In times past, it is said man had a much longer lifespan than the 80 - 90 years we now consider to be the norm. Yet, in certain parts of the world, there are still people who reach the age of one hundred and older. Do they have the key to longevity? And if they do, what is it exactly? What do they know, or what do they do, that the average man on the street is clueless about? The key to their longevity may simply be a much more heightened immune system!