In 1976, I arrived in Okinawa from Tokyo to
serve in the post of Professor of Community
Medicine in the newly established medical
faculty of the University of the Ryukyus. One
of my early observations when I visited local
towns and villages to assess the community's
condition was that there were many robust, hale
and healthy elderly people, living freely in their
own private houses. I was quite interested in this
fact, and when I checked the statistical yearly
data at the Okinawa Prefectural office, I realized
that the prevalence of centenarians, and the
average life expectancy in Okinawa were the
highest in Japan. In my research on these
matters, I have found that longevity is not
desirable solely for the duration of one's life, but
also must be accompanied by excellent health in
order to be truly celebrated. To be considered
successful, the super-elderly should have enjoyed
a high quality of life through their whole life.
It can be said they are people who have spent
their long life aging naturally, to some extend
by their own volition. We have checked comprehensive medical examinations and sociological surveys on 675 centenarians since 1970, and visited them in their own residential areas. As reported in our earlier results, it was discovered, that serum SOD levels of healthy centenarians were higher than in the ordinary elderly (a 70-year old group). According to HLA-DR pattern analysis, the DR1 allele, which was considered to be associated with enhanced immune reactions, was recognized in 6.1% of centenarians, compared to almost 0% of ordinary

70 year olds. On the other hand, lower frequency of DR9 was found (Lancet, 1987), which has been considered to be related to the susceptibility to autoimmune diseases. Although the existence of hereditary factors is assured, as for the above evidence, environmental factors are more important. For example, the average life expectancy of Okinawans living in Brazil is 17 years shorter than Okinawans who lived in Okinawa. According to government statistical reports, extremely low mortality has been observed for coronary heart disease, stroke, breast cancer, ovarian cancer, prostate cancer, and colon cancer. We have done further analysis in order to extract the most contributory factors leading to successful longevity. There were, amongst other research findings, low levels of LDL cholesterol, low levels of plasma lipid peroxide, high levels of estrogen, and high levels of hydroxyproline. These factors might hold important clues to the successful longevity in Okinawa. Related interventions might be developed as preventive measures against pathological aging, perhaps by the improvement of dietary habits or by diversion of negative stressors and healthier coping styles. Many of these traits might be hidden in the traditional culture and folk customs in Okinawa. We believe that the
Okinawan traditional way of life quite possibly
has contributed to Okinawan longevity.