The Symbolic Citrus of Okinawa: Shikuwasa

Citrus Family

Citrus Depressa

Japanese plant native to Okinawa and Taiwan

Shikuwasa or Shikwasa (Shee-koo-wah-sah/Sheek-wah-sah) is a popular fruit in Okinawa. The word Shikuwasa means ‘eating vinegar‘ in Okinawan language. It is not only Okinawans who love Shikuwasa drinks and flavored foods, but also tourists from China, Korea, and all over the world who come to Okinawa to buy Shikuwasa goods. The fruit turns yellow when fully ripened but used while it is still small and green, similar looking to a lime. It is popular for its distinct taste different from other citruses. The taste is much more tart than your regular citrus flavored juice, however, to really understand the taste you will need to try it for yourself!

Shikuwasa has been consumed by Okinawans for years and has contributed to their longevity for many reasons.

Shikuwasa, although highly unheard of outside most Asian countries, is being researched for its surprising health benefits. (click the title to see more information about the research)


A compound called nobiletin in Shikuwasa was tested for its effects on human gastric cancer cell lines. Shikuwasa showed antiproliferative (suppression of cell growth) effects, to induce apoptosis (programmed cell death), and deregulate the cell cycle of possibly cancerous cells. The study concluded that nobiletin is may be used in new gastric cancer suppression treatments and have fewer side-effects than current treatments.


In one study, the body weight gain, white adipose tissue, sizes of adipocytes, and plasma triglycerides (stored fatty acids) and leptin levels were all effectively suppressed in high-fat-diet-induced obese mice who were also given the Shikuwasa peel extract. The study suggests Shikuwasa may possibly prevent the onset of obesity and hyperlipidemia (abnormal lipid levels in the blood).


The liver is an organ that detoxifies, produces biochemicals for digestion, helps with metabolism, regulates glycogen storage, decomposes red blood cells, and plays a role in hormone production. It is easily written off by some, but it is a given that this organ should be highly considered to keep the body functioning healthily. According to research, Shikuwasa juice has hepatoprotectives aspects, mainly due to the several polymethoxy flavonoids contained within it. In one study, the compound nobiletin showed to have suppressive effects on rats with D-galactosamine-induced liver injury.


Like other citrus foods, Shikuwasa also expresses anti-oxidant effects due to the vitamin-C content. Vitamin-C has shown to reduce muscle soreness, delay creatine kinase (seen in heart attacks and trauma cases), and prevent blood glutathione oxidation (oxidative stress) without influencing muscle function loss when consumed pre-exercise.

Shikuwasa trees can be found all over Okinawa, even in many people’s own backyards. Given its health benefits and important role in Okinawan food culture, one can agree with the common idea that this fruit contributes to the famous Okinawan longevity and Okinawa diet among the people. 100% Shikuwasa juice is hard to find in other countries outside of Okinawa. This Shikuwasa juice shown here is Okinawan grown and contains no sodium chloride, no sugar, and no fragrance or flavorings. This Japanese-given quality cannot be found anywhere else.

* The statements contained herein have not been evaluated by the Food and Drug Administration. The information contained in this website is intended for education, entertainment and information purposes only. This information is not intended to be used to diagnose, prescribe or replace proper medical care. The plant described herein is not intended to treat, cure, diagnose, mitigate or prevent any disease.