January 11, 2012
Longer Telomeres Mean Longer Lifespan
A new study has found a possible predictor of lifespan. According to researchers at the University of Glasgow in England, the link lies in the telomeres that are located on an individual´s DNA.
Telomeres are pieces of DNA that are located on the ends of chromosomal strands. They serve the same purpose as aglets on the ends of shoelaces, keeping the chromosome intact and preventing it from losing viable information over the course of a person´s lifetime.
According to professor Pat Monaghan, who headed the research, “Each time a cell divides, some DNA can be lost at the end of the chromosome. The cap is worn down without affecting the integrity of the chromosome itself. But each time a cell divides, some of this protective cap is lost. Eventually it´s eroding or fraying away until no cap is left. Then genetic structure in the cell is lost, so that the cell may die or malfunction.”
When the genetic material is lost the cell is no longer able to divide leading to cell death, organ malfunction or possibly even cancer. But individuals with longer telomeres in early life receive more protection over time.
The study was conducted on 99 zebra finches. The researchers measured the lengths of their telomeres through blood samples throughout their lifetime. In order to measure the longevity of the birds, researchers had to wait until the birds died. The first bird died only after six months while the longest-lived bird lasted nine years.
In all the cases the longest-lived birds had the longest telomeres, but the best predictor was the length of the telomere at 25 days old.
The researchers are unsure as to the predictability of human longevity according to the length of our telomeres. Human´s can live to be more than a century old before the data could be collected and analyzed. Another roadblock researchers face is how much environmental or other hereditary factors add to the longevity equation.
But researchers caution that even though the length of telomeres is a strong predictor of longevity, it is still only a predictor.
The study results are published in the Proceedings of the National Academy of Sciences (PNAS).
On the Net: