What is biological age?

When asked about their age, people usually give their chronological age – the number of years they have lived. However, chronological age does not tell us much about the current state of the body: One person may be able to run a marathon at the age of 50, while another may be exhausted just climbing the stairs to the first floor. To find out what condition the body is actually in, the biological age can be determined. This is done by analysing various indicators in the human body, known as biomarkers. Biomarkers of ageing are characteristics that allow a better prediction of the actual functional state of the organism at an older age and are more reliable than chronological age [Jazwinski & Kim 2019]. These include blood pressure, vision, hearing and joint mobility. Other measurable biomarkers include the length of the telomeres and certain proteins in the bloodstream. Probably the best known biomarker that can be measured in the blood is cholesterol, but certain inflammatory markers are also suitable for determining biological age [Jylhävä et al. 2017]. Another biomarker that can be used to determine biological age is the epigenetic clock [Horvath & Raj 2018]. The values of these biomarkers together give the estimated biological age.

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