This is orthogonal.<p>One guy getting in a better shape after diet and exercise is quite expected.<p>Whole society being virtually free of big bad diseases is, on the other hand, extraordinary claim:<p><i>"When it comes to the top 10 health risks facing American men, the Tarahumara are practically immortal: Their incidence rate is at or near zero in just about every category, including diabetes, vascular disease, and colorectal cancer."</i><p>This sounds quite dishonest if what mark_l_watson said indeed holds. You could then equally say:<p><i>"When it comes to #1 health risk facing Tarahumara men, Americans are practically immortal: almost all their babies survive."</i>