, , , , , , ,

“How old are you?” someone asks. Number of years since birth is the generally the answer – that is your Chronological Age or CA.

But how hold do you feel? How old do you act? How old do you look? That is your Biological Age or BA.

Wouldn’t it be nice to actually be able to measure your biological age?

CA and BA is the difference between being 40 year old and going on 60. Or, may be being 60 year old and going on 40.

Wouldn’t it be more useful to have a single number like BA, than understanding individual factors like your total cholesterol, HDL, A1c, VO2 Max, etc?

Recently, in the media there has been a buzz about a recent research published by scientists led by Duke University School of Medicine about measuring biological age. For example, see the article in WSJ: How Quickly Are You Growing Old?

Now there are a quite a few websites, where you answer a bunch of question and they will tell you, your biological age as compared to your chronological age.

For example, here are three such sites, I tried (my CA is 60.9 years):

http://www.biological-age.com/ calculated my biological age as 36

https://www.sharecare.com told me my BA was 53.6.

http://www.growyouthful.com/gettestinfo.php said my BA was 46.

Each of the sites followed up with advice and helpful hints on what I could start or stop doing to further increase my expected health and lifespan.

Unfortunately, none of these websites show exactly what they do with the information you provide and how they arrive at the number they call Biological Age.

But this recent study, “Quantification of biological aging in young adults”, by Daniel W. Belsky et al, is very rigorous treatment of this subject and gives you all the details behind the curtain. And, for me, these details are not only fascinating but actually quite useful to understand what matters for biological age to start diverging from chronological age. In other words, what slows down or speed up aging.

The study calculated the aging rate of 954 men and women—taking various measurements of their bodies’ health—when they were each 26, 32 and 38 in chronological years. By analyzing how these measures changed over time, the researchers were able to see who aged faster and who slower than normal.

To measure the pace of biological aging, which the study defined as the declining integrity of multiple organ systems, the researchers relied on 18 separate biomarkers, summarized in figure below.

These ranged from common measures such as HDL-cholesterol levels and mean arterial blood pressure to more obscure ones like the length of telomeres—the protective caps on the ends of chromosomes that shorten with age.

Go on in Years

Chronological age of all participants was 38 years. However, researchers found that the biological ages varied from 26 years to 60 years.

For measuring how fast people aged, they calculated aging over 12 years. About 30 percent aged biologically one year for every calendar year. There were those who aged as much as 3 years for every calendar year. And, there were four members of the group who aged not at all or actually got biologically younger during the 12 year period.


Finding one’s Biological Age is a fascinating concept and can be very useful in optimizing health and life span. However, this is not an exact science just yet, although good strides are being made in research.

However, if you want to focus on living optimally, you can focus on changing your lifestyle to optimize the basic 18 or so biomarkers used in this study. Most of these can be impacted by lifestyle choices. Only 20% depend upon genetics.

Proper food, hydration, exercise, supplements and medical care are the key methods to managing these primary biomarkers.

Websites that compute biological ages also suggest additional actionable items that seem to strongly correlate to optimal health span and life span. These include:

  1. Optimal sleep (7 to 9 hours)
  2. Reduced stress (meditation, perspective management)
  3. Reduced exposure to toxins (organic food, reduced use of chemicals, clean water)
  4. Increased social contact (having friends, family, living with a life partner)
  5. Purposeful living (satisfying work, hobbies, social endeavors)

What is your take on this subject?

Please feel free to leave comment to share your perspective.