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New Ideas About Life and Living in the Okanagan
Disagreements have emerged as researchers suggest that alternative medicines be subject to DNA barcoding. According to research published from the University of Guelph in Ontario, most herbal products, available to buy as alternative medicines, may be contaminated.
Reporting in BioMed Central's open access journal BMC Medicine researchers demonstrate the presence of contamination and substitution of plant species in a selection of herbal products using DNA barcoding.
According to the journal there is currently no best practice for identifying plant species in herbal products. Traditionally plants are identified through the appearance of the whole plant. This method is not useful though when analyzing processed plant material. DNA barcoding analyses a short genetic sequence from the plant's genome and identifies small differences that allows species identification. In this new study the researchers used barcoding to examine the plant species found in a sample of herbal plant products.
The results showed that 59% of the products contained plant species not listed on the labels. Over two thirds of the products tested had plant species present which were a substitution for the plants listed on the label and a third of products also contained other species that may be a filler or contamination.
In a media release about these findings, BioMed stated that this concern was echoed by the World Health Organization, which stated that the adulteration of herbal products is a threat to consumer safety. In this current analysis the researchers detected plant species that could pose serious health risks when consumed. The results revealed plant species with known toxicity, side effects and/or negatively interact with other herbs, supplements, or medications were present in some products.
The authors concluded that the contamination and substitution dilute the effectiveness of otherwise useful remedies, lowering the perceived value of all related products because of a lack of consumer confidence in them. 'We suggest that the herbal industry should embrace molecular diagnostic tools such as DNA barcoding for authenticating herbal products through testing of raw materials used in manufacturing products. This would be a minor cost to industry with a limited amount of bulk product testing, which would certify a high quality, authentic product', said Dr. Steven Newmaster of the University of Guelph and lead author of the paper.
The BioMed media broadcast was circulated world-wide but in the process caught the attention of the American Botanical Council (ABC), an independent nonprofit research and education organization which has now published a critique of the Guelph paper and co-authored by five herb quality control experts.
ABC claims that the research contains numerous flaws, calculation errors, taxonomic anomalies, and unreliable conclusions, and should be retracted by the journal and appropriately corrected before it is republished. ABC is concerned that the paper was published in October in the journal BMC Medicine which was then cited by various media outlets, including the Nov. 5 “Science Times” section of the New York Times in an article that raises questions about the quality of dietary supplements.
ABC emphasizes that DNA technology, in general, is reliable when used appropriately. “We have published two articles in our peer-reviewed journal HerbalGram discussing the merits and benefits of DNA-based analytical methods for establishing the accurate identity of plant material, including botanical materials found in herbal teas, as well as dried powders in numerous capsules and tablets found in herbal dietary supplements and related products,” said Mark Blumenthal, founder and executive director of ABC, and a co-author of ABC’s critique.
“However,” added Blumenthal, “DNA-based analysis is not appropriate when used in some of the ways that the authors appear to have done so, i.e., when trying to use DNA to determine the identity of commercial herb products that may contain plant extracts. It is not clear from the DNA paper whether some of the commercial herb capsules analyzed by the Canadian researchers contained dried powdered herb extracts or not. If they did, then DNA sequencing would not reveal the identity of the labeled plant extract, and might provide confusing results based on other excipient and ‘filler’ ingredients, or contamination with other DNA that also may be in the capsule.”
ABC Chief Science Officer Stefan Gafner, PhD, was interviewed by New York Times reporter Anahad O’Connor for the Times article. During the approximately 15-minute interview, Dr. Gafner enumerated many of the paper’s inconsistencies, errors, and potential flaws, none of which were reported by the Times, except for the writer’s not confusing Latin names for the herb feverfew, unlike the authors of the DNA paper.
“The article published in the New York Times, as well as other media stories on this subject, appears to have totally overlooked many of this paper’s problems and inconsistencies that we have enumerated in our critique,” said Dr. Gafner. The ABC critique lists 10 problems, errors, and areas of confusion in the DNA paper.
The ABC critique also is co-authored by Danica Harbaugh Reynaud, PhD—resident and CEO of AuthenTechologies in Richmond, Calif.—and Natascha Techen, PhD, of the National Center for Natural Products Research (NCNPR) at the University of Mississippi. Both Drs. Reynaud and Techen are experienced in using DNA technology to identify botanical materials, particularly those in herbal teas and dietary supplements.
ABC’s Blumenthal added that ABC and some of its nonprofit herb expert associates have taken leadership in the United States in the past three years in helping to bring to the herb and dietary supplement industry’s attention the problem of accidental and intentional adulteration of herbal raw materials. ABC is the managing partner in an international consortium of independent analytical laboratories, nonprofit organizations, industry companies, trade associations, and others who are supporting the ABC-AHP-NCNPR Botanical Adulterants Program, which ABC is conducting with the nonprofit American Herbal Pharmacopoeia (AHP) and the NCNPR at the University of Mississippi. The NCNPR is a Center of Excellence with the US Food and Drug Administration. It analyzes botanical ingredients on contract for the FDA and develops laboratory analytical methods for determining proper identity and the possible presence of contaminants and/or adulterants in botanical raw materials and extracts.
Dr. Gafner, lead author of the ABC critique, is the technical manager of the Botanical Adulterants Program. Botanist Steven Foster, another critique co-author, is Chair of the ABC Board of Trustees and the author or co-author of four of the five extensive, highly peer-reviewed papers on adulteration of herbs published in HerbalGram by the Botanical Adulterants Program.
The ABC paper ends with the following statement, calling for revision of the DNA paper:
“[I]n our view, and in the opinion of expert reviewers of this critique, and with all due respect to the authors and BMC Medicine, the journal should retract this paper, and require that the authors address various errors and ambiguities by appropriately rewriting, correcting, and resubmitting it to the journal. The editors of the journal should then submit the corrected revision to an appropriate peer-review process that employs numerous expert reviewers (not just the two who presumably reviewed the initial paper) who are knowledgeable not only in the fields of DNA testing, but also botanical analytics, and related disciplines. Only then, if the paper passes such appropriately expanded peer review, should the paper be republished. Until then, despite the good intentions of its authors, this paper creates confusion, promotes false conclusions, and, unfortunately, may constitute a disservice to scientific researchers and other responsible members of the botanical products community."
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The DNA Barcoding of Herbs Gets Interesting
The agricultural industrial complex continues to seek to control our food supply. DNA Barcoding is emerging as a gatekeeper between the farmer and the marketplace. So one might suggest that who or whatever controls the DNA Barcoding process might control the future of our food supply. Who will ensure our food security? This article describes a process that now questions DNA Barcoding of herbs that may impact the future of alernative medicine.
New Ideas About Life and Living in the Okanagan
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