Blood test: a clue to how fast we age?

A blood test for babies may hold a clue to ageing rates near the end of life, scientists believe.

The results raise the chance that the simple test at birth could help doctors fight disease in old age.

It has long been established that a person's weight at the time of birth can determine their health in middle and old age.

People with low birthweight are especially more susceptible to age-related diseases.

Now, study leader Professor Tim Spector, from King's College London, and his team have for the first time found one of the molecular pathways involved in the ageing process.

Researchers identified 22 metabolites, tiny molecules associated with metabolism, that may be useful markers of how we can anticipate growing older.

One particular metabolite, C-glyTrp, associated with a variety of characteristics including lung function, bone density, blood pressure and cholesterol levels, was highlighted by the researchers.

It is also closely linked to birthweight.

Birth weight connected to health in later life

Researchers think C-glyTrp rates could reflect hastened ageing in later adulthood.

Higher C-glyTrp rates were associated with lower weight at birth in comparisons between pairs of identical twins.

Since identical twins have the same genes, this implies that metabolite levels are changed by nutrition or different conditions in the womb.

Prof Spector said that scientists have known for years that a person's weight at the time of birth is a big determinant of health in middle and old age, and that people with low birthweight are more susceptible to age-related diseases.

He added: '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 researched blood samples donated by 6,055 twins.

They identified 22 metabolites directly linked to chronological age, with higher levels in older than in younger people.

Further study showed that the gene affecting C-glyTrp rates could be modified by epigenetics.

This is a process where environmental factors switch genes on or off and change their activity.

The epigenetic alterations may affect metabolism during a person's lifetime, so affecting susceptibility to age-related diseases.

The findings are published in the International Journal of Epidemiology.

Paving the way for future therapies

Co-author Dr Ana Valdes, also from King's College London, said: 'Understanding the molecular pathways involved in the ageing process could ultimately pave the way for future therapies to treat age-related conditions.'

She said as these 22 metabolites associated with ageing are detectable in the blood, they can now predict actual age from a blood sample 'pretty accurately'.

Dr Valdes said this can be refined in future to potentially identify future rapid biological ageing in individuals.

Age UK Head of Research, Professor James Goodwin, said, 'New understanding of the biological mechanisms of ageing is always welcome. Although the blood test could be some years away, developments like these enable us more and more to advise people how to age well and avoid health conditions commonly associated with ageing.'

Copyright Press Association 2013