ABC: DNA Study Requires Correction

AUSTIN, Tex.A recent BMC Medicine article on adulteration and substitution in herbal products should be corrected, revised and re-peer-reviewed, according to the American Botanical Council (ABC). The independent nonprofit research organization published a critique of the article, citing numerous flaws including calculation errors, taxonomic anomalies and unreliable conclusions drawn by the original researchers.

In the original study, University of Guelph researchers blindly tested 44 products from 12 companies using DNA barcoding analysis. Researchers reported 59 percent of the products tested contained DNA barcodes from plant species not listed on the label, while 33 percent contained contaminants or fillers not listed on the label.

Industry organizations, including ABC, the American Herbal Products Association (AHPA) and the Council for Responsible Nutrition (CRN) were quick to note the study's flaws, as media outlets questioned dietary supplement safety.

ABC maintained DNA technology is reliable, but only 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 ABCs critique.

"However, 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," Blumenthal said. "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."

In total, the ABC critique lists 10 errors, problems and confusing elements found in the BMC Medicine paper. Danica Harbaugh Reynaud, Ph.D., president and CEO of AuthenTechologies in Richmond, California, and Natascha Techen, Ph.D., of the National Center for Natural Products Research (NCNPR), co-authored the critique.

Take a closer look at industry response to the controversial study in INSIDER's News Desk, "Industry Questions Barcoding Study."