Herbal Remedy Linked to Kidney Cancer

(CBS)  A study in the June 8 New England Journal of Medicine provides evidence that the herbal supplement Aristolochia fangchi causes kidney cancer. CBSHealthWatch correspondent Dr. Emily Senay spoke to The Early Show about the herb.

Researchers followed a group of kidney patients in Belgium who had taken weight loss pills that contain the herb, and found the incidence of cancer to be unusually high. This new information comes after previous studies that show the herb to be highly carcinogenic in lab rats, and it's already been banned in Canada, Great Britain, Germany and Australia, but not the U.S.

Senay says that Aristolochia fangchi is used for a number of reasons, such as weight loss or low back pain relief. In fact, she said, a producer found a recipe for a low back pain remedy on the Internet that included Aristolochia fangchi and 13 other herbs, and was able to buy the herbs in New York City's Chinatown.

So why isn't Aristolochia fangchi banned in the US? Senay says the Food and Drug Administration (FDA) issued a warning about the herb, but the 1994 Dietary Supplement Act took away the FDA's power to act before products get on the market.

"They really have to be shown to be problematic once they're on the market before the FDA can do anything. They don't have to be proven to be safe and effective before they're marketed," says Senay.

People should be cautious when it comes to herbs, even those that you can buy in the supermarket, Senay says. Some easy-to-find herbs are potentially dangerous, such as the weight loss aid Ephedra, which has been linked to cardiovascular problems and death in people with pre-existing heart trouble.

"I think you have to talk to your doctor about it, and a really good herbalist if you're interested in this, to make sure you know what you're getting," Senay says.

Don't automatically assume that your doctor will tell you not to take herbal remedies, Senay says. "I think doctors take this very seriously, and you should tell your doctor if you're taking this stuff. A recent study showed that almost half of people don't even mention to their doctors that they're taking herbal remedies."

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