Out of everyone in the world, the people of Okinawa (the largest of Japan’s Ryukyu Islands) have been historically proven to live the longest lives. In 1980, they achieved the highest global lifespan (with men living to an average of 84 years and women 90 years). At least, this was the case until the 2020 census, which revealed that the Okinawa lifespan had dropped to an average of 80.27 and 87.44 years for men and women, respectively. The secret to their astonishingly long lives had been a combination of genetic, environmental, and lifestyle factors, with the most important being their Okinawa diet. However, globalization led western influences to impact this diet, leading to their loss in average lifespan. This article will explore those circumstances and what changes led to the loss in average lifespan.
But first, what is the Okinawa diet?
While similar to the Japanese diet, with low fat, high intake of soy products and vegetables, addition of miso, abundant sea and fish, vegetables, and the absence of dairy products, the Okinawa diet also included some very distinct changes. The basis of the diet was the sweet potato, and other components such as a specific taste for flavorings and regular use of spices and herbs differentiated it as well.
A typical meal would start with an Okinawan miso soup. The differentiating change between the Japanese and Okinawan miso soup is the addition of small amounts of fish, pork, tofu, or vegetables. The overall traditional cuisine centers itself on the staple sweet potato, yellow-root or green-leafy vegetables, and soy products along with minute portions of noodles, fish, and lean meats flavored with spices, herbs, and cooking oil.
The Okinawan diet is very close to becoming vegetarian. This was not by choice, but rather a product of their circumstances. In the 1950s, typical Asian families could not afford meat or processed goods (such as sugar, cooking oil, or salt). For Okinawan specifically, staple foods were a much more convenient and cheaper option than importing polished white rice. Okinawa’s subtropical islands supported fresh plant foods, and rice was supplanted with the more robust sweet potato.
The diet is high in carbohydrates and low in calories and fat. The presence of many antioxidant-rich foods protect cells from free radical damage and inflammation. All these factors combined contribute to a longer lifespan. In addition, Okinawans enjoy fewer chronic illnesses (such as heart disease, diabetes, and cancer). The staple sweet potato includes healthy levels of fiber, have a low glycemic index (don’t advance high levels of blood sugar), and provide essential nutrients (such as potassium, calcium, magnesium, and vitamins A and C). The high levels of soy are associated with lessened risk of chronic diseases, as explained earlier.
The downsides are that the traditional Okinawan diet is very restrictive. It prohibits many healthy food groups (such as fruit, nuts, dairy, and seeds). If missing some of these nutrients will impact your health negatively, this diet is not recommended. This is why the mainstream version of the diet is more popular, as it promotes weight loss while not possessing as many restrictions.
Also, the Okinawan diet can be high in sodium (some variants of the diet include up to 3,200 mg of sodium per day—the Dietary Guidelines for Americans recommends a limit of 2,300 mg of sodium per day). Because high sodium can increase risk of high blood pressure by trapping water in blood vessels. The Okinawan diet is, however, also high in potassium, which may help alleviate the severity of high sodium content.
Now that you have a better understanding of the Okinawan diet, let’s examine the changes from the traditional to the current diet. The main proposed reason for the fall in average longevity for Okinawans is the failure of the new generation to follow the ways of earlier generations. After Japan surrendered at the end of World War II, Okinawa has hosted many large U.S. military and tens of thousands of troops. The western culture of fast food and television has negatively influenced Okinawans’ lifespans, with less commitment to exercise and growing commitments to work.
Immigration is another contributing factor. Ironically, Okinawa’s fame as a place with the greatest longevity had attracted people to move in, bringing in new cultures. Eventually, Okinawa’s diet and traditions shifted. By 1990, Okinawan men only held the fifth highest average life expectancy out of 47 in Japan. By 2020, they had declined to 36th. Until 2005, Okinawan women were originally at the top of the prefectural list but fell to the seventh spot in 2020.
And so, while Okinawan is still a very healthy country, it does not hold the highest spot for longevity anymore.
Works Cited
Hill, Ansley. "What Is the Okinawa Diet? Foods, Longevity, and More." Healthline, Healthline Media, 11 July 2023, www.healthline.com/nutrition/okinawa-diet.
Madden, Duncan. "Live Long and Prosper: Five Countries Where People Live the Longest." Forbes, 27 June 2022, www.forbes.com/sites/duncanmadden/2022/06/27/live-long-and-prosper-five-countries-where-people-live-the-longest/.
Ryall, Julian. "Japan: What's behind Okinawans' falling life expectancy?" Deutsche Welle, 12 June 2022, www.dw.com/en/japan-whats-behind-okinawans-falling-life-expectancy/a-62088176.
"Sodium in Your Diet." U.S. Food and Drug Administration, USA, www.fda.gov/food/nutrition-education-resources-materials/sodium-your-diet.
Willcox, Donald C., et al. "Healthy aging diets other than the Mediterranean: a focus on the Okinawan diet." Mechanisms of ageing and development, vol. 136-137, 2014, pp. 148-62, https://doi.org/10.1016/j.mad.2014.01.002.
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