What is the "biological age" ??

How old are you really?

Simple tests that might reveal your "biological age".

They are based on Noble prize winning research-but are they worth anything? Much less the hundreds of dollars that companies are charging?
   Using a blood sample, the tests measure the length of your telomeres, the DNA caps on the end of chromosomes. Like the plastic bits on shoelaces, telomeres keep important genetic material from fraying.Longer is better;short telomeres have been associated with an increased risk of health problems such as cardiovascular disease, diabetes, and some cancers.
   But telomeres are no crystal ball. "it's silly to say this will tell you your life length," says Elizabeth Blackburn, the Australian scientist who shared the 2009 Nobel prize for her work on telomeres. Nevertheless, Blackburn, who co-founded a company that's making one of these tests, says the results can give you a better picture of your risk of serious ailments.

   Still, protecting telomeres may be a matter of common sense.For instance, it looks like smoking and obesity whittle away at them.