Herbal Remedies: Just Because Its Natural Doesn't Mean Its Safe

Despite a lack of scientific evidence to back up their claims, herbal remedies are used by millions. effectiveness isn't the only issue. Could they be dangerous, too?

A news story with this headline appeared in Delaware Online today, highlighting the complex relationship that Americans have with herbal remedies. I personally am quite interested in this topic for several reasons:
1) Most effective pharmaceuticals originated in plants or animals, in a more dilute form (opium, growth hormones, aspirin, etc.)
2) A paucity of peer-reviewed clinical studies back up the health benefits of a variety of "natural" remedies
3) Herbal remedies are often cheaper than prescriptions
4) They can be acquired without a prescription
5) They are not approved or certified by the FDA to effectively "treat" a disease
6) Just because its "natural" doesn't mean its safe

All these issues contribute to both the intrigue, and the problems associated with herbal medicine. (More below the fold.....)

A smart approach was mentioned in the online article:

But before he starting taking ....natural products, [this herbal remedy user] checked with his doctor.

"I always mention whenever I introduce anything to my body," he said.

This is quite important because many popular herbal remedies can have dangerous interactions with prescription and over-the-counter drugs. The herb St. John's Wort, used as a natural mood-enhancer and anti-depressant, may result in a reduction in the effectiveness of 50% of all prescription drugs, from blood thinners to birth control.

But the real concern is not what we know, it's what we don't know, said Dr. Brian Strom, chairman and professor of biostatistics and epidemiology at the University of Pennsylvania. There's almost no good scientific research to support the effectiveness of any herbal supplement, despite a $20 billion market for such products. And when it comes to interactions, we're flying blind, he said.

This is because herbal remedies do not undergo the same rigorous FDA-testing process that all pharmaceuticals must pass. Therefore the side effects, best doses, interactions, and actual therapeutic effects are largely unknown. In fact, in many herbs, we don't even know what the active ingredient is.

Another obstacle is highlighted.......

Increasing our knowledge of herb-drug interactions will be difficult, said David Kroll, senior research pharmacologist at RTI International, an independent research group. Manufacturers have little incentive to fund research because their products don't need to be FDA-approved. And while there's plenty of interest among researchers for this sort of study, only a small amount of the National Institutes of Health budget is allocated for this topic.

More alarming, Kroll said, is the lack of standardization among herbal products. A recent report by the independent testing organization Consumer Lab.com found that six of 19 ginseng supplements failed quality tests due to lead contamination, lack of ingredients or inadequate labeling. One product had less than 10 percent of the claimed amount of ginsenosides, the compound suspected of being the primary active ingredient in ginseng.

"The lot-to-lot variability and variability between manufacturers is quite great," he said. "The quality control is still not what it is for comparative over-the-counter drugs."

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The largely unregulated market in herbal remedies and dietary supplements is pretty creepy and weird. I've occasionally seen vanadyl chloride being sold as a supplement. Some altie somewhere must have been sitting around and noticed that vanadium was a trace element we required and thought, "Hey, it must be good for you!" It probably won't kill you, but it's unlikely to do much good. Orac (sciencblogs.com/insolence) is a good source on all things altie.

Robert, the NCCAM branch of NIH does fund some studies but they cover way too much ground in so many different therapeutic areas that the support is spread too thin. Herbal medicines represent only about 40% of their portfolio and they have strict rules against isolating the pure components of herbal products. So many researchers apply to NCCAM for funding that it is harder to get funding from them than almost any other NIH agency.

Josh, the folks over at Terra Sigillata provide a nice basic science complement to Orac. If you ever have any questions, give a holler to abelpharmboy x*AT*x gmail Y*dot*Y com.

Shelley, thanks for covering this story.

Abel--

Thanks for the link. I followed PZ Myers and Orac to Scienceblogs and am still exploring the other blogs here. Yours, as with the others, looks very interesting. If I keep discovering good blogs, I may never get my dissertation written.