In the northern Okinawa village of Ogimi, a stone marker displays the declaration of village elders that reads “at eighty you are merely a youth, at ninety if the ancestors invite you into heaven, ask them to wait until you are one hundred… and then you might consider it.”
In the northern Okinawa village of Ogimi, a stone marker displays the declaration of village elders that reads “at eighty you are merely a youth, at ninety if the ancestors invite you into heaven, ask them to wait until you are one hundred… and then you might consider it.”
The significance of Okinawa’s health phenomenon can be appreciated by considering a typical age-associated disease and its impact upon a typical city of 100,000 inhabitants in Okinawa, Japan and the United States. For coronary heart disease (CHD)—the leading cause of death in the United States—if the city was located in Okinawa, about 3 times fewer males and more than 4 times fewer females would have died from this ailment in a typical year, than if this was a city in the United States. That is a striking difference.
GENERAL METHODS OF THE OCS:
- Population-based study
- Cross-sectional, Longitudinal, Case-control
- Age validation
- Geriatric exam with past medical history, social history, family history, health habits, anthropometry, electrocardiogram, psychosocial/cognitive tests
- Family pedigree
- Evaluation of Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL)
- Blood draw and analysis
Key Findings
The OCS has found that cigar-smoking, whiskey swilling hundred-year olds who effortlessly trek across mountain ranges to be myth. Rather population-based research demonstrates wide differences in the centenarian population from functional independence to high levels of disease and disability. In Okinawa, about one third of centenarians were found to be functionally independent, about one third needed major assistance with activities of daily living (ADL), and about one third were very ill and disabled (Sanabe et al. 1977; Suzuki et al. 1995 PMID: 7500549).
Although high levels of disability are present in a significant portion of these exceptional survivors, an important caveat is that most centenarians seem to be healthier than the average person throughout their lives, and remain functionally independent until their mid-nineties (Willcox et al. 2008 PMID: 19038835). Below, we discuss three important aspects of the Okinawan lifestyle—their diet, social practices, and genetics.
The Okinawan Diet
Much of the longevity advantage in Okinawa is thought to be related to the traditional Okinawan diet, which is low in calories yet nutritionally dense, especially with regard to phytonutrients in the form of antioxidants and flavonoids. Research suggests that diets associated with a reduced risk of chronic diseases are similar to the traditional Okinawan diet, that is, vegetable and fruit heavy (therefore phytonutrient and antioxidant rich) but reduced in meat, refined grains, saturated fat, sugar, salt, and full-fat dairy products.
Prior to World War 2, the traditional Okinawan diet was a mixed plate of Chinese, Japanese and South East Asian influences. In the Okinawan language, this fusion was often referred to as “champuru” or “chample,” which means “mixture.” The staple food of traditional Okinawan cuisine was many varieties of colorful sweet potatoes, in contrast to the polished white rice of their mainland Japanese counterparts. In addition to steamed sweet potatoes, meals regularly included large varieties of simmered or steamed green leafy, yellow root vegetables, and soy-based products such as tofu, miso soup and miso flavorings. These staples were often accompanied with smaller servings of fish, lean meats such as pork, and tropical fruit such as shikuwasa (Citrus depressa). Okinawans favored bonito flavored broths for seasoning and used herbs and spices such as turmeric or mugwort liberally in place of salt. Okinawans also celebrated various festivals on a regular basis that supplemented their diet with a variety of different foods including rice, kombu seaweed, various meats and other seafoods.
In fact, the traditional Okinawan diet shares many characteristics with other healthy dietary patterns, such as the traditional Mediterranean diet or the modern DASH (Dietary Approaches to Stop Hypertension) diet. Low levels of saturated fat, high antioxidant intake, and low glycemic load in these diets are likely contributing to a decreased risk for cardiovascular disease, some cancers, and other chronic diseases through multiple mechanisms, including reduced oxidative stress.
In Okinawa, the low-calorie, phytonutrient-rich and nutritionally dense food choices, the healthy eating habits, and high levels of physical activity resulted in a naturally calorically restricted population without malnutrition. In the traditional dietary habits, there was a focus on small portion sizes and not eating until completely full. Even now a common saying among Okinawan elderly is hara hachi bu (eat until only 80 percent full). We estimate that Okinawans prior to the 1960s consumed 10-15% fewer calories than would normally be required per caloric guidelines (Willcox et al. 2007 PMID: 17986602). When faced with a persistent energy deficit, mammals adapt by becoming more energy efficient, producing less heat and converting a higher proportion of food into usable energy. A host of other metabolic adaptations occur that confer longevity. These changes are commonly observed in animal studies of “caloric restriction” (CR) and this is the only consistently reproducible manner of increasing mean and maximum lifespan in animal experiments, other than select genetic manipulations. (Fontana et al. 2010 PMID: 20395504).
Additionally, the traditional Okinawan diet appears to be a rich source of foods that may mimic the biological effects of CR, acting as caloric restriction “mimetics.” CR-mimetics are compounds that provide the physiological benefit of CR without the need for restriction of calories through multiple mechanisms, including reduced oxidative stress. In the Okinawan language, a common parlance is “nuchi gusui,” which can best be translated as “let food be your medicine.” This reflects the cultural context wherein the distinction between food and medicine blurs in Okinawa and deeper analyses reveals that many of the traditional foods, herbs, or spices in the Okinawan diet have medicinal properties, which are under investigation (Willcox & Willcox 2014 PMID: 24462788).