A sign of a cell's age could help predict the onset of dementia, a new study has said.
The new research, by US researchers, has shown that elderly people are more likely to develop cognitive problems if their telomeres - the stretches of DNA that cap the ends of chromosomes - are shorter than those of their peers.
The shortening of telomeres is associated with reduced lifespan, heart disease and osteoarthritis, reports New Scientist.
Telomeres naturally shorten with age as cells divide, but also contract when cells experience oxidative damage linked to metabolism. Such damage is linked cognitive problems like dementia.
In order to determine if healthy individuals with short telomeres are at risk of developing dementia, Kristine Yaffe at the University of California, San Francisco, and colleagues, followed 2734 physically fit adults with an average age of 74.
Yaffe's team tracked them for seven years and periodically assessed memory, language, concentration, attention, motor and other skills.
At the beginning, the researchers measured the length of telomeres in blood cells and grouped each person according to short, medium or long telomeres.
After accounting for differences in age, race, sex and education, the researchers found that those with long telomeres experienced less cognitive decline compared to those with short or medium-length telomeres.
The study appears in the journal Neurobiology of Aging.