Fellow Italian here: in Sardinia consumption of seafood is not particularly higher than the Italian average, certainly not higher than South Italy (i.e. from Ro

Fellow Italian here: in Sardinia consumption of seafood is not particularly higher than the Italian average, certainly not higher than South Italy (i.e. from Rome downwards) especially Sicily or Naples area. In Sardinia they eat a lot of blue fish (or oily fish), not surprisingly the European pilchard also called "sardine" of the genus "Sardine" has a very similar name to "Sardinia". According to some recent study Aristotle himself named the fish after the population of Sardinia Island that were the first ones to trade it in ancient Mediterranean markets (looks like the most popular way to prepare it was in salt, as we still do nowadays). But that's probably not why they are a "blue zone", an important difference is the kind of meat they eat: there is an abundance of sheep meat but much less beef red meat. But that's probably no it either, Sardinians have genetic markups that protects them from entire classes of diseases, being a quite homogeneous population from the DNA point of view, they passed them on from a generation to the next.