A chemical “fingerprint” in the blood may provide clues to an infant’s health and rate of ageing near the end of life, research suggests.
The discovery raises the prospect of a simple test at birth that could help doctors stave off the ravages of disease in old age.
Scientists identified 22 metabolites, small molecules linked to metabolism, that may be useful indicators of how we can expect to grow old.
One in particular, linked to range of traits including lung function, bone density, blood pressure and cholesterol levels, was singled out by the researchers. It is also strongly associated with birthweight – itself a known determinant of healthy ageing.
Levels of this metabolite, C-glyTrp, could reflect accelerated ageing in later adulthood, the scientists believe.
Higher levels of the molecule were associated with lower weight at birth in comparisons between pairs of identical twins.
Since identical twins share the same genes, this suggests that levels of the metabolite are altered by nutrition or different conditions in the womb.
Study leader Professor Tim Spector, from King’s College London, said: “Scientists have known for a long time that a person’s weight at the time of birth is an important determinant of health in middle and old age, and that people with low birthweight are more susceptible to age-related diseases.
“So far the molecular mechanisms that link low birthweight to health or disease in old age had remained elusive, but this discovery has revealed one of the molecular pathways involved.”
Prof Spector’s team analysed blood samples donated by more than 6,000 twins. The researchers identified 22 metabolites directly linked to chronological age, with higher concentrations in older than in younger people.
Further work showed that the gene influencing levels of C-glyTrp could be modified by epigenetics, a process whereby environmental factors switch genes on or off and alter their activity.
The epigenetic changes may influence metabolism during a person’s lifetime, thereby affecting susceptibility to age-related diseases.
The findings are published in the International Journal of Epidemiology.
Co-author Dr Ana Valdes, also from King’s College London, said: “Human ageing is a process influenced by genetic, lifestyle and environmental factors, but genes only explain a part of the story. Molecular changes that influence how we age over time are triggered by epigenetic changes. This study has for the first time used analysis of blood and epigenetic changes to identify a novel metabolite that has a link to birthweight and rate of ageing.
“This unique metabolite, which is related to age and age-related diseases, was different in genetically identical twins that had very different weight at birth. This shows us that birthweight affects a molecular mechanism that alters this metabolite. This may help us understand how lower nutrition in the womb alters molecular pathways that result in faster ageing and a higher risk of age-related diseases 50 years later.
“Understanding the molecular pathways involved in the ageing process could ultimately pave the way for future therapies to treat age-related conditions. As these 22 metabolites linked to ageing are detectable in the blood, we can now predict actual age from a blood sample pretty accurately and in the future this can be refined to potentially identify future rapid biological ageing in individuals.”