Eat Your Purples

An Okinawan sweet potato that’s picking up steam!

September 13, 2023  |   by Daniel Osser

okinawan sweet potatoes unpeeled

The Okinawan sweet potato is a delicious and popular staple food in Okinawa, Japan. Its sweet flavor and striking purple hue make it a versatile side for many dishes. With Okinawa known for having one of the highest percentages of centenarians in the world (rare population of people who reach 100 years of age of more), this sweet potato is believed to be one of the secrets to the longevity of the people.


Although the Okinawan sweet potato is well known in Okinawa, Japan, it was originally cultivated in the Peruvian Andes and introduced to Japan sometime in the early 1400s. The Japanese island of Okinawa had too wet of a climate to grow the staple rice eaten in the rest of the country, with monsoon season regularly wiping out rice paddies. The potato, they found, grew quite well! Known locally as beni-imo, it was initially grown as an ornamental plant due to its attractive purple color. However, it soon gained popularity in the region due to its delicious taste and perceived health benefits.

okinawan sweet potatoes sliced in half
okinawan sweet potatoes sliced length wise


Today, Okinawa is one of the regions of the world with the most centenarians, possibly due in part to their diet. The Okinawan sweet potato plays a central role. It’s rich in anthocyanins, giving it a deep purple color, and anti-inflammatory compounds. These compounds may help to protect against age-related diseases such as Alzheimer’s, heart disease, and cancer. Purple sweet potatoes are also a good source of fiber, potassium, and vitamin C, known to lower blood pressure and boost the immune system. Despite being sweet, these purple tubers have a surprisingly low glycemic index, lower even than regular potatoes, and much lower than rice. They are thought to be a safer alternative for diabetics.


Over time, the Okinawan sweet potato became an important part of the Okinawan diet and culture. It was used in traditional Okinawan imo-ryori, cuisine that focuses on the use of sweet potatoes in various preparations, such as tempura, soup, and even ice cream. The Okinawan sweet potato’s popularity gradually spread beyond the region, and it’s now widely cultivated and enjoyed around the world. Its unique flavor and nutritional benefits have made it a popular ingredient in many dishes, particularly in vegan and vegetarian cuisine.

sliced and cooked okinawan sweet potato in a bowl

New to this delicious root vegetable? Try it as the Okinawans would: simply steam until tender, top with green onion, and drizzle with toasted sesame oil. Or try mashing in some miso paste and sprinkle with chopped toasted nori seaweed for a savory, umami flavor boost! Eat as a side dish anytime you would eat rice.

From its humble beginnings as an ornamental plant, the Okinawan sweet potato has become an important part of not only Okinawan culture and cuisine but also the diets of people all around the world. Its unique flavor, rich purple color, and numerous health benefits have made it a popular ingredient in many dishes, particularly in vegan and vegetarian cuisine. Whether you steam it and serve it as a side dish or get creative with it in the kitchen, the Okinawan sweet potato is a delicious and nutritious addition to any diet. Give it a try!