Okinawa (Japan)

Okinawa, a group of some 160 islands the most Southern of Japan Japan’s 47 prefectures counts more than 1000 centenarians in Okinawa out of a total population of 1.37 million inhabitants. A special attention has been devoted to the validation of the individual ages of the oldest people in order to ascertain this exceptional longevity. Since 1976, the Okinawa Centenarian Study has investigated the causes of the exceptional longevity of the islanders, attributing an essential role to genetic, dietary, climatic, cultural, and social factors, although it is likely that the real explanation lies in a combination of all of these. Okinawans are genetically distinct from the Japanese, and even show some of the features of a genetic isolate that may favor life extension. A considerable amount of research has addressed the relationship between diet and longevity in Okinawa. A reduced calorie intake has been claimed to be responsible for longer survival of Okinawans, probably due to reduced mortality from cardiovascular diseases, diabetes, and cancer. However, it is clear that in Okinawa, the post-war generations have largely modified their diet, under the influence of mainland Japan and US cultures. Due to globalization, these post-war generations have largely westernized their lifestyle, thus recently causing a drop in Okinawa’s ranking among the Japanese prefectures in terms of life expectancy.