Blue zones

Étudier les centenaires pour tenter de déterminer les conditions environnementales, les modes de vie et d’alimentation qui permettent une santé optimale et une grande longévité est peut-être une bonne idée. Il existe quelques zones dans le monde qui possèdent de grandes densité de ces centenaires. La légende raconte que la première équipe de recherche à avoir étudié ces zones notait les centenaires par un point au stylo bleu. Sur les cartes, apparaissaient des zones bleues, et le nom est resté.
Mais l’étude de ces zones souffre de plusieurs fragilités. Certaines zones avaient, il y a un siècle, de mauvais registres d’état civil. Les données sur l’alimentation des populations sont très parcellaires, il est souvent difficile de définir avec précision ce que pouvaient être les alimentations traditionnelles des populations qui portent aujourd’hui ces centenaires. Des considérations idéologiques viennent encore compliquer les choses.
Les blue zones sont par ailleurs assez fortement médiatisées, et quelques auteurs en ont fait un véritable business…
1. Okinawa
2. Autres Blue Zones
3. Fiabilité des données et controverses


Okinawa

Entre ce qu’on fantasme de l’alimentation des blue zones et la réalité, il peut y avoir un certain décalage…
Beyond Merroir : The Okinawan Taste for Clams
C. Anne Claus
In southwestern Okinawa, local residents are reinvigorating their culinary heritage through a clam restoration project that began in 2009. The clams—giant clams, locally known as geera—have declined recently due to overharvesting on the reef. This article examines intersecting notions of heritage and community by contrasting the clam mariculture project with other heritage foods. The clams do not fit within prevalent images of Okinawan foods as nutritious and multicultural, and they are not among the Okinawan tastes that are celebrated outside of Okinawa. For islanders, the clams encapsulate place through their actual taste, the way they are acquired, and the social landscape of their consumption. Amidst the increasing influx of mainlanders in Okinawa, the clams become symbols that distinguish native islanders from newcomers.

Traditional Food Items in Ogimi, Okinawa: l-Serine Content and the Potential for Neuroprotection
Paul Alan Cox & James S. Metcalf
Current nutrition reports, 2017
https://link.springer.com/article/10.1007/s13668-017-0191-0

The Ogimi diet has unique elements based on marine algae. Ogimi villagers who move to the Okinawan capital of Naha ask family members to supply them with those seaweeds. To explore a possible neuroprotective function for l-serine, we surveyed the Ogimi diet and analyzed the most frequently consumed items for l-serine content.

Ici, on prend l’alimentation en 1949 (4 ans après la fin de la guerre, en pleine période de rationnement drastique à Okinawa, période très transitoire), comme modèle de l’alimentation de l’île pour toute la durée de vie des centenaires, en contradiction avec les études qui ont été réellement menées sur des centenaires. C’est… surprenant.

New Horizons: Dietary protein, ageing and the Okinawan ratio
David G. Le Couteur
et al.
Age and Ageing 2016.
https://academic.oup.com/ageing/article/45/4/443/1680839

The longest living people are the residents of the Japanese island of Okinawa, who have as many as five times more centenarians than other developed nations [8]. There are many factors that contribute to their exceptional longevity including mild caloric restriction, food quality, genes and physical activity. The energy from their diets was derived from 9% protein and 85% carbohydrates [9] (Figure 1).

Le couteur, Okinawa 1949

Healthy aging diets other than the Mediterranean: A focus on the Okinawan diet
Willcox et al.
Mecanisms of ageing and development, 2014
https://www.sciencedirect.com/science/article/abs/pii/S0047637414000037

All families raised pigs, and chickens and sometimes other farm animals, such as goats. The majority of the population was engaged in farming or fishing or combined farming with local cottage industries such as carpentry or weaving (Willcox et al, 2004; 2006; 2007; Todoriki et al, 2004).Living on an island meant ready access to fish, other sea creatures, and marine vegetables (particularly in the coastal areas), which were readily consumed. Of land animal meats, pork was the most commonly consumed meat and when pigs were slaughtered nothing was wasted. Typically, a pig was slaughtered early in the year at festival time and what was not eaten at that time was stored and consumed over the remainder of the year. A common expression is that “everything is eaten but the voice.” The entrails and the ears are still commonly consumed today (Willcox et al, 2004).

