*Update, 2/5/15: Industry spokespeople have raised questions about the applicability of DNA barcoding on herbal supplements. The New York Attorney General maintains that the use of DNA barcoding is supported by more than 70 scientific papers.
Four major national retailers were told this week by the New York State Attorney General to stop selling their store brands of certain herbal supplements because many of them do not contain what they’re supposed to. The stores are Walmart, Target, Walgreens, and GNC, and the supplements are Echinacea, Ginkgo, Ginseng, St. John’s Wort, Garlic, and Saw Palmetto. The Attorney General also said that many of these products contain plant materials not listed on the labels.
Using a new technology called DNA barcoding that can accurately identify a plant from tiny snippets of DNA, the Attorney General’s office reported that it found that only 21 percent of the herbal supplements purchased from these four chains throughout New York State appeared to contain the herbs listed on the labels. About a third of them contained unlisted plant material not listed on the labels, such as rice, beans, asparagus, and wheat. Many others didn’t contain any identifiable DNA from plants.
Here are the products that flunked and were ordered off store shelves:
|Store||store brand||herbal supplement|
|GNC||Herbal Plus||ginkgo biloba|
|GNC||Herbal Plus||St. John’s wort|
|GNC||Herbal Plus||saw palmetto|
|Target||Up & Up||ginkgo biloba|
|Target||Up & Up||St. John’s wort|
|Target||Up & Up||valerian root|
|Walgreens||Finest Nutrition||ginkgo biloba|
|Walgreens||Finest Nutrition||St. John’s wort|
|Walmart||Spring Valley||ginkgo biloba|
|Walmart||Spring Valley||St. John’s wort|
|Walmart||Spring Valley||saw palmetto|
Here are the products that passed:
|Store||store brand||herbal supplement|
|Target||Up & Up||echinacea|
|Target||Up & Up||garlic|
|Target||Up & Up||saw palmetto|
|Walgreens||Finest Nutrition||saw palmetto|
Here’s a link to the New York State Attorney General’s “cease and desist” letters to the four companies.
This isn’t the first time that DNA barcoding has detected problems with herbal supplements.
In 2012, researchers at Stony Brook University Medical Center in New York used it to test commercial black cohosh products and found that just 75 percent of them contained black cohosh. Only about half of 44 herbal products from 12 companies passed DNA barcoding tests at Canada’s University of Guelph in 2013. Two of 34 samples of saw palmetto analyzed by scientists at the New York Botanical Garden in the Bronx in 2013 contained, instead of saw palmetto, plants that cannot be legally sold as dietary supplements, and 6 of 37 samples of ginkgo biloba they tested in 2014 did not contain any ginkgo.
The Food and Drug Administration is also using this new technology to look for fish fraud, in which cheaper species of fish are sold to unsuspecting consumers as more expensive kinds.
What should you know if you’re interested in trying herbal supplements? First, bear in mind that most of them have not shown clear benefits in well-designed studies conducted in the United States, even when the products tested were verified to be of high-quality. Supplement manufacturers are not required to have convincing evidence before they make most claims about the health benefits of their products.
Second, this new study confirms what industry insiders already know, that there are many inferior herbal supplements on the market. Plant materials may be harvested all over the world and pass through many hands before they reach supplement manufacturers. Along the way, there can be opportunities for substituting lookalike cheaper plants, whether intentionally or unintentionally.
Manufacturers of store brands may be particularly vulnerable to this adulteration because they compete on price and need to keep costs down, including the cost of testing what they’re selling.
If you’re interested in purchasing herbs for your health, follow the advice of a health professional you trust. Look for quality seals on the product labels from organizations such as USP or NSF. Or subscribe to ConsumerLab.com, an independent company which has been analyzing the quality of dietary supplements since 1999 and makes its results available to subscribers at consumerlab.com.
Other relevant links:
• We downgraded our rating of Ginkgo biloba from safe to avoid. See: Urgent Consumer Alert on Ginkgo biloba Supplements and Drinks
• Are herbal supplement labels lying? See: Name that Herb
• Should you be taking a multivitamin? See: Dietary Supplements: Are Multivitamins Useless?