Miso in the Morning — The Secrets to Longevity in Okinawa
By Rita E. Carey, MS, RD, CDE
Today’s Dietitian
Vol. 7 No. 6 P. 34

An RD explores the diet and lifestyle of a country that boasts the world’s largest number of centenarians.

The world’s longest-living people inhabit what once was called the Kingdom of the Ryukyus, a group of islands that lie southwest of mainland Japan. The islands, now known collectively as Okinawa, have been battered throughout history by the political and economic agendas of powerful nations as well as the vagaries of the local climate. Native Okinawans, however, have managed to survive the many changes brought to their shores with gentle dignity. Today they enjoy a unique notoriety. Okinawa boasts the world’s largest number of centenarians and may well lay claim to the healthiest elder population on the planet.

The extraordinary health and longevity of Okinawans seems to be due to an unusual and unique mix of history, environmental circumstances, diet, and lifestyle that makes a 90th birthday a common, but still much-respected, milestone among elders.

History of the Land of the “Happy Immortals”
The Ryukyus have attracted the attention of neighboring and distant nations for many centuries. In 219 BC, the Emperor of China sent 3,000 young men and women with a cargo of seeds to the “islands of the Eastern seas” to find the legendary “happy immortals” purported to dwell there.1 No one returned from that voyage and historians suggest that the survivors may have settled on what is now mainland Japan and on the islands of present-day Okinawa. While visiting the court of Kublai Khan, Marco Polo first learned of the magical islands lying south of Japan that held the secrets to alchemy and immortality.

Many nations have laid claim to these islands, including Mongolia, China, Japan and the United States. The various nations eyeing Okinawa throughout the ages did so with political, economic, or spiritual gains in mind. Mongolia wanted Ryukyu to expand its vast Asian land holdings and regional influence. China saw no other nation as its equal and thus sought to culturally assimilate and receive elaborate tributes from all border nations, including Japan, Ryukyu, Korea, Burma, Cambodia, Vietnam, and Tibet.

Though poor in natural resources, the Ryukyu Kingdom was at one time the center of a thriving and vast Asian trade economy. This piqued the economic interests of China and Japan. Missionaries from the West ostensibly came to save souls. The United States set up strategic bases on the islands when Commodore Perry first arrived in the mid-19th century and later, in the aftermath of the most devastating battle of World War II. Finally, Japan formalized the takeover of the kingdom in the 1870s for strategic reasons and renamed the islands Okinawa Prefecture.

The Peaceful and Active Okinawan Lifestyle
Historic travelers and merchants often referred to the kindly, inquisitive, and dignified behavior of the Ryukyan people. Many historians theorize that the threats and burdens consequent to a quixotic tropical climate, and the relative dearth of natural resources on the islands, promoted a culture that valued cooperation and adaptability. Because native Ryukyans were dependent on trade for their economic survival, records indicate that they promoted honest and profitable business relationships with countries throughout the Far East and Southeast Asia for more than 500 years. Frequent contact with other cultures probably contributed to their inquisitive natures and certainly influenced their long history of selecting useful and pleasing aspects of other cultures and altering them to suit their own needs. Much of what was chosen and creatively altered in centuries past contributes to the longevity and good health of people living on Okinawa today.

The peaceable nature of Okinawans, as well as their respect for elders and strong spirituality, may contribute to their long lives. Many studies underscore the health risks associated with hostility and aggression and the health benefits of cooperation and a positive outlook on life.2 Spirituality (not necessarily one and the same with religion) is generally described as an inner sense of something greater than oneself and recognition of a meaning to existence.

The healing powers of spiritual practices and beliefs are being studied and may prove beneficial.3 The spiritual practices of Okinawans are generally based on ancestor veneration. In Okinawa, the ancestors are never far away and family gatherings are held at the tombs of the deceased. Large numbers of relatives often come together, thus strengthening the support structure connecting the living members of a patriarchy. Many villages have noro, or divine priestesses, who communicate with ancestors and serve as spiritual advisors.

