How can you measure biological age?

When asked about your age, you usually state your chronological age, i.e. the number of years you have already lived. However, chronological age says little about the current state of the body: while one person can easily run a marathon at 50, another is already exhausted just climbing the stairs to the first floor. To find out the actual state of the body, you can try to determine the biological age.

There are several methods for determining biological age:

Epigenetic tests: These tests measure DNA methylation patterns that change with age (see FAQ ‘What is the epigenetic clock?’).
Telomere length: Telomeres are the ends of chromosomes that shorten with each cell division. The length of telomeres can serve as an indicator of biological age. (Bekaert et al. 2005)
Markers in body fluids: Body fluid-based markers can be measured in blood or other body fluids. These markers include, among others, inflammation levels, metabolic markers, such as insulin or glucose, hormone levels or markers of the immune system (Jylhävä et al. 2017). The Deelen research group investigated the association between metabolomics and predicted survival and identified a set of 14 metabolic markers (Deelen et al. 2019). In addition, there are the so-called ‘proteomic aging clocks’, which are based on measurements of protein levels in body fluids (Agientieri et al. 2024, Rutledge et al. 2022, Lehallier et al. 2019).
Physiological tests: These tests assess the function of organs and systems in the body, such as lung capacity, blood pressure, vision or hearing, cardiovascular fitness and joint mobility.
Cognitive tests: These tests examine different areas of thinking, such as memory, attention, problem-solving ability and how quickly information is processed.

The most promising method for determining biological age is a combination of different approaches, as this allows the various aspects of ageing to be fully taken into account. Although there are already some commercial tests that claim to be able to measure biological age, the scientific evidence for the relationship between the underlying measurements and biological age is not yet fully established. These tests can only capture partial aspects of the ageing process.

At the Max Planck Institute for Biology of Ageing, we unfortunately cannot determine the biological age of individuals. Our research focuses on fundamental scientific questions, using samples from clinical studies or data from biobanks. We do not test individuals.

The Research Group Deelen at our institute is investigating biomarkers of ageing.