Peter Russell, author of the Brain Book and long time collaborator
with Tony Buzan, has created a cool Life Expectancy Calculator. 
http://www.peterrussell.com/Odds/VirtualAge.php

My Biological age is 44 (though I prefer 40+gst)

The good news is that my virtual age is 31 and my life expectancy is 88 (I'm halfway there).

The calculator gives you real clues on what impacts on life expectancy and how to Age-proof your brain and body.