American Botanical Council Clarifies Importance of Ginkgo Toxicology Report
AUSTIN, Texas, April 18, 2013 /PRNewswire-USNewswire/ -- The nonprofit American Botanical Council (ABC) says that clinically tested ginkgo extracts sold as dietary supplements in the United States are safe for most consumers. The ABC statement follows news of the publication of a report by the National Toxicology Program that showed that a special formulation of a Chinese ginkgo extract produced cancers in certain strains of rats and mice in a series of animal toxicology studies performed over two years In the conclusion of the report, the authors wrote, "We conclude that Ginkgo biloba extract caused cancers of the thyroid gland in male and female rats and male mice and cancers of the liver in male and female mice." 1
In February 2012, ABC sent public comments to NTP for the authors of the ginkgo study to consider in revising the draft report. 2 The ABC comments were compiled by a committee of medicinal plant science and toxicology experts.ABC emphasized that the Chinese ginkgo extract manufactured in Shanghai is not consistent with any compendial botanical and chemical standards for quality as set forth in various official pharmacopeias and does not conform to the well-established chemical profiles, quality, and purity of the leading, clinically tested ginkgo extracts produced by the pioneering Willmar Schwabe Pharmaceuticals of Karlsruhe, Germany, and Indena SpA in Milan, Italy. The ginkgo used in the NTP study was manufactured by the Shanghai Xing Ling Science and Technology Pharmaceutical Co., Ltd. "The ginkgo extract used in this study is different from the high-quality ginkgo extracts used in published clinical trials showing safety and various beneficial activities of ginkgo," said Mark Blumenthal, founder and executive director of ABC. "That is, the Shanghai ginkgo extract used by NTP does not represent the quality of German ginkgo extract that is the world standard for ginkgo. It is highly unfortunate that NTP chose to use this ginkgo extract as it means that the results of the NTP's studies are not applicable to the standard-setting ginkgo extracts." In addition, ABC noted that the dosage levels administered to the test animals was significantly higher (up to 55-108 times higher) than the levels of ginkgo extract that are normally ingested by consumers (120-240 milligrams per day), as calculated by ABC's consulting toxicologist.