Okinawa is a unique modern society where women often still function as the main providers of religious services at the local level. A common ritual in Okinawa celebrates the health and good fortune of the oldest living member of a family. Many Okinawans believe the health and longevity of elders can be transferred via the noro and shared by other family members. Certainly maintaining the respect of family and community members well into old age contributes to a better quality of life, outlook, and will to live among the elders in Okinawa.

Regular physical activity is associated with lower mortality and disease rates in all human populations. Gardening, traditional dance, and martial arts (karate is a form of martial art created on Okinawa) are daily activities for many Okinawans. Elders are typically physically active throughout their long lives. In fact, in 2000, a 96-year-old karate master defeated a 30-something-year-old World Boxing Association Flyweight champion from Okinawa in a match commemorating the new millennium. As the young man walked away in disbelief, the elder Okinawan reportedly smiled and graciously stated that his opponent was just still too young and had not yet matured enough to defeat him.3

Traditional Diet Patterns
The traditional Okinawan diet developed over centuries in response to many environmental and economic factors. Summer typhoons frequently leveled crops and trees and thus limited what individuals could grow. The purple sweet potato (imo) was introduced to the islands from China in 1606. This humble but highly nutritious tuber grew well and was a lifesaver when tropical storms destroyed rice paddies and other crops. Imo is still a staple of many meals in Okinawa and is used as a nutritious additive in everything from ice cream to noodles. Sugar cane cultivation followed the sweet potato, though most cane was exported to pay tribute and taxes to China and Japan. Today, most is still shipped off-island, and the Okinawan people eat very few sweets. Sugar is generally eaten in Japanese style—as chunks of solidified, dark brown whole cane juice taken with a cup of green tea. Sugar is also blended with Okinawan sea salt and is used as a unique and flavorful condiment, known as kuro-shio.

The warm, crystalline waters surrounding the islands provide the fish and nutrient-rich sea vegetables that are still prominent in Okinawan dishes. Some seaweeds, such as mozuku and a delightfully crunchy sea vegetable referred to as sea grapes or umi-budo, are unique to the waters surrounding Okinawa. Okinawan soils are conducive to growing such nutritious imports as bitter melon (goya), hechima (related to Luffa cylindrica), and turmeric, as well as a wide variety of healthful native herbs, such as mugwort and Okinawan pepper. Tofu is also commonly eaten and, in Okinawa, it is made with seawater, which adds both to its taste and mineral content. Okinawans also make a fermented tofu called tofuyo that is a rich and flavorful delicacy.

Okinawans, masters at adopting useful aspects of the cultures they encounter, combined their natural resources with beneficial foods culled from other countries to create a remarkably healthful and unique diet. Roughly 80% of the foods eaten by elders in Okinawa are derived from plants.4 The beneficial aspects of plant-based diets are widely documented. In addition to the foods mentioned above, sweet and chili peppers, pumpkin, cabbage, bean sprouts, onions, yellow carrots, a variety of herbs, taro, miso (fermented soybean paste), mochi (dense rice cakes occasionally combined with imo or herbs), soba noodles, and rice are also mainstays in the Okinawan diet. The remainder of the traditional diet is composed of small amounts of dried tuna (bonito), white fish, pork, and dairy (Okinawans usually drink milk only during childhood). Jasmine green tea (sanpin), Japanese genmaicha (powdered green tea), and coffee are the most frequently consumed beverages. The people also drink fermented turmeric tea, which, like green tea, has potent antioxidant and anti-inflammatory properties.

Disease Prevention and the Benefits of Ingenuity and Location
Diet and lifestyle have made the elder population of Okinawa the healthiest and oldest in the world. Individuals following traditional ways are remarkably free of the diseases that plague other nations. Okinawans enjoy the lowest incidence of cancer, stroke, osteoporosis, and coronary heart disease in the world.3 They have the lowest blood homocysteine levels and suffer 80% fewer heart attacks than North Americans. They have one-half the risk of osteoporotic fracture compared with U.S. citizens and suffer 20% fewer hip fractures than their Japanese neighbors. They are leaner than many North Americans and their average body mass index falls between 18 and 22. Most elders enjoy mental clarity throughout their long lives. One study reports that among nonogenarians in Okinawa, 80% of men and 60% of women were cognitively intact compared with less than 40% reported in European and North American populations.5 In Okinawa, 34 people per 100,000 are aged 100 or older. This compares with five per 100,000 in the United States.3

