Chronological Age Vs. Biological Age

Chronological age is the age that we have attained since our birth. Biological age refers to the age of our cells, which is our true age.

While chronological age is not reversible and does not depend on the lifestyle and habits. On the other hand, biological age varies depending on the lifestyle (exercise, diet, sleep, stress, attitude, etc.)

Depending on lifestyle and habits, the biological age can either more or less than your chronological age. People having a lower biological age than the chronological age are at lesser risk of contracting an age-related illness as well as early mortality.

DNA Testing

So, how do you calculate your biological age?

It is simple. Your DNA is extracted from your saliva, cheek swab, or blood, and the companies will let you know about your ancestry, family tree, or whether you are prone to a specific illness.

Rapid technological advancements have ensured the development of tests that help in determining your biological age by measuring the length of telomeres – the chromosomal tips.


What is the telomere, and how can it determine your biological age?

Despite its’ size and limited presence in the human DNA, telomeres have a significant role to play in keeping our chromosomes and subsequently, our bodies healthy. Its origins lie in the Greek words “telo,” which means “end” and “mere” that means “part.”

Telomeres are found at both ends of our chromosomes. Present in all chromosomes, telomeres helps the storing of the genetic materials safely in chromosomes. Telomere length indicates the overall health status of an individual. It reflects the physiological age. The length of the telomere is indicative of how various factors can impact our health.

While telomeres are a vital component of human health, it is not destructible. Every time a cell divides, the telomeres shorten, and it happens progressively as one age. When telomeres become very short, the chromosomal tips are unprotected and get sticky and fuses with another chromosome.

To prevent further chromosomal shortening, the cells enter into a state of senescence – a state where they no longer get divided. Senescent cells, while losing the ability to regenerate, can still result in inflammation and promote the secretion of factors that can help in the growth of cancerous or pre-cancerous cells.

Unfortunately, lifestyle can accelerate telomere shortening. Environmental exposures like air pollution, sunlight, cigarette smoke, poor diet, and even inflammation can lead to damaging the cell components.

This is done by the generation of free radicals or unstable oxygen molecules. Telomeres are very susceptible to any damage caused by free radicals.

Telomere Testing

A telomere test is not and will never be life’s crystal ball – at least in the near foreseeable future. We have other theories that can explain aging – mutated DNA and damaged cell membranes.

But new research is showing that measuring the length of telomeres present in leukocytes (white blood cells) of the immune system, can reliably help in predicting age-related disease.

Based on the research, many new companies have been set up, which helps in revealing our biological age by measuring the telomere length.

These companies analyze our DNA and send us a report which tells data regarding our biological age, the average telomere length and the percentile of specific short telomeres as well as median length.

Median length and short telomeres show us why we stand in terms of aging and why our cells get senescent.

The Long Road Ahead

While the research sound too exciting and help in knowing ourselves more, there are many problems associated with testing telomere length.

The first and foremost problem is that these tests are unregulated and the evidence presented does not have the backing of any reputed agencies or even the US FDA.

Regulation is essential as these tests are done by companies who will always claim that their analysis is the best and most accurate, and this can lead to confusion and unnecessary panic in the mind of potential customers.

Experts in the field of DNA and cellular technology opine that while they are all for research and finding vital information about human DNA, it pertains to the health and longevity of a person, as well as their privacy.

Another problem with the testing is generalizing things – short is terrible, long is good. It can not be applied to every person.

Every individual is different, and what applies to one individual does not necessarily apply to another.

There also is another aspect of the data being misutilized. Lack of regulation also makes the information prone to being misutilization.


Telomere testing should be treated like any other test that we undergo during our physical.

Telomere testing will not tell you if you will die at a particular age or if you will have a stroke at this specific time, but it does tell you whether you are prone to stroke or cancer and can help you be more aware.

The moot point is that by having a better diet and healthier lifestyle, one can lead a healthy life.

So, again what is your biological age? Any guesses.