You're as Old as Your Spit Says You Are
Despite the advanced tools of forensic science, it hasn't been possible to establish definitively the age of a body at the time of death. DNA, it seems, doesn't give away your age.
Until now. Thanks to some sophisticated analysis of a relatively simple body fluid — saliva — researchers from UCLA reported in June that it may now be possible for scientists to glean the age of a dead body from genetic material. Working with saliva samples, the researchers focused on epigenetic changes to DNA. These alterations — which are caused by environmental influences like diet, stress, exposure to sunlight and carcinogens and even toxins — do not change the DNA itself, but are layered on top of the genome, affecting how genes are turned on or off. At specific areas of the genome, say the scientists, these changes build up or decrease in almost chronological fashion, allowing them to serve as a timeline to predict a person's age to within five years.
But don't expect the spit test to show up on CSI anytime soon. It will take some additional studies to confirm and validate the results. But as any crime buff knows, every clue helps.