I’ve written before about markers that allow forensic scientists to age the donators of blood stains to within nine years. Now UCLA researchers have found completely different age markers in saliva.
The blood study relied on the accumulation of a by-product of T-cell function. This time, the scientists looked at the DNA itself, or more specifically, the amount of methylation of that DNA within saliva samples. The researchers compared the DNA of 34 sets of identical male twins and found 88 sites that correlated methylation with age. In other words, the older the man was, the more likely those sites were to be methylated. This held true in a later study of 31 men and women aged 18 to 70. In fact, the researchers were able to estimate most people’s ages to within five years.
It’s just a matter of time before dating services start offering saliva-authenticated proof of age certificates.