History and characteristics of Okinawan longevity food
Director Hiroko Sho
Asia Pacific Journal of Clinical Nutrition, 2008
https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1440-6047.2001.00235.x

The Satsamu sweet potato provides the largest part of the energy intake (and contributes to self‐sufficiency), there is a wide array of plant foods including seaweed (especially konbu) and soy, and of herbaceous plants, accompanied by fish and pork, and by green tea and kohencha tea. Infusing multiple foodstuff and drinking the broth is characteristic.

Suggère un improbable 90% de glucides dans l’alimentation d’Okinawa, ce qui est encore plus extrême que les données de 1949. Pas de référence donnée à l’appui de cette affirmation.

Dietary Patterns and Longevity
Expanding the Blue Zones
Lawrence J. Appel.
American heart association journals, 2008
https://www.ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.108.788497

Equally notable is the wide variation in other aspects of healthy diets, particularly macronutrient intake. Traditional Okinawan diets provide ≥90% of calories from carbohydrate (predominantly from vegetables), whereas the traditional Mediterranean diet provides >40% of calories from fat, mostly monounsaturated and polyunsaturated fat.

Ici, on admet que les données de 1949 à Okinawa n’ont pas été publiées dans une revue à comité de lecture (outre qu’elles concernent une période historique totalement atypique), et que celles de 1972 ne reflètent sans doute pas une alimentation traditionnelle. Mais on continuera à faire comme si.
Cet article est la source de l’article de Le Couteur et al. de 2017, les Willcox étant par ailleurs co-auteurs de cet article. Quoi de plus pratique que de se citer soi-même…
On signale par ailleurs que l’avantage de mortalité des Okinawaiens a disparu chez les moins de 65 ans, c’est-à-dire précisément les cohortes correspondant à l’alimentation citée…
Caloric Restriction, the Traditional Okinawan Diet, and Healthy Aging
Willcox et al.
New York Academy of Sciences, 2007
http://www.hsph.jp/JT2009/documents/Caloric%20Restriction,%20the%20Traditional%20Okinawan%20Diet,%20and%20Healthy%20Aging.pdf
[…] to our knowledge no population-based dietary information has been reported in a peer-reviewed journal on Okinawan adults before the 1972 National Nutrition Sur-vey. Since the Japanese lifestyle underwent radical changes from the 1950s, including changes in food choices, caloric intake, and energy expenditure, it is unlikely that the 1972 Japan National Nutrition Survey reflects the traditional diet that may be implicated in Okinawan longevity.
[…] Three, since the Okinawan mortality advantage has all but disappeared except in older cohorts (aged 65-plus), it would be informative to have a more detailed, population-based epidemiologic analysis of the traditional diet, energy intake,energy expenditure, phenotype, and the subsequent mortality experience of this older cohort.
Willcox Okinawa 1949 joke

L’évolution de la longévité à Okinawa, 1921-2000
Michel Poulain, Kusuto Naito
Cahiers québécois de démographie, 2005
https://www.erudit.org/en/journals/cqd/2004-v33-n1-cqd861/010851ar/

Pour de nombreux auteurs, l’alimentation est la cause principale de la plus faible mortalité des Japonais. Les recherches mettent en évidence le rôle bénéfique de la trilogie « poisson-riz-soja » ou, de façon un peu contradictoire, celui de l’occidentalisation de l’alimentation, notamment de la consommation accrue de nourriture de source animale. Takahashi (1993) et Goldman et Takahashi (1996) attribuent également au régime alimentaire l’avantage d’Okinawa au chapitre de la longévité. Okinawa, expliquent-ils, a connu un développement historique et culturel complètement différent de celui du Japon; durant l’ère Tokugawa, du début du 16e siècle à la moitié du 19e, les populations d’Okinawa consommaient de la viande, alors que le reste du Japon s’en abstenait, conformément aux traditions bouddhistes. Éloignée des îles principales du Japon, Okinawa est restée à l’écart des préceptes du bouddhisme, qui professe de ne pas tuer les animaux. On y consomme la viande de porc en quantité raisonnable, dégraissée (mijotée plutôt que grillée, la viande perd ses graisses mais non ses protéines).

