Here's a fascinating article from the New York Times with implications for both of our arguments:
In light of this, and other evidence, I've decided to restate my argument regarding life expectency:
Life expectencies and health in general vary from region to region and from time period to time period, however one thing is constant: The more a group is dependant upon agriculture, the lower its health, including life expectency will be (with the exception of elites, who only exist in agricultural communities; it must be remembered that Northern industrialized states represent a very very large elite in today's global system).
Evidence includes the posted article, Richard Lee's data regarding the !Kung, sections from Guns Germs and Steel (which recent discussion inspired me to reread) and "The Worst Mistake..." by Jared Diamond, including the facts that farmers have much higher population densities, rely on domestic animals (you'd be surprised how many diseases they've brought us; anthrax is just one example), and various comparisons between forager and agriculturalist populations. Diamond demonstrates a drop in life expectency among Plains Indians when they adopted agriculture, and decreases in health among other populations measurable by various factors - in Turkey for example heigh plumeted, from 5'9 average for a man at the end of the Pleistocene to a low of 5'3 for a man 3000 years ago; the 5'9 level still hasn't been reattained in modern times.
Life expectencies among hunter-gatherers vary from 26 to 40 to over 60 years, depending on where and when you are, but they are always better those of farming communities, as is health in general.