A comprehensive analysis of DNA barcode testing on botanical dietary supplements has called conclusions reached by the New York Attorney General’s (NY AG) office in an investigation of four major retailers of botanical supplements, a “misuse of the technologies” that led to a “misinterpretation of test results.”

In the new white paper, four expert authors identified five potential weaknesses of the investigation, which generated extensive publicity and unwarranted damages to the dietary supplement industry, including materially undermining consumer confidence in products that can benefit their health.

According to lead author Danica T. Harbaugh Reynaud, PhD, CEO, AuthenTechnologies LLC, “As the Attorney General’s office has not released the full methodology, the testing procedures or the analytics of the tests, it is impossible to place any confidence in the publicized results. However, we can conclude that because of the limitations of DNA barcoding, especially on botanical extracts, that the claim by the NY AG’s office that the majority of supplements lacked any botanicals at all is, quite simply, unjustified.”

The white paper raises five critical questions, including the following two, which, unless answered completely by the NY AG, cast serious doubts about the conclusions reached by his office:

• Were the DNA barcoding methods inappropriately used on botanical extracts? The fact is that most, if not all, of the material containing cells (with the DNA) is typically removed during extraction (or at the very least, damaged), leaving the phytochemicals but not the DNA in the finished product.

• Did the laboratory performing the test have sufficient knowledge of the complexities of testing botanical dietary supplements? Specialized training and extensive experience in the field of plant-species identification on top of a solid understanding of the various processing and extraction techniques used by each manufacturer are necessary to obtain reliable results from testing botanical dietary supplements. 

The remaining questions raised by the authors focused on: whether adequate procedures were used in the testing lab; if validated reference sequences and appropriate analytical tools were used to identify species; and if valid conclusions were reached from the results. The authors concluded that the NY AG’s refusal to release answers to these five questions, along with a detailed explanation of the DNA testing methods used, raises serious concerns about the validity of the results.

The white paper also provided a scientific primer on DNA barcoding, offering a definition of the method, how it works, its capabilities and limitations, and seven key areas that need to be addressed in order to perform accurate species identification using any DNA method.

In addition to Dr. Harbaugh Reynaud, the co-authors were Brent D. Mishler, PhD, University of California, Berkeley; James Neal-Kababick, Flora Research Laboratories, LLC; and Paula N. Brown, PhD, British Columbia Institute of Technology.

The white paper was commissioned by four trade associations representing the dietary supplement industry: the American Herbal Products Association (AHPA), the Consumer Healthcare Products Association (CHPA), the Council for Responsible Nutrition (CRN), and the United Natural Products Alliance (UNPA).