With people living longer, some into their 90s and over 100, there has been an understandable interest in trying to find out why. One approach is to study "blue zones," microregions showing a concentration of such people. Among the blue zones that have been identified are a Sardinian village; Okinawa; Loma Linda, CA; and the Nicoya Peninsula in Costa Rica. Thanks to a recent New York Times story, there has been a flurry of interest in the Greek island of Ikaria, which has been added to the list. 

 

 

Blue-zones researchers tend to emphasize diet and climate. However, they commonly neglect genes. The actual numbers are also small, suggesting that these spots may be statistical anomalies, rather than genuine answers to the problem. On Ikaria, for example, there are only about 240 people who are older than 80, evidently from a very few families with a restricted number of genetic lines. 

 

 

In short, some caution is warranted in evaluating this data. http://en.wikipedia.org/wiki/Blue_Zone