Washington: A team of scientists has identified a biological clock in human DNA that can tell how long a person will live.
Researchers at University of Edinburgh studied a chemical modification to DNA, known as methylation, that take place over a lifetime and can help them predict an individual's age and by comparing individuals' actual ages with their predicted biological clock age, they saw a pattern emerging.
The modification does not alter the DNA sequence, but plays an important role in biological processes and can influence how genes are turned off and on. Methylation changes can affect many genes and occur throughout a person's life.
People whose biological age was greater than their true age were more likely to die sooner than those whose biological and actual ages were the same.
Researchers found that the link between having a faster-running biological clock and early death held true even after accounting for other factors such as smoking, diabetes and cardiovascular disease.
Researcher Riccardo Marioni said that the same results in four studies indicated a link between the biological clock and deaths from all causes and at present, it is not clear what lifestyle or genetic factors influence a person's biological age. They have several follow-up projects planned to investigate this in detail.
Researcher Ian Deary said that this new research increases our understanding of longevity and healthy ageing, which is exciting as it has identified a novel indicator of ageing, which improves the prediction of lifespan over and above the contribution of factors such as smoking, diabetes, and cardiovascular disease.