People taking “ephedra-free” weight loss products that contain the herb Citrus aurantium, or Seville orange, may be doing more harm to their body than good, according to a new review published by Georgetown University Medical Center researchers.
The review, published in the September issue of Experimental Biology and Medicine, found that no reliable scientific evidence supports the use of C. aurantium for losing weight. More importantly, high doses of the herb, which contains synephrine, may not be safe. Synephrine can cause hypertension, and C. aurantium also interacts with drugs in a manner similar to grapefruit juice.
“C. aurantium has many of the same potential deleterious cardiovascular effects as ephedra, and it also potentially affects the metabolism of other drugs,” said Adam Myers, PhD, professor of physiology and co-author of the review. “The public and the medical community should be concerned about the growing use of C. aurantium without adequate data on safety and efficacy.”
Since the banning of ephedra-containing products by the Food and Drug Administration, a new wave of “ephedra-free” herbal weight loss preparations has surfaced. Many of these products contain C. aurantium, a small, sour citrus used to flavor Curacao, Cointreau, and Triple Sec. CA has also been used in traditional Chinese medicine to treat digestive problems.
Among the points highlighted in their review, Myers and co-author Adriane Fugh-Berman, MD, associate professor of Physiology, discuss that C. aurantium, like grapefruit, contain flavonoids that affect drug metabolism and can increase blood levels of drugs, thus increasing side effects.
"The effects on drug-metabolizing systems are not identical. C. aurantium juice, but not grapefruit, increased levels of indinavir, a drug used to treat AIDS. Grapefruit juice, but not C. aurantium juice, increased cyclosporine levels. Both citruses increased levels of felodipine, a calcium channel drug used to treat high blood pressure,” said Myers who directs the first Master's degree-granting graduate level program in Complementary and Alternative Medicine in the United States.
"Potential drug interactions could be serious," states Fugh-Berman, author of the 5-Minute Herbs and Dietary Supplement Consult (Lippincott Williams and Wilkins 2002). "Anyone who is taking daily medication should consult a physician before combining it with the use of C. aurantium. This and other herbal weight loss products should not be considered safe simply because they are available over-the-counter. The best way to lose weight is through exercise and diet."
Myers and Fugh-Berman encourage much more research on the effects of C. aurantium. As part of the Complementary and Alternative Medicine (CAM) Master’s Program they help guide at Georgetown, Myers, Fugh-Berman, and their colleagues are focused on training scientists to address the research gaps in CAM, educating health care practicioners on the benefits and risks of CAM, and promoting critical, interdisciplinary thinking. The second year of this pioneering graduate biomedical program has enrolled double the students as the first year of the program, demonstrating a sincere and growing interest in exploring the science behind CAM and helping to fill in missing data to determine the safest recommendations for consumers.