The traditional diet and lifestyle in Okinawa lay the foundation for long life and disease prevention, but additional uniquely Okinawan factors related to location, soil type, and human ingenuity significantly boost the nutrient density and protective qualities of the foods produced on the islands. Many of the foods produced on Okinawa are higher in antioxidant and mineral levels than foods produced elsewhere. The islands are located between 24° and 27° north latitude; clear skies and high levels of ultraviolet (UV) radiation at this latitude probably contribute to the superconcentrated antioxidant content of foods grown there. Yoko Aniya, PhD, professor at the School of Physiology and Pharmacology, University of the Ryukyus, has compared antioxidant levels of foods and herbs grown in Okinawa, China, and India. Her research indicates that plants grown on the islands of Okinawa consistently exhibit higher antioxidant levels than their counterparts grown in other countries. She theorizes that the additional stress placed on plants by high levels of UV radiation may cause those plants to produce significant antioxidant compounds as a means of self-defense.4

Aniya has also extensively studied the antioxidant content and cardio- and hepato-protective effects of turmeric (Curcuma sp.) grown in Okinawa. Turmeric is consumed daily as a tea or tablet here rather than being used as a culinary spice. Turmeric tea is quite bitter, and in the past was usually taken as a tonic but was not necessarily enjoyed. Roughly 10 years ago, Seiyu Inafuku, an Okinawan businessman familiar with traditional Ryukyan fermentation processes, developed a method to ferment turmeric that vastly improved its flavor. Fermented turmeric tea is now found frequently in shops and bars and has become a common part of social life because it may help the liver to detoxify alcohol.6

Sugar cane, sea salt, and vegetables produced or grown in Okinawa may also be nutritionally superior to those same products grown or produced elsewhere. Okinawan sugar cane is exposed to the same high levels of UV radiation as other plants grown on the islands, and consequently contains very high levels of antioxidants; these are preserved by the processing methods used in Okinawa. The soil has abundant amounts of calcium and iron, so sugar cane and other plants grown on the islands are also good sources of these nutrients. Many vegetables, like the bitter melon, or goya, have a pronounced bitter flavor when compared with the same vegetables grown elsewhere. This may be a consequence of high UV radiation; in fact, health-promoting antioxidant compounds and alkaloids in plants typically taste bitter. Sea salts, especially brands from Miyako and Aguni islands, contain higher levels of potassium, magnesium, and calcium and lower levels of sodium than salts from other regions.

Learning From Okinawa
Though some factors contributing to good health and long life in Okinawa are specific to environmental aspects of the islands and to the culture of its people, we can borrow and learn from the Okinawans as they have successfully done with foreign cultures throughout the ages. Perhaps the first and most important thing we can glean from Okinawans is their respect for food. This attitude is expressed throughout Okinawa, from market farmers and fisherman to herbalists, healers, and chefs. Okinawans view food as medicine, and healing qualities are attributed to all traditional foods. Most food items available to Okinawans are also incredibly nutrient-dense, with exceptions found in areas that have been strongly influenced by American culture. A local convenience store typically has these ready-made foods to choose from: miso soup, sushi, Chinese dumplings, various noodle dishes, and green tea. Junk food is not prominent. Filling plates with mostly nutrient-dense foods and eliminating most processed snack foods would contribute significantly to improving the health of most North Americans.

