Earlier researches on humans have shown that the length of telomeres determines the potential lifespan of people. The same as has been proven for young zebra Finches (Taeniopygia Guttata). The telomeres are the protective caps (ends) of chromosomes, and the longer the telomere the stronger is the protection of the chromosomes.
Telomeres gives DNA sequences present at the end of chromosomes a protection to sustain cell viability, and also to avoid different chromosomes to mess-up. Several studies have been carried out to comprehend the relation between typical aging and telomere decline. However, no clear evidence has been revealed on humans.
Longevity studies relying on telomere length has commonly been scrutinized only against one to two hallmarks being the lifespan itself of an individual. From University of Glasgow, in UK, ecologist Pat Monaghan and his team found that continuous evaluation of telomere length of zebra Finch’s lifespan clearly showed that the length of telomere were a strong indicator of the lifespan of the bird. The most accurate measures were revealed as per those taken on birds being only 25 days old. The study was recently published in: Proceeding of the National Academy of Sciences.
At the Spanish, national Cancer Research Centre in Madrid, María Blasco says that understanding the importance of telomere length as an indicator of longevity is very important. Basco wasn’t involved in the study but as a Chief Scientific Adviser for a Madrid-based company, life length which advertises for their products; measuring telomere lengths as to find an individual’s ‘biological age’
According to Monaghan, the study doesn’t say that you should go and have your telomeres measured. It will take quite some time makes sure that it has the same effect on long-lived species such as humans.
Early Studies, have constantly linked telomere shortening to accelerated ageing as well as diseases such as Dyskeratosis Congenita. However, researchers have been unable to fully link how telomere length affects normal aging. According to Monaghan, previous studies had the weakness that samples were mainly taken from only one individual rather than periodical samples.
Monaghan selected the Zebra finch which is a small Australian bird with a lifespan in captivity of nine years. The relatively short lifespan of the bird made it possible to have astounding results within a single decade. As for human, a similar study would take decades to complete. Although that mouse has an even shorter lifespan, they aren’t really comparable to humans as species with shorter lifespan doesn’t have sophisticated body maintenance mechanisms.
In the study of the Australian birds, a total of 99 zebra finches was included. The finding concluded that longer telomeres were associated with longer lifespan. Apparently, the link was the strongest for birds who were only 25 days – at 25 days a Zebra Finch is almost fully grown – but reliant on their parents for food. However, for humans, it is difficult to find the comparative age.
Monaghan’s team is now trying to determine the reason why the longest telomere at only 25 days does show a more accurate indication of longevity. Is it inheritance or environmental factors, which influence the length of the telomeres? It has been noted that stress tend to fasten the shortening of telomeres.
According to Baird, the fact that telomere length is linked to longevity doesn’t mean that telomeres are the drivers for the aging process. Telomere might simply be a marketer for cellular aging. There are other factors such as weight of the birds that need to be analyzed, to comprehend how other determinants are also influencing lifespan.
Sat, Jan 14, 2012
Bioscience, Gerontology, Longevity