While we all celebrate our birthdays every 12 months (our chronological age), it doesn’t always match up with the rate at which our bodies are wearing out (our biological age).
Scientists have now identified 10 different blood markers that can help spot the difference.
We already have multiple ways to measure biological age, but there’s a need to develop tests that are even more reliable and simpler to run. A blood test looking for specific biomarkers would fit that description.
This work was led by a team from the University of Konstanz in Germany, and the hope is that the new blood-scanning technique could help improve our understanding of biological aging, as well as act as a warning system for age-related disease risk.
“The biological aging process is very complex,” says biologist Maria Moreno-Villanueva from the University of Konstanz.
“It affects all of the body’s tissues and organs, and it is not the result of a single cause.”
“As a result, single biomarkers are not enough to reliably determine a person’s biological age. On top of this, there are also differences in how men and women age.”
The researchers started by measuring 362 different parameters in the blood samples of 3,300 people, aged between 35 and 74. They used statistical modeling and machine learning to reduce these biomarkers down to the 10 most important – with separate lists of 10 chosen for males and for females.
This filtering was done by comparing each of the biomarkers – which covered chemical, genetic, cellular, and molecular signaling – against chronological age. The combinations that predicted age most closely were picked.
That gave the researchers a blend of predictors showing what someone’s blood tends to look like at certain chronological ages. When someone’s blood ‘age rating’ misses the mark of their actual age, that’s an indicator of slower or faster biological aging.
To evaluate the accuracy of the biomarkers, the researchers ran their blood tests on groups of people already known to age faster or slower in biological terms: people with Down Syndrome (also known by its genetic name of trisomy 21), smokers, and women on hormone therapy.
The blood tests picked out the expected changes in biological aging – either faster or slower – showing that the identified biomarkers were being interpreted correctly.
“Against the backdrop of current research on the aging effects of smoking, hormone replacement therapy, or trisomy 21, all of these results are plausible and confirm the validity of our bioage score,” says molecular toxicologist Alexander Bürkle, from the University of Konstanz.
Another interesting finding from the study is that certain biomarkers from those selected seem to contribute to biological aging (described as the “drivers”) while others are only indicators of it (the “bystanders”).
That potentially gives experts more insight into someone’s health from a blood test. Biological aging is a useful measure of fitness and well-being, with a ‘younger’ body usually correlating to better health and a longer life.
The researchers think that the newly developed test could be useful in a wide variety of scenarios – not just assessing health but also testing the effectiveness of treatments designed to ward off illness and disease related to aging.
With a global population that continues to trend older and older, researchers are hard at work looking for ways of making sure a longer lifespan also means a healthier one, and a fuller knowledge of how biological aging works – and how it might be affected by various factors – is going to be important in that.
Related: The Blood of Centenarians Reveals 37 Proteins Linked With Slower Aging
“If we look at the bioage scores of a lot of people born in the same year, we see a wide range of values,” says Morena-Villanueva.
“This shows very clearly that each person has their own individual biological aging process and, for example, that some people are significantly younger biologically than their chronological age would seem to indicate.”
The research has been published in Aging Cell.
