HerbalGram: Bitter Orange Safe 55163

AUSTIN, Texas Another scientific review has concluded that bitter orange and bitter orange extract are safe in normal use as foods and ingredients in dietary supplements (HerbalGram 2011;89:34-39). After critically reviewing the available published chemical, pharmacological, toxicological, and clinical data available on bitter orange and its extracts, the authors of the HerbalGram safety review concluded that there is confusion in the medical literature that has caused misinformation among health professionals, journalists and others.

 In summary," they wrote, based on current research as well as the extensive ingestion of bitter orange and p-synephrine in the form of dietary supplements as well as fruits, juices and other citrus food products, the data demonstrate that bitter orange extract is safe for human consumption. No credible adverse events have been directly attributed to bitter orange, or its primary protoalkaloid, p-synephrine, in association with oral ingestion."

The safety review was conducted by two medicinal plant experts, Sidney J. Stohs, Ph.D., dean emeritus of the Creighton University School of Pharmacy and Health Professions, and Harry G. Preuss, M.D., professor of medicine and pathology at Georgetown University Medical Center.

Bitter orange extracts increased in popularity in herbal dietary supplements circa 2004 after FDA banned the controversial herb ephedra (Ephedra sinica), also known in Chinese as ma huang. Because bitter orange contains the a chemical known as p-synephrine, many writers and regulators incorrectly assumed that bitter orange was potentially unsafe, as a chemical type of synephrinem-synephrine, which is not found in bitter orangecan have pronounced effects on the cardiovascular system.

Stohs and Preuss emphasize the difference between these two chemical types of synephrine. First, m-synephrine, a synthetic form of the chemical which is also known as the drug neosynephrine, can produce adverse cardiovascular effects. However, bitter orange peel contains a natural type of synephrine called p-synephrine which has a slightly different chemical structure, producing different biological activity.

The HerbalGram safety review documents the scientific and human clinical research on bitter orange which has confused the 2 different types of synephrine, often leading to erroneous and misleading conclusions in medical and lay literature about the overall safety of bitter orange and its extracts.

For example, the September 2010 issue of Consumer Reports stated that bitter orange has been linked by clinical research or case reports to serious side effects." The Consumer Reports article stated bitter orange contains synephrine, which is similar to ephedrine, banned by the FDA in 2004."

Due to the widespread confusion about the relative safety of bitter orange, we employed an extra level of peer review for this article," said Mark Blumenthal, founder and executive director of the American Botanical Council and editor of HerbalGram. We normally use three expert peer reviewers for articles in HerbalGram," he noted, but for this article we went an extra few miles by having additional expert reviewers comment on and check the accuracy of all of the information in this safety review. This included experts who have published on bitter orange and synephrine in pharmacology and medical journals."

Bitter orange, also known as Seville orange (Citrus aurantium), and its peel have long been used as a food, and the dried immature fruits of bitter orange have various medicinal uses in Traditional Chinese Medicine (TCM), particularly for gastrointestinal (GI) disorders, including indigestion, diarrhea and dysentery and constipation. Its also used as an expectorant.