Ginko Biloba Linked to Cancer

The ginkgo tree is thought to be one of the oldest living trees, dating back more than 200 million years. Ginkgo leaf is often taken by mouth for memory and thought problems, anxiety, vision problems, and many other conditions. But there is no good scientific evidence to support most of these uses. There is emerging evidence however that it causes certain cancers, at least in laboratory animals.

Scientists at the National Toxicology Program fed lab mice Ginko biloba extract five times a week for two years. Researchers then found "clear evidence" that is caused liver cancer in some of the mice and "some evidence" of thyroid cancers. Some of the mice developed especially aggressive liver cancers and some developed more cancers "than had ever been seen in a NTP lab".

The FDA, in an uncharacteristic action, has been telling supplement manufacturers to stop adding Ginko biloba to foods or drinks but the Dietary Supplement Health and Education Act (a sick joke of a name if ever there was one) severely limits the FDA's ability to require compliance.

Although the cancers showed up in animals that were given very large doses, you may want to reconsider if you are presently taking Ginko biloba. No amount of a known carcinogen is really safe, and the supposed benefits of the supplement are largely unsupported by the science.