History and characteristics of Okinawan longevity food
Hiroko Sho et al.
University of the air, 2001

Cliquer pour accéder à 159.pdf

The Satsamu sweet potato provides the largest part of the energyintake (and contributes to self-sufficiency), there is a wide array of plant foods including seaweed (especiallykonbu) and soy, and of herbaceous plants, accompanied by fish and pork, and by green tea and kohencha tea.Infusing multiple foodstuff and drinking the broth is characteristic. Raw sugar is eaten.

Les centenaires, à Okinawa, sont particulièrement petits, probablement signe d’une alimentation très frugale durant leur enfance. Explique aussi les besoins nutritionnels plus faibles.

Nutritional Status of Centenarians Assessed by Activity and Anthropometric, Hematological and Biochemical Characteristics
Chan et al.
Journal of nutritionnal science and vitaminology, 1997
https://www.jstage.jst.go.jp/article/jnsv1973/43/1/43_1_73/_pdf

Chan et al. 1997. Okinawa

Le problème, pour tirer des conclusions sur l’alimentation des centenaires d’Okinawa, c’est qu’elle a considérablement varié au cours de leur vie, du fait de l’histoire mouvementée de l’archipel. Comme d’autres, cette petite étude ne confirme absolument pas l’énorme consommation de patates douces répétée par les Willcox, qui semble bien avoir été une nourriture de famine post-guerre (voir aussi Shibata et al., 1992).

Energy and Nutrient Intakes of Okinawan Centenarians
Akisaka et al.
Journal of Nutritional Science and Vitaminology, 1996
https://www.jstage.jst.go.jp/article/jnsv1973/42/3/42_3_241/_pdf

Akisaka okinawa 1996

Nutrition for the Japanese Elderly
Shibata et al.
Nutrition and health, 1992
https://journals.sagepub.com/doi/abs/10.1177/026010609200800312

Nutrient intakes in 94 Japanese centenarians investigated between 1972 and 1973 showed a higher proportion of animal protein to total proteins than in contemporary average Japanese. High intakes of milk and fats and oils had favorable effects on 10-year (1976–1986) survivorship in 422 urban residents aged 69–71. The survivors revealed a longitudinal increase in intakes of animal foods such as eggs, milk, fish and meat over the 10 years. Nutrient intakes were compared, based on 24-hour dietary records, between a sample from Okinawa Prefecture where life expectancies at birth and 65 were the longest in Japan, and a sample from Akita Prefecture where the life expectancies were much shorter. Intakes of Ca, Fe, vitamins A, B1, B2, C, and the proportion of energy from proteins and fats were significantly higher in the former than in the latter. Intakes of carbohydrates and NaCl were lower.

Shibata et al. 1997. japanese centenarians

Impact of westernization on the nutrition of Japanese: Changes in physique, cancer, longevity and centenarians
Yasuo Kagawa
Preventive medicine, 1978
https://www.sciencedirect.com/science/article/pii/0091743578902463

Okinawa Kagawa 1978 meats

La période sur laquelle les Willcox se basent comme modèle d’alimentation traditionnelle à Okinawa…

Military government in the Ryukyu islands, 1945-1950
Arnold G. Fish, Jr
Center of military history, United States Army, 1988
https://archive.org/stream/militarygovernme00arno/militarygovernme00arno_djvu.txt

The program to restore the livestock population made great strides,
but farm animals numbered only a fraction of prewar levels.
The crop situation was even worse. By 1949 Ryukyuan farm output was
at its lowest ebb.
[…]
They noted that Okinawa was in a « particularly deplorable state
agriculturally, with approximately one-fifth of its arable land
being used for military purposes. Charging that the services had used
farm land  »arbitrarily » and with no regard for its economic value,
they concluded that postwar agricultural reconstruction had been
extremely slow, in part because it had been hampered by a lack
of adequate policies.


