The Bitter Orange And Concerns Over Its Impacts

The fruit C. aurantium often is named “bitter orange” and yields herbs such as Fructus Aurantii  and Fructus Aurantii Immaturus and many others in Chinese medicine, and is known for improving a body’s gastrointestinal function. But bitter orange is controversial because its chemical content is linked to heart ailments.

Food supplements containing C. aurantium herbs have been used as an energy stimulant, or to reduce appetite. Its use in Chinese medicine to improve the inner workings of the gastrointestinal tract potentially impacts many people because gastrointestinal tract disorders are common. They include constipation, irritable bowel syndrome, colitis and cancer.

There are a variety of common names, including bitter orange, Seville orange, sour orange, Zhi shi. The bitter orange is a plant and may be distinguished from the sweet orange by its rougher and usually darker rind. The peel, flower, leaf, fruit and juice are used to make medicine. The rind is aromatic and also has a bitter taste.

Uses of Bitter Orange

The bitter orange also is used essential oils, and is also tapped as a perfume or flavoring component. The fruit, peel, flower and oil can be taken by mouth in tablets and capsules. Bitter orange oil can be applied to the skin. Applying bitter orange to the skin may help with ringworm, jock itch and athlete’s foot infections. The Seville orange variety is used to make marmalade.

Fructus Aurantii

One of the major bitter orange herbs is Fructus Aurantii, which has a history of being a national Chinese drug for many years. The fruit is unripe, sour and rarely eaten. Flavonoids, volatile oils and alkaloids are the main components of Fructus Aurantii. Flavonoids are kinds of important active components promoting gastrointestinal motility.

Fructus Aurantii Immaturus and Quzhou Fructus Aurantii

Other herbs used for gastrointestinal illnesses include Fructus Aurantii Immaturus, which has been studied for its impact on promoting bowel movement, bowels, and Quzhou Fructus Aurantii, which studies show may have a positive impact on treating respiratory illnesses. Respiratory inflammation is related to many respiratory diseases, including acute lung injury and its more severe manifestation, acute respiratory distress syndrome.

Bitter Orange Chemical Component

The bitter orange peel contains essential oils, aurantimarin, hesperidin, isohesperidin, and hesperic acid. The seed contains about 40 percent of fixed oil pectin and a crystalline bitter principle, limonene.

Concerns About Bitter Orange

There are concerns, however, about the bitter orange and its impact on the heart especially when it is taken or used in herbal weight loss products. It has been used in the manufacture of such products as a replacement for ephedra, which was banned by the U.S. Food and Drug Administration more than a decade ago for serious heart side effects, including heart attack and stroke.  Bitter orange also is banned by the U.S. National Collegiate Athletic Association, which declared it a stimulant.

Inconclusive Evidence

While there have been case reports of healthy people experiencing fainting, heart attack and stroke after taking bitter orange alone or with coffee, the evidence regarding the effects of bitter orange, alone or combined with other substances such as caffeine and green tea on the heart and cardiovascular system are inconclusive, according to U.S. health agencies. Due to a lack of safety evidence, a pregnant woman should avoid products that contain bitter orange.

Only a few studies have investigated the usefulness of bitter orange as a dietary supplement for health purposes in people.


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