Spit Analysis Reveals Your Age

Brief: The researchers studied DNA in saliva contributed by 34 pairs of male identical twins, ages 21 to 55, and they found that they could estimate the ages of their saliva contributors to within five years.

Saliva contains many useful components. Lubricants. Enzymes for breaking down food. And now, compounds that can reveal a person's age. That's according to a study in the journal Public Library of Science ONE.

During normal development, DNA in your body gets what's called methylated. Small chemicals called methyl groups bind to the DNA, helping to determine which genes become active. But the patterns of methylation change as we grow older. Which was a clue that measuring methylation might give away age.

The researchers studied DNA in saliva contributed by 34 pairs of male identical twins, ages 21 to 55. They found 88 sites on the men's DNA where the amount of methylation correlated with their ages. The scientists next verified that finding in 60 men and women, ages 18 to 70.

Then they narrowed in on two genes that had the strongest age-related correlation. And using just that data, they found that they could estimate the ages of their saliva contributors to within five years.

This technique might help in crime scene investigations -- recovered saliva could tell the age of a perpetrator. So if you're worried about anyone knowing how old you are, be careful where you spit.

* Originally Posted: Top Diagnosis

Baby, Obesity is Not your Fault!

If you can't shift those extra pounds, no matter how hard you try, blame your mother. Research suggests we can be programmed to be fat while still in the womb, with a mother-to-be’s lifestyle affecting the health of her baby for years to come.

It is thought that her diet, the amount she exercises, whether she smokes or drinks alcohol and even which pollutants she is exposed to can alter the DNA of her unborn child. The changes are not to the letters of the code of life itself, but to its ‘punctuation’. These chemical marks can activate, silence or crank up genes and their actions.

The latest evidence for the theory, which is known as epigenetics, comes from researchers at Newcastle University who analyzed the genes of children aged between nine and 11.

They specifically looked for genes that had the same letters but behaved differently in children who were overweight and those who were slim. Blood samples stored since the children's births were then analyzed. This step showed that in many cases, youngsters who were overweight had displayed different chemical marks on their DNA at birth.

Dr Caroline Relton, who led the research, said: ‘This suggests that our DNA could be marked before birth and these marks could predict our later body composition.’ Dr Relton, whose findings are detailed in the journal PLoS Medicine, does not know why some DNA is marked in the womb.

But previous research suggests it is largely to do with the mother's lifestyle. However, Dr Relton added: ‘These marks are open to change. I think this puts the onus on the individual to do something about the way their genes work.’

* Originally Posted: Top Diagnosis