The New York Times noted a study last week from a Canadian research team claiming roughly three out of four herbal supplements contain little more than weeds or powdered rice.

The research team used a test called DNA barcoding, which has previously been used to uncover fraudulent seafood labeling, on 44 bottles of herbal supplements from 12 companies they, upon request, refused to name. Their findings have been published in the BMC Medicine journal.

Entire bottles of supplement were either diluted or entirely replaced by soybean, wheat, or rice filler. The team hopes their results will provide evidence of the questionable practices inside the herbal supplement industry, which rakes in a solid $5 billion from Americans alone.

Of the 44 tested bottles, one in three had a completely different plant in place of the one advertised. Even more had unlisted ingredients: two bottles labeled as St. John’s wort contained none at all, with one containing rice and the other a powerful Egyptian laxative called Alexandrian senna.

David Schardt, a senior nutritionist from an advocacy group, the Center for Science in the Public Interest, said regarding the research that “This suggests that the problems are widespread and that quality control for many companies, whether through ignorance, incompetence or dishonesty, is unacceptable… Given these results, it’s hard to recommend any herbal supplements to consumers.”

Meanwhile, the supplement industry doesn’t seem to see a problem with their business practices. Dr. Stefan Gafner, chief science officer with the American Botanical Council (which supports herbal supplement use) said “Over all, I would agree that quality control is an issue in the herbal industry, but I think that what’s represented here is overblown. I don’t think it’s as bad as it looks according to this study.”

Attempting to police the supplement industry presents difficulties for the Food & Drug Administration, which requires that all companies test the products they sell to guarantee safety. But since it’s an honor system, people (and the companies that employ them) lie all the time.

Spokesman Duffy MacKay with the Council for Responsible Nutrition (which is a trade group for the supplement industry) tried to lay the problem on the FDA, saying “we need a strong regulator enforcing the full force of the law. FDA resources are limited, and therefore enforcement has not historically been as rigorous as it could be.”

FDA spokeswoman Shelly Burgess said that, in spite of regulation, many companies are ignoring the rules anyway. “We are seeing a very high percentage — approximately 70 percent — of firms’ noncompliance, and we are very active in taking enforcement actions against such violations,” she asserts.

A professor of obstetrics, gynecology and reproductive medicine from Stony Brook named Dr. David A. Baker conducted a similar study last year on black cohosh supplements he purchased from a variety of online and local stores. Barcoding tests on Baker’s supplements showed that over 25 percent of them contained no black cohosh, but a ground-up Chinese ornamental plant.

If you want to read more, the Times piece is found here; it has a great section explaining how the DNA barcoding process works.

[Image via Wikimedia Commons]