UK-NETHERLANDS: The long and short of ageing
The variation is related to telomeres - parts of the chromosome that shorten as cells divide and age and are considered a marker of ageing. In some people, the telomeres are shorter and they therefore appear to be older biologically than they are chronologically.
Researchers from the University of Leicester, King's College London, and the University of Groningen in the Netherlands, analysed more than 500,000 genetic variations across the entire human genome to identify the variants which are located near a gene called TERC.
British Heart Foundation Professor of Cardiology at the University of Leicester, Nilesh Samani, co-led the project. He said there was growing evidence that the risk of age-associated diseases including heart disease and some types of cancers were more closely related to biological rather than chronological age.
The research project had identified the factor that led to some people being biologically 'older' than their chronological age would suggest.
"In this study what we found was that those individuals carrying a particular genetic variant had shorter telomeres, that is, looked biologically older. Given the association of shorter telomeres with age-associated diseases, the finding raises the question whether individuals carrying the variant are at greater risk of developing such diseases."
Professor Tim Spector from King's College London who co-led the project, said: "The variants identified lie near a gene called TERC which is already known to play an important role in maintaining telomere length. What our study suggests is that some people are genetically programmed to age at a faster rate.
"The effect was quite considerable in those with the variant, equivalent to between three to four years of 'biological ageing' as measured by telomere length loss. Alternatively genetically susceptible people may age even faster when exposed to proven 'bad' environments for telomeres like smoking, obesity or lack of exercise - and end up several years biologically older or succumbing to more age-related diseases. "
The study was published in Nature Genetics . It was funded by The Wellcome Trust and the British Heart Foundation.