Chromosome clue to longer life

The length of your life could be related to the length of your telomeres - the segments of DNA that make up the ends of chromosomes. A new study suggests that people with shorter telomeres may die earlier than those with longer telomeres, either from an infectious disease or a heart attack. 'This is the first research study showing that telomere length is predictive of survival in humans' said team leader Dr Richard Cawthon. Some cloned animals have shorter telomeres than expected for their age, indicating they may have a shortened lifespan.

It has long been known that telomeres act as a kind of cellular clock, marking the number of times a cell has replicated its genetic material. Each time a cell divides to make two new cells, its telomeres get shorter, until eventually it stops multiplying altogether.

Scientists at the University of Utah, Salt Lake City, looked at blood donated by 143 people between 1982 and 1986, all of whom were 60 or older at the time. By measuring the telomere length of the blood cell chromosomes and examining the death records of 101 donors who have since died, the researchers found that people with shorter telomeres had an 86 per cent higher death rate. They were three times more likely to die of a heart attack, and eight times more likely to contract a fatal infectious disease. Cawthon says that the results, published in the Lancet, suggest that it 'may be possible to extend the duration of healthy adult life using medical interventions that maintain telomere length'.