Letter to the Editor Accuracy of the centenarian numbers in Okinawa and the role of the Okinawan diet on longevity Responses to Le Bourg about the article “Exploring the impact of climate on human longevity” Jean-Marie Robine a, ⁎, François R. Herrmann b , Yasumichi Arai c , D. Craig Willcox d,e,f , Yasuyuki Gondo g , Nobuyoshi Hirose c , Makoto Suzuki d,e,h , Yasuhiko Saito i a National Institute on Health and Medical Research, INSERM U988 and U710, France b Division of Geriatrics, Department of Internal Medicine, Rehabilitation and Geriatrics, Geneva University Hospitals and University of Geneva, Switzerland c Division of Geriatric Medicine, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan d Department of Human Welfare, Okinawa International University, Ginowan, Japan e Okinawa Research Center for Longevity Science, Urasoe, Japan f Department of Research, Kuakini Medical Center, HI, USA g Osaka University, Graduate School of Human Sciences, Clinical Thanatology and Geriatric Behavioral Science, Osaka, Japan h Faculty of Medicine, University of the Ryukyus, Nishihara, Japan i Nihon University Advanced Research Institute for the Sciences and Humanities, Tokyo, Japan abstract article info Article history: Received 3 January 2013 Received in revised form 5 March 2013 Accepted 26 April 2013 Available online 25 May 2013 Section Editor: Diana Van Heemst Keywords: Centenarians Japan Climate Okinawan diet Agricultural production Socioeconomic factors This response letter addresses two points raised by le Bourg when discussing our previous paper entitled “Exploring the impact of climate on human longevity”. First, the arguments explaining the accuracy of the numbers of centenarian in Okinawa are developed, and second the composition and healthfulness of the tra- ditional Okinawan diet are described as well as the changes in dietary pattern and their impact on longevity. © 2013 Elsevier Inc. All rights reserved. 1. Introduction Le Bourg (2012) raises two important points about our paper. The first deals with the reported centenarian numbers in Okinawa. The second concerns the healthfulness of the Okinawa diet. 2. Are the reported centenarian numbers in Okinawa accurate? Quoting Poulain (2011) Le Bourg questions centenarian numbers in Okinawa and states that the “main possible cause of error is the reconstruction of the population registers following widespread destruction in World War 2” and that it was probably because “the US staff could have misreported the age of the Okinawans who were in their forties or older because these citizens probably appeared older than they really were due to the traumas of WW2”. This interesting con- jecture does not fit with the actual reconstruction process as recorded in the historical literature. US staff were not directly involved in interviews of locals to determine their ages but merely recipients of the data collected at the municipal level by local authorities (Kugai, 1970). This was in keeping with the USCAR (United States Civil Administration of the Ryukyus) top down system of military government set up in post-war Okinawa in which US authorities decided on important matters but left daily local matters to the “natives” (Fisch, 1987). Le Bourg suggests that worsening mortality rates in comparison to Japan averages and differences between older and younger generations is “evidence” for potential demographic artifacts due to possible age misreporting. However, these have long been part of the demographic Experimental Gerontology 48 (2013) 840–842 ⁎ Corresponding author at: INSERM, ICM Val D'Aurelle, Bâtiment Recherche, Parc Euromedecine, 34298 Montpellier Cedex 5, France. Tel.: +33 4 67 61 30 43. E-mail address: Jean-marie.robine@inserm.fr (J.-M. Robine). 0531-5565/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.exger.2013.04.015 Contents lists available at SciVerse ScienceDirect Experimental Gerontology journal homepage: www.elsevier.com/locate/expgero