Ginkgo biloba, one of the most popular herbal supplements despite repeated trials failing to show any of its promised dementia-prevention benefits, may not be as safe as long believed. The first US government toxicology study on the supplement found a pattern of causing cancer in lab animals. The consistency of the tumors associated with ginkgo biloba in mice and rats was disturbing, according to the lead National Toxicology Program scientist, even though the results dont prove its dangerous to humans. Supplement-industry officials sharply criticized the findings, saying the ginkgo extract tested was different than whats typically sold here; government scientists said they purchased their samples from a major US supplier. Industry officials also pointed out that doses tested were far in excess of what human users would consume.
