Over 50% of Ginkgo leaf extract samples may be adulterated: BAPP review

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A new systematic literature review of five popular botanical ingredients indicates a wide range of estimated adulteration rates, with the highest reported for Ginkgo leaf extract samples at 56.7%.

The new paper from the ABC-AHP-NCNPR Botanical Adulterants Prevention Program (BAPP) found that the second highest estimated adulteration rate was for powdered plant materials or extracts of black cohosh (Actaea racemosa) root/rhizome with 42.2%, followed by echinacea (Echinacea angustifolia, E. pallida, and E. purpurea) herb and/or root with 28.5%.

Concerning results were also observed for elder (Sambucus nigra) and turmeric (Curcuma longa) rhizome, with 17.1% and 16.5%, respectively, according to findings published in Natural Product Reports.

These five botanicals are among the top selling herbal supplements in the market. Data from the American Botanical Council (ABC) Herb Market Report for 2022 indicate that sales of supplements formulated with these botanicals accounted for over $526 million in the U.S. mainstream and natural channels (HerbalGram #139).

The review included a total of 77 publications and 2,995 samples across the five botanicals in the United States and international markets. The paper is authored by natural products pharmacology expert Nilüfer Orhan, PhD, ABC Chief Science Officer and BAPP Director Stefan Gafner, PhD, and Founder and Executive Eirector of ABC and Founder of BAPP Mark Blumenthal.

“Adulteration and fraud are unfortunate facts of commerce,” Blumenthal said. “The question is to what extent does it affect the current market for herbal dietary supplements and related natural plant- and fungal-based ingredients?

“Our paper demonstrates that estimating the extent of adulteration using published data is a very challenging and imperfect process, and the results cannot be deemed to be definitive,” he added. “They must be viewed within the context of creating a process with inadequate data.”

Dr. Ikhlas Khan, director of the National Center for Natural Products Research (NCNPR) at the University of Mississippi, told NutraIngredients that the new review illustrates the complexity of discovering the adulteration in well-known herbs. "Just think about the herbs that are not well studied and not well known, and it provides a picture of the adulteration level of marketed products," he said. 

Challenges and limitations

The review highlights the many challenges and limitations in determining the accurate number of adulterated products in a specific market.

For example, Orhan, Gafner and Blumenthal noted that results from comprehensive testing/analysis of all products sold in a geographic region are not available, criteria of what exactly represents adulteration vary from author to author, and some of the laboratory analytical methods used to determine the presence of adulteration may not be fit for purpose.

“The numbers obtained for the extent of adulteration of the five botanicals investigated for this systematic review may not be representative for the overall adulteration rate in the global herbal dietary and food supplement industry, but it is clear that adulteration of botanical ingredients is a problem and impacts a substantial portion of products sold as dietary or food supplements,” Dr. Gafner said.

The data indicated that products sold as licensed or registered herbal medicines, as is the case in many European countries, were all found to be authentic (not adulterated), contrary to products sold as dietary or food supplements.

“This highlights the importance of regulatory frameworks that mandate quality control and proper identity analysis to ensure the effectiveness and safety of botanical products (although safety concerns have not been documented in most of the published literature with respect to these five botanicals),” wrote Orhan, Gafner and Blumenthal.

“Quality control methods used by suppliers, manufacturers, researchers and regulators need to be sufficiently specific to detect possible adulterants in botanical ingredients and produce high-quality authentic products.

“There are numerous examples where some analytical methods used in industry quality control or government regulatory laboratories have been shown to be inadequate to detect adulteration and properly authenticate the botanical material(s). For this reason, BAPP has published a series of extensively peer-reviewed Laboratory Guidance Documents that evaluate the fitness for purpose of various analytical methods employed for some botanicals that BAPP has determined are subject to adulteration.”

Moving the needle

Commenting independently on the review’s findings, Daniel Fabricant, PhD, president and CEO of the Natural Products Association (NPA), told us: "These are important issues, and it's great to have this initiative [BAPP], but to ultimately move the needle FDA needs to be getting to the right number of facilities and putting the force of law behind their inspections.  

"I appreciate ABC trying to put a number on this, but we then need to have engagement with FDA. Is FDA going to those companies and facilities where there are problems?" 

BAPP

The new review is the 90th peer-reviewed publication published by the ABC (American Botanical Council)-AHP (American Herbal Pharmacopoeia)-NCNPR (National Center for Natural Products Research at the University of Mississippi) Botanical Adulterants Prevention Program (BAPP).

BAPP publications confirm that almost 30 (so far) of botanicals are subject to adulteration. More information is available HERE.

Source: Natural Product Reports

2024; doi: https://doi.org/10.1039/D4NP00014E

“Estimating the extent of adulteration of the popular herbs black cohosh, echinacea, elder berry, ginkgo, and turmeric – its challenges and limitations”

Authors: N. Orhan, S. Gafner, M. Blumenthal