hey gentelman , this is sajjad hyder from Ganish Villageof Hunza Valley,
The claim of Longevity in Hunzais correct and I can refer you a book and a documented movie about Long Life: in Hunza which is written and made by some British Doctors in late 60s.

But now I agree for what you said: we can hardly find a person who lives over 90 years: because of sudden deaths in current era, specialy young people ages between 25-50 within the last couople of years rasing drasticly,

Infact I am planing of making a documentary about the threats of Longevity in Hunza, if you have any further information please send it to me. 
Thanks