Americans could also copy the Okinawans by eating more plant-based foods. The unusually high antioxidant levels found in Okinawan produce and herbs appear to be specific to plants grown at certain latitudes. North Americans may not have access to produce with remarkable antioxidant content, so all the more reason to boost the number of servings of fruits and vegetables we eat each day. Where we purchase produce, and the methods used in cultivation, may improve antioxidant profiles. The soils in which plants are grown and the distance they travel to get to local markets can significantly affect their nutrient density. A recent study comparing organically grown and conventionally grown vegetables found higher levels of antioxidants in the organically grown items.7 Foods that must travel a long distance to markets are generally picked in an unripe (and less nutritious) state and they lose some nutrients (mostly water-soluble vitamins) along the way. Produce that arrives at markets several weeks after it has been harvested also does not last long in home refrigerators; consequently, many people are discouraged from buying fresh produce that may quickly rot. Buying from local growers and farmer’s markets can ensure freshness and quality.

Fortunately, some Okinawan foods are making their way into North American markets and some readily available products can be substituted. A new Web site, www.okinaturals.com, is currently being constructed and will soon be a good resource for both purchasing and obtaining additional information on Okinawan products. Locally grown, organic produce may be nutritionally superior to conventionally grown fruits and vegetables. Tofu and sea vegetables are usually available in markets or by mail order. Green tea in myriad flavors is sold in most groceries and coffee shops. Soba noodles can be purchased in any store stocking Asian ingredients.

The following recipe makes a dish similar to the noodle bowls available in a local soba shop on Okinawa. This version is vegetarian; most Okinawan noodle dishes also contain pork. To get the full benefit of this food, close your eyes and imagine yourself in a small shop on a subtropical island, shoes off and seated at a low table. Friendly faces may be gazing your way as you attempt to manipulate soupy noodles into your mouth with only chopsticks to rely on. You soon forget what your mother told you and start slurping and immensely enjoying your meal like the others around you. You pay your bill, bow slightly in thanks to the shop owners, and take your health-full leave, hopefully with shoes in tow.

Okinawan Noodle Bowl

Serves 2

Dashi — this is a simple soup stock made with kombu, or kelp. You may also use chicken or vegetable stock for this recipe. Add the kombu if you can, as it will give the stock a rich and classic Asian flavor.

1 strip kombu, 18 inches long

5 C cold water

5 dried shitake mushrooms, optional

Place kombu and mushrooms in a 2-quart saucepan and cover with water. Turn burner to medium heat so the stock just comes to a simmer in 15 minutes. Remove from heat as soon as stock reaches a simmer and strain.

Noodles

2 ounces dried soba or somen noodles

1 C cubed tofu

1 C chopped spinach

Chopped scallions, shredded daikon radish, shredded carrots, sliced nori seaweed for garnish

Bring stock to a boil, add noodles, cooking according to package directions. When noodles are nearly done, add tofu and spinach. Serve topped with suggested garnishes.
Note: Okinawans also use pickled radish and a spicy condiment made from pickled chili peppers to garnish noodle bowls.

— Rita E. Carey, MS, RD, CDE, is on staff at Yavapai Regional Medical Center in Prescott, Ariz. She recently completed a summer culinary training program at the Culinary Institute of America in Hyde Park, N.Y., and plans to continue culinary training.

References
1. Kerr GH. Okinawa: The History of an Island People. Revised ed. North Clarendon, Vt.: Tuttle Publishing; 2000.

2. Yousfi S, et al. Personality and disease: Correlations of multiple trait scores with various illnesses. J Health Psychol. 2004;9(5):627-647.

3. Willcox BJ, Willcox DC, Suzuki M. The Okinawa Program: Learn the Secrets to Healthy Longevity. New York: Three Rivers Press; 2001.

4. Personal interview, University of the Ryukyus. December 2004.

5. Ogura C, Nakamoto H, Uema T, et al. Prevalence of senile dementia in Okinawa. Int J Epidemiol. 1995;24(2):373-380.

6. Rukkumani R, et al. Comparative effects of curcumin and an analog of curcumin on alcohol and PUFA induced oxidative stress. J Pharm Pharm Sci. 2004;7(2):274-283.

7. Asami DK, et al. Comparison of the total phenolic and ascorbic acid content of freeze-dried and air-dried marionberry, strawberry, and corn grown using conventional, organic, and sustainable agricultural practices. J Agric Food Chem. 2003;51(5):1237-1241.

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