Autres Blue Zones

Dietary Habits, Anthropometric Features and Daily Performance in Two Independent Long‐Lived Populations from Nicoya peninsula (Costa Rica) and
Ogliastra (Sardinia)
Nieddu et al.
Nutrients, 2020
https://www.researchgate.net/publication/341847593_Dietary_Habits_Anthropometric_Features_and_Daily_Performance_in_Two_Independent_Long-Lived_Populations_from_Nicoya_peninsula_Costa_Rica_and_Ogliastra_Sardinia

Nieddu et al 2020 sardinia costa rica

Nieddu et al 2020 sardinia costa rica 2

Ici, consommation quotidienne de riz blanc et de maïs chez presque tous, idem pour le lait, consommation d’oeufs et/ou de poisson et/ou de poulet et/ou de viande rouge plusieurs fois par semaine pour la majorité, fruits et légumes moins de 3 fois par jour, on est loin des céréales complètes et de l’alimentation presque végétalienne souvent mise en avant.

Dietary habits and lifestyle among long-lived residents from the Nicoya Peninsula of Costa Rica
Chacon et al.
Dialnet, 2017
https://dialnet.unirioja.es/servlet/articulo?codigo=6230780

Chacon Nicoya 2017

Rien de tel qu’un pseudo article scientifique pour crédibiliser une démarche marketing. 4 références en tout et pour tout, dont 2 de l’auteur de l’article. Aucune méthodologie présentée, repose sur des anecdotes. Aucune référence citée pour les allégations de résultats dans diverses communautés. Ressemble plus à un article de magazine que de revue scientifique.
Les affirmations sur l’alimentation des Sardes font beaucoup rire les chercheurs de l’Université de Sassari spécialistes de la blue zone sarde, avec lesquels nous travaillons à l’Université de Corse. Apparemment, les auteurs n’ont pas vu le fromage, la charcuterie et la chasse omniprésents dans la région.

Blue Zones
Lessons From the World’s Longest Lived
Dan Buettner & Sam Skemp
American journal of lifestyle medicine, 2016
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6125071/

What began as a National Geographic expedition, lead by Dan Buettner, to uncover the secrets of longevity, evolved into the discovery of the 5 places around the world where people consistently live over 100 years old, dubbed the Blue Zones. Dan and his team of demographers, scientist and anthropologists were able to distill the evidence-based common denominators of these Blue Zones into 9 commonalities that they call the Power 9. They have since taken these principles into communities across the United States working with policy makers, local businesses, schools and individuals to shape the environments of the Blue Zones Project Communities. What has been found is that putting the responsibility of curating a healthy environment on an individual does not work, but through policy and environmental changes the Blue Zones Project Communities have been able to increase life expectancy, reduce obesity and make the healthy choice the easy choice for millions of Americans.

Food intake diet and sperm characteristics in a blue zone: a Loma Linda Study.
Eliza M. Orzylowska et al.
European journal of obstetrics, gynecology and reproductive biology, 2016
https://www.researchgate.net/publication/303692674_Food_intake_diet_and_sperm_characteristics_in_the_Blue_Zones_a_Loma_Linda_Study

Lacto-ovo vegetarians had lower sperm concentration (50.7±7.4M/mL versus non-vegetarians 69.6±3.2M/mL, mean±S.E.M.). Total motility was lower in the lacto-ovo and vegan groups (33.2±3.8% and 51.8±13.4% respectively) versus non-vegetarians (58.2±1.0%). Vegans had lowest hyperactive motility (0.8±0.7% versus lacto-ovo 5.2±1.2 and non-vegetarians 4.8±0.3%). Sperm strict morphologies were similar for the 3 groups. There were no differences in rapid progression and chromatin integrity. Conclusions: The study showed that the vegetables-based food intake decreased sperm quality. In particular, a reduction in sperm quality in male factor patients would be clinically significant and would require review. Furthermore, inadequate sperm hyperactivation in vegans suggested compromised membrane calcium selective channels. However, the study results are cautiously interpreted and more corroborative studies are needed.

The Blue Zones: areas of exceptional longevityaround the world
Michel Poulain et al.
Vienna Yearbook of Population Research, 2013
https://www.uu.nl/sites/default/files/articlestopicskeynotes.pdf
Poulain et al, 2013
Lifestyle and nutrition related to male longevity in Sardinia: An ecological study
G.M. Pes et al.
Nutrition, metabolism and cardiovascular diseases, 2011
https://www.nmcd-journal.com/article/S0939-4753(11)00132-3/pdf
Most nutritional variables do not show any significant difference between these two areas whereas a significant difference was found with respect to pastoralism (P = 0.0001), physical activity estimated by the average slope of the territory in each municipality (P = 0.0001), and average daily distance required by the active population to reach the usual workplace

