The Okinawa Centenarian Study More about the Okinawa Centenarian Study Meet the centenarians Meet the research team Contact the OCS team
evindence

Evidence-based Extreme Longevity: The Case of Okinawa, Japan

B. J. Willcox, D.C. Willcox, M. Suzuki.

Division of Gerontology, Beth-Israel Deaconess Medical Center, Harvard Medical School; College of Nursing, Okinawa Prefectural University; Department of Gerontology, Okinawa International University and Okinawa Gerontology Research Center.

At present it is generally accepted that there are approximately 10 centenarians per 100,000 people in most industrialized countries. Nevertheless, we have documented a much higher prevalence of centenarians in Okinawa, a prefecture (state) of Japan that consists of a group of 44 inhabited islands that stretches 800 miles between the Japan main islands and Taiwan.

In a demographic study of the entire Okinawan population we identified a total of approximately 560 centenarians out of a population of 1.27 million inhabitants as of 2003. Ages were validated through the koseki (family registry) system that has been recording complete birth, marriage, and death statistics for every Okinawan-Japanese citizen since 1879. A prevalence of 42 centenarians per 100,000 population was identified of which 85.7% were female. The age range was 100-111 with a mean age of 101.6 There were 35 (8.2%) centenarians over the age of 105 and 1 (0.2%) over the age of 110. This is the highest prevalence of centenarians ever documented with a reliable database. Okinawan emigration is balanced by the highest fertility rate in Japan with a net positive population growth so this phenomenon cannot be attributed to attrition of younger age groups.

Okinawa has the longest life expectancy in Japan, and likely the world, at 86.01 years for women and 77.64 years for men (Japan Ministry of Health, 2000) therefore it seems plausible that this high centenarian prevalence is secondary to a higher percentage of Okinawans living closer to the maximum human life span than in other populations. Further study is required to identify the reasons behind this fascinating phenomenon.

We thank the Japan Ministry of Health, the Japan Foundation for Aging and Health (JAFAH), and the Division on Aging, Harvard Medical School for their support. BW is a JAFAH Scholar.

Based on a scientific abstract of research presented at the Presidential Poster Session of the American Geriatrics Society Annual Meeting, 2001 with updated information.