Sardinia contains only 1/60 of Italian population.
The post you linked does not look very reliable
Moreover I'm not talking about super centenaries, but basic life expectancy
People who live more in general have probably better genes, we don't care how many die if we are counting those that survive longer than average
In US life expectancy is very low for being a developed country
And we can't really say that crime rate or frauds are higher in Okinawa than in Los Angeles
Nobody would believe that
Btw, what about France?