Siblings of Okinawan centenarians share lifelong mortality advantages

Okinawa, an isolated island prefecture of Japan, has among the highest prevalence of exceptionally long-lived individuals in the world; therefore, we hypothesized that, within this population, genes that confer a familial survival advantage might have clustered. We analyzed the pedigrees of 348 centenarian families with 1142 siblings and compared sibling survival with that of the 1890 Okinawan general population cohort. Both male and female centenarian siblings experienced approximately half the mortality of their birth cohort-matched counterparts. This mortality advantage was sustained and did not diminish with age in contrast to many environmentally based mortality gradients, such as education and income. Cumulative survival advantages for this centenarian sibling cohort increased over the life span such that female centenarian siblings had a 2.58-fold likelihood, and male siblings a 5.43-fold likelihood, versus their birth cohorts, of reaching the age of 90 years. These data support a significant familial component to exceptional human longevity.