Social stress takes a toll and affects how you age

by Kounteya Sinha for The Times Of India:Humans experiencing high levels of social stress and deprivation have shorter telomeres.Telomeres are the protective caps at the end of chromosomes which are the best indicators of biological age (cell age) as against chronological age.Scientists say the length of telomeres is crucial in deciding biological age - long ones indicate healthy ageing, short ones indicate some form of irreparable damage.Several studies suggest that telomere shortening is accelerated by stress but until now no studies examined the effects of social isolation on telomere shortening.To test whether social isolation accelerates telomere shortening, Denise Aydinonat, a doctorate student at the Vetmeduni Vienna conducted a study using DNA samples that she collected from African grey parrots during routine check-ups.African greys are highly social birds, but they are often reared and kept in isolation from other parrots. She and her collaborators compared the telomere lengths of single birds versus pair-housed individuals with a broad range of ages (from 1 to 45 years).The telomere lengths of older birds were shorter compared to younger birds, regardless of their housing.But the important finding of the study was that single-housed birds had shorter telomeres than pair-housed individuals of the same age group.Dustin Penn from the Konrad Lorenz Institute of Ethology at the Vetmeduni Vienna said, "This study is the first to examine the effects of social isolation on telomere length in any species."Penn and his team previously conducted experiments on mice which were the first to show that exposure to crowding stress causes telomere shortening. He points out that this new finding suggests that both extremes of social conditions affect telomere attrition.There is extensive scientific evidence showing the strong correlation between the percentage of short telomeres and the risk of developing diseases associated with ageing, such as cancer, cardiovascular diseases and Alzheimer's.In turn, lifestyle habits (nutrition, obesity and exercise) are increasingly being shown to impact telomere length.Telomeres shorten with each cell division, and once a critical length is reached, cells are unable to divide further. Although cellular senescence is a useful mechanism to eliminate worn-out cells, it appears to contribute to aging and mortality.Source: http://bit.ly/1syeMwf