NMA: Nonprescription Medicines Academy

Carcinogenicity of Ginkgo Disputed

May 29th, 2013

The American Herbal Products Association (AHPA) has taken issue with information in a recently finalized National Toxicology Program (NTP) Technical Report on the toxicology and carcinogenesis studies of Ginkgo biloba extract (available for download at http://ntp.niehs.nih.gov/ntp/htdocs/LT_rpts/TR578_508.pdf). The studies investigated the long-term effects of ginkgo extract in mice and rats. Ginkgo extract was given orally to the animals for up to 105 weeks; results showed an increase in liver cancer in male and female mice, as well as an increase in cancer of the thyroid gland in male and female rats and male mice.

According to the AHPA, the Ginkgo biloba extract used in the study was not chemically similar to ginkgo products sold for commercial use in the United States. The AHPA contends that the assertions and conclusions in the final NTP report are not necessarily relevant to readily available consumer products. Additional information is available on the association’s website at http://www.ahpa.org/Default.aspx?tabid=69&aId=913.

The New York Times addressed the controversy in an article titled “New Doubts About Ginkgo Biloba” published online on April 29, 2013 (http://well.blogs.nytimes.com/2013/04/29/new-doubts-about-ginkgo-biloba/).