30 August 2004
Common Weight Loss Ingredient A Risk
People taking weight loss formulations that contain the herb Citrus aurantium, or Seville orange, may be doing more harm to their bodies than good, according to research from the Georgetown University Medical Center.
The research, published in 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 similar way 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, co-author of the research. "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 FDA, a number of "ephedra-free" herbal weight loss products have surfaced. Many of these products contain C. aurantium, a small, sour citrus used to flavor liquers. C. aurantium has also been used in Chinese medicine to treat digestive problems. Among the points highlighted in their research, the authors 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.
Co-author Fugh-Berman said, "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."