A “biological age” predicts that men, obesity, smokers, and depression all contribute to biological aging, according to a new study.
Biological aging or functional aging is the progressive decline in the physiological ability to meet requirements and, in addition to genetics, is also influenced by factors such as chronological age, diet, stress, exercise and sleep.
Aging can be measured in a number of ways. While chronological age is measured by date of birth, scientists have developed a series of measurements to determine our biological age. These include measuring the length of telomeres (small caps at the end of our chromosomes that shorten as we age), chemical changes in our DNA (epigenetics), and changes in the proteins and metabolites in our body (proteomic and metabolomic measures).
Although studies have linked these individual measures to physical and mental health, it is not known whether they affect one another – a or whether they cumulatively affect our general wellbeing as we age. This new study, published in eLife, is the first to combine these individual measurements of biological age and show how they are related to mental and physical health.
‘To gain a better understanding of the mechanisms underlying biological aging, we set out to examine how indicators of biological aging are related, how they are related to determinants of physical and mental health, and whether a combined biological clock consists of all age indicators are a better predictor of health, “explains lead author Rick Jansen, assistant professor at the UMC’s Department of Psychiatry.
The team used blood samples from nearly 3,000 people who participated in the Dutch study of depression and anxiety. They used computer models to create custom indicators of biological aging based on five commonly used measurements: telomere length, epigenetics, gene values, metabolites, and proteomics. The five indicators were then linked to various factors such as gender, lifestyle factors, and known physical and mental disorders such as depression.
Of the five biological aging indicators, it was found that only three interact significantly in individuals, so that an increase in one indicator was also accompanied by an increase in the other indicator. There have been many overlapping and diverse associations between certain aging indicators and certain lifestyle factors or diseases. But being male, having a high body mass index (BMI), smoking, and having metabolic syndrome were most consistently linked to more advanced biological aging.
The team also confirmed that depression was linked to more advanced aging, as measured by epigenetics, genetic scores, and proteomics. This suggests that biological aging is related to both mental and physical health.
When they combined all five metrics into a composite biological age score, they found more and stronger associations for the composite score than for any individual biological aging indicator. This composite score had larger associations with BMI, gender, smoking, depression severity, and metabolic syndrome, highlighting the interplay of different systems on cumulative biological aging.