What is Biological Age? Why is it important?

Abheetha P
3 min readJan 4, 2023


Age is not just a number

What if I told you, that you could measure how healthily you’ve lived?

Did you know your age can be determined in two ways?

chronological age

Chronological age — It is the total number of years you have been existing till now.

biological age

Biological age — It is the age at which your body appears to be based on various factors such as lifestyle and environmental exposure, including how your chromosomes have changed over time.

If a person has a very unhealthy lifestyle, the chances are that they are aging quicker than their healthier peers. For example, if a person’s age is 25, it is likely that their body might mimic the health of a person much older than them. So, their biological age could be 30–35, even though their chronological age is 25.

But wait! Your biological age can also be lesser than your chronological age! The key to this is to maintain a healthy lifestyle of exercise, nutritious diet, stress management, healthy relationships and most importantly getting a good night’s sleep every day .

How is biological age calculated?

Biological age is determined using biomarkers. A biomarker can be anything from a specific molecule found in blood, tissues, blood pressure, pulse, and heart rate. It can indicate a normal or abnormal process and it can also indicate that a biological process has occurred or is ongoing.

For example, a biomarker for heart disease can be blood pressure. Blood sugar levels can be a biomarker for diabetes.

Similarly, there are biomarkers for aging as well. One such biomarker for aging is DNA Methylation.

An epigenome is a set of chemical compounds that attaches itself to the DNA. A genome is the complete DNA. An epigenome tells the DNA what to do; it could be to generate a particular protein. When the epigenome attaches itself to the DNA, it is said to have marked the DNA.

DNA methylation is one type of mark that can be tracked as a sign of aging in different parts of the genome. To calculate biological age, scientists take a sample of cells and look at specific sites along the genome and see what proportion of the cells are marked with DNA methylation.

Although a biological age number can be determined, your tissues and organs have their own biological age. It is actually the combination of biological ages of different parts of your body that dictate how your body can function. So, in the future, scientists aim to become more and more specific in determining the biological age in different parts of your body.

Why do you need to know your biological age?

Here’s how you can measure how you are aging -

Biological age, relative to chronological age can tell you your cumulative rate of aging.

But, knowing your biological age once is insufficient. You need to track your biological age over time, as biological age isn’t fixed and it can change depending on a number of factors such as diet, weight loss, exercise, stress, and sleep. Aging is accelerated by an unhealthy lifestyle that can include smoking, alcoholism, lack of sleep, poor stress management, unhealthy diet, and inactivity.

Keeping track of your biological age can help you in identifying what is good and bad for your health. However, there is no guarantee that your biological age will improve by changing or including different things in your lifestyle. But you can do a few things to decrease the likelihood of aging faster and to improve your overall health: a nutritious diet, exercise, good sleep, managing stress, keeping your mind active, and forming healthy relationships.

Keep in mind that you must never use the results of a biological test to diagnose or treat a disease or condition, or to assess the risk of a disease or condition unless the test specifically directs it. In addition, do not use biological age to determine or change age-related health or treatment unless recommended by your doctor.