I wonder if a good amount of people could live to an old age despite eating various things that we no longer can get away with eating because of so many other factors that are in our environment.  My Mom is 86, my Dad is 93, and my Aunt is 88.  They eat the Standard American Diet, which has gone through many changes in their lifetime.  They were lucky enough to not eat the current diet when they were children, though, and so their bodies had a better chance of not being so poisoned as each generation after them.  The more poisoned the world gets, the more vital it is to find out what's good for the human body and what isn't.