Okinawan Sweet Potato (Japanese sweet potato/yam)
Although these are native to North America, and not Japan, they serve as the main carbohydrate source in the traditional diet of the Okinawan people, the longest-living people in the world.
So what’s good about this purple sweet potato? It has all the nutrients the average American person lacks! One potato (~180g) has 700% of the Daily Recommended Value of Vitamin A. Unlike others foods like nuts & oils which are rich in Vitamin E, this sweet potato has the antioxidant without the extra fats.
- High in fiber
- Rich in Vitamins A, C, B6
- Good source of Potassium, Iron, & Calcium
- Low to medium GI (Glycemic Index)
It’s also really tasty & easy to prepare! They can be found at any Asian market or even regular markets marked as “Japanese sweet potato/yam.” But from my understanding, all sweet potatoes are generally as nutritious.
- Poke the sweet potato with a fork several times all around
- Wrap in a wet paper towel
- Microwave for 5 minutes, turning once at 2.5 minutes.
PS: This was from New Year’s day!
Food Pyramid of Traditional Okinawan Diet
I think this is a good idea! For me, I have to practice eating more vegatables than grains since they are more nutrient dense & offer complex carbohydrates in more limited quantities. It’s definitely hard for me since breads, oatmeal, and rice are so abundant, and yes, very satisfying.
J Am Coll Nutr August 2009 vol. 28 no. 4 Supplement 1 500S-516S
I’m very interested in the diet of the indigenous population of Okinawa, the southernmost cluster of islands of Japan. The Okinawan are known for having the longest life expectancy, high numbers of centenarians, & low risk of age-associated diseases. Researchers believe that the longevity of Okinawan people is attributed to their food! Their traditional Okinawan diet is:
- low in calories, but nutritionally dense
- rich in antioxidants & flavonoids
- plant-based: vegetable & fruit heavy
- moderate intake of fish
- limited intake of meat & poultry, refined grains, & sugar
- almost no use of dairy products
- "hara hachi bu," the conscious practice of eating until 80% full
(following info from http://www.fyiliving.com/diet/special-diets/health-benefits-of-the-okinawa-diet/)
Okinawa diet is lots of complex carbohydrates from sweet potatoes and green leafy vegetables. Plus, the diet is very low in fat, sugar, and dairy products. Instead, Okinawans eat lots of soy, some meat (typically fish), fruits, and lots of vegetables. What researchers set out to discover was what were the key “functional foods” in the Okinawan diet. A functional food is a food that provides health benefits for your body beyond just meeting a basic nutritional need; for example, foods that contain disease-fighting phytochemicals in addition to providing basic requirements like protein, fiber or vitamins.
Researchers gathered a list of 12 functional foods that were eaten regularly by Okinawan elders.
- Sweet Potatoes/Yams (Ipomoea Batatas): The Japanese sweet potato is often referred to as the Yam here in the United States. Packed with vitamins A, B and C, yams are high in fiber, and also are a good source of magnesium, potassium and iron. The sweet potatoes in Okinawa are usually eaten daily, served as a side dish rather then rice as in other parts of Japan, which may partially explain why people in Okinawa live longer then the people in the rest of Japan. According to the researchers “In Japan, sweet potatoes are even prescribed to people with type two diabetes and to help manage cholesterol.”
- Soy: In the traditional diet, soy was the main source of protein. According to the researchers, “the tofu in Okinawa is lower in water content than the Japanese version and higher in healthy fat.” Furthermore, they concluded, “this not only increases the flavor of the tofu but also increases the isoflavone content, which may possibly be connected to the extremely low rates of breast and prostate cancer in Okinawa.”
- Goya which is a type of melon that is bitter in taste. Because of its taste, it is not served as a dessert, but rather in Okawana it is served in main dishes to add flavor. Goya is high fiber andVitamin C. Not only is Goya used as medicine to aid digestion in Okinawa, the researchers explained Goya is “often prescribed as medicinal herb in other parts of the world.”
- Konnyaku is a Japanese jelly derived from the starchy tuber of the Konjac plant. Konnyaku is a low calorie, low fat food that is high in fiber and calcium. The researchers explain, “Konnyaku is more than 90% water, and the rest is glucomannan [a type of soluble fiber], making it an effective treatment for constipation.” They added, ”The Okinawans say that konnyaku ‘cleans your stomach.’”
- Shiitake Mushroom: Shiitakes, like all mushrooms, are very low in calories, but are “high in protein (containing all 8 essential amino acids), fiber, antioxidants, and vitamins A, niacin, B12, C, and especially vitamin D, a nutrient often lacking in the diets of older Americans.” In Japan, these mushrooms are prescribed for their purported anticancer properties, and the researchers claim “it has been reported to increase survival for patients with stomach or pancreatic cancer, particularly when used in combination with chemotherapy immune booster.” The researchers were quick to point out that more research needs to be done to examine whether the shiitake mushroom does indeed have cancer fighting properties.
- Gobo is a root vegetable packed with fiber. Fiber is a type of carbohydrate that is not digestible. Fiber is an important part of the digestion process; not only does it help keep bowel movements regular, it also helps maintain an even blood sugar level by slowing down the rate of stomach-emptying.
- Hechimais a gourd. This squash is a “low-calorie vegetable that is high in vitamin C, folate, carotenoids, and some very interesting proteins that could have important health consequences anti-cancer properties.”
- Seaweed is eaten regularly in many parts of Asia, and is gaining popularity here in the U.S. thanks to the popularity of sushi. “Seaweeds are very low in caloric density; nutrient-dense; high in protein, iodine, folate, magnesium, iron, calcium, and carotenoids; and contain significant antioxidant capabilities.” The researches go on to say that seaweeds “may harbor medicinal properties, as they have been used to treat arthritis, colds, flu, and even cancer (although most of these claims have yet to be substantiated in clinical trials).”
- Turmeric (Ucchin) is an herb very popular in tea in Okinawa and is also garnering attention lately in the U.S. because of its potential healing properties. In Okinawa it is taken in pill form to “prevent a hangover.” It is also used as a spice to add flavor to foods. The researchers say that tumeric may have”anti-inflammitory potential” as well as help with rheumatoid arthritis, it may fight cancer cell growth, prevent leukemia and help stave off Alzheimers disease.
- Mugwort (Fuchiba) is used as a spice or found in Okinawan tea. It is also readily used for its medicinal powers in many parts of Asia because Mugwort ”appears to have sedative effects; they are used in traditional Chinese medicine to treat neuroses, depression, irritability, restlessness, insomnia, and anxiety. More than 100 studies have been done on mugwort, many of them supporting its folk uses…. The best evidence for the Artemisia class of plants, of which mugwort is a member, is for the treatment of infectious disease, such as malaria.”
- Hihatsu is a type of pepper, used in cooking or to sprinkle on food just like in the Western world. Okinawans use Hihatsu to “treat stomach problems and gout.”
- Fennel (Ichoba) is eaten as a spice, like here, and also as a vegetable. There have been studies that claim fennel may help in “weight loss, and is used to treat upset stomach, heartburn and gas.”
Original research here! It’s an interesting and fairly easy read.
*All quoted research was from and article published in the 2009 issue of the Journal of the American College of Nutrition,
entitled “The Okinawan Diet: Health Implications of a Low-Calorie, Nutrient-Dense,
Antioxidant-Rich Dietary Pattern Low in Glycemic Load”