According to new research by scientists at the University of Glasgow published in the January issue in the Proceedings of the National Academy of Sciences USA, a good indicator of an individual’s life expectancy can be obtained from early in life using the length of specialized pieces of DNA called telomeres, which occur at the ends of the chromosomes that contain our genetic code.

Telomeres work similar to plastic caps at the end of shoelaces. They mark the end of the chromosome, and protect them from various processes that gradually cause the ends to be worn away. This DNA protection method is equal to that in most animals and plants, as well as humans. The eventual loss of the telomere cap has been proven to cause malfunction in cells.

The study, funded by the European Research Council, with additional support from the UK Natural Environment Research Council, the Wellcome Trust and the US National Science Foundation, is the first study in which researchers have measured the length of telomere in the same individuals from early life onwards, and repeatedly during the rest of their natural lives. The findings have revealed that the length of telomere length in early life is a strong predictor of an individual’s subsequent lifespan.

The researchers measured telomere lengths in small samples of blood cells from a group of zebra finches at various ages. The animals’ lifespan varied from only 210 days to nearly nine years. They established that the best predictor of longevity was telomere length measured at just 25 days.

Dr Britt Heidinger from the University of Glasgow stated:

“While there was a lot of variation amongst individuals in telomere length, those birds that lived longest had the longest telomeres at every measurement point.”

Researchers know that variations in telomere length are partly inherited, and also that they are subject to vary because of changes in environmental factors, for example exposure to stress.

Leading researcher Professor Pat Monaghan commented:

“Our study shows the great importance of processes acting early in life. We now need to know more about how early life conditions can influence the pattern of telomere loss, and the relative importance of inherited and environmental factors. This is the main focus of our current research.”

Written by Petra Rattue