KING’S COLLEGE LONDON (UK)—After analyzing more than 500,000 genetic variations across the entire human genome, a research team has identified definitive variants associated with biological aging in humans.
There are two forms of aging: chronological aging—how old someone is in years—and biological aging—whereby the cells of some individuals are older (or younger) than suggested by their actual age.
“There is accumulating evidence that the risk of age-associated diseases including heart disease and some types of cancers are more closely related to biological rather than chronological age,” says Nilesh Samani, a professor in the Department of Cardiovascular Sciences at the University of Leicester.
“What we studied are structures called telomeres which are parts of one’s chromosomes. Individuals are born with telomeres of certain length and in many cells telomeres shorten as the cells divide and age. Telomere length is therefore considered a marker of biological aging.
“In this study what we found was that those individuals carrying a particular genetic variant had shorter telomeres—they 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”
Tim Spector, a professor at King’s College London, who co-led the project explains that the variants identified are 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 aging’ 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 funded by the Wellcome Trust and the British Heart Foundation.
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