1. How does he know how old "tribe" members are? Do they have extensive written vital records? Anything that can be verified by something other than "she said she was over 180, officer, I swear"?
2. By what method did he determine that "civilized" people would have an additional 50 years--and how does he reconcile that with the fact that the difference between "civilized" and "tribal" is the very technologies he blames for allegedly halving our lifespans?
3. How old is his oldest patient?

If someone wants me to change my beliefs about something, he'd better have some solid proofs. So, I hope you can satisfy me on those counts.