Do Aging Clocks Actually Work?

There are tests now that claim to measure how old you really are. Not the number on your birth certificate, but your biological age, the idea being that two people born on the same day can be aging at different speeds, and that a blood or saliva sample can tell them apart. It starts with a discovery from fifteen years ago, that chemical marks on your DNA shift as you get older. Since then, the clocks built on it have moved fast, from reading your age, to forecasting how long you have left, to scoring each organ, to scoring individual cell types from a single vial of blood. So what does one of these numbers actually measure, how good have they become, and would one handed to your doctor change anything about what happens to you?

0:00 – Can You Really Measure Your Age?
1:04 – The Cheek Swab That Started It
4:00 – Reading Death, Not Birthdays
5:45 – The Hidden Flaw
7:51 – Your Organs Age Differently
8:36 – 11 Ages, One Blood Draw
10:06 – 40 Clocks, One Vial
11:36 – The Missing Proof
14:15 – The Verdict

*Citations can be found on my website