Herbal contamination continues to damage industry

Twelve people in Japan suffered from liver injury after taking two kinds of Chinese herbal to lose weight, according to a communication in today's issue of the Annals of Internal Medicine​.

One patient died and another needed a liver transplant after taking the products, Chaso and Onshido. The remaining patients recovered after stopping the products, which had been sold on the Internet, said the report.

Both products were advertised by their manufacturers as containing only botanicals, but tests found that they contained N-nitroso-fenfluramine, a relative of the drug fenfluramine that was taken off the market in the United States after it was linked to heart problems.

The study of 12 patients who presented with herb-related liver injury between April and July 2002 revealed that most were hospitalised for more than a month. Two patients developed liver failure and one of these died as a result, while the other required transplantation, write Dr Hiromasa Ishii and colleagues from Keio University School of Medicine in Tokyo.

"Although it is not clear why these products contained N-nitroso-fenfluramine, it might have been added by the manufacturers to enhance the weight loss effect of fenfluramine or to mask the presence of fenfluramine,"​ noted the authors.

They urged consumers and health professionals to be aware that so-called herbal supplements for weight loss may be harmful.