Limitations of DNA barcoding call into question NY Attorney General's investigation, AHPA says

Use of an 'inadequate and unproven' method of testing makes the New York attorney general office's analysis of herbal supplements invalid, AHPA says.

The American Herbal Products Association (AHPA) stated today that the New York State Attorney General used an inadequate and unproven analytical method to test herbal supplement products at the core of the State's allegations that several retailers are selling adulterated and/or mislabeled herbal dietary supplements. The results of this analysis, therefore, cannot be considered valid.

According to AHPA Chief Science Officer Maged Sharaf, Ph.D., the New York State Attorney General and the laboratory that conducted the analysis relied on an analytical technology that does not have the capacity to reach the degree of certainty represented by the State in its accusations.

"Using  DNA barcoding as the only method for identifying ingredients in popular herbal dietary supplements and ignoring all other well-established and validated methods of herbal analysis is a suspect analytical process at best, and likely to provide results that are inaccurate," Dr. Sharaf said.

"DNA testing is an emerging technology that has the potential to be useful in the future when it has been rigorously tested and validated - the usual course with new analytical methodologies," said AHPA President Michael McGuffin.

"Even after maturity, DNA testing is foreseen by the scientific community to play a complementary role to other well-established and validated techniques such as various forms of chromatography, microscopy and organolepsis," Dr. Sharaf added.

Some of the known limitations of DNA barcoding is its inability, in most cases, to identify extracts and highly processed herbal products due to the loss or denaturation of DNA material during processing. DNA barcoding may also provide misleading results by disproportionally amplifying minor components in a product, which could erroneously imply its higher content in the tested product.

"It appears that many, if not all, of the products the New York State Attorney General tested were herbal extracts and this processing would likely disrupt or destroy the DNA," Dr. Sharaf said. "If an herbal product manufacturer used this analysis, without any additional confirmation, to prove that an herbal extract is accurately identified, the U.S. Food and Drug Administration (FDA) would almost certainly dismiss this as inadequate to verify identity."

Another factor that undermines the legitimacy of this analysis is the lack of data released by the Attorney General.

"It is difficult to evaluate the test results provided by the Attorney General office due to the lack of the study protocol" added DNA botanical testing expert Damon Little, Ph.D., Associate Curator of Bioinformatics at The New York Botanical Garden.

All facilities that manufacture herbal supplements are required by U.S. law to comply with strict current good manufacturing practice (cGMP) requirements that are enforced by the FDA. These cGMP requirements mandate that manufacturers have proper controls in place to ensure the quality of their dietary supplement products and to help assure consumers that they get accurately labeled and unadulterated dietary supplements. One section of the cGMP requirements directs manufacturers to verify the identity of botanical ingredients and document the testing used to verify identity. FDA regularly inspects dietary supplement manufacturing facilities to ensure compliance with cGMP requirements and has authority to take action to protect consumers when products are not manufactured in compliance with cGMP requirements and could pose a danger to consumers.


About AHPA 

The American Herbal Products Association (AHPA) is the national trade association and voice of the herbal and botanical products industry. AHPA is comprised of more than 300 domestic and foreign companies doing business as growers, processors, manufacturers, and marketers of herbs and herbal products, including foods, dietary supplements, cosmetics, and non-prescription drugs. Founded in 1982, AHPA's mission is to promote the responsible commerce of herbal products. Website:

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