Sweet potatoes in general are known to be a healthy addition to most diets. Purple Okinawan sweet potatoes recently have become popular for their superior health benefits such as their very high antioxidant content that is now believed to help resist age-related cognitive decline.
In this article we will take a look at the evidence-based health benefits of the Okinawan variety of sweet potato.
What Are Okinawan Sweet Potatoes?
Okinawan sweet potatoes are a type of sweet potato that is native to Okinawa, Japan. They are also known as Hawaiian purple sweet potatoes or purple yams. They have a deep purple-colored inside and a thin, purple-light brown skin. The inside of the Okinawan sweet potatoes is sweeter and moister than other types of sweet potatoes and has a nutty flavor.
Nutritional Content of Okinawan Sweet Potatoes
Here’s a table showing the nutritional content of 100 grams of cooked Okinawan sweet potatoes, including the percentage of the recommended daily intake (RDI) of each nutrient:
| Nutrient | Amount | % RDI |
|---|---|---|
| Calories | 115 | 6% |
| Carbohydrates | 27 g | 9% |
| Fiber | 4 g | 14% |
| Protein | 2 g | 4% |
| Fat | 0 g | 0% |
| Vitamin A | 709 IU | 14% |
| Vitamin C | 12 mg | 20% |
| Vitamin E | 1 mg | 5% |
| Vitamin K | 1 mcg | 1% |
| Thiamin | 0.1 mg | 8% |
| Riboflavin | 0.1 mg | 4% |
| Niacin | 0.7 mg | 3% |
| Vitamin B6 | 0.2 mg | 10% |
| Folate | 16 mcg | 4% |
| Pantothenic acid | 0.4 mg | 4% |
| Potassium | 398 mg | 11% |
| Calcium | 30 mg | 3% |
| Iron | 1 mg | 6% |
| Magnesium | 27 mg | 7% |
| Phosphorus | 55 mg | 6% |
| Zinc | 0.2 mg | 1% |
Note that the nutritional content of Okinawan sweet potatoes may vary depending on factors like how they are prepared and the size of the potato. The %RDI is based on a 2000 calorie diet for an average adult, and may vary depending on individual needs.
Health Benefits of Purple Sweet Potatoes
Here are some of the potential health benefits of Okinawan sweet potatoes:
Longevity – Anti-Aging and Brain Health
The antioxidants found in Okinawan sweet potatoes have been shown to have anti-aging properties. They may help prevent age-related cognitive decline, improve heart health, and reduce the risk of chronic diseases.
Full of Antioxidants and Flavonoids
Okinawan sweet potatoes are a great source of antioxidants like anthocyanins, which give them their deep purple color. These antioxidants can help protect your cells from damage caused by free radicals and may reduce the risk of chronic diseases like cancer and heart disease.
Here’s a table showing the flavonoid and antioxidant content of 100 grams of cooked Okinawan sweet potatoes:
| Nutrient | Amount |
|---|---|
| Anthocyanins | 150 mg |
| Cyanidin | 3.1 mg |
| Peonidin | 2.5 mg |
| Chlorogenic acid | 19.5 mg |
| Caffeic acid | 9.3 mg |
| Quercetin | 2.8 mg |
| Kaempferol | 1.4 mg |
| ORAC value | 6,554 ฮผmol TE |
Note that these values may vary depending on factors like how the sweet potatoes are grown and prepared.
High in Dietary Fiber
Okinawan sweet potatoes are a great source of dietary fiber, which can help promote regularity and improve digestive health.
Immune System Support
Okinawan sweet potatoes are high in vitamin C, which is important for immune function. They also contain other nutrients like potassium and vitamin A, which can help support overall health and wellbeing.
Low Glycemic Index
Okinawan sweet potatoes have a lower glycemic index than other types of sweet potatoes and can be a good option for those looking to manage blood sugar levels.
How to Cook Okinawan Sweet Potatoes
Okinawan sweet potatoes can be prepared in a variety of ways like other types of sweet potatoes. Here are a few ideas:
- Roasting: Preheat your oven to 400ยฐF (204ยฐC). Wash and peel the Okinawan sweet potatoes, then cut them into cubes or wedges. Toss with a little olive oil and seasonings like salt, pepper, and herbs. Roast in the oven for about 25-30 minutes, or until tender and golden brown.
- Boiling: Peel and chop the sweet potatoes into chunks, then place them in a pot of boiling water. Boil for about 15-20 minutes, or until the sweet potatoes are soft and easily pierced with a fork. Drain the water and mash the sweet potatoes with butter and seasonings to taste.
- Baking: Preheat your oven to 350ยฐF (177ยฐC). Wash and dry the sweet potatoes, then prick them all over with a fork. Place them on a baking sheet and bake for about 45-60 minutes, or until they are tender and the skin is slightly crisp.
- Frying: Peel and slice the sweet potatoes into thin rounds. Heat some oil in a frying pan and add the sweet potato slices. Fry for a few minutes on each side, or until they are crispy and golden brown. Drain on paper towels and sprinkle with salt. For a low fat alternative, try using an air fryer, with just enough oil on the pan to avoid sticking!
You can also use Okinawan sweet potatoes in a variety of other dishes, such as soups, stews, salads, and even desserts, and you can find a few ideas below!
Recipe Ideas for Okinawan Sweet Potatoes
Okinawan sweet potatoes can be cooked in a variety of ways, including roasting, boiling, or baking. They can be used in both sweet and savory dishes, and their vibrant color makes them a great addition to salads, stews, and curries. They are a nutritious and delicious food that can provide a range of health benefits.
Here are a few recipe ideas to try out:
Mashed Okinawan Sweet Potatoes: Boil Okinawan sweet potatoes until tender, then mash them, optionally adding in some skim milk, and seasonings like pepper, and nutmeg.
Okinawan Sweet Potato Fries: Cut Okinawan sweet potatoes into thin wedges, toss with olive oil and seasonings like paprika and garlic powder, and bake in the oven until crispy. Serve as a healthier alternative to regular French fries.
Okinawan Sweet Potato Salad: Cube boiled Okinawan sweet potatoes and toss with a dressing made from olive oil, lemon juice, honey, and Dijon mustard. Add in other ingredients like chopped kale, dried cranberries, and crumbled feta cheese.
Okinawan Sweet Potato Curry: In a pot, sautรฉ onions, garlic, and ginger until fragrant. Add cubed Okinawan sweet potatoes, diced fresh or canned tomatoes, coconut milk, and a curry powder. Simmer until the sweet potatoes are tender and the sauce has thickened. Serve with rice and naan bread.
Okinawan Sweet Potato Dessert: Mash boiled Okinawan sweet potatoes with coconut milk, maple syrup, and vanilla extract. Pour the mixture into a pie crust and bake until set. Top with whipped cream and toasted coconut flakes for a delicious and healthy dessert.
These are just a few recipe ideas for Okinawan sweet potatoes, but there are a lot of other possibilities. Experiment with different flavors and cooking techniques to create your own unique dishes!
Disadvantages of Okinawan Sweet Potatoes
There are some minor potential disadvantages to be aware of:
Slightly higher calorie content: Okinawan sweet potatoes are slightly higher in calories than other varieties of sweet potatoes, which could be a disadvantage for those trying to limit their calorie intake.
High levels of oxalates: Okinawan sweet potatoes contain high levels of oxalates, which can contribute to the formation of kidney stones in some people. People with a history of kidney stones should limit their consumption of Okinawan sweet potatoes.
Difficulty finding them: Okinawan sweet potatoes may be harder to find in some areas compared to other varieties of sweet potatoes, which could be a disadvantage for those who want to incorporate them into their diet.
Possible allergic reactions: As with any food, some people may be allergic to Okinawan sweet potatoes, which could lead to adverse reactions like skin rash, itching, or difficulty breathing.
Overall, Okinawan sweet potatoes are a nutritious and delicious addition to any diet. They are packed with antioxidants and other important nutrients that can support overall health and wellbeing.