The vibrantly beautiful and nutritious Purple Okinawan Sweet Potato is loaded with antioxidants, phytonutrients, and health-promoting fiber. It is touted as one of the reasons Okinawans are living active disease-free lives past the age of 100.
While chronic diseases such as diabetes, cancer, heart disease, and obesity are becoming more common in our aging population, there are 5 areas of the world called Blue Zones that are home to some of the world’s oldest people, called centenarians, that are living to be more than 100 years old.
- Okinawa, Japan
- Ikaria, Greece
- Ogliastra in Sardinia, Italy
- Loma Linda, California
- Costa Rica’s Nicoya Peninsula.
The amazing thing is that these centenarians are still living productive and active lives in their communities.
The key to their longevity seems to be a combination of a number of lifestyle factors including a primarily plant-based diet, daily exercise, plenty of sleep, and community involvement with tight-knit family and friends.
Okinawa in Japan is one of these Blue Zones, and their purple sweet potatoes seem to be playing a role in their longevity.
Purple sweet potatoes are healthy
The Okinawan purple sweet potato is a staple in the diet of this Asian population, and we can learn a lot about the healthiness of this group of people by looking at one of their main food sources.
This sweet potato is not actually related to the potato but instead is in the morning glory family. Unlike regular potatoes, it is not a nightshade vegetable.
Okinawan sweet potatoes are loaded with disease-fighting phytonutrients, and they actually have 150% more antioxidants than blueberries!
Shopping for Okinawan potatoes
We love to shop at Asian markets and, every time we are there, I always pick up fresh purple sweet potatoes.
It can be tricky though because there are different types of sweet potatoes. A potato that is purple on the outside does not necessarily mean it’s also purple on the inside. You might have to ask the store clerk.
I have also been told that some Trader Joe’s and Whole Food stores carry these purple sweet potatoes, so check with your local stores.
The recipe card at the bottom of the page has the full list of ingredients with measurements and instructions.
How to bake purple sweet potatoes
There are different ways to cook Okinawan sweet potatoes including boiling, steaming, and baking. My favorite way to cook them is baking.
Slow baking, in my opinion, makes the potato softer and sweeter than other methods. As you can see in some of these photos, during baking, the outer part--the jacket–actually pulls away from the flesh making them easy to peel.
Wrapping sweet potatoes for baking
To cook potatoes, begin by washing them well. Then, wrap each one in parchment paper followed by a sheet of foil. I do this because there is some research linking aluminum to Alzheimer’s disease. Though the research isn’t conclusive, I like to err on the side of caution.
Baking sweet potatoes
I know that many people poke holes in their potatoes before baking them, but since mine are double-wrapped in parchment paper and foil, I’ve never done this.
The reason for the holes is to prevent them from exploding in the oven. However, the layers I use around my potatoes help keep the moisture in, and I’ve never had one to explode using this method in nearly 5 decades of cooking. So far, so good!
After wrapping the potatoes, put them on a baking pan and place them in the oven.
Cooking times will vary depending on the size of your potatoes. I tend to buy larger ones when available.
Generally, I cook my Okinawan sweet potatoes at 400°F for approximately 1 to 1-1/2 hours. To check for doneness, remove the pan of potatoes from the oven and insert a knife into the center of the largest one. If it goes in smoothly, they should be ready.
What to serve them with
There are a lot of options for serving purple sweet potatoes. Oftentimes, I will let them take over the center of our plate and serve with sides like a garden salad and corn on the cob.
Other times, I will make a hearty stir fry and serve these Japanese sweet potatoes on the side. For those looking for some great ideas, check out my Stir Fry Category for inspiration.
No matter how you decide to serve these perfectly healthy and delicious Asian sweet potatoes, they will be a huge hit with the family!
Your Questions Answered:
- Q: What are purple sweet potatoes good for? These colorful potatoes are loaded with fiber and antioxidants which make them a very healthy food. They are great eaten alone or served as a side dish with stir-fries and other recipes.
- Q: What do they taste like? The taste is very different from a regular orange sweet potato. The taste is very rich, dense, and lightly sweet.
- Q: How do you store them before cooking? They do best in a dry, dark, and cool storage place such as in a pantry. Storing them in the refrigerator can throw off the flavor and lead to a harder center.
Other great potato recipes
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Baked Okinawan Purple Sweet Potatoes
The vibrantly beautiful and nutritious Okinawan sweet potato is loaded with antioxidants, phytonutrients, and health-promoting fiber. It is touted as one of the reasons Okinawans are living active disease-free lives past the age of 100.
- 4 large Okinawan sweet potatoes
- Begin by washing the potatoes well.
- Then, wrap each one in parchment paper followed by a sheet of foil. I do this because there is some research linking aluminum to Alzheimer’s disease. Though the research isn’t conclusive, I like to err on the side of caution.
- After wrapping the potatoes, place them on a baking pan and place them in the oven.
- Bake at 400°F for approximately 1 hour and sometimes a little longer. To check doneness, remove the pan of potatoes from the oven and insert a knife into the center of the largest one. If it goes in smoothly, they should be ready.
Detailed instructions, in-process photos, and my personal helpful tips can be found in the article above.
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Nutrition Information:Yield: 4 servings Serving Size: 1
Amount Per Serving: Calories: 162Total Fat: 0gSaturated Fat: 0gTrans Fat: 0gUnsaturated Fat: 0gCholesterol: 0mgCarbohydrates: 37gFiber: 6gSugar: 12gProtein: 4g
To obtain the most accurate representation of the nutritional information in a given recipe, you should calculate the nutritional information with the actual ingredients used in your recipe, using your preferred nutrition calculator. You are solely responsible for ensuring that any nutritional information provided is accurate, complete, and useful.
Saturday 15th of January 2022
I cook them in the slow cooker, no foil, just wash then well and pop them in the crock and cook on high for about 4 hours
Tuesday 5th of October 2021
I love purple sweet potatoes! Although they can be quite sweet so I don't eat them often. I like what you said about using parchment paper before the foil, I'll try that. Drs Dean and Ayesha Sherzai, Alzheimers experts, have also said that the data is inconclusive regarding aluminum and they also recommend erring on the side of caution.
Arlisha Delores Scarborough
Friday 20th of August 2021
Hello, I am interested in the purple sweet potato 🍠.Do you know where I can find them and how much will they be?
Tuesday 5th of October 2021
@Arlisha Delores Scarborough, I ordered mine online. They are also known as Hawaiian Sweet Potatoes because the soil in Hawaii is apparently similar to that in Japan so that variety of potato thrives. You can find them online. I've never found them locally in Asian stores near me. But I do find Japanese sweet potatoes locally - although those are completely different. Delicious, but not purple.
Saturday 21st of August 2021
Hi Arlisha- I find them at the Asian markets around town. The price will likely depend on your location. They are more pricey than regular white or sweet potatoes but well worth the splurge every so often.