Tuesday, February 09, 2010

Shorter Telomeres Mean Faster Biological Aging

While we all chronically age at the same rate (i.e. one year every 12 months) we do not biologically age at the same rate. And this means some people have higher risks of morbidity and mortality than others. This study in the latest issue of Nature Genetics has found that a genetic variant is linked to faster biological aging.

Scientific American has the scoop here. A sample:

Why is it that some people just look older (or younger) than they really are? Scientists may have found the answer.

Chronological age is very different from biological age—the condition of chromosomes after each cellular division—according to Nilesh Samani of the University of Leicester, co-author of a February 7 report published in Nature Genetics. Biological age, Samani says, is related to the length of telomeres—stretches of DNA at the ends of chromosomes, which protect these precious packages of genes from daily wear and tear. We're born with telomeres of a certain length, and these get shorter as our cells divide, resulting in aging, scientists think.

...The odds of carrying the variant are relatively high, Samani says. "In the populations we studied, about 7 percent of people carried two copies of the variant and about 38 percent of people [carried] one copy." But it's unknown whether shorter telomeres make their carriers physically appear older than they really are. "We haven't looked at that—it's an interesting question," he says; pondering how to measure the age someone looks in a follow-up study. Maybe we'll take pictures of the participants and a have a panel guess their age," he adds jokingly.

Samani, a cardiologist and professor of cardiology, is more interested in whether people carrying the variant are at a higher risk for developing age-associated illnesses like heart disease.