harms the mitochondria. That’s why healthy lifestyle should include active stress relief. Here is how to increase telomere length and stop telomere shortening:
Meditation, resistance training and intermittent fasting can stabilize telomeres and extend cellular life. These activities support telomere length and also manage oxidative stress which can damage both telomeres and mitochondria.
Especially muscle building and resistance training counteract aging. During aging you reduce the number of satellite cells, satellite cells are precursor cells of skeletal muscle cells, and you lose muscle mass. Satellite cell telomeres shorten and prevent satellite cell replication and contribute to sarcopenia associated with ageing [
Conclusion: Telomeres and Longevity
Understanding and managing telomere health is the key to extending health span and reducing age-related diseases. As we learn more about telomeres and how lifestyle affects them we can use this knowledge for healthier aging.