A biological-age calculation does not depend only on which biomarkers are measured.
It can also depend on the population used to develop the method.
Many methods used to assess biological aging interpret a person's biomarkers using patterns identified in a reference population. These reference data help establish what different physiological profiles mean within the calculation.
Why does this matter?
Reference populations can differ in age, health and other characteristics. They may also come from studies conducted in different places or at different times. As a result, the reference data used to develop a biological-aging method can influence how its results are interpreted.
Researchers in the United States explored this question using data from 220 healthy, non-obese adults studied over two years. Participants were randomly assigned either to reduce their calorie intake or to continue eating as usual.
Clinical measurements collected during the study were used to assess biological aging in several different ways, including a method called Homeostatic Dysregulation.
In this analysis, Homeostatic Dysregulation did not show a significant difference between the calorie-restriction and control groups.
An earlier analysis of the same study had found a difference using the same general approach, but with different reference data.
This suggests that even when the same general method is used, changing the reference data can influence the result.
For someone reading a biological-age result, there is therefore another useful question to ask: What population was used as the reference for this method?
The answer can provide important context for understanding what the result means and how it should be interpreted.