Fiabilité des données et controverses

Dans certaines zones des Etats-Unis, lorsque les registres d’état civil deviennent fiables, soudain, le nombre de centenaires s’effondre. Pour l’Italie, les auteurs soulignent une contradiction entre l’espérance de vie des zones bleues et le nombre de centenaires. Il faut remarquer qu’en soi, ce n’est pas forcément contradictoire, l’espérance de vie et la longévité étant deux notions pas forcément parfaitement corrélées (relire mon thread sur Twitter à ce sujet).
Supercentenarians and the oldest-old are concentrated into regions with no birth certificates and short lifespans
Saul Justin Newman, 2019 (preprint)
In the United States, supercentenarian status is predicted by the absence of vital registration. The 15 state-specific introduction of birth certificates is associated with a 69-82% fall in the number of supercentenarian records. In Italy, which has more uniform vital registration, remarkable longevity is instead predicted by low per capita incomes and a short life expectancy. Finally, the designated ‘blue zones’ of Sardinia, Okinawa, and Ikaria corresponded to regions with low incomes, low literacy, high crime rate and short life expectancy relative to their national average. 20 As such, relative poverty and short lifespan constitute unexpected predictors of centenarian and supercentenarian status, and support a primary role of fraud and error in generating remarkable human age records.

Dietary Restriction Studies in Humans: Focusing on Obesity, Forgetting Longevity
Eric Le Bourg
Gerontology, 2012
https://www.karger.com/Article/Abstract/328675

Dietary restriction (DR: food restriction without malnutrition) is often considered as a nearly universal means to extend longevity in animal species and we could make the hypothesis that DR could increase longevity in humans. Some authors support the opinion that DR has already increased longevity in Okinawa inhabitants, and thus that DR can increase longevity in humans. The purpose of this article is to stress that no data on humans with a normal body mass index (neither overweight nor obese) indicate that DR can increase life span and health span, particularly because the results observed in Okinawa inhabitants can probably be considered as showing mainly deleterious effects of malnutrition rather than positive effects of DR. Since DR does not appear to increase human life span, studies testing for the effect of DR in humans should focus on the health effects of a mild DR in overweight and obese people, rather than in normal-weight people.

Comments on Dietary Restriction, Okinawa Diet and Longevity
Natalia S. Gavrilova & Leonid A. Gavrilov
Gerontology, 2012
https://www.karger.com/Article/PDF/329894
Longevity in Okinawa is considered to be a result of tradi-tional low calorie diet. Le Bourg suggests that Okinawa is an example of severe malnutrition, which is harmful for later generations. We believe that current loss of longevity advan-tage in Okinawa is a result of diet westernization and that the dietary restriction is a valid way of life extension in humans.

They Really Are That Old: A Validation Study of Centenarian Prevalence in Okinawa
Willcox et al.
The journals of gerontology, 2008
https://academic.oup.com/biomedgerontology/article/63/4/338/625612

we performed comprehensive age validation of a subset (8%) of the total centenarian population and assessed the reliability of the age registration system. Self-reported age was validated with several common methods and found to correlate well with documented age. Demographic methods, including assessment of age heaping, maximum age at death, centenarian proportions, and male to female ratios of centenarians indicate that the age registration system is reliable. We conclude that the high reported centenarian prevalence in Okinawa is valid and warrants further study for its genetic and environmental correlates.


Divers

Health Span Approximates Life Span Among Many Supercentenarians: Compression of Morbidity at the Approximate Limit of Life Span
Stacy L. Andersen et al.
The journals of gerontology, 2012
https://academic.oup.com/biomedgerontology/article/67A/4/395/623695

We observed a progressive delay in the age of onset of physical and cognitive function impairment, age-related diseases, and overall morbidity with increasing age. As the limit of human life span was effectively approached with supercentenarians, compression of morbidity was generally observed.


Articles de presse, blogs, etc…

Pourquoi les japonais vivent-ils plus longtemps ?

https://www.tanoshi.fr/dossier-ishoku-dogen/

Les Okinawaïens mangent 18 fois moins de viande que les occidentaux, et trois fois moins de produits laitiers, ce qui facilite l’absorption des calories et permet une digestion plus rapide.