How old are you really? Find out your "biological age"

Biological age is the age that is calculated based on your ovarian status. So your cells and organs have ages that differ from your normal age.

Many aging research scientists believe that knowing your biological age can help you delay or avoid Alzheimer's, cancer, cardiovascular disease or other age-related diseases. Some also believe that biological age can better predict an individual's lifespan.

Other scientists agree that biological age is important, but disagree that it can predict your life.

They say there is no standard way to measure biological age, and many of the tools in development have yet to be proven. At the heart of the debate are hopes that people can extend their lives by changing their behaviour; a number of companies are betting on it.