Want to conceal your age? Don't spit
By Bernd Debusmann Jr.
NEW YORK (Reuters Life!) - American researchers said Thursday they can use saliva samples to predict a person's age, a discovery that could help CSI investigators track suspects and open the door to personalized medicine.
Using a process call methylation, a chemical modification of one of the four building blocks that compose human DNA, scientists at the University of California at Los Angeles (UCLA), were able to determine a person's age to within five years.
"With just a saliva sample, we can accurately predict a person's age without knowing anything else about them," said Dr. Eric Vilain, the director of the Center for Society and Genetics at UCLA.
He added that if some saliva is found around the butt of a cigarette, scientists could use the technique to tell if the saliva is from a person in their 20's or their 70's.
"It could also be used for victim identification in which you have very little and have no idea who the person is, whether it's a young or an old person," Vilain explained.
Vilain and his team, whose findings are reported in the online edition of the Public Library of Science One journal, made the discovery while studying 34 pairs of identical male twins with different sexual orientations.
They studied the men's genome and found sites on DNA that linked methylation to age.
After identifying two or three genes with the strongest age-link to methylation, they used data from the twins and 60 men and women to predict their age. Continued...