The Natural Products Association (NPA) released a new white paper, authored by two former Food and Drug Administration (FDA) regulators, questioning the scientific validity of DNA barcoding. The New York Attorney General used this methodology in his study of herbal supplements, which has still not been released publicly or made available for peer review, and served as the basis for four cease-and-desist orders to dietary supplement retailers.
Daniel Fabricant, Ph.D., the former director of the Division of Dietary Supplement Programs at the FDA and current CEO of NPA, and Corey Hilmas, M.D., Ph.D., NPA’s senior vice president of scientific and regulatory affairs and the former chief of the Dietary Supplement Regulation Implementation Branch at the FDA, authored the white paper.
In the paper, Drs. Fabricant and Hilmas reviewed the appropriateness and fit-for-purpose of DNA barcoding in the absence of a chemical method for botanical authentication. Botanical extracts and highly processed finished products are not expected to have enough intact DNA to isolate a barcode. What’s more, they argue that DNA barcoding methodology is sensitive, leading to false positives, and is not specific enough for the dietary supplement industry to adopt for use in botanical identification.
“Anyone who knows anything about how these tests were conducted knows that the results are going to be fatally flawed,” Dr. Hilmas said. “This white paper released today is a step toward setting the record straight and transparency in the study data. Attorney General Schneiderman’s refusal to release the details of the report’s findings fails to live up to the rigors of scientific scrutiny and good government standards for transparency.”
Key arguments presented in the white paper by the association in support of its position include:
- The Attorney General and researcher at Clarkson University need to release the study data out of transparency, scientific validation, and research integrity.
- Researchers at Clarkson University failed to use a confirmatory method such as chemical fingerprinting to rule out the most likely explanation. Failure to obtain DNA evidence does not mean products fail to meet label claims.
- NPA supports chemical fingerprinting using a chromatographic method as the gold standard for botanical extracts and finished products.
- All botanical experts contend that botanical extracts should not contain DNA. Controversial research findings, rebuked by scientific experts, should be open to scientific scrutiny.
- DNA barcoding is not fit for purpose, and, at present, there is no universally accepted DNA barcode or combination of loci for plants in contrast to the animal kingdom.
- Until the study data is made transparent, NPA will continue to question:
- Whether DNA barcoding is fit for purpose for DNA extracts and finished supplements
- Whether DNA sequences in the reference library are tied to voucher specimens
- Robustness of the reference library
- Chain of custody regarding test material and reference standards
- Botanical DNA expertise and certification status of the laboratory chosen to perform DNA analysis by the New York Attorney General
- DNA barcoding is a powerful tool for raw botanical material authentication BEFORE the material has been extracted and processed.
- DNA barcoding involves DNA amplification and is therefore not a quantitative method for determining the level of contaminants in test material.
- Contaminants can be amplified as a result of cross-contamination in the analytical laboratory, obviating the need for an ISO accredited facility.
- DNA barcoding is not sensitive when the selected DNA barcode region in the test material is fragmented and deteriorated.
- Botanical dietary supplements are regulated by the FDA’s Good Manufacturing Practices (21 CFR part 111) (GMPs) for dietary supplements to ensure their identity, strength, purity and composition.