To start if off, I think there are two things here. First, these people leading “natural” way of life also enjoy all the benefits and protection the modern civilization has to offer. There is little doubt people in the year 1600 could have lived till 100, but they were either killed in a war, died from disease, had an accident, or just had to work too hard. The long-livers nowadays may not drive cars, run nuclear power plants, etc., but they still don’t have to fight the nearby villages/towns, get treated by modern doctors, and work much safer and less stringent hours (and probably use modern supermarkets too). This point is often overlooked by the proponents of the “natural way of live”, as well as the people buying into their ideas. To sum this up, some do live in Armenia or Japan now till age 100, but they probably wouldn’t have even 200 years ago. There is also genetics, but I’ll